A thyristor driven pump is operated by varying the DC input signal in the firing circuit of thyristor drive. This operation suffers from difficulties due to the nonlinear relation between thyristor output and DC input. In the present paper, an opto-isolator based linearization technique of a typical thyristor driven pump has been proposed. The design, fabrication and the necessary circuit diagram along with theoretical explanations of the resultant output has been described. The operation of the linearized thyristor driven pump has been studied experimentally and the experimental data before and after linearization are reported. The characteristic graphs are found to have very good linearity.
Development of an automatic subsea blowout preventer stack control system usi...ISA Interchange
An extremely reliable remote control system for subsea blowout preventer stack is developed based on the off-the-shelf triple modular redundancy system. To meet a high reliability requirement, various redundancy techniques such as controller redundancy, bus redundancy and network redundancy are used to design the system hardware architecture. The control logic, human–machine interface graphical design and redundant databases are developed by using the off-the-shelf software. A series of experiments were performed in laboratory to test the subsea blowout preventer stack control system. The results showed that the tested subsea blowout preventer functions could be executed successfully. For the faults of programmable logic controllers, discrete input groups and analog input groups, the control system could give correct alarms in the human–machine interface.
Tuning a complex multi-loop PID based control system requires considerable experience. In today's power industry the number of available qualified tuners is dwindling and there is a great need for better tuning tools to maintain and improve the performance of complex multivariable processes. Multi-loop PID tuning is the procedure for the online tuning of a cluster of PID controllers operating in a closed loop with a multivariable process. This paper presents the first application of the simultaneous tuning technique to the multi-input–multi-output (MIMO) PID based nonlinear controller in the power plant control context, with the closed-loop system consisting of a MIMO nonlinear boiler/turbine model and a nonlinear cluster of six PID-type controllers. Although simplified, the dynamics and cross-coupling of the process and the PID cluster are similar to those used in a real power plant. The particular technique selected, iterative feedback tuning (IFT), utilizes the linearized version of the PID cluster for signal conditioning, but the data collection and tuning is carried out on the full nonlinear closed-loop system. Based on the figure of merit for the control system performance, the IFT is shown to deliver performance favorably comparable to that attained through the empirical tuning carried out by an experienced control engineer.
Analysis of Induction Motor Speed Control Using SCADA Based Drive Operated Sy...IJSRD
This Paper represents the analysis of induction motor speed control using VFD (Variable Frequency Drive) system operated by PLC-SCADA system. The main aim of the paper is to dealt with the concept of speed control of a three-phase induction motor with energy saving. To do so, a VFD (Variable Frequency Drive) is used for controlling the speed of a three-phase induction motor with variable load attached to the motor. It certainly leads to the best performance and high efficiency of the induction motor. Programmable Logic Controller (PLC) and Supervisory Control And Data Acquisition (SCADA) are two new systems to control a Variable Frequency Drive (VFD) whose output is given to a three-phase induction motor and driving a conveyor belt. The conveyor belt has three sensors are inputs which senses a passing object and carries out the necessary instructions programmed in ladder logic programming of the PLC through the computer (PC). The SCADA software installed in the PC in turn enables the human operator to control the entire operation away from the plant and just by using the virtual inputs designated on his computer screen.
The batteries used in electric and hybrid vehicles
consists of several cells with voltages between 3.6V battery and
4.2 V in series or parallel combinations of configurations for
obtaining the necessary available voltages in the operation of a
hybrid electric vehicle. How malfunction of a single cell affects
the behavior of the entire battery pack, BMS main function is to
protect individual cells against over-discharge, overload or
overheating. This is done by correct balancing of the cells. In
addition BMS estimates the battery charge status
Speed Control of Induction Motor Using PLC and SCADA SystemIJERA Editor
Automation or automatic control is the use of various control systems for operating equipment such as
machinery, processes in factories, boilers and heat-treating ovens, switching in telephone networks, steering and
stabilization of ships, aircraft and other applications with minimal or reduced human intervention. Some
processes have been completely automated. The motor speed is controlled via the driver as an open loop control.
To make a more precise closed loop control of motor speed we will use a tachometer to measure the speed and
feed it back to the PLC, which compares to the desired value and take a control action, then the signal is
transferred to the motor – via driver – to increase / decrease the speed. We will measure the speed of the motor
using an incremental rotary encoder by adjusting parameters (PLC, driver) and also we need to reduce the
overall cost of the system. Our control system will be held using the available Siemens PLC. In addition, we will
monitor motor parameters via SCADA system.
This work presents a fast response and stable computer based a brushed DC motor speed controller. The controller configured of gate drive circuits for H-Bridge accompanied with data acquisition unit DAQ-6211. These gate drive circuits include, phase comparator, current booster and wave forms cleaning circuits. An optical encoder is used for motor speed to frequency conversion. The CD4046 PLL chip compares phases of the encoder output frequency (motor speed) with a reference frequency (desired speed). The obtained phase difference (error) is used to allocate the suitable PWM duty cycles. An H-Bridge BJT switches driven by PWM is interfaced with the motor. The system hardware is provided with a simple and accurate data acquisition unit DAQ-6211 to be interfaced with the LabVIEW software Package. This allows monitoring and storing the different measured data of this platform. The system relative stability is determined and examined based on the Bode plot analysis and design. Then the relative stability criterion (Phase Margin) is measured the closed-loop stability of the system. This system considers the fast feedback response with indication of its stability state as well as the stable wide dynamic range. It compensates the changes in system parameters due to the environmental effects and other disturbances.
Development of an automatic subsea blowout preventer stack control system usi...ISA Interchange
An extremely reliable remote control system for subsea blowout preventer stack is developed based on the off-the-shelf triple modular redundancy system. To meet a high reliability requirement, various redundancy techniques such as controller redundancy, bus redundancy and network redundancy are used to design the system hardware architecture. The control logic, human–machine interface graphical design and redundant databases are developed by using the off-the-shelf software. A series of experiments were performed in laboratory to test the subsea blowout preventer stack control system. The results showed that the tested subsea blowout preventer functions could be executed successfully. For the faults of programmable logic controllers, discrete input groups and analog input groups, the control system could give correct alarms in the human–machine interface.
Tuning a complex multi-loop PID based control system requires considerable experience. In today's power industry the number of available qualified tuners is dwindling and there is a great need for better tuning tools to maintain and improve the performance of complex multivariable processes. Multi-loop PID tuning is the procedure for the online tuning of a cluster of PID controllers operating in a closed loop with a multivariable process. This paper presents the first application of the simultaneous tuning technique to the multi-input–multi-output (MIMO) PID based nonlinear controller in the power plant control context, with the closed-loop system consisting of a MIMO nonlinear boiler/turbine model and a nonlinear cluster of six PID-type controllers. Although simplified, the dynamics and cross-coupling of the process and the PID cluster are similar to those used in a real power plant. The particular technique selected, iterative feedback tuning (IFT), utilizes the linearized version of the PID cluster for signal conditioning, but the data collection and tuning is carried out on the full nonlinear closed-loop system. Based on the figure of merit for the control system performance, the IFT is shown to deliver performance favorably comparable to that attained through the empirical tuning carried out by an experienced control engineer.
Analysis of Induction Motor Speed Control Using SCADA Based Drive Operated Sy...IJSRD
This Paper represents the analysis of induction motor speed control using VFD (Variable Frequency Drive) system operated by PLC-SCADA system. The main aim of the paper is to dealt with the concept of speed control of a three-phase induction motor with energy saving. To do so, a VFD (Variable Frequency Drive) is used for controlling the speed of a three-phase induction motor with variable load attached to the motor. It certainly leads to the best performance and high efficiency of the induction motor. Programmable Logic Controller (PLC) and Supervisory Control And Data Acquisition (SCADA) are two new systems to control a Variable Frequency Drive (VFD) whose output is given to a three-phase induction motor and driving a conveyor belt. The conveyor belt has three sensors are inputs which senses a passing object and carries out the necessary instructions programmed in ladder logic programming of the PLC through the computer (PC). The SCADA software installed in the PC in turn enables the human operator to control the entire operation away from the plant and just by using the virtual inputs designated on his computer screen.
The batteries used in electric and hybrid vehicles
consists of several cells with voltages between 3.6V battery and
4.2 V in series or parallel combinations of configurations for
obtaining the necessary available voltages in the operation of a
hybrid electric vehicle. How malfunction of a single cell affects
the behavior of the entire battery pack, BMS main function is to
protect individual cells against over-discharge, overload or
overheating. This is done by correct balancing of the cells. In
addition BMS estimates the battery charge status
Speed Control of Induction Motor Using PLC and SCADA SystemIJERA Editor
Automation or automatic control is the use of various control systems for operating equipment such as
machinery, processes in factories, boilers and heat-treating ovens, switching in telephone networks, steering and
stabilization of ships, aircraft and other applications with minimal or reduced human intervention. Some
processes have been completely automated. The motor speed is controlled via the driver as an open loop control.
To make a more precise closed loop control of motor speed we will use a tachometer to measure the speed and
feed it back to the PLC, which compares to the desired value and take a control action, then the signal is
transferred to the motor – via driver – to increase / decrease the speed. We will measure the speed of the motor
using an incremental rotary encoder by adjusting parameters (PLC, driver) and also we need to reduce the
overall cost of the system. Our control system will be held using the available Siemens PLC. In addition, we will
monitor motor parameters via SCADA system.
This work presents a fast response and stable computer based a brushed DC motor speed controller. The controller configured of gate drive circuits for H-Bridge accompanied with data acquisition unit DAQ-6211. These gate drive circuits include, phase comparator, current booster and wave forms cleaning circuits. An optical encoder is used for motor speed to frequency conversion. The CD4046 PLL chip compares phases of the encoder output frequency (motor speed) with a reference frequency (desired speed). The obtained phase difference (error) is used to allocate the suitable PWM duty cycles. An H-Bridge BJT switches driven by PWM is interfaced with the motor. The system hardware is provided with a simple and accurate data acquisition unit DAQ-6211 to be interfaced with the LabVIEW software Package. This allows monitoring and storing the different measured data of this platform. The system relative stability is determined and examined based on the Bode plot analysis and design. Then the relative stability criterion (Phase Margin) is measured the closed-loop stability of the system. This system considers the fast feedback response with indication of its stability state as well as the stable wide dynamic range. It compensates the changes in system parameters due to the environmental effects and other disturbances.
Simulation of Automatic Water Level Control System by using Programmable Logi...ijtsrd
This research focuses on the design and implementation of a PLC based water level control system. In this research, there are three primary objectives the water level indicator circuit design, manual control system of water level control and the PLC based automatic water level control. Float switches cannot be able to use to indicate the multi water level in the desired control system. Therefore, AND gate based digital electronic water sensor is invented and used in this proposed not only manual water level control but also PLC based automatic water level control by dividing in eight steps. Induction motor is used to drive the pump as a one set package. So, induction motor starting method is selected according to the power rating of motor, type of motor and nature of application. Star delta starting method is used to reduce the starting current of induction motor. For PLC based automatic water level control, Siemens S7 1200 PLC is used to control the desire water level. There are 10 inputs and 10 outputs in the proposed automatic water level control. Ladder diagram programming is used for this control. Mrs Yin Yin Mon | Mrs Win Moet Moet Htwe | Mrs Khin Ei Ei Khine ""Simulation of Automatic Water Level Control System by using Programmable Logic Controller"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-4 , June 2019, URL: https://www.ijtsrd.com/papers/ijtsrd25172.pdf
Paper URL: https://www.ijtsrd.com/engineering/electrical-engineering/25172/simulation-of-automatic-water-level-control-system-by-using-programmable-logic-controller/mrs-yin-yin-mon
Novel Discrete Components Based Speed Controller for Induction MotorIJPEDS-IAES
This paper presents an electronic design based on general purpose discrete
components for speed control of a single phase induction motor drive. The
MOSFETs inverter switching is controlled using Sampled Sinusoidal Pulse
Width Modulation (SPWM) techniques with V/F method based on Voltage
Controlled Oscillator (VCO). The load power is also controlled by a novel
design to produce a suitable SPWM pulse. The proposed electronic system
has ability to control the output frequency with flexible setting of lower limit
to less than 1 Hz and to higher frequency limits to 55 Hz. Moreover, the
proposed controller able to control the value of load voltage to frequency
ratio, which plays a major parameter in the function of IM speed control.
Furthermore, the designed system is characterized by easy manufacturing
and maintenance, high speed response, low cost, and does not need to
program steps as compared to other systems based on Microcontroller
and digital signal processor (DSP) units. The complete proposed electronic
design is made by the software of NI Multisim version 11.0 and all the
internal sub-designs are shown in this paper. Simulation results show the
effectiveness of electronic design for a promising of a high performance IM
PWM drive.
Introduction of Programmable Logic Controller to Electric Overhead Travelling...paperpublications3
Abstract: In this paper, we are using PLC programmes to control the crane movement. The application of PLC could simplify circuits and make the design easier, safer and more reliable. Earlier in Industry, relays and contactors are adopted to control the crane motion in desired directions. Starting of the cranes and speed control of the crane is realized through convectional starters and resistance series. This kind of design has low reliability, complex operation, high electrical failure rate, power waste and low efficiency .These problems can be rectified by using programmable logic controller.
Design and development of programmable controller for air sampling machineeSAT Journals
Abstract A programmable Controller is designed and developed for time pedestal controlling of Air Sampling Machine. The major purpose of the designed system is to reduce filter damage of Air Sampling Machine. The main function of the controller is to automatically switching the Air Sampling Machine with predefined On-Off time interval for 24 hours operation. This is a low cost system which is designed using locally available components and user friendly. The controlling operation is maintained by ATMEL AT89C52 microcontroller. A programmable real time clock PCF8583 is used to produce timing control signal for automatic switching of the Air Sampling Machine. Control signals generated by real time clock operate opto-isolator and an electromechanical relay for switching the Air Sampling Machine. EEPROM (M24C64) is used to store necessary data. The instruction firmware for the designed controller has been developed in BASIC platform using BASCOM-8051 software. The designed system is functioning properly and serving the purpose of the design. Keywords: Programmable Controller, AT89C52 microcontroller, RTC, EEPROM, I2C Protocol, BASCOM-8051 IDE
In this paper, we first write a description of the operation of DC motors taking into account which parameters the speed depends on thereof. The PID (Proportional-Integral-Derivative) controllers are then briefly described, and then applied to the motor speed control already described , that is, as an electronic controller (PID), which is often referred to as a DC motor. The closed loop speed control of a Brush DC motor is developed applying the well-known PID control algorithm. The objective of this work is to designed and simulate a new control system to keep the speed of the DC motor constant before variations of the load (disturbances), automatically depending to the PID controller. The system was designed and implementation by using MATLAB/SIMULINK and DC motor.
CONTROL OF AN INDUCTION MOTOR WITH DOUBLE ANN MODEL BASED DTCcsandit
Direct torque control (DTC) is preferably control method on high performance control of induction motors due to its dvantages such as fast dynamic response, simple and robust control structure. However, high torque and current ripples are mostly faced problems in this control method. This paper presents artificial neural network (ANN) based approach to the DTC method to overcome mentioned problems. In the study, by taking a different perspective to ANN and DTC integration, two different ANN models have been designed, trained and implemented. The first ANN model has been used for switch selecting process and the second one has been used for sector determine process. Matlab/Simulink model of the proposed ANN based DTC method has created in order to compare with the conventional DTC and the proposed DTC
methods. The simulation studies have proved that the induction motor torque and current
ripples have been reduced remarkably with the proposed method and this approach can be a
good alternative to the conventional DTC method for induction motor control
Ls catalog thiet bi tu dong master p 5000-e_dienhathe.vnDien Ha The
Khoa Học - Kỹ Thuật & Giải Trí: http://phongvan.org
Tài Liệu Khoa Học Kỹ Thuật: http://tailieukythuat.info
Thiết bị Điện Công Nghiệp - Điện Hạ Thế: http://dienhathe.org
The established PTC-1 offers a robust and reliable solution to the growing demands of modern junctions and pedestrian facilities. The original PTC-1 offers efficient control for larger junctions, whilst the smaller PTC-1 Lite has been developed to run small junctions and pedestrian crossings. Capable of working in conjunction with old technology 240v aspects and the new 48v LED energy efficient aspects, the PTC-1 family of controllers is truly adaptable and able to deliver in any given situation.
The Peek EuroController EC-2® is a state-of-the-art traffic
controller, rooted in a long tradition of innovation and
robustness. On the one hand it has an innovative design
which integrates a flexible software architecture on a high
power processor with extensive open connectivity. On
the other hand it has a safety architecture that complies
with European and local directives and electronics that is
durable, robust and easy to maintain.
Solar Photo Voltaic Water Pumping: Harnessing Maximum PowerIDES Editor
Among alternate sources of electricity, Solar Photo
Voltaic (PV) energy is gaining prominence due to its plentiful
availability. Water pumping is an important application of
solar PV power. However people are not opting for it in large
numbers as the ‘cost per watt’ for solar pumping systems is
high. The cost can be reduced by harnessing more power per
unit installed capacity of the solar panel. One method of
realising this is by Maximum Power Point Tracking (MPPT)
wherein a power electronic converter is used to match pump
with the PV panel. Widely employed approach for MPPT is to
monitor the PV panel power and keep on adjusting the duty
cycle of converter so that tapped power is always maximum.
Present paper proposes a novel method to realise MPPT for
standalone solar PV water pumping system. It is shown that
the output power becomes the maximum when the motor
voltage becomes the maximum. Conversely, varying the duty
cycle of the converter such that load voltage is always maximum
leads to harnessing maximum power output. This approach
can be referred to as Maximum Load Voltage Point Tracking
(MVPT). We need to monitor only load voltage. It is simpler
than monitoring PV panel power as in that case it’s necessary
to measure both panel voltage and current and then find their
product.
The proposal of MVPT for realizing MPPT is substantiated
by theoretical explanation considering two types of loads: Pure
Resistance and Centrifugal Pump driven by Permanent Magnet
(PM) brushed DC Motor. The Matlab-Simulink based
simulation is also carried out. Simulation results are found
to be in close conformity with the theoretical findings.
Simulation of Automatic Water Level Control System by using Programmable Logi...ijtsrd
This research focuses on the design and implementation of a PLC based water level control system. In this research, there are three primary objectives the water level indicator circuit design, manual control system of water level control and the PLC based automatic water level control. Float switches cannot be able to use to indicate the multi water level in the desired control system. Therefore, AND gate based digital electronic water sensor is invented and used in this proposed not only manual water level control but also PLC based automatic water level control by dividing in eight steps. Induction motor is used to drive the pump as a one set package. So, induction motor starting method is selected according to the power rating of motor, type of motor and nature of application. Star delta starting method is used to reduce the starting current of induction motor. For PLC based automatic water level control, Siemens S7 1200 PLC is used to control the desire water level. There are 10 inputs and 10 outputs in the proposed automatic water level control. Ladder diagram programming is used for this control. Mrs Yin Yin Mon | Mrs Win Moet Moet Htwe | Mrs Khin Ei Ei Khine ""Simulation of Automatic Water Level Control System by using Programmable Logic Controller"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-4 , June 2019, URL: https://www.ijtsrd.com/papers/ijtsrd25172.pdf
Paper URL: https://www.ijtsrd.com/engineering/electrical-engineering/25172/simulation-of-automatic-water-level-control-system-by-using-programmable-logic-controller/mrs-yin-yin-mon
Novel Discrete Components Based Speed Controller for Induction MotorIJPEDS-IAES
This paper presents an electronic design based on general purpose discrete
components for speed control of a single phase induction motor drive. The
MOSFETs inverter switching is controlled using Sampled Sinusoidal Pulse
Width Modulation (SPWM) techniques with V/F method based on Voltage
Controlled Oscillator (VCO). The load power is also controlled by a novel
design to produce a suitable SPWM pulse. The proposed electronic system
has ability to control the output frequency with flexible setting of lower limit
to less than 1 Hz and to higher frequency limits to 55 Hz. Moreover, the
proposed controller able to control the value of load voltage to frequency
ratio, which plays a major parameter in the function of IM speed control.
Furthermore, the designed system is characterized by easy manufacturing
and maintenance, high speed response, low cost, and does not need to
program steps as compared to other systems based on Microcontroller
and digital signal processor (DSP) units. The complete proposed electronic
design is made by the software of NI Multisim version 11.0 and all the
internal sub-designs are shown in this paper. Simulation results show the
effectiveness of electronic design for a promising of a high performance IM
PWM drive.
Introduction of Programmable Logic Controller to Electric Overhead Travelling...paperpublications3
Abstract: In this paper, we are using PLC programmes to control the crane movement. The application of PLC could simplify circuits and make the design easier, safer and more reliable. Earlier in Industry, relays and contactors are adopted to control the crane motion in desired directions. Starting of the cranes and speed control of the crane is realized through convectional starters and resistance series. This kind of design has low reliability, complex operation, high electrical failure rate, power waste and low efficiency .These problems can be rectified by using programmable logic controller.
Design and development of programmable controller for air sampling machineeSAT Journals
Abstract A programmable Controller is designed and developed for time pedestal controlling of Air Sampling Machine. The major purpose of the designed system is to reduce filter damage of Air Sampling Machine. The main function of the controller is to automatically switching the Air Sampling Machine with predefined On-Off time interval for 24 hours operation. This is a low cost system which is designed using locally available components and user friendly. The controlling operation is maintained by ATMEL AT89C52 microcontroller. A programmable real time clock PCF8583 is used to produce timing control signal for automatic switching of the Air Sampling Machine. Control signals generated by real time clock operate opto-isolator and an electromechanical relay for switching the Air Sampling Machine. EEPROM (M24C64) is used to store necessary data. The instruction firmware for the designed controller has been developed in BASIC platform using BASCOM-8051 software. The designed system is functioning properly and serving the purpose of the design. Keywords: Programmable Controller, AT89C52 microcontroller, RTC, EEPROM, I2C Protocol, BASCOM-8051 IDE
In this paper, we first write a description of the operation of DC motors taking into account which parameters the speed depends on thereof. The PID (Proportional-Integral-Derivative) controllers are then briefly described, and then applied to the motor speed control already described , that is, as an electronic controller (PID), which is often referred to as a DC motor. The closed loop speed control of a Brush DC motor is developed applying the well-known PID control algorithm. The objective of this work is to designed and simulate a new control system to keep the speed of the DC motor constant before variations of the load (disturbances), automatically depending to the PID controller. The system was designed and implementation by using MATLAB/SIMULINK and DC motor.
CONTROL OF AN INDUCTION MOTOR WITH DOUBLE ANN MODEL BASED DTCcsandit
Direct torque control (DTC) is preferably control method on high performance control of induction motors due to its dvantages such as fast dynamic response, simple and robust control structure. However, high torque and current ripples are mostly faced problems in this control method. This paper presents artificial neural network (ANN) based approach to the DTC method to overcome mentioned problems. In the study, by taking a different perspective to ANN and DTC integration, two different ANN models have been designed, trained and implemented. The first ANN model has been used for switch selecting process and the second one has been used for sector determine process. Matlab/Simulink model of the proposed ANN based DTC method has created in order to compare with the conventional DTC and the proposed DTC
methods. The simulation studies have proved that the induction motor torque and current
ripples have been reduced remarkably with the proposed method and this approach can be a
good alternative to the conventional DTC method for induction motor control
Ls catalog thiet bi tu dong master p 5000-e_dienhathe.vnDien Ha The
Khoa Học - Kỹ Thuật & Giải Trí: http://phongvan.org
Tài Liệu Khoa Học Kỹ Thuật: http://tailieukythuat.info
Thiết bị Điện Công Nghiệp - Điện Hạ Thế: http://dienhathe.org
The established PTC-1 offers a robust and reliable solution to the growing demands of modern junctions and pedestrian facilities. The original PTC-1 offers efficient control for larger junctions, whilst the smaller PTC-1 Lite has been developed to run small junctions and pedestrian crossings. Capable of working in conjunction with old technology 240v aspects and the new 48v LED energy efficient aspects, the PTC-1 family of controllers is truly adaptable and able to deliver in any given situation.
The Peek EuroController EC-2® is a state-of-the-art traffic
controller, rooted in a long tradition of innovation and
robustness. On the one hand it has an innovative design
which integrates a flexible software architecture on a high
power processor with extensive open connectivity. On
the other hand it has a safety architecture that complies
with European and local directives and electronics that is
durable, robust and easy to maintain.
Solar Photo Voltaic Water Pumping: Harnessing Maximum PowerIDES Editor
Among alternate sources of electricity, Solar Photo
Voltaic (PV) energy is gaining prominence due to its plentiful
availability. Water pumping is an important application of
solar PV power. However people are not opting for it in large
numbers as the ‘cost per watt’ for solar pumping systems is
high. The cost can be reduced by harnessing more power per
unit installed capacity of the solar panel. One method of
realising this is by Maximum Power Point Tracking (MPPT)
wherein a power electronic converter is used to match pump
with the PV panel. Widely employed approach for MPPT is to
monitor the PV panel power and keep on adjusting the duty
cycle of converter so that tapped power is always maximum.
Present paper proposes a novel method to realise MPPT for
standalone solar PV water pumping system. It is shown that
the output power becomes the maximum when the motor
voltage becomes the maximum. Conversely, varying the duty
cycle of the converter such that load voltage is always maximum
leads to harnessing maximum power output. This approach
can be referred to as Maximum Load Voltage Point Tracking
(MVPT). We need to monitor only load voltage. It is simpler
than monitoring PV panel power as in that case it’s necessary
to measure both panel voltage and current and then find their
product.
The proposal of MVPT for realizing MPPT is substantiated
by theoretical explanation considering two types of loads: Pure
Resistance and Centrifugal Pump driven by Permanent Magnet
(PM) brushed DC Motor. The Matlab-Simulink based
simulation is also carried out. Simulation results are found
to be in close conformity with the theoretical findings.
Distributed energy resources (DER) based micro grid and Nano-grid framework is most technically viable bottom-top approach to sustainably meet ever-increasing demand of rural and urban communities. Recently the growth of DC operative home appliances like mobile and lap top chargers, ovens and hair dryer’s etc. are increasing and therefore a DC/DC converter is an efficient way to meet the electricity need from the local DER and helps in improving the system efficiency. This paper presents simulation results of a buck boost converter, MPPT algorithm (P & O method) for solar PV module and closed loop PI control system for obtaining constant 12 V and 24 V DC output voltage at DC bus. The proposed methodology is to extract maximum DC power from solar PV system and it is directly fed to DC load or DC Nano grid.
Solar water pump (swp) in india "Research thesis presentation"kevIN kovaDIA
Life is very is easy, sometimes we do complex rocket science and at last we realize it is just a common sense which can work, just a common sense...
#SolarPower #SolarEnergy #RenewableEnergy #Energy #SolarPanels #GreenEnergy #GoSolar #PV #Renewables #Electricity #CleanEnergy #OffGrid #EnergyEfficiency #Wind #WindPower #Renewable #Green #FossilFuels #Power #Flashmob #MakeInIndia #Water
This was part our ENGR493 Presentation where we had to do some research for concept and design generation and then possess the knowledge to create a solar powered submersible water pump using a parabolic solar collector, a gamma stirling engine and a pump for irrigation use in Senegal.
Closed Loop Speed Control of a BLDC Motor Drive Using Adaptive Fuzzy Tuned PI...IJERA Editor
Brushless DC Motors are widely used for many industrial applications because of their high efficiency, high
torque and low volume. This paper proposed an improved Adaptive Fuzzy PI controller to control the speed of
BLDC motor. This paper provides an overview of different tuning methods of PID Controller applied to control
the speed of the transfer function model of the BLDC motor drive and then to the mathematical model of the
BLDC motor drive. It is difficult to tune the parameters and get satisfied control characteristics by using normal
conventional PI controller. The experimental results verify that Adaptive Fuzzy PI controller has better control
performance than the conventional PI controller. The modeling, control and simulation of the BLDC motor have
been done using the MATLAB/SIMULINK software. Also, the dynamic characteristics of the BLDC motor (i.e.
speed and torque) as well as currents and voltages of the inverter components are observed by using the
developed model.
DTC Scheme for a Four-Switch Inverter-Fed PMBLDC Motor Emulating the Six-Swit...IJRST Journal
The paper deals with the direct torque control (DTC) of brushless DC (BLDC) motor drives fed by four-switch three phase inverters (FSTPI) rather than six-switch inverters (SSTPI) in conventional drives. For any three phase inverter require six switches, but these switches are reduced to four. This reduction of power switches from six to four improves the reliability of the inverter, size of the inverter is reduced and cost of the inverter is also reduces. The FSTPI could be regarded as a reconfigured topology of the SSTPI in case of a switch/leg failure which represents a crucial reliability benefit for many applications especially in electric and hybrid propulsion systems. The DTC of FSTPI-fed BLDC motor drives is treated considering two strategies, such as: 1) DTC-1: a strategy inspired from the one intended to SSTPI-fed BLDC motor drives; 2) DTC-2: a strategy that considers a dedicated vector selection subtable in order to independently control the torques developed by the phases connected to the FSTPI legs during their simultaneous conduction. The operational principle of the four-switch BLDC motor drive and the developed control scheme are theoretically analyzed and the performance is demonstrated by simulation.
Experimental Investigations of the Self-Controlled Synchronous Motor Connecte...IJPEDS-IAES
This paper concerns the experimental investigations of the three-phase line
commutated SCR inverter fed synchronous motor. The fabricated system
consists of a line-commuted inverter, a three-phase synchronous motor with
the excitation winding connected in series to the inverter input, a terminal
voltage sensor and a gate-pulse generating circuit. The firing pulses for SCRs
of the inverter are generated by the microprocessor in proper sequence with
the help of synchronizing signal derived from the terminal voltages of the
synchronous machine. The steady state performance characteristics are
obtained experimentally using the fabricated system. The experimental
results show that a three-phase synchronous motor supplied by a line
commutated inverter with the excitation winding connected in series to the dc
link provide excellent characteristics of the conventional dc series motor.
Power Quality Analysis of Vienna Rectifier for BLDC Motor Drive ApplicationIJPEDS-IAES
This paper presents the power quality improvements for a BLDC driver using
Vienna rectifier as front end converter. The major drawbacks in the BLDC
motor drive and non linear load applications are the line pollution and
depreciation of the power factor. The conventional power factor correction
method is not economical and efficient. It requires bulky components as load
changes and produce high THD and less Power factor. The front end
converter of BLDC bridge inverter drive is proposed by the Vienna rectifier,
which can contribute more significantly in improving the power factor and
reduce the line pollution. The Vienna rectifier topology is controlled by the
constant switching frequency control technique for wide range of load
variation and it reduces the THD, improve the power factor and provide a
steady DC link voltage to the bridge inverter to drive the BLDC motor. The
design calculation and performance characteristics of BLDC motor and
Vienna rectifier are verified by using Matlab simulation.
QUICK DYNAMIC TORQUE CONTROL IN DTC-HYSTERESIS-BASED INDUCTION MOTOR BY USING...ijiert bestjournal
Induction machines are widely employed in industries due to their r ugged structure,high maintainability and economy than DC motors. There has been constant development in the i nduction motor drive system and their implementation in industrial applications. The improvement of switching speed of power electronic devices has enabled control techniques which possess high switching f requency and feasibility of high efficiency drive systems. In this pretext,Direct Torque Contr ol (DTC) was introduced to obtain quick and better dynamic torque response. The DTC scheme in its basic c onfiguration comprises torque and flux estimator DTC controller,stator voltage vector selector and voltage source inverter. Direct Torque Control of induction motor has increasingly become the best alternative to Field- Oriented Control methods. The performance of an induction motor under the classical Direct Torque Control method and improved scheme have been studied and confirmed by simulation using MATLAB.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal,
A solar fed BLDC motor drive for mixer grinder using a buck converter IJECEIAES
In large and small scale applications, different kinds of variable speed driving systems can be found. For saving the energy consumption of these devices, eco-friendly electronics are used, which lead to the development of the Brushless DC motor (BLDC). Its higher power density, higher efficiency, higher torque at low speed, and low maintenance enhances the use of a BLDC motor. The existing mixer grinder consists of the universal motor, which operates in alternating current supply due to high starting torque characteristics and simple controlling of the speed. The absence of brushes and the reduction of noise in the BLDC extends its life and makes it ideal in a mixer grinder. A solar-powered BLDC motor drive for a mixer grinder is presented in this paper. A DC-DC buck converter is utilized to operate the PV (photovoltaic) array at its maximum power. The proposed hysteresis current control BLDC system has been developed in the MATLAB. The commercially available mixer grinder is presented along with the proposed simulated system for performance comparison. It can be concluded that at the no load condition, the efficiency of the experimental existing mixer grinder is 51.03% and simulated proposed system is 81.25% and at load condition, the efficiency of the experimental mixer grinder is 49.32% and simulated system is 79.85%.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Review of the DTC Controller and Estimation of Stator Resistance in IM DrivesIAES-IJPEDS
In recent years an advanced control method called direct torque control
(DTC) has gained importance due to its capability to produce fast torque
control of induction motor. Although in these systems such variables as
torque, flux modulus and flux sector are required, resulting DTC structure is
particularly simplistic. Conventional DTC does not require any mechanical
sensor or current regulator and coordinate transformation is not present, thus
reducing the complexity. Fast and good dynamic performances and
robustness has made DTC popular and is now used widely in all industrial
applications. Despite these advantages it has some disadvantages such as
high torque ripple and slow transient response to step changes during start
up. Torque ripple in DTC is because of hysteresis controller for stator flux
linkage and torque. The ripples can be reduced if the errors of the torque and
the flux linkage and the angular region of the flux linkage are subdivided into
several smaller subsections. Since the errors are divided into smaller sections
different voltage vector is selected for small difference in error, thus a more
accurate voltage vector is selected and hence the torque and flux linkage
errors are reduced. The stator resistance changes due to change in
temperature during the operation of machine. At high speeds, the stator
resistance drop is small and can be neglected. At low speeds, this drop
becomes dominant. Any change in stator resistance gives wrong estimation
of stator flux and consequently of the torque and flux. Therefore, it is
necessary to estimate the stator resistance correctly. This paper aims to
review some of the control techniques of DTC drives and stator resistance
estimation methods.
An optimal general type-2 fuzzy controller for Urban Traffic NetworkISA Interchange
Urban traffic network model is illustrated by state-charts and object-diagram. However, they have limitations to show the behavioral perspective of the traffic information flow. Consequently, a state space model is used to calculate the half-value waiting time of vehicles. In this study, a combination of the general type-2 fuzzy logic sets and the modified backtracking search algorithm (MBSA) techniques are used in order to control the traffic signal scheduling and phase succession so as to guarantee a smooth flow of traffic with the least wait times and average queue length. The parameters of input and output membership functions are optimized simultaneously by the novel heuristic algorithm MBSA. A comparison is made between the achieved results with those of optimal and conventional type-1 fuzzy logic controllers.
Embedded intelligent adaptive PI controller for an electromechanical systemISA Interchange
In this study, an intelligent adaptive controller approach using the interval type-2 fuzzy neural network (IT2FNN) is presented. The proposed controller consists of a lower level proportional - integral (PI) controller, which is the main controller and an upper level IT2FNN which tuning on-line the parameters of a PI controller. The proposed adaptive PI controller based on IT2FNN (API-IT2FNN) is implemented practically using the Arduino DUE kit for controlling the speed of a nonlinear DC motor-generator system. The parameters of the IT2FNN are tuned on-line using back-propagation algorithm. The Lyapunov theorem is used to derive the stability and convergence of the IT2FNN. The obtained experimental results, which are compared with other controllers, demonstrate that the proposed API-IT2FNN is able to improve the system response over a wide range of system uncertainties.
State of charge estimation of lithium-ion batteries using fractional order sl...ISA Interchange
This paper presents a state of charge (SOC) estimation method based on fractional order sliding mode observer (SMO) for lithium-ion batteries. A fractional order RC equivalent circuit model (FORCECM) is firstly constructed to describe the charging and discharging dynamic characteristics of the battery. Then, based on the differential equations of the FORCECM, fractional order SMOs for SOC, polarization voltage and terminal voltage estimation are designed. After that, convergence of the proposed observers is analyzed by Lyapunov’s stability theory method. The framework of the designed observer system is simple and easy to implement. The SMOs can overcome the uncertainties of parameters, modeling and measurement errors, and present good robustness. Simulation results show that the presented estima- tion method is effective, and the designed observers have good performance.
Fractional order PID for tracking control of a parallel robotic manipulator t...ISA Interchange
This paper presents the tracking control for a robotic manipulator type delta employing fractional order PID controllers with computed torque control strategy. It is contrasted with an integer order PID controller with computed torque control strategy. The mechanical structure, kinematics and dynamic models of the delta robot are descripted. A SOLIDWORKS/MSC-ADAMS/MATLAB co-simulation model of the delta robot is built and employed for the stages of identification, design, and validation of control strategies. Identification of the dynamic model of the robot is performed using the least squares algorithm. A linearized model of the robotic system is obtained employing the computed torque control strategy resulting in a decoupled double integrating system. From the linearized model of the delta robot, fractional order PID and integer order PID controllers are designed, analyzing the dynamical behavior for many evaluation trajectories. Controllers robustness is evaluated against external disturbances employing performance indexes for the joint and spatial error, applied torque in the joints and trajectory tracking. Results show that fractional order PID with the computed torque control strategy has a robust performance and active disturbance rejection when it is applied to parallel robotic manipulators on tracking tasks.
Fuzzy logic for plant-wide control of biological wastewater treatment process...ISA Interchange
The application of control strategies is increasingly used in wastewater treatment plants with the aim of improving effluent quality and reducing operating costs. Due to concerns about the progressive growth of greenhouse gas emissions (GHG), these are also currently being evaluated in wastewater treatment plants. The present article proposes a fuzzy controller for plant-wide control of the biological wastewater treatment process. Its design is based on 14 inputs and 6 outputs in order to reduce GHG emissions, nutrient concentration in the effluent and operational costs. The article explains and shows the effect of each one of the inputs and outputs of the fuzzy controller, as well as the relationship between them. Benchmark Simulation Model no 2 Gas is used for testing the proposed control strategy. The results of simulation results show that the fuzzy controller is able to reduce GHG emissions while improving, at the same time, the common criteria of effluent quality and operational costs.
Design and implementation of a control structure for quality products in a cr...ISA Interchange
In recent years, interest for petrochemical processes has been increasing, especially in refinement area. However, the high variability in the dynamic characteristics present in the atmospheric distillation column poses a challenge to obtain quality products. To improve distillates quality in spite of the changes in the input crude oil composition, this paper details a new design of a control strategy in a conventional crude oil distillation plant defined using formal interaction analysis tools. The process dynamic and its control are simulated on Aspen HYSYS dynamic environment under real operating conditions. The simulation results are compared against a typical control strategy commonly used in crude oil atmospheric distillation columns.
Model based PI power system stabilizer design for damping low frequency oscil...ISA Interchange
This paper explores a two-level control strategy by blending a local controller with a centralized controller for the low frequency oscillations in a power system. The proposed control scheme provides stabilization of local modes using a local controller and minimizes the effect of inter-connection of sub-systems performance through a centralized control. For designing the local controllers in the form of proportional-integral power system stabilizer (PI-PSS), a simple and straight forward frequency domain direct synthesis method is considered that works on use of a suitable reference model which is based on the desired requirements. Several examples both on one machine infinite bus and multi-machine systems taken from the literature are illustrated to show the efficacy of the proposed PI-PSS. The effective damping of the systems is found to be increased remarkably which is reflected in the time-responses; even unstable operation has been stabilized with improved damping after applying the proposed controller. The proposed controllers give remarkable improvement in damping the oscillations in all the illustrations considered here and as for example, the value of damping factor has been increased from 0.0217 to 0.666 in Example 1. The simulation results obtained by the proposed control strategy are favorably compared with some controllers prevalent in the literature.
A comparison of a novel robust decentralized control strategy and MPC for ind...ISA Interchange
Abstract: In this work we have developed a novel, robust practical control structure to regulate an industrial methanol distillation column. This proposed control scheme is based on a override control framework and can manage a non-key trace ethanol product impurity specification while maintaining high product recovery. For comparison purposes, an MPC with a discrete process model (based on step tests) was also developed and tested. The results from process disturbance testing shows that, both the MPC and the proposed controller were capable of maintaining both the trace level ethanol specification in the distillate (XD) and high product recovery (β). Closer analysis revealed that the MPC controller has a tighter XD control, while the proposed controller was tighter in β control. The tight XD control allowed the MPC to operate at a higher XD set point (closer to the 10 ppm AA grade methanol standard), allowing for savings in energy usage. Despite the energy savings of the MPC, the proposed control scheme has lower installation and running costs. An economic analysis revealed a multitude of other external economic and plant design factors, that should be considered when making a decision between the two controllers. In general, we found relatively high energy costs favor MPC.
Fault detection of feed water treatment process using PCA-WD with parameter o...ISA Interchange
Feed water treatment process (FWTP) is an essential part of utility boilers; and fault detection is expected for its reliability improvement. Classical principal component analysis (PCA) has been applied to FWTPs in our previous work; however, the noises of T2 and SPE statistics result in false detections and missed detections. In this paper, Wavelet denoise (WD) is combined with PCA to form a new algorithm, (PCA- WD), where WD is intentionally employed to deal with the noises. The parameter selection of PCA-WD is further formulated as an optimization problem; and PSO is employed for optimization solution. A FWTP, sustaining two 1000 MW generation units in a coal-fired power plant, is taken as a study case. Its operation data is collected for following verification study. The results show that the optimized WD is effective to restrain the noises of T2 and SPE statistics, so as to improve the performance of PCA-WD algorithm. And, the parameter optimization enables PCA-WD to get its optimal parameters in an auto- matic way rather than on individual experience. The optimized PCA-WD is further compared with classical PCA and sliding window PCA (SWPCA), in terms of four cases as bias fault, drift fault, broken line fault and normal condition, respectively. The advantages of the optimized PCA-WD, against classical PCA and SWPCA, is finally convinced with the results.
Model-based adaptive sliding mode control of the subcritical boiler-turbine s...ISA Interchange
As higher requirements are proposed for the load regulation and efficiency enhancement, the control performance of boiler-turbine systems has become much more important. In this paper, a novel robust control approach is proposed to improve the coordinated control performance for subcritical boiler-turbine units. To capture the key features of the boiler-turbine system, a nonlinear control-oriented model is established and validated with the history operation data of a 300 MW unit. To achieve system linearization and decoupling, an adaptive feedback linearization strategy is proposed, which could asymptotically eliminate the linearization error caused by the model uncertainties. Based on the linearized boiler-turbine system, a second-order sliding mode controller is designed with the super-twisting algorithm. Moreover, the closed-loop system is proved robustly stable with respect to uncertainties and disturbances. Simulation results are presented to illustrate the effectiveness of the proposed control scheme, which achieves excellent tracking performance, strong robustness and chattering reduction.
A Proportional Integral Estimator-Based Clock Synchronization Protocol for Wi...ISA Interchange
Clock synchronization is an issue of vital importance in applications of wireless sensor networks (WSNs). This paper proposes a proportional integral estimator-based protocol (EBP) to achieve clock synchronization for wireless sensor networks. As each local clock skew gradually drifts, synchronization accuracy will decline over time. Compared with existing consensus-based approaches, the proposed synchronization protocol improves synchronization accuracy under time-varying clock skews. Moreover, by restricting synchronization error of clock skew into a relative small quantity, it could reduce periodic re-synchronization frequencies. At last, a pseudo-synchronous implementation for skew compensation is introduced as synchronous protocol is unrealistic in practice. Numerical simulations are shown to illustrate the performance of the proposed protocol.
An artificial intelligence based improved classification of two-phase flow patte...ISA Interchange
Flow pattern recognition is necessary to select design equations for finding operating details of the process and to perform computational simulations. Visual image processing can be used to automate the interpretation of patterns in two-phase flow. In this paper, an attempt has been made to improve the classification accuracy of the flow pattern of gas/ liquid two- phase flow using fuzzy logic and Support Vector Machine (SVM) with Principal Component Analysis (PCA). The videos of six different types of flow patterns namely, annular flow, bubble flow, churn flow, plug flow, slug flow and stratified flow are re- corded for a period and converted to 2D images for processing. The textural and shape features extracted using image processing are applied as inputs to various classification schemes namely fuzzy logic, SVM and SVM with PCA in order to identify the type of flow pattern. The results obtained are compared and it is observed that SVM with features reduced using PCA gives the better classification accuracy and computationally less intensive than other two existing schemes. This study results cover industrial application needs including oil and gas and any other gas-liquid two-phase flows.
New Method for Tuning PID Controllers Using a Symmetric Send-On-Delta Samplin...ISA Interchange
In this paper we present a new method for tuning PI controllers with symmetric send-on-delta (SSOD) sampling strategy. First we analyze the conditions that produce oscillations in event based systems considering SSOD sampling strategy. The Describing Function is the tool used to address the problem. Once the conditions for oscillations are established, a new robustness to oscillation performance measure is introduced which entails with the concept of phase margin, one of the most traditional measures of relative stability in closed-loop control systems. Therefore, the application of the proposed robustness measure is easy and intuitive. The method is tested by both simulations and experiments. Additionally, a Java application has been developed to aid in the design according to the results presented in the paper.
Load estimator-based hybrid controller design for two-interleaved boost conve...ISA Interchange
This paper is devoted to the development of a hybrid controller for a two-interleaved boost converter dedicated to renewable energy and automotive applications. The control requirements, resumed in fast transient and low input current ripple, are formulated as a problem of fast stabilization of a predefined optimal limit cycle, and solved using hybrid automaton formalism. In addition, a real time estimation of the load is developed using an algebraic approach for online adjustment of the hybrid controller. Mathematical proofs are provided with simulations to illustrate the effectiveness and the robustness of the proposed controller despite different disturbances. Furthermore, a fuel cell system supplying a resistive load through a two-interleaved boost converter is also highlighted.
Effects of Wireless Packet Loss in Industrial Process Control SystemsISA Interchange
Timely and reliable sensing and actuation control are essential in networked control. This depends on not only the precision/quality of the sensors and actuators used but also on how well the communications links between the field instruments and the controller have been designed. Wireless networking offers simple deployment, reconfigurability, scalability, and reduced operational expenditure, and is easier to upgrade than wired solutions. However, the adoption of wireless networking has been slow in industrial process control due to the stochastic and less than 100% reliable nature of wireless communications and lack of a model to evaluate the effects of such communications imperfections on the overall control performance. In this paper, we study how control performance is affected by wireless link quality, which in turn is adversely affected by severe propagation loss in harsh industrial environments, co-channel interference, and unintended interference from other devices. We select the Tennessee Eastman Challenge Model (TE) for our study. A decentralized process control system, first proposed by N. Ricker, is adopted that employs 41 sensors and 12 actuators to manage the production process in the TE plant. We consider the scenario where wireless links are used to periodically transmit essential sensor measurement data, such as pressure, temperature and chemical composition to the controller as well as control commands to manipulate the actuators according to predetermined setpoints. We consider two models for packet loss in the wireless links, namely, an independent and identically distributed (IID) packet loss model and the two-state Gilbert-Elliot (GE) channel model. While the former is a random loss model, the latter can model bursty losses. With each channel model, the performance of the simulated decentralized controller using wireless links is compared with the one using wired links providing instant and 100% reliable communications. The sensitivity of the controller to the burstiness of packet loss is also characterized in different process stages. The performance results indicate that wireless links with redundant bandwidth reservation can meet the requirements of the TE process model under normal operational conditions. When disturbances are introduced in the TE plant model, wireless packet loss during transitions between process stages need further protection in severely impaired links. Techniques such as re-transmission scheduling, multi-path routing and enhanced physical layer design are discussed and the latest industrial wireless protocols are compared.
Fault Detection in the Distillation Column ProcessISA Interchange
Chemical plants are complex large-scale systems which need designing robust fault detection schemes to ensure high product quality, reliability and safety under different operating conditions. The present paper is concerned with a feasibility study of the application of the black-box modeling method and Kullback Leibler divergence (KLD) to the fault detection in a distillation column process. A Nonlinear Auto-Regressive Moving Average with eXogenous input (NARMAX) polynomial model is firstly developed to estimate the nonlinear behavior of the plant. Furthermore, the KLD is applied to detect abnormal modes. The proposed FD method is implemented and validated experimentally using realistic faults of a distillation plant of laboratory scale. The experimental results clearly demonstrate the fact that proposed method is effective and gives early alarm to operators.
Neural Network-Based Actuator Fault Diagnosis for a Non-Linear Multi-Tank SystemISA Interchange
The paper is devoted to the problem of the robust actuator fault diagnosis of the dynamic non-linear systems. In the proposed method, it is assumed that the diagnosed system can be modelled by the recurrent neural network, which can be transformed into the linear parameter varying form. Such a system description allows developing the designing scheme of the robust unknown input observer within H1 framework for a class of non-linear systems. The proposed approach is designed in such a way that a prescribed disturbance attenuation level is achieved with respect to the actuator fault estimation error, while guaranteeing the convergence of the observer. The application of the robust unknown input observer enables actuator fault estimation, which allows applying the developed approach to the fault tolerant control tasks.
A KPI-based process monitoring and fault detection framework for large-scale ...ISA Interchange
Large-scale processes, consisting of multiple interconnected sub-processes, are commonly encountered in industrial systems, whose performance needs to be determined. A common approach to this problem is to use a key performance indicator (KPI)-based approach. However, the different KPI-based approaches are not developed with a coherent and consistent framework. Thus, this paper proposes a framework for KPI-based process monitoring and fault detection (PM-FD) for large-scale industrial processes, which considers the static and dynamic relationships between process and KPI variables. For the static case, a least squares-based approach is developed that provides an explicit link with least-squares regression, which gives better performance than partial least squares. For the dynamic case, using the kernel re- presentation of each sub-process, an instrument variable is used to reduce the dynamic case to the static case. This framework is applied to the TE benchmark process and the hot strip mill rolling process. The results show that the proposed method can detect faults better than previous methods.
An adaptive PID like controller using mix locally recurrent neural network fo...ISA Interchange
Being complex, non-linear and coupled system, the robotic manipulator cannot be effectively controlled using classical proportional integral derivative (PID) controller. To enhance the effectiveness of the conventional PID controller for the nonlinear and uncertain systems, gains of the PID controller should be conservatively tuned and should adapt to the process parameter variations. In this work, a mix locally recurrent neural network (MLRNN) architecture is investigated to mimic a conventional PID controller which consists of at most three hidden nodes which act as proportional, integral and derivative node. The gains of the mix locally recurrent neural network based PID (MLRNNPID) controller scheme are initi- alized with a newly developed cuckoo search algorithm (CSA) based optimization method rather than assuming randomly. A sequential learning based least square algorithm is then investigated for the on- line adaptation of the gains of MLRNNPID controller. The performance of the proposed controller scheme is tested against the plant parameters uncertainties and external disturbances for both links of the two link robotic manipulator with variable payload (TL-RMWVP). The stability of the proposed controller is analyzed using Lyapunov stability criteria. A performance comparison is carried out among MLRNNPID controller, CSA optimized NNPID (OPTNNPID) controller and CSA optimized conventional PID (OPTPID) controller in order to establish the effectiveness of the MLRNNPID controller.
A method to remove chattering alarms using median filtersISA Interchange
Chattering alarms are the most found nuisance alarms that will probably reduce the usability and result in a confidence crisis of alarm systems for industrial plants. This paper addresses the chattering alarm reduction using median filters. Two rules are formulated to design the window size of median filters. If the alarm probability is estimated using process data, one rule is based on the probability of alarms to satisfy some requirements on the false alarm rate, or missed alarm rate. If there are only historical alarm data available, the other rule is based on percentage reduction of chattering alarms using alarm duration distribution. Experimental results for industrial cases testify that the proposed method is effective.
Vaccine management system project report documentation..pdfKamal Acharya
The Division of Vaccine and Immunization is facing increasing difficulty monitoring vaccines and other commodities distribution once they have been distributed from the national stores. With the introduction of new vaccines, more challenges have been anticipated with this additions posing serious threat to the already over strained vaccine supply chain system in Kenya.
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
NO1 Uk best vashikaran specialist in delhi vashikaran baba near me online vas...Amil Baba Dawood bangali
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Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
2. S.C. Bera et al. / ISA Transactions 51 (2012) 220–228 221
with high harmonic content. Riyaz et al. [6] have studied the
performance of a thyristor driven variable voltage induction motor
and have developed simple and flexible models for simulation
and validation of the system. Bennett and Jones [12] have studied
the operation of thyristor driven dc and ac motors in various
applications. Pauwels [13] have shown that a good amount of
energy can be saved by using a thyristor driven variable speed
pump. Huang et al. [14] have presented an on-state model for
MCST and the results are compared with MCT and IGBT. It has been
observed that during the on-state, MCST operates like thyristor
at a low anode voltage and enters IGBT with increasing anode
voltage. Zehringer et al. [15] have described two types of current
IGBT modules which are evolved from opposing requirements
of tractions and power applications. Liu and Daley [16] have
proposed an analytic physical dynamic model for the tuning of
nonlinear PID control of hydraulic systems. In this technique, a
nonlinear PID control with an inverse of dead zone is implemented
to overcome the dead zone in the hydraulic systems. Montanari
et al. [17] have developed a nonlinear control technique of an
induction motor without using any actual speed sensor. Here,
stator current has been taken as a measure of motor speed. Ben
Azza et al. [18] also have proposed a single phase induction motor
drive with sensorless indirect stator field control using tuning of
stator resistance and the estimated speed of the induction motor
is measured by measurements of stator currents.
The nonlinear relation between motor speed and dc input
voltage of a thyristor may cause operational problems in speed
control of the motor or output flow rate control of the pump. In the
present paper, an opto-isolator based linearization technique of a
thyristor driven pump has been studied. In an ordinary thyristor
driven motor it has been observed that the output voltage of
the thyristor, motor speed, motor load current and outlet flow
rate of water produced by a thyristor driven motor and pump
etc. are all nonlinearly related with the dc input signal of the
thyristor firing circuit. Moreover, the response time of the motor
driven pump to any change of load is found to be very small.
So when an ordinary PID controller is used to adjust the speed
of the motor to obtain a desired flow rate, it may suffer from
wide fluctuations from the desired value. In order to overcome
these difficulties of a thyristor driven motor coupled to a pump,
a modified design of the control system with PIDD−1
controller has
been described in this paper. After proper tuning of this control
loop, its performance has been experimentally studied. A quite
linear characteristic of the pump with much more stable operation
has been observed. The experimental results are presented in this
paper. Moreover, the measured output speed and flow rate of the
pump are automatically maintained at the values as dictated by the
set point value. Hence pump speed and flow rate follow a linear
relationship with the set point value taken as the input signal of
the thyristor firing circuit.
2. Method of approach
Let us consider an ordinary thyristor operated ac/dc universal
motor driven pump lifting water from a reservoir tank through a
pipeline as shown in Fig. 1. The thyristor firing circuit has the input
dc supply in the range 1–5 V so that the pump can be operated from
a minimum to maximum range to obtain a water flow rate through
the pipeline in a given range. Under this condition the thyristor
output voltage, load current, the pump output flow rate and motor
speed vary nonlinearly with input dc voltage signal of the firing
circuit.
Now in order to design an electronic linearization network with
the motor load current linearly varying with the dc input voltage
of the thyristor driven pump, it is required to measure the load
current derived from thyristor output and the measuring system
Fig. 1. Circuit diagram of a thyristor operated electric motor driven pump before
linearization.
should be isolated from the supply voltage. So an opto-isolator
based measuring circuit of the load current is designed as shown
in Fig. 2.
In Fig. 2, an A.C. ammeter (A) is used to measure the load
current of the thyristor, passing through the pump motor. A light
emitting diode (LED) D1 shunts the ammeter and produces light
of an intensity according to the load current of the pump motor.
The light produced by the LED is allowed to be incident on a
light dependent resistor (LDR) R1. The resistance R1 of the LDR unit
changes in accordance with the intensity of the light emitted by
LED. The LED and LDR combination is placed in a black enclosure,
so that no external light can interfere with their operation. The LDR
is used as the input resistance of an inverting amplifier with op-
amp A1. The input signal of the amplifier is a stabilized negative dc
voltage signal (−V) so that the output of the amplifier is a positive
dc voltage signal and is given by,
V1 =
R2V
R1
(1)
where R1 is the resistance of LDR for a particular load current IL.
Let RD be the forward resistance of the LED (D1) and RA be the
resistance of the A.C. ammeter (A), both connected in parallel and
placed in series with the motor circuit. Let Im be the current passing
through the ammeter. So the current ID passing through the LED
will be given by,
ID =
ImRA
RD
. (2)
Now the light power PL emitted by LED is directly propor-
tional [19,20] to the current (ID) flowing through it i.e.,
PL ∝ ID
or,
PL = K1ID (3)
where K1 is the constant of proportionality.
From (2) and (3),
PL =
K1ImRA
RD
. (4)
3. 222 S.C. Bera et al. / ISA Transactions 51 (2012) 220–228
Fig. 2. Circuit diagram of proposed thyristor operated electric motor driven pump after linearization.
Now one terminal of LDR is connected to a stabilized negative
dc voltage source (−V) and the other end is connected to a virtual
ground inverting terminal of op-Amp A1. So if the current passing
through the LDR in dark condition is Id and in the lit condition is Iph
then the resistance of the LDR is given by
R1 =
V
Id + Iph
. (5)
Again, in the dark region Iph is zero and Id is very small. So the
value of R1 is very high in the dark region. In the lighted region the
incident light power Pinc on the LDR surface is proportional to the
developed power PL by LDR i.e.
Pinc ∝ PL
or,
Pinc = K2PL (6)
where K2 is a constant of proportionality.
Combining (4) and (6) we have,
Pinc =
K1K2ImRA
RD
. (7)
Now the current Iph produced in the LDR material by the
incident photons is given by,
Iph =
ηqPinc
hν
(8)
where,
q = Electronic charge
η = Quantum efficiency of generation of electron–hole pairs
by the incident photons
h = Plank’s constant
ν = Frequency of light, emitted by LED
From (5) and (8) we have,
R1 =
V
Id + ηqPinc
hν
. (9)
Hence from (1) and (8) the output voltage V1 of op-Amp A1 is
given by,
V1 = R2
Id +
η q Pinc
hν
. (10)
Combining (6) and (10),
V1 = R2
Id +
ηqK2PL
hν
. (11)
From (4) and (11) we get,
V1 = R2
Id +
ηqK1K2ImRA
hνRD
. (12)
Now from the shunt principle,
Im =
RDIL
RD + RA
. (13)
4. S.C. Bera et al. / ISA Transactions 51 (2012) 220–228 223
Combining (12) and (13), we get,
V1 = R2
[
Id +
ηqK1K2RAIL
hν (RA + RD)
]
(14)
or,
V1 = K3 + K4IL (15)
where,
K3 = R2Id and K4 =
ηqK1K2R2RA
hν(RA + RD)
. (16)
Now assuming no losses of a motor driven pump in the ideal
case, the power consumed in a pump motor may be given by the
simple relation, power = mass flow rate of the liquid × the height
to which the liquid is lifted × acceleration due to gravity.
Hence under ideal conditions the motor load current is directly
proportional to the mass flow rate of the liquid if the motor supply
voltage, power factor and height of fluid lift are kept constant.
However, in actual cases there is always loss of energy in a motor
and pump. So the relation between motor load current (IL) and
mass flow rate (Q ) of the liquid may be nonlinear as shown by the
following equation.
IL = ILO +
∂IL
∂Q
QO
Q +
1
2!
∂2
IL
∂Q 2
QO
Q 2
+ · · · (17)
where ILO is the load current for a given mass flow rate QO and IL
is the load current when the mass flow rate increases from QO by
Q .
Or,
IL = ILO + a Q + b Q 2
+ · · · (18)
where,
a =
∂IL
∂Q
QO
and b =
1
2!
∂2
IL
∂Q 2
QO
. (19)
For small values of Q , the higher order terms are negligible
and (18) may be reduced to
IL = ILO + a Q + b Q 2
. (20)
From (14) and (20) we get,
V1 = K3 + K4(ILO + a Q + b Q 2
) (21)
or,
V1 = K5 + K4(a Q + b Q 2
) (22)
where
K5 = K3 + K4ILO. (23)
If the mass flow rate increases from an initial value Qo to a value
Q by a very small amount Q then Q = Q − Qo and (22) is
reduced to
V1 = K5 + K4[a(Q − Qo) + b(Q − Qo)2
]. (24)
If we start from no flow condition then Qo = 0 and (24) reduce
to
V1 = K5 + K4[aQ + bQ 2
]
or,
V1 = K5 + K6Q + K7Q 2
(25)
where,
K6 = K4a and K7 = K4b. (26)
Fig. 3. Circuit diagram of a linearizing PID controller with inverse derivative control
action.
For smaller pumps there is an almost linear relation between
flow rate Q and load current IL. Hence b = 1
2′
∂2IL
∂Q 2
QO
may be
assumed to be zero or negligible. So K7 = K4b may be assumed to
be zero or negligible and (25) may be reduced to
V1 = K5 + K6Q . (27)
Let VZ be the output voltage of the zero adjustment potentiome-
ter RZ and R3 = R5 = R6 = R. So the output (Vm) of the differential
amplifier circuit consisting of op-Amp A2 is given by,
Vm =
R4
R3
(V1 − VZ ) (28)
or,
Vm =
R4
R3
[K3 + K4IL − VZ ]
or,
Vm = K8 + K9Q + K10Q 2
(29)
where,
K8 =
R4
R3
(K5 − VZ ), K9 =
K6R4
R3
and
K10 =
K7R4
R3
. (30)
For smaller pumps K10 is very small since K7 is negligible and
(29) is reduced to
Vm = K8 + K9Q . (31)
By adjusting the gain K9 or gain adjustment potentiometer R2 and
zero adjustment voltage VZ or zero adjustment potentiometer RZ , the
output voltage Vm in the range 1–5 V may be obtained. In order to
obtain a linear characteristic between Vm and Q as well as to obtain
a linear characteristic of the thyristor driven pump, the measuring
circuit shown in Fig. 2 is combined with a modified PID controller
circuit with inverse derivative control action to form a linearization
network of a thyristor operated pump as shown in Fig. 3.
In Fig. 3, the measured signal (Vm) is subtracted from the input
or set point signal (VS ) to obtain the error or deviation signal (Ve)
by the differential amplifier consisting of op-amp A3.
Assuming, R7 = R8 = R9 = R10.
So,
Ve = VS − Vm. (32)
Combining (29) and (32) we have,
Ve = VS − K8 − K9Q − K10Q 2
. (33)
The linearizing controller circuit consists of only two op- Amps
A4 and A5 as shown in Fig. 2. This controller circuit is separately
shown in Fig. 3.
The deviation signal Ve is now applied at the input terminal A of
the amplifier A4. The output signal VB at the output terminal B of
5. 224 S.C. Bera et al. / ISA Transactions 51 (2012) 220–228
Fig. 4. Equivalent circuit of Fig. 3.
the amplifier A4 is obtained from the equivalent circuit shown in
Fig. 4.
Since the input impedance of the operational amplifier is high,
the input signals e1 and e2 at the inverting and non-inverting
terminals respectively of the amplifier A4 may be assumed to be
identical. Again, due to the high input impedance of the op-Amp,
negligible current passes through the input resistance R11 from the
input deviation signal source (Ve). Hence, the input signal e2 at
the non-inverting terminal of A4 will be almost equal to the input
signal Ve.
i.e. e1 ≈ e2 and Ve ≈ e2. (34)
Now assuming, R11 = R12
e1 =
R12
(R12 + R13)
VB. (35)
Hence,
Ve ≈ e1 =
R12
(R12 + R13)
VB
or,
VB = αVe (36)
where,
α =
R12 + R13
R12
. (37)
Hence, the equivalent circuit of the network of amplifier A4
between the terminals ‘A’ and ‘D’ may be as shown in Fig. 4 and
the Laplace transform of the circuit is given by,
I(s) =
[αVe(s) − Ve(s)]
RD + 1
CDs
. (38)
Hence in the frequency plane, the voltage signal at ‘D’ will be
given by,
VD(s) = Ve(s) + RDI(s)
or,
VD(s) =
(1 + TDs)
1 + TDs
α
Ve(s) (39)
where,
TD = αRDCD =
[
(R12 + R13)RDCD
R12
]
. (40)
Now this voltage signal is again input to the non-inverting
terminal of the second amplifier A5 through the resistance R − RD
of the derivative potentiometer R. Since the current drawn by A5
is negligibly small, the voltage signal e4(s) at the non-inverting
terminal at the amplifier A5 will be approximately equal to VD(s),
i.e. e4(s) = VD(s). (41)
Let the voltage signal at the output terminal E of the amplifier
A5 be ‘m’ and that at its inverting input terminal be e3. Hence in
the frequency plane, the voltage signal VF (s) at the point F of the
circuit diagram as shown in Fig. 3 is given by,
VF (s) =
RP
(R14 + R′)
m(s) = Km(s) (42)
where
K =
RP
(R14 + R′)
. (43)
This voltage is being discharged through RI and CI . Hence the
voltage across the capacitor CI will be given by,
VF (s) =
[
1 +
1
RI CI s
]
e3(s). (44)
From (41) and (43) we have,
Km(s) =
[
1 +
1
TI s
]
e3(s) (45)
where,
TI = RI CI . (46)
Now, from the op-Amp A5 we have,
e3(s) = e4(s). (47)
From (39), (41), (45) and (47) we have,
Km(s) =
[
1 +
1
TI s
]
VD(s)
Km(s) =
[
1 +
1
TI s
]
(1 + TDs)
1 + TDs
α
Ve(s).
Thus the transfer function of the controller circuit as shown in
Fig. 3 is given by
m(s)
Ve(s)
= KC
[
1 +
1
TI s
]
(1 + TDs)
1 + TDs
α
(48)
where, KC = 1
K
.
The above transfer function is the transfer function of a
PID controller with inverse derivative control action where the
proportional constant KC , integral action time TI , derivative action
time TD and dynamic gain α are given by,
KC =
1
K
=
(R3 + R′
)
RP
, TI = RI CI , TD = αRDCD
and α =
(R12 + R13)
R12
. (49)
From (29), it is observed that Vm is directly related with the
speed of the pump or mass flow rate (Q ). Hence if the speed of
the pump or the mass flow rate of the liquid deviates from an ideal
linear value as dictated by set-point, then a control action will be
generated which will change the firing angle of the thyristor until
the desired flow rate is restored. Hence Vm is forced to follow VS
i.e. the mass flow rate of the fluid produced by the pump. Thus Vm
must be linearly related with speed of the pump and mass flow rate
under steady condition and after proper tuning of the control loop.
6. S.C. Bera et al. / ISA Transactions 51 (2012) 220–228 225
Fig. 5. A photographic view of the experimental setup.
3. Design
The above linearization control circuit has been designed and
fabricated using a commercially available thyristor driven single
phase motor integrated with a centrifugal pump (ac/dc cont. Tullu-
25 Pump, M/s Tullu Motors (p) Ltd., India) sending tap water
through a 25 mm diameter pipeline. The thyristor drive unit
is made by M/s. Microtech Industries, Kolkata, India, with the
provision of 1–5 V dc input in its firing circuits has a 230 V, 50 Hz
single phase, ac supply. The LED and LDR combination used as an
opto-isolator is placed in a black polyvinyl chloride (PVC) tube of
4 mm internal diameter and 6 mm outside diameter and 15 mm
length closed at both ends with black PVC sheets. The remainder
of the circuits is fabricated on a printed circuit board (PCB) and
connections are made as shown in Fig. 2. The op-Amps used in
the circuits were OP-07, the color of the LED was selected to be
red and the LDR was selected to be a small low cost type 4 mm
diameter available in the market. All resistances were selected to
Fig. 6. On-line display of motor load current.
be 1/2 W, with 1% tolerance. A photographic view of experimental
setup is shown in Fig. 5. The on-line display of the motor current
using Storage CRO in the form of voltage drop across a 10 , 1 A
standard resistance connected in series with the motor load circuit
is shown in Fig. 6.
4. Experiment
The experiment is performed in two steps using tap water
at room temperature as the process liquid. In the first step, the
characteristic graphs of the thyristor driven pump before control
are determined. The thyristor drive unit is connected to the pump
as shown in Fig. 1. The output flow rate of water produced by
the pump is measured with a rotameter and the speed of the
pump motor is measured by a digital tachometer. The dc input
voltage of the thyristor firing circuit is now increased in steps
1 2 3 4 5
100
150
200
250
D.C input(volts)
Thyristoroutput(volts)
D.C input(volts)
1 2 3 4 5
1400
1600
1800
2000
2200
2400
Motorspeed(rpm)
D.C input(volts)
1 2 3 4 5
0.1
0.15
0.2
0.25
Loadcurrent(amp)
(a) Thyristor output voltage vs. D.C input
characteristic.
(b) Motor speed vs. thyristor input characteristic
before control.
(c) Motor load current vs. thyristor input
characteristic.
D.C input(volts)
1 2 3 4 5
0
2
4
6
8
10
Flowrate(LPM)
(d) Output flow rate vs. thyristor input characteristic.
Fig. 7. Characteristics of thyristor drive unit and thyristor driven pump.
7. 226 S.C. Bera et al. / ISA Transactions 51 (2012) 220–228
1 2 3 4 5
120
140
160
180
200
D.C input(volts)
Outputvoltage(volts)
1 2 3 4 5
D.C input(volts)
Percentagedeviationfromlinearity
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
(a) Thyristor output voltage vs. D.C input characteristic along with percentage deviation from linearity.
1 2 3 4 5
1600
1800
2000
2200
2400
D.C input(volts)
Motorspeed(rpm)
1 2 3 4 5
D.C. input(volts)
Percentagedeviationfromlinearity
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
(b) Observed speed vs. thyristor input characteristic along with percentage deviation from linearity.
1 2 3 4 5
0.15
0.16
0.17
0.18
0.19
0.2
Loadcurrent(amps)
1 2 3 4 5
D.C input(volts)D.C input(volts)
Percentagedeviationfromlinearity
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
(c) Motor load current vs. thyristor input characteristic along with percentage deviation from linearity.
D.C input(volts) D.C input(volts)
1 2 3 4 5
3
4
5
6
7
Flowrate(LPM)
1 2 3 4 5
Percentagedeviationfromlinearity
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
(d) Output flow rate vs. thyristor input characteristic along with percentage deviation from linearity.
Fig. 8. Characteristic graphs of thyristor driven pump after control.
and in each step, the thyristor output voltage across the pump
motor, motor speed, motor load current and corresponding reading
of the rotameter are monitored. Characteristics graphs are drawn
by plotting thyristor output voltage, pump speed, motor load
current and output flow rate against thyristor input voltage. The
characteristic graphs thus obtained are shown in Fig. 7(a)–(d)
respectively.
Now in the second step, the pump is connected with the
proposed linearization or control circuit and the characteristic
parameters of the controller are determined by using the ultimate
closed loop tuning method of Ziegler and Nichols. In this method,
the controller was kept in proportional mode by shortening the
derivative capacitor CD and integral capacitor CI in close loop. Now
the gain of the controller was increased in steps by varying the
gain adjustment potentiometer RP and at each step the controller
output was observed in storage CRO until a sustained oscillation
with constant amplitude was obtained. The time period of this
sustained oscillation was measured from CRO. This time period
is the ultimate time period TU . The corresponding gain of the
controller was calculated from the value of RP from (49). This
gain gives the ultimate gain KU . From these values of TU and KU ,
the tuned parameters of the PID controller are calculated using
8. S.C. Bera et al. / ISA Transactions 51 (2012) 220–228 227
Ziegler–Nichols’ formula: KC = 0.6KU , TI = 0.5TU , TD = 0.125TU .
The tuned parameters thus obtained were KC = 5.217, TI =
300 µs, Td = 75 µs. The values of CI and CD were selected to be
each of 0.1 µF, 100 V, R12 and R13 were also selected to be equal, so
that the value of α was equal to 2. The values of RP , RI and RD were
than calculated by using the relation (30). Thus the controller was
tuned by adjusting the values of RP , RI and RD to these tuned values
and by removing the short circuiting wires of capacitors CI and CD.
The controller parameters are accordingly adjusted. Now the
dc input voltage of the thyristor drive is increased in steps and
in each step the thyristor output voltage across the pump motor,
motor speed, motor load current and corresponding reading of the
rotameter are monitored. Now the similar characteristic graphs as
in the first steps are drawn and are shown in Fig. 8(a)–(d) along
with their respective percentage deviation curves from linearity.
5. Discussions
From the experimental graphs as shown in Fig. 7(a)–(d), it is
found that the output voltage of the thyristor drive unit, motor
speed, motor load current and the flow rate produced by the pump
all vary nonlinearly with the input dc voltage when no linearization
technique is used.
In order to minimize the nonlinearity of the pump, the proposed
PID controller circuit with inverse derivative control action has
been used. The load current is measured by the opto-isolator based
technique. When the output voltages of the load current measuring
circuit deviates from input set point dc voltages, the thyristor
conduction changes until the deviation reduces to zero. Thus the
load current of the thyristor operated pump is found to follow
the input dc signal and vary linearly with dc input voltage. After
tuning of the control loop the controller parameters are selected.
With these controller parameters the characteristics graphs of the
whole thyristor driven pump are drawn experimentally. These
graphs are shown in Fig. 8(a)–(d) and we observe that all the
characteristics graphs of the thyristor driven pump are quite linear
and the percentage deviation of the characteristic graphs from
linearity lies within ±0.5%, which is within a tolerable limit in
industry applications.
During the design and experimental work, a few obstacles like
obstructions in the pump, malfunction of electronic components,
loose connections of connecting wires etc. were observed. The
future scope of the present work is to extend the technique in a
three phase IGBT based and thyristor based system and to develop
a marketable commercial unit.
The basic aim of the present work is to remove the nonlinearity
of a thyristor driven pump and to operate it linearly with the help of
a 1–5 V dc signal. From the experimental graphs shown in Fig. 7 for
a low capacity pump, it may be concluded that a very good linearity
can be achieved in other high capacity pumps by utilizing the
proposed technique in both single and three phase applications.
The technique can be used in various applications such as the final
control element of a control loop, flow control of a water lift pump
etc.
Due to external disturbance the ordinary electronic PID
controller suffers from derivative over run effect. But due to inverse
derivative control action [5] this derivative over run problem is
easily eliminated in a PIDD−1
controller. The other disturbances
such as malfunctioning of electronic components, malfunctioning
of thyristor drive etc. are easily eliminated due to the negative
feedback technique used in the control system. So a very stable
and linear response of the proposed system has been observed as
shown in Fig. 8.
6. Conclusions
From the study of the present work, the following conclusion
may be drawn regarding the major contributions of the work.
(a) The motor has been successfully coupled with an analog
electronic circuit. Through a suitable DAS card the motor can
also be coupled with a PC based system.
(b) The proposed opto-coupler technique successfully measures
the motor load current and flow rate of the liquid produced by
the pump without using an conventional flow meter.
(c) The nonlinear characteristic of the pump as shown in Fig. 5 in
the revised paper has been successfully linearized by using the
proposed technique.
(d) The linearization technique is very simple and requires
no complicated piecewise linearization technique and no
microprocessor or microcontroller for linearization.
(e) The linear control of pump speed and output flow rate
according to a desired value or set point value has been
successfully implemented.
(f) Only two op-Amps have been used to design the PIDD−1
controller. Thus the controller may be considered to be very
cheap compared to the conventional PID controller where more
IC’s are used.
(g) The inverse derivative control action helps in reducing the
noise due to incidental change of motor speed caused by
various disturbances like sudden change of supply voltage,
sudden malfunction of thyristor drive etc.
Acknowledgments
The authors are thankful to the All India Council of Technical
Education (AICTE), MHRD, Govt. of India for their financial
assistance in the present investigation and the Department of
Applied Physics, University of Calcutta, for providing the facilities
to carry out this work.
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