Close Loop Control of Induction Motor Using Z-Source InverterIJSRD
In this paper a new closed loop control of induction motor fed by a Z – source inverter based on the vector control or field oriented control strategy is presented. Induction motor is supplied by Z – source inverter, in the Z – source inverter the term Z denotes impedance which means a combination of L & C element which are cross connected. The Z-source inverter consists of a unique impedance network (or circuit) to couple the inverter main circuit to the power supply, hence providing great features that cannot be observed in the conventional voltage-source inverter and current-source inverters in which capacitor and inductor are used, respectively.In the field oriented control method or vector control method speed of the induction motor, torque & 3 phase stator current is given to the field oriented controller and gate pulses for the inverter is generated to obtain the desired operation of the induction motor.
Grid-Connection Control and Simulation of PMSG Wind Power System Based on Mul...ijsrd.com
This dissertation proposes a wind energy conversion system is composed of a wind turbine PMSG, a rectifier, and an inverter. The wind turbine PMSG transforms the mechanical power from the wind into the electrical power, while the rectifier converts the AC power into DC power and controls the speed of the PMSG. The controllable inverter helps in converting the DC power to variable frequency and magnitude AC power. With the voltage oriented control, the inverter also possesses the ability to control the active and reactive powers injected into the grid. Multilevel inerter is used to step up the voltage and to reduce the THD. Here nine level and eleven level inverter are used and the voltage increases and THD reduces from 12.87 % to 7.46 %. Active and reactive power is controlled dc stabilization and the reactive power is near to unity Here PI controller is used to control the inverter output rms voltage and LC filter is used to remove the harmonics available in the system.
Close Loop Control of Induction Motor Using Z-Source InverterIJSRD
In this paper a new closed loop control of induction motor fed by a Z – source inverter based on the vector control or field oriented control strategy is presented. Induction motor is supplied by Z – source inverter, in the Z – source inverter the term Z denotes impedance which means a combination of L & C element which are cross connected. The Z-source inverter consists of a unique impedance network (or circuit) to couple the inverter main circuit to the power supply, hence providing great features that cannot be observed in the conventional voltage-source inverter and current-source inverters in which capacitor and inductor are used, respectively.In the field oriented control method or vector control method speed of the induction motor, torque & 3 phase stator current is given to the field oriented controller and gate pulses for the inverter is generated to obtain the desired operation of the induction motor.
Grid-Connection Control and Simulation of PMSG Wind Power System Based on Mul...ijsrd.com
This dissertation proposes a wind energy conversion system is composed of a wind turbine PMSG, a rectifier, and an inverter. The wind turbine PMSG transforms the mechanical power from the wind into the electrical power, while the rectifier converts the AC power into DC power and controls the speed of the PMSG. The controllable inverter helps in converting the DC power to variable frequency and magnitude AC power. With the voltage oriented control, the inverter also possesses the ability to control the active and reactive powers injected into the grid. Multilevel inerter is used to step up the voltage and to reduce the THD. Here nine level and eleven level inverter are used and the voltage increases and THD reduces from 12.87 % to 7.46 %. Active and reactive power is controlled dc stabilization and the reactive power is near to unity Here PI controller is used to control the inverter output rms voltage and LC filter is used to remove the harmonics available in the system.
SRF THEORY BASED STATCOM FOR COMPENSATION OF REACTIVE POWER AND HARMONICSIAEME Publication
The power electronic devices like converters and inverters inject harmonic currents into AC
system due to their non linear characteristics. These devices draw high amount of reactive power
from source. The commencement of Nonlinear Load into the ac power system will have the effect of
harmonics. The presence of harmonics in system it will effected with power quality problems. Due
to this high amount of power losses and disoperation of power electronics devices is caused, along
with this Harmonics have a number of undesirable effects like Voltage disturbances. These
harmonics are needed to mitigate for Power Quality Enhancement in distributed system. Here the
device called STATCOM is one of the FACTS Devices which can be used to mitigate the harmonics
and reactive power compensation. The voltage source converter is core of the STATCOM and the
hysteresis current control is indirect method of controlling of VSC. In this paper we implement with
SRF based STATCOM control. SRF theory is implemented for the generation of controlling
reference current signals for controller of STATCOM. The Matlab\Simulink based model is
developed and simulation results are showed for linear and nonlinear load conditions.
Direct current (DC) electronic load is a useful equipment for testing the electrical system. It can emulate various load at a high rating. The electronic load requires a power converter to operate and a linear regulator is a common option. Nonetheless, it is hard to control due to the temperature variation. This paper proposed a DC electronic load using the boost converter. The proposed electronic load operates in the continuous current mode and control using the integral controller. The electronic load using the boost converter is compared with the electronic load using the linear regulator. The results show that the boost converter able to operate as an electronic load with an error lower than 0.5% and response time lower than 13 ms.
Alternating current (AC) electrical drives mainly require smaller current (or torque) ripples and lower total harmonic distortion (THD) of voltage for excellent drive performances. Normally, in practice, to achieve these requirements, the inverter needs to be operated at high switching frequency. By operating at high switching frequency, the size of filter can be reduced. However, the inverter which oftenly employs insulated gate bipolar transistor (IGBT) for high power applications cannot be operated at high switching frequency. This is because, the IGBT switching frequency cannot be operated above 50 kHz due to its thermal restrictions. This paper proposes an alternate switching strategy to enable the use of IGBT for operating the inverter at high switching frequency to improve THD performances. In this strategy, each IGBT in a group of switches in the modified inverter circuit will operate the switching frequency at one-fourth of the inverter switching frequency. The alternate switching is implemented using simple analog and digital integrated circuits.
Transmission lines react to an unexpected increase in power, and if these power changes are not controlled, some lines will become overloaded on certain routes. Flexible alternating current transmission system (FACTS) devices can change the voltage range and phase angle and thus control the power flow. This paper presents suitable mathematical modeling of FACTS
devices including static var compensator (SVC) as a parallel compensator and high voltage direct current (HVDC) bonding. A comprehensive modeling of SVC and HVDC bonding in the form of simultaneous applications for power flow is also performed, and the effects of compensations are compared. The comprehensive model obtained was implemented on the 5-bus test system in MATLAB software using the Newton-Raphson method, revealed that generators have to produce more power. Also, the addition of these devices stabilizes the voltage and controls active and reactive power in the network.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
The growing demand for electricity and the increasing integration of clean energies into the electrical grids requires the multiplication and reinforcement of high-voltage direct current (HVDC) projects throughout the world and demonstrates the interest in this electricity transmission technology. The transmitting system of the voltage source converter-high-voltage direct current (VSC-HVDC) consists primarily of two converter stations that are connected by a dc cable. In this paper, a nonlinear control based on the backstepping approach is proposed to improve the dynamic performance of a VSC-HVDC transmission system, these transport systems are characterized by different complexities such as parametric uncertainties, coupled state variables, neglected dynamics, presents a very interesting research topic. Our contribution through adaptive control based on the backstepping approach allows regulating the direct current (DC) bus voltage and the active and reactive powers of the converter stations. Finally, the validity of the proposed control has been verified under various operating conditions by simulation in the MATLAB/Simulink environment.
This paper provides a new approach to reducing high-order harmonics in 400 Hz inverter using a three-level neutral-point clamped (NPC) converter. A voltage control loop using the harmonic compensation combined with NPC clamping diode control technology. The capacitor voltage imbalance also causes harmonics in the output voltage. For 400 Hz inverter, maintain a balanced voltage between the two input (direct current) (DC) capacitors is difficult because the pulse width modulation (PWM) modulation frequency ratio is low compared to the frequency of the output voltage. A method of determining the current flowing into the capacitor to control the voltage on the two balanced capacitors to ensure fast response reversal is also given in this paper. The combination of a high-harmonic resonator controller and a neutral-point voltage controller working together on the 400 Hz NPC inverter structure is given in this paper.
This paper presents a real-time emulator of a dual permanent magnet synchronous motor (PMSM) drive implemented on a field-programmable gate array (FPGA) board for supervision and observation purposes. In order to increase the reliability of the drive, a sensorless speed control method is proposed. This method allows replacing the physical sensor while guaranteeing a satisfactory operation even in faulty conditions. The novelty of the proposed approach consists of an FPGA implementation of an emulator to control the actual system. Hence, this emulator operates in real-time with actual system control in healthy or faulty mode. It gives an observation of the speed rotation in case of fault for the sake of continuity of service. The observation of the rotor position and the speed are achieved using the dSPACE DS52030D digital platform with a digital signal processor (DSP) associated with a Xilinx FPGA.
Analysis and Simulation of Solar PV Connected with Grid Accomplished with Boo...YogeshIJTSRD
This paper deals with a solar PV array connected with grid system. This system consists of PV cells with 30 KW system, Boost converter, three phase inverter with suitable control system and three phase load. This paper gives analysis of each components of the system. The output voltage from the solar PV cells are variable according to radiation intensity and temperature so in order to connect with grid the output voltage should be fixed and converted to AC voltage and this job will be done by an inverter. A very effective control system has been developed for the inverter based on pulse width modulation. This paper presents an intensive performance and dynamic behavior of a grid related PV energy conversion system. The PV system is developed and simulated with the help of MATLAB Simulink software environment. Abhishek Verma | Dr. Anup Mishra | Brahma Nand Thakur "Analysis and Simulation of Solar PV Connected with Grid Accomplished with Boost Converter and PWM Based Inverter" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-3 , April 2021, URL: https://www.ijtsrd.com/papers/ijtsrd40056.pdf Paper URL: https://www.ijtsrd.com/engineering/electrical-engineering/40056/analysis-and-simulation-of-solar-pv-connected-with-grid-accomplished-with-boost-converter-and-pwm-based-inverter/abhishek-verma
This paper presents the design and the implementation of a new microcontroller-based solar
Power inverter. The aim of this paper is to design single phase inverter which can convert DC voltage
to AC voltage at high efficiency and low cost. Solar and wind powered electricity generation are
being favored nowadays as the world increasingly focuses on environmental concerns. Power
inverters, which convert solar-cell DC into domestic-use AC, are one of the key technologies for
delivering efficient AC power The hardware and software design are oriented towards a single-chip
microcontroller-based system, hence minimizing the size and cost. With this new approach the
modularization of the conversion from solar power to electric power at its maximum power point can
be made more compact and more reliable.
Environmental factors such as air pollution and increase in global warming by using polluting fuels are the most important reasons of using renewable and clean energy that runs in global community. Wind energy is one of the most suitable and widely used kind of renewable energy which had been in consideration so well. This paper introduces an electric power generation
system of wind based on Y-source and improved Y-source inverter to deliver optimal electrical power to the network. This new converter is from impedance source converters family. This presented converter has more degrees of freedom to adjust voltage gain and modulation. Also, by limiting the range of simultaneous control (shooting through) while it maintains the
highest power of maximizer, it can operate in higher modulation range. This causes the reduce of stress in switching and thus it will improve the quality of output. Recommended system had been simulated in MATLAB/Simulink and shown results indicate accurate functionality.
Grid tied photovoltaic (PV) system is an operation mode of PV system working together with utility power supply to provide power to the power load. Conventionally, transformer is used together with the power inverter. The power transformer works as galvanic insolation amongst PV system and power grid. It works also to raise the voltage of power inverter. However, use of transformer will add system complexity, price, weight and size of the entire system. Transformer-less system is an alternative to make the system simpler and more practical in use. The paper discusses performance of transformer-less grid tied PV systems using diode clamped and neutral point shorted inverters. Effects of transformer elimination to the feat of the grid tied PV system especially harmonics content and leakage current of PV system were examined and analyzed. The performance was also compared with the traditional system using H-bridge inverter. The leakage currents did not flow in the system applying diode clamped inverter, and neutral point shorted inverter. In case of harmonics content, the diode clamped inverter injected less harmonics components than the neutral point shorted inverter. The neutral point shorted provides a simpler inverter circuit in the transformerless systems.
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability
Improving Electrical Power Grid of Jordan and Control the Voltage of Wind Tur...IJAPEJOURNAL
In this paper, we improved the national grid of Jordan country by adding a renewable resources specifically a wind turbines generation unites distributed on different places in Jordan to compensate the losses of the power in Jordan and to dispense with using the generation of fuel and gas by representing the national grid of Jordan in ETAB simulator and we solved the voltage problems of wind turbines using a new mythology using smart grid techniques
The emerging of inductive wireless power transfer (IWPT) technology provides more opportunities for the electric vehicle (EV) battery to have a better recharging process. With the development of IWPT technology, various way of wireless charging of the EV battery is proposed in order to find the best solution. To further understand the fundamentals of the IWPT system itself, an ample review is done. There are different ways of EV charging which are static charging (wired), static wireless charging (SWC) and dynamic wireless charging (DWC). The review starts with a brief comparison of static charging, SWC and DWC. Then, in detailed discussion on the fundamental concepts, related laws and equations that govern the IWPT principle are also included. In this review, the focus is more on the DWC with a little discussion on static charging and SWC to ensure in-depth understanding before one can do further research about the EV charging process. The in-depth perception regarding the development of DWC is elaborated together with the system architecture of the IWPT and DWC system and the different track versions of DWC, which is installable to the road lane.
This paper presents a grid-connected photovoltaic (PV) interface for delivering both active and reactive powers. The PV interface employs H-bridge topology DC-DC converter and inverter with analog control technology. The power flow is controlled solely by the adjustable DC output voltage of the DC to DC converter. In order to evaluate the PV interface system’s performances, it is tested by delivering power to the grid with low pawer factor. The experimental results show that at 300W active load, the inverter could deliver the reactive power of 400VAR. The PV interface could also produce very low harmonic voltage and current distorsions. The laboratory measurements show that the total harmonic distortions of inverter output voltage and current are 0.46% and 0.05%, respectively.
Integration of Unified Power Quality Controller with DGIJRST Journal
This paper gives an insight into the analytical results of the intergration of Unified power quality controller (conditioner) with distribution generation system. The intergration is achieved by connecting the DClink throught rectifier to the distribution generatoion along with thwe connection of the series and shunt inverter to the same dc link. This type of connection can account for the voltage sag, voltage swell, along with the reduction of harmonics and also compensation of reactive power. The analysis is supported with the simulation which will are discussed in detail in the paper.
A new bidirectional multilevel inverter topology with a high number of voltage levels with a very reduced number of power components is proposed in this paper. Only TEN power switches and four asymmetric DC voltage sources are used to generate 25 voltage levels in this new topology. The proposed multilevel converter is more suitable for e-mobility and photovoltaic applications where the overall energy source can be composed of a few units/associations of several basic source modules. Several benefits are provided by this new topology: Highly sinusoidal current and voltage waveforms, low Total Harmonic Distortion, very low switching losses, and minimum cost and size of the device. For optimum control of this 25-level voltage inverter, a special Modified Hybrid Modulation technique is performed. The proposed 25-level inverter is compared to various topologies published recently in terms of cost, the number of active power switches, clamped diodes, flying capacitors, DC floating capacitors, and the number of DC voltage sources. This comparison clearly shows that the proposed topology is cost-effective, compact, and very efficient. The effectiveness and the good performance of the proposed multilevel power converter (with and without PWM control) are verified and checked by computational simulations.
SRF THEORY BASED STATCOM FOR COMPENSATION OF REACTIVE POWER AND HARMONICSIAEME Publication
The power electronic devices like converters and inverters inject harmonic currents into AC
system due to their non linear characteristics. These devices draw high amount of reactive power
from source. The commencement of Nonlinear Load into the ac power system will have the effect of
harmonics. The presence of harmonics in system it will effected with power quality problems. Due
to this high amount of power losses and disoperation of power electronics devices is caused, along
with this Harmonics have a number of undesirable effects like Voltage disturbances. These
harmonics are needed to mitigate for Power Quality Enhancement in distributed system. Here the
device called STATCOM is one of the FACTS Devices which can be used to mitigate the harmonics
and reactive power compensation. The voltage source converter is core of the STATCOM and the
hysteresis current control is indirect method of controlling of VSC. In this paper we implement with
SRF based STATCOM control. SRF theory is implemented for the generation of controlling
reference current signals for controller of STATCOM. The Matlab\Simulink based model is
developed and simulation results are showed for linear and nonlinear load conditions.
Direct current (DC) electronic load is a useful equipment for testing the electrical system. It can emulate various load at a high rating. The electronic load requires a power converter to operate and a linear regulator is a common option. Nonetheless, it is hard to control due to the temperature variation. This paper proposed a DC electronic load using the boost converter. The proposed electronic load operates in the continuous current mode and control using the integral controller. The electronic load using the boost converter is compared with the electronic load using the linear regulator. The results show that the boost converter able to operate as an electronic load with an error lower than 0.5% and response time lower than 13 ms.
Alternating current (AC) electrical drives mainly require smaller current (or torque) ripples and lower total harmonic distortion (THD) of voltage for excellent drive performances. Normally, in practice, to achieve these requirements, the inverter needs to be operated at high switching frequency. By operating at high switching frequency, the size of filter can be reduced. However, the inverter which oftenly employs insulated gate bipolar transistor (IGBT) for high power applications cannot be operated at high switching frequency. This is because, the IGBT switching frequency cannot be operated above 50 kHz due to its thermal restrictions. This paper proposes an alternate switching strategy to enable the use of IGBT for operating the inverter at high switching frequency to improve THD performances. In this strategy, each IGBT in a group of switches in the modified inverter circuit will operate the switching frequency at one-fourth of the inverter switching frequency. The alternate switching is implemented using simple analog and digital integrated circuits.
Transmission lines react to an unexpected increase in power, and if these power changes are not controlled, some lines will become overloaded on certain routes. Flexible alternating current transmission system (FACTS) devices can change the voltage range and phase angle and thus control the power flow. This paper presents suitable mathematical modeling of FACTS
devices including static var compensator (SVC) as a parallel compensator and high voltage direct current (HVDC) bonding. A comprehensive modeling of SVC and HVDC bonding in the form of simultaneous applications for power flow is also performed, and the effects of compensations are compared. The comprehensive model obtained was implemented on the 5-bus test system in MATLAB software using the Newton-Raphson method, revealed that generators have to produce more power. Also, the addition of these devices stabilizes the voltage and controls active and reactive power in the network.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
The growing demand for electricity and the increasing integration of clean energies into the electrical grids requires the multiplication and reinforcement of high-voltage direct current (HVDC) projects throughout the world and demonstrates the interest in this electricity transmission technology. The transmitting system of the voltage source converter-high-voltage direct current (VSC-HVDC) consists primarily of two converter stations that are connected by a dc cable. In this paper, a nonlinear control based on the backstepping approach is proposed to improve the dynamic performance of a VSC-HVDC transmission system, these transport systems are characterized by different complexities such as parametric uncertainties, coupled state variables, neglected dynamics, presents a very interesting research topic. Our contribution through adaptive control based on the backstepping approach allows regulating the direct current (DC) bus voltage and the active and reactive powers of the converter stations. Finally, the validity of the proposed control has been verified under various operating conditions by simulation in the MATLAB/Simulink environment.
This paper provides a new approach to reducing high-order harmonics in 400 Hz inverter using a three-level neutral-point clamped (NPC) converter. A voltage control loop using the harmonic compensation combined with NPC clamping diode control technology. The capacitor voltage imbalance also causes harmonics in the output voltage. For 400 Hz inverter, maintain a balanced voltage between the two input (direct current) (DC) capacitors is difficult because the pulse width modulation (PWM) modulation frequency ratio is low compared to the frequency of the output voltage. A method of determining the current flowing into the capacitor to control the voltage on the two balanced capacitors to ensure fast response reversal is also given in this paper. The combination of a high-harmonic resonator controller and a neutral-point voltage controller working together on the 400 Hz NPC inverter structure is given in this paper.
This paper presents a real-time emulator of a dual permanent magnet synchronous motor (PMSM) drive implemented on a field-programmable gate array (FPGA) board for supervision and observation purposes. In order to increase the reliability of the drive, a sensorless speed control method is proposed. This method allows replacing the physical sensor while guaranteeing a satisfactory operation even in faulty conditions. The novelty of the proposed approach consists of an FPGA implementation of an emulator to control the actual system. Hence, this emulator operates in real-time with actual system control in healthy or faulty mode. It gives an observation of the speed rotation in case of fault for the sake of continuity of service. The observation of the rotor position and the speed are achieved using the dSPACE DS52030D digital platform with a digital signal processor (DSP) associated with a Xilinx FPGA.
Analysis and Simulation of Solar PV Connected with Grid Accomplished with Boo...YogeshIJTSRD
This paper deals with a solar PV array connected with grid system. This system consists of PV cells with 30 KW system, Boost converter, three phase inverter with suitable control system and three phase load. This paper gives analysis of each components of the system. The output voltage from the solar PV cells are variable according to radiation intensity and temperature so in order to connect with grid the output voltage should be fixed and converted to AC voltage and this job will be done by an inverter. A very effective control system has been developed for the inverter based on pulse width modulation. This paper presents an intensive performance and dynamic behavior of a grid related PV energy conversion system. The PV system is developed and simulated with the help of MATLAB Simulink software environment. Abhishek Verma | Dr. Anup Mishra | Brahma Nand Thakur "Analysis and Simulation of Solar PV Connected with Grid Accomplished with Boost Converter and PWM Based Inverter" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-3 , April 2021, URL: https://www.ijtsrd.com/papers/ijtsrd40056.pdf Paper URL: https://www.ijtsrd.com/engineering/electrical-engineering/40056/analysis-and-simulation-of-solar-pv-connected-with-grid-accomplished-with-boost-converter-and-pwm-based-inverter/abhishek-verma
This paper presents the design and the implementation of a new microcontroller-based solar
Power inverter. The aim of this paper is to design single phase inverter which can convert DC voltage
to AC voltage at high efficiency and low cost. Solar and wind powered electricity generation are
being favored nowadays as the world increasingly focuses on environmental concerns. Power
inverters, which convert solar-cell DC into domestic-use AC, are one of the key technologies for
delivering efficient AC power The hardware and software design are oriented towards a single-chip
microcontroller-based system, hence minimizing the size and cost. With this new approach the
modularization of the conversion from solar power to electric power at its maximum power point can
be made more compact and more reliable.
Environmental factors such as air pollution and increase in global warming by using polluting fuels are the most important reasons of using renewable and clean energy that runs in global community. Wind energy is one of the most suitable and widely used kind of renewable energy which had been in consideration so well. This paper introduces an electric power generation
system of wind based on Y-source and improved Y-source inverter to deliver optimal electrical power to the network. This new converter is from impedance source converters family. This presented converter has more degrees of freedom to adjust voltage gain and modulation. Also, by limiting the range of simultaneous control (shooting through) while it maintains the
highest power of maximizer, it can operate in higher modulation range. This causes the reduce of stress in switching and thus it will improve the quality of output. Recommended system had been simulated in MATLAB/Simulink and shown results indicate accurate functionality.
Grid tied photovoltaic (PV) system is an operation mode of PV system working together with utility power supply to provide power to the power load. Conventionally, transformer is used together with the power inverter. The power transformer works as galvanic insolation amongst PV system and power grid. It works also to raise the voltage of power inverter. However, use of transformer will add system complexity, price, weight and size of the entire system. Transformer-less system is an alternative to make the system simpler and more practical in use. The paper discusses performance of transformer-less grid tied PV systems using diode clamped and neutral point shorted inverters. Effects of transformer elimination to the feat of the grid tied PV system especially harmonics content and leakage current of PV system were examined and analyzed. The performance was also compared with the traditional system using H-bridge inverter. The leakage currents did not flow in the system applying diode clamped inverter, and neutral point shorted inverter. In case of harmonics content, the diode clamped inverter injected less harmonics components than the neutral point shorted inverter. The neutral point shorted provides a simpler inverter circuit in the transformerless systems.
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability
Improving Electrical Power Grid of Jordan and Control the Voltage of Wind Tur...IJAPEJOURNAL
In this paper, we improved the national grid of Jordan country by adding a renewable resources specifically a wind turbines generation unites distributed on different places in Jordan to compensate the losses of the power in Jordan and to dispense with using the generation of fuel and gas by representing the national grid of Jordan in ETAB simulator and we solved the voltage problems of wind turbines using a new mythology using smart grid techniques
The emerging of inductive wireless power transfer (IWPT) technology provides more opportunities for the electric vehicle (EV) battery to have a better recharging process. With the development of IWPT technology, various way of wireless charging of the EV battery is proposed in order to find the best solution. To further understand the fundamentals of the IWPT system itself, an ample review is done. There are different ways of EV charging which are static charging (wired), static wireless charging (SWC) and dynamic wireless charging (DWC). The review starts with a brief comparison of static charging, SWC and DWC. Then, in detailed discussion on the fundamental concepts, related laws and equations that govern the IWPT principle are also included. In this review, the focus is more on the DWC with a little discussion on static charging and SWC to ensure in-depth understanding before one can do further research about the EV charging process. The in-depth perception regarding the development of DWC is elaborated together with the system architecture of the IWPT and DWC system and the different track versions of DWC, which is installable to the road lane.
This paper presents a grid-connected photovoltaic (PV) interface for delivering both active and reactive powers. The PV interface employs H-bridge topology DC-DC converter and inverter with analog control technology. The power flow is controlled solely by the adjustable DC output voltage of the DC to DC converter. In order to evaluate the PV interface system’s performances, it is tested by delivering power to the grid with low pawer factor. The experimental results show that at 300W active load, the inverter could deliver the reactive power of 400VAR. The PV interface could also produce very low harmonic voltage and current distorsions. The laboratory measurements show that the total harmonic distortions of inverter output voltage and current are 0.46% and 0.05%, respectively.
Integration of Unified Power Quality Controller with DGIJRST Journal
This paper gives an insight into the analytical results of the intergration of Unified power quality controller (conditioner) with distribution generation system. The intergration is achieved by connecting the DClink throught rectifier to the distribution generatoion along with thwe connection of the series and shunt inverter to the same dc link. This type of connection can account for the voltage sag, voltage swell, along with the reduction of harmonics and also compensation of reactive power. The analysis is supported with the simulation which will are discussed in detail in the paper.
A new bidirectional multilevel inverter topology with a high number of voltage levels with a very reduced number of power components is proposed in this paper. Only TEN power switches and four asymmetric DC voltage sources are used to generate 25 voltage levels in this new topology. The proposed multilevel converter is more suitable for e-mobility and photovoltaic applications where the overall energy source can be composed of a few units/associations of several basic source modules. Several benefits are provided by this new topology: Highly sinusoidal current and voltage waveforms, low Total Harmonic Distortion, very low switching losses, and minimum cost and size of the device. For optimum control of this 25-level voltage inverter, a special Modified Hybrid Modulation technique is performed. The proposed 25-level inverter is compared to various topologies published recently in terms of cost, the number of active power switches, clamped diodes, flying capacitors, DC floating capacitors, and the number of DC voltage sources. This comparison clearly shows that the proposed topology is cost-effective, compact, and very efficient. The effectiveness and the good performance of the proposed multilevel power converter (with and without PWM control) are verified and checked by computational simulations.
Performance Evaluation for Production of 5000kgHydraulic JackIOSR Journals
The report submitted presents detailed performance evaluation analysis for production of 5tonne
hydraulic jack. The main task is to produce it using two approaches namely conversional and reverse
engineering. Conversional design team were able to design the jack with all the necessary tolerance and limits,
those involve design calculations, producing standard drawing and cost analysis on each part involve. While
reverse engineering team were able to produce the jack through reverse engineering procedures and approach,
this involve selection of materials needed to produce the parts with our machines in the workshop, test analysis
for each component, assembling and testing to ensure effective performance
The effect of rotational speed variation on the static pressure in the centri...IOSR Journals
The current investigation is aimed to simulate the three-dimensional complex internal flow in a
centrifugal pump impeller with five twisted blades by using specialized computational fluid dynamics (CFD)
software ANSYS /FLUENT 14code with a standard k-ε two-equation turbulence model.
A single blade passage will be modeled to give more accurate results for static pressure contours on (blade,
hub, and shroud). The potential consequences of static pressure associated with operating a centrifugal
compressor in variable rotation speed.
A numerical three-dimensional, through flow calculations to predict static pressure through a
centrifugal pump were presented to examined the effect of rotational speed variation on the static pressure of
the centrifugal pump . The contours of the static pressure of the blade, hub, and shroud indicates negative low
static pressure in the suction side at high rotational speed (over operation limits )and the static pressure
increases gradually until reach maximum value at the leading edge (6×105 Pa) of the blade.
Correlation Study For the Assessment of Water Quality and Its Parameters of G...IOSR Journals
In the present work water samples are collected from six different Ghats of Ganga river in Kanpur city from March 2010 to February 2011 on monthly basis and water quality assessment is carried out. Pearson’s correlation coefficient (r) value is determined using correlation matrix to identify the highly correlated and interrelated water quality parameters. To test the significance of the pair of parameters p-value is carried out and in order to test the joint effects of several independent variables, without frequent or repeated monitoring of water quality in a location. Higher concentration of Chromium (6.7 mg/l) at Siddhnath ghat in June, and its monthly variation showed highly adverse effect on river Ganga due to tanneries effluent. It is found that significant positive correlation holds for Temp vs BOD GH1 (r= 0.99, p<0.01),><0.01),><0.01);><0.01),><0.01),><0.01).><0.01),><0.01),><0.01). Chromium is found that non significant correlation. The mean values of all the measured physico-chemical parameters of Ganga river water are within the highest desirable limit set by WHO except BOD.
Multiple Equilibria and Chemical Distribution of Some Bio Metals With β-Amide...IOSR Journals
Abstract: Solution Chemistry of some bivalent metal ions (viz. CoII , NiII ,CuII ,ZnII ) with β-amide α-aminosuccinate (Asparagine)/ α-aminoisoverate( Valine ) (A) and 5-methyl 2,4- dioxopyrimidine ( Thymine ) (B)ligands have been analyzed. Formation constant of quaternary metal complexes and complexation equilibria at 30±1ºC and at constant ionic strength (I=0.1M NaNO3 ) have been explored potentiometrically. Formation of quaternary species in addition to hydroxyl, protonated, binary and ternary species have been reported. Overall formation constant have been evaluated using SCOGS computer program.Species distribution curves of complexes have been plotted as a function of pH to visualize the equlibria system and was refined using ORIGIN program.The metal ligand formation constant of MA,MB,MAB and M1M2AB type of complexes follow Irving William order. The order of stability constants of quaternary systems have been observed as: Cu – Ni > Cu –Zn > Cu–Co > Ni – Zn > Ni – Co > Co –Zn. Solution structures of metal complexes with said ligands have been compared and discussed.
IOSR Journal of Humanities and Social Science is an International Journal edited by International Organization of Scientific Research (IOSR).The Journal provides a common forum where all aspects of humanities and social sciences are presented. IOSR-JHSS publishes original papers, review papers, conceptual framework, analytical and simulation models, case studies, empirical research, technical notes etc.
Studies On The Effectiveness of Mixed Diet of Garden Egg, Groundnut And Garli...IOSR Journals
The use of medicinal plants as food supplements and in the treatment of specific diseases dates back to antiquity. Age old anecdotal reports from many cultures strongly suggests a role for diet of plant origin in preventive and therapeutic medicine. Anaemia remains a major public-health problem especially in developing countries. This study aimed at investigating the antianaemic potentials of combined diet of garlic (Allium sativum), garden egg (Solanum melongena) and groundnut (Arachis hypogaea).Twenty five wistar rats of both sexes weighing 160-200g were divided equally into five groups. Group 1 served as the non-anaemic control and fed with normal rat chow. Groups 2, 3, 4 and 5 were induced with anaemia by oral administration of phenylhydrazine (PHZ) given at 50mg/kgBW. Group 2 served as anaemic control, fed with normal rat chow; Group 3 were fed with 20g (75%ww) of garlic, garden egg and groundnut in the ratio of 1:1:1 with normal rat chow; Group 4 fed with 10g of garden egg (50%ww) in the ratio 1:1 with normal rat chow and Group 5 fed with 10g of ground, nut (50%ww) in the ratio 1:1 with normal rat chow. Animals were sacrificed at the end of fourteen days of dietary feeding using chloroform vapour with blood collected at the left ventricle to test for haematological parameters such as red blood cell (RBC) count, white blood cell (WBC) count, hemoglobin concentration (Hb) and packed cell volume (PCV). Results showed that RBC, WBC, Hb and PCV values increased in all the experimental as compared to anaemic control with a significant (P<0.05) in WBC values of groups 3 and 4 as compared to the anaemic control. This suggests a consumption of garlic, garden egg and groundnut will moderately improve anaemic condition.
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.
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.
A voltage sensitivity index application for power system load shedding consid...IJAEMSJORNAL
This paper proposes a method for calculating the minimum amount of power load needed to shed and distributing it for each load bus in order to recover the frequency and voltage back to the allowable range. Based on the consideration of the primary control of the turbine governor and the reserve power of the generators for secondary control, the minimum amount of load shedding was calculated in order to recover the frequency of the power system. Computation and analysis of Voltage Sensitivity Index (VSI) of the load bus to prioritize distribution of the amount power load shedding at these positions. The lower the load bus have the Voltage Sensitivity Index (VSI), the higher the amount of load shedding will shed and vice versa. With this technique, frequency and voltage value are still within allowable range, and a large amount of load shedding could be avoided, hence, saved from economic losses, and customer service interruption. The effectiveness of the proposed method tested on the IEEE 37 bus 9 generators power system standard has demonstrated the effectiveness of this method.
In a power system, Low Frequency Oscillations (LFOs) are dangerous and make system unstable. These oscillations are referred to small signal stability and they are mainly due to lack of damping torque. This insufficient damping torque is because of high gain and low time constant of Automatic Voltage Regulator (AVR). AVR is useful for maintaining the terminal voltage of synchronous machine as constant. While doing so, it will make the system damping torque as negative. For providing required damping torque thereby minimizing the LFOs, Power System Stabilizer is used in conjunction with AVR. In this paper for SMIB system, the stability is studied with the help of eigen values before and after placement of PSS with optimized PSS parameters using Particle Swarm Optimization (PSO) and Cat Swarm Optimization (CSO). The simulation work is performed in the MATLAB/SIMULINK and corresponding results are presented and analyzed.
Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency Power System Frequency
MUTUAL EFFECT BETWEEN LFC AND AVR LOOPS IN POWER PLANTelelijjournal
This paper is proposed to show the mutual interaction between of both LFC and the AVR loops. The coupling effects of these two AVR and LFC loops are studied by extending the linear zed AGC system and it include the excitation system also. For a complete system model we have to study the oscillation of LFC and AVR loops with PID CONTROLLERS. This combined model of LFC and AVR loops is tested on single-area power system. These results are shown in simulation; and will be reachable in dynamic and steady state responses [1][2].
Load shedding in power system considering the generator control and AHP algor...IJAEMSJORNAL
This paper proposes the load shedding method with considering the ranking load importance factors. The amount of shedding power is calculated based on the Primary and Secondary adjustments to restore the system’s frequency back to allowed range. The ranking and distribution shedding power on each load bus will be prosed based on the AHP algorithm. Loads with the smaller importance factor will have priority to be shed with the larger amount of shedding power and vice versa. The experimental and simulated results will be estimated on IEEE 37- bus system, the results show that the proposed method can help the frequency restores back to nominal range and reduce damages compared to the UFLS method.
Load Frequency Control of Multi Area System using Integral-Fuzzy ControllerIJERA Editor
The power system is interconnected to enhance the security and reliability. With large interconnected system, unexpected external disturbances, parameter uncertainties and the model uncertainties make big challenges for stability of system. Load Frequency Control (LFC) deals with the control of real power and frequency of the system. The LFC is used to reduce the transient deviations in the power system. It limits the frequency within limits and controls the tie-line exchange power. Various controllers are used for this purpose. Recently Artificial Intelligence Techniques such as Artificial Neural Network (ANN), fuzzy logic, Genetic Algorithm etc. are used for the designing of controllers. These controllers provide a faster response and are flexible to adjust according to system conditions. In this paper, I have designed integral controller which is conventional method for Load Frequency Control and Artificial Intelligence Technique based Fuzzy Logic controller to deal with the Load Frequency Control Problem for Multi-area System. The simulation of the system is done with MATLAB. These controllers provide a robust system which is more stable and reliable and helps the system to regain its normal state after any disturbance.
Load Frequency Control of Multi Area System using Integral-Fuzzy ControllerIJERA Editor
The power system is interconnected to enhance the security and reliability. With large interconnected system, unexpected external disturbances, parameter uncertainties and the model uncertainties make big challenges for stability of system. Load Frequency Control (LFC) deals with the control of real power and frequency of the system. The LFC is used to reduce the transient deviations in the power system. It limits the frequency within limits and controls the tie-line exchange power. Various controllers are used for this purpose. Recently Artificial Intelligence Techniques such as Artificial Neural Network (ANN), fuzzy logic, Genetic Algorithm etc. are used for the designing of controllers. These controllers provide a faster response and are flexible to adjust according to system conditions. In this paper, I have designed integral controller which is conventional method for Load Frequency Control and Artificial Intelligence Technique based Fuzzy Logic controller to deal with the Load Frequency Control Problem for Multi-area System. The simulation of the system is done with MATLAB. These controllers provide a robust system which is more stable and reliable and helps the system to regain its normal state after any disturbance.
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
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DPFC is proposed in the present work to improve voltage stability of fourteen bus system during line interruption. The voltage across the load decreases due to the interruption of the line. State space method is used to calculate Line currents and bus voltages. The ability of DPFC to bring voltage, real power and reactive power to normal level is presented in this paper. The simulation results for healthy system, line interrupted system without DPFC and with DPFC are presented. The results of comparative study are presented to show the improvement in power quality. The simulation studies indicate that the power flow with DPFC during line outage is almost equal to the power during healthy condition.
Search and Society: Reimagining Information Access for Radical FuturesBhaskar Mitra
The field of Information retrieval (IR) is currently undergoing a transformative shift, at least partly due to the emerging applications of generative AI to information access. In this talk, we will deliberate on the sociotechnical implications of generative AI for information access. We will argue that there is both a critical necessity and an exciting opportunity for the IR community to re-center our research agendas on societal needs while dismantling the artificial separation between the work on fairness, accountability, transparency, and ethics in IR and the rest of IR research. Instead of adopting a reactionary strategy of trying to mitigate potential social harms from emerging technologies, the community should aim to proactively set the research agenda for the kinds of systems we should build inspired by diverse explicitly stated sociotechnical imaginaries. The sociotechnical imaginaries that underpin the design and development of information access technologies needs to be explicitly articulated, and we need to develop theories of change in context of these diverse perspectives. Our guiding future imaginaries must be informed by other academic fields, such as democratic theory and critical theory, and should be co-developed with social science scholars, legal scholars, civil rights and social justice activists, and artists, among others.
Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...Jeffrey Haguewood
Sidekick Solutions uses Bonterra Impact Management (fka Social Solutions Apricot) and automation solutions to integrate data for business workflows.
We believe integration and automation are essential to user experience and the promise of efficient work through technology. Automation is the critical ingredient to realizing that full vision. We develop integration products and services for Bonterra Case Management software to support the deployment of automations for a variety of use cases.
This video focuses on the notifications, alerts, and approval requests using Slack for Bonterra Impact Management. The solutions covered in this webinar can also be deployed for Microsoft Teams.
Interested in deploying notification automations for Bonterra Impact Management? Contact us at sales@sidekicksolutionsllc.com to discuss next steps.
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
Let's dive deeper into the world of ODC! Ricardo Alves (OutSystems) will join us to tell all about the new Data Fabric. After that, Sezen de Bruijn (OutSystems) will get into the details on how to best design a sturdy architecture within ODC.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
Dev Dives: Train smarter, not harder – active learning and UiPath LLMs for do...UiPathCommunity
💥 Speed, accuracy, and scaling – discover the superpowers of GenAI in action with UiPath Document Understanding and Communications Mining™:
See how to accelerate model training and optimize model performance with active learning
Learn about the latest enhancements to out-of-the-box document processing – with little to no training required
Get an exclusive demo of the new family of UiPath LLMs – GenAI models specialized for processing different types of documents and messages
This is a hands-on session specifically designed for automation developers and AI enthusiasts seeking to enhance their knowledge in leveraging the latest intelligent document processing capabilities offered by UiPath.
Speakers:
👨🏫 Andras Palfi, Senior Product Manager, UiPath
👩🏫 Lenka Dulovicova, Product Program Manager, UiPath
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
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UI automation Sample
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Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
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GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
To Graph or Not to Graph Knowledge Graph Architectures and LLMs
M0104198105
1. IOSR Journal of Electrical and Electronics Engineering (IOSR-JEEE)
e-ISSN: 2278-1676,p-ISSN: 2320-3331, Volume 10, Issue 4 Ver. I (July – Aug. 2015), PP 98-105
www.iosrjournals.org
DOI: 10.9790/1676-104198105 www.iosrjournals.org 98 | Page
Design and Simulation of Integral Controller Based LFC
Prem Kumar1
, Mr. BSSPM Sharma2
1
Mewar University, Department of Electrical Engineering, Chittorgarh, Rajasthan, India
2
Mewar University, Department of Electrical Engineering, Chittorgarh, Rajasthan, India
Abstract: The main objectives of Load Frequency Control (LFC) are to hold the frequency constant ( Δf = 0)
against any load change, each area must contribute to absorb any load change such that frequency does not
deviate, each area must maintain the tie-line power flow to its pre-specified value. In LFC there are two major
loops. Automatic Voltage Regulator (AVR) and Automatic Load Frequency Control (ALFC) Loops. AVR Loop
controls the magnitude of the terminal voltage V. The ALFC Loop regulates the megawatt output and frequency
(speed) of Generator via the speed governor and the control valves that the steam flow is regulated to match the
megawatt output. There are many controllers used in LFC such as Integral Controller based LFC, Fuzzy
Controller based LFC, ANN based LFC, Genetic Algorithm based LFC and Power System Optimization (PSO)
based LFC. In this paper the integral controller based LFC is used to hold the frequency constant. Here the
SIMULINK Model of single area and two area power systems are simulated using SIMULINK.
Keywords: LFC, AGC, Integral controller, AVR, ALFC, ACE.
I. Introduction
Power systems are very large and complex electrical networks consisting of generation networks,
transmission networks and distribution networks along with loads which are being distributed throughout the
network over a large geographical area. In the power system, the system load keeps changing from time to time
according to the needs of the consumers. So properly designed controllers are required for the regulation of the
system variations in order to maintain the stability of the power system as well as guarantee its reliable
operation. For large scale power systems which consists of inter-connected control areas, load frequency then it
is important to keep the frequency and inter area tie power near to the scheduled values. The input mechanical
power is used to control the frequency of the generators and the change in the frequency and tie-line power are
sensed, which is a measure of the change in rotor angle. A well designed power system should be able to provide
the acceptable levels of power quality by keeping the frequency and voltage magnitude within tolerable limits.
Changes in the power system load affects mainly the system frequency, while the reactive power is less sensitive
to changes in frequency and is mainly dependent on fluctuations of voltage magnitude. So the control of the real
and reactive power in the power system is dealt separately. The load frequency control mainly deals with the
control of the system frequency and real power whereas the automatic Voltage regulator loop regulates the
changes in the reactive power and voltage magnitude. Load frequency control is the basis of many advanced
concepts of the large scale control of the power system.
II. Reasons for the need of maintaining constant frequency
(1) The speed of a.c. motors are directely related to the frequency.
(2) If the normal operating frequency is 50 Hz and the turbines run at speeds corresponding to frequencies less
than 47.5 Hz or above 52.5 Hz, then the blades of the turbines may get damaged.
(3) The under frequency operation of the power transformer is not desirable. For constant system voltage if the
frequency is below the desired level then the normal flux in the core increases. This sustained under frequency
operation of the power transformer results in low efficiency and over-heating of the transformer windings.
(4) With reduced frequency the blast by ID fans and FD fans decrease, and so the generation decreases and thus
it becomes a multiplying effect and may result in shut down of the plant.
(5) The electric clocks are driven by the synchronous motors. The accuracy of the clocks are not only dependent
on the frequency but also is an integral of the this frequency error. The speed of a.c. motors are directely related
to the frequency.
III. Load Frequency Control
Electric power is generated by converting mechanical energy into electrical energy. The rotor mass,
which contains turbine and generator units, stores kinetic energy due to its rotation. This stored kinetic energy
accounts for sudden increase in the load. Let us denote the mechanical torque input by Tm and the output
electrical torque by Te. Neglecting the rotational losses, a generator unit is said to be operating in the steady state
2. Design And Simulation Of Integral Controller Based Lfc
DOI: 10.9790/1676-104198105 www.iosrjournals.org 99 | Page
at a constant speed when the difference between these two elements of torque is zero. In this case we say that the
accelerating torque is zero.
Ta=Tm-Te (3.1)
When the electric power demand increases suddenly, the electric torque increases. However, without
any feedback mechanism to alter the mechanical torque, Tm remains constant. Therefore the accelerating torque
given by becomes negative causing a deceleration of the rotor mass. As the rotor decelerates, kinetic energy is
released to supply the increase in the load. Also note that during this time, the system frequency, which is
proportional to the rotor speed, also decreases. We can thus infer that any deviation in the frequency for its
nominal value of 50 or 60 Hz is indicative of the imbalance between Tm and Te. The frequency drops when Tm <
Te and rises when Tm > Te. The steady state power-frequency relation is shown in Fig.1.1. In this figure the slope
of the ΔPref line is negative and is given by
-R= (3.2)
Where R is called the regulating constant. From this figure we can write the steady state power
frequency relation as
Fig. 3.1 A typical steady-state power-frequency curves.
(3.3)
Suppose an interconnected power system contains N turbine-generator units. Then the steady-state
power-frequency relation is given by the summation of (3.3) for each of these units as
(3.4)
In the above equation, ΔPm is the total change in turbine-generator mechanical power and ΔPref is the
total change in the reference power settings in the power system. Also note that since all the generators are
supposed to work in synchronism, the change is frequency of each of the units is the same and is denoted by Δf.
Then the frequency response characteristics is defined as
(3.5)
We can therefore modify (1.4) as
(3.6)
Modern day power systems are divided into various areas. For example in India, there are five regional
grids, e.g., Eastern Region, Western Region etc. Each of these areas is generally interconnected to its
neighboring areas. The transmission lines that connect an area to its neighboring area are called tie-lines. Power
sharing between two areas occurs through these tie-lines. Load frequency control, as the name signifies,
regulates the power flow between different areas while holding the frequency constant. As we have seen that the
system frequency rises when the load decreases if ΔPref is kept at zero. Similarly the frequency may drop if the
load increases. However it is desirable to maintain the frequency constant such that Δf=0. The power flow
through different tie-lines are scheduled - for example, area- i may export a pre-specified amount of power to
3. Design And Simulation Of Integral Controller Based Lfc
DOI: 10.9790/1676-104198105 www.iosrjournals.org 100 |
Page
area- j while importing another pre-specified amount of power from area- k . However it is expected that to
fulfill this obligation, area- i absorbs its own load change, i.e., increase generation to supply extra load in the
area or decrease generation when the load demand in the area has reduced. While doing this area- i must
however maintain its obligation to areas j and k as far as importing and exporting power is concerned. A
conceptual diagram of the interconnected areas is shown in Fig. 3.2.
Fig 3.2. Interconnected areas in a power system.
We can therefore state that the load frequency control (LFC) has the following two objectives:
Hold the frequency constant (Δ f = 0) against any load change.
Each area must contribute to absorb any load change such that frequency does not deviate.
Each area must maintain the tie-line power flow to its pre-specified value.
The first step in the LFC is to form the area control error (ACE) that is defined as
(3.7)
Where Ptie and Psch are tie-line power and scheduled power through tie-line respectively and the
constant Bf is called the frequency bias constant.
The change in the reference of the power setting ΔPref, i , of the area- i is then obtained by the feedback of the
ACE through an integral controller of the form
(3.8)
Where Ki is the integral gain. The ACE is negative if the net power flow out of an area is low or if the
frequency has dropped or both. In this case the generation must be increased. This can be achieved by increasing
ΔPref, i. This negative sign accounts for this inverse relation between ΔPref, i and ACE. The tie-line power flow and
frequency of each area are monitored in its control center. Once the ACE is computed and ΔPref, i from (3.8),
commands are given to various turbine-generator controls to adjust their reference power settings.
IV. Design and Simulations
4.1 SIMULINK model
A SIMULINK model is constructed for isolated uncontrolled power system as shown in Fig
DPc (s)
Turbine
1
0.3s+1
To Workspace
simout
Speed Governor
1
0.08s+1
ScopeGenerator
120
20s+1
DPd(s)
1/R
1/2.4
Fig.4.1 SIMULINK model for uncontrolled isolated area.
4.2 SIMULINK model results
The results of the SIMULINK model constructed for isolated uncontrolled power system are shown in Fig
4. Design And Simulation Of Integral Controller Based Lfc
DOI: 10.9790/1676-104198105 www.iosrjournals.org 101 |
Page
Fig.4.2 SIMULINK dynamic response of change in frequency without controller
4.3 MATLAB program results
The MATLAB program written above for uncontrolled case is run and the results obtained are given in Fig.
0 5 10 15 20 25 30
-0.035
-0.03
-0.025
-0.02
-0.015
-0.01
-0.005
0
dynamic response of change in frequency for step change in load
time (sec.)
Deltaf(pu)
Fig. 4.3 MATLAB command results for uncontrolled single-area
We observe that both the responses match with each other, also the steady-state frequency deviation ∆f
(steady state) is -0.0235 Hz and frequency returns to its steady value in approximately 6 seconds.
4.4 SIMULINK model with integral controller (single-area case)
A SIMULINK model named is constructed as shown in Fig.
Integral Controller
b
0.425
Turbine
1
0.3s+1
To Workspace
simout
Scope
Ki
-0.671
Integrator
1
s
Governor
1
0.08s+1
Generator
120
20s+1
DPd(s)=0.01
1/R
1/2.4
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FIG 4.4 SIMULINK model with integral controller (single-area case)
4.5 SIMULINK model results
The results of the SIMULINK model constructed for isolated controlled power system are shown in Fig.
0 5 10 15 20 25 30
-0.03
-0.025
-0.02
-0.015
-0.01
-0.005
0
0.005
Time (s)
Deltaf(pu)
FIG 4.5 SIMULINK dynamic response of change in frequency with integral control action
4.6 MATLAB program results
The MATLAB program for controlled case is run and the results obtained are given in Fig.
0 5 10 15 20 25 30
-0.03
-0.025
-0.02
-0.015
-0.01
-0.005
0
0.005
dynamic response of change in frequency for step change in load
time (sec.)
Deltaf(pu)
FIG.4.6 Frequency deviation step response with MATLAB program
We observe that both the responses match with each other, also the steady-state frequency deviation ∆f
(steady state) is zero as derived in Eq. (3.20) and frequency returns to its steady value in approximately 6
seconds.
4.7 SIMULINK model of two area system is shown as
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FIG 4.7 SIMULINK models of two areas
4.7.1 Result of the SIMULINK model is shown:
0 5 10 15 20 25 30
-0.025
-0.02
-0.015
-0.01
-0.005
0
Fig. 4.8 Result of SIMULINK model of two area
4.7.2 Programming is done in MATLAB and result is obtained as:
0 5 10 15 20 25 30
-0.025
-0.02
-0.015
-0.01
-0.005
0
Time (sec.)
Deltaf1(pu),Deltaf2(pu)
Two-area LFC without controller
Delta f1
Delta f2
Fig. 4.9 Result of two area LFC without integral controller
4.8 SIMULINK model of two areas with integral controller:
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Fig. 4.10 SIMULINK model of two area with integral controller
4.8.1 Result of SIMULINK model is obtained as:
0 5 10 15 20 25 30
-0.025
-0.02
-0.015
-0.01
-0.005
0
0.005
Fig 4.11 Result of SIMULINK model of two area with integral controller
4.8.2 MATLAB Programming is done in workspace and results are obtained as:
0 5 10 15 20 25 30
-0.025
-0.02
-0.015
-0.01
-0.005
0
0.005
0.01
Time (sec.)
Deltaf1(pu),Deltaf2(pu)
Two area LFC with Integral controller
Delta f1
Delta f2
Fig 4.12 Result of two area LFC with integral controller in MATLAB
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V. Conclusion
In this work frequency deviation problem associated with load frequency control is evaluated. It is seen
that Integral Controller is required to stable the frequency. By properly selecting the control parameters of the
dual mode controller, frequency deviations and the tie line power can be effectively controlled. Due to
disturbances in the power system, the frequency is deviates. So Integral Controller is used to over this problem.
By using the Integral Controller frequency can be stable. Load-frequency control in a deregulated environment
may result in free choice by units to participator not in this operation. It is shown that if the percentage of the
units participating in this control action is very small, system performance deteriorates to a point that is
unacceptable. It is therefore recommended that minimum requirements be established. The minimum
requirements are system-dependent. The whole structures of power system have non- linear dynamic and their
operation points may change. Therefore Integral Controller should be used. From the simulations we have seen
that the proposed control approach achieves better control results than other controllers. Simulations results
show that the proposed Integral Controller approach can be effectively suppress exogenous disturbance in steady
state.
VI. Future Work
Various controllers may be used to manage the frequency deviations and changes in tie line power.
It may be implemented to system with three and four areas and also the performance of the system
may be studied.
The LFC of power system can be designed by PID controller via different optimization technique.
The parameters in this work has been taken constant throughout the whole operation.But there may be
parameter uncertainty due to wear and tear, temperature variation, imperfection of component, aging effect,
environment changes etc. So during controller design the variation of parameter may be taken in to
consideration.
References
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Author Profile
Author:- Prem Kumar
M.Tech scholar Mewar University, Department of Electrical
Engineering, Chittorgarh, Rajasthan, India
Co Author – Mr. BSSPM Sharma
Mewar University, Department of Electrical Engineering, Chittorgarh, Rajasthan, India.
9. Design And Simulation Of Integral Controller Based Lfc
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