This presentation discusses brushless DC motors. It explains that brushless DC motors do not have brushes, instead using electronics for commutation. This makes them highly efficient over a wide speed range with smooth operation and holding torque when stationary. The presentation describes the basic working principles of brushless DC motors, including their rotor, stator, and electronic control of electromagnets. It discusses how brushless DC motors eliminate the need for commutators through electronic position sensing and switching. Examples of applications are provided, along with advantages like increased efficiency and high performance. Disadvantages include higher cost compared to brushed DC motors and limited high power capabilities.
Efficiency Of A DC Machine And Condition For Maximum EfficiencyMuhammadFazilMemon
The document discusses the efficiency of DC machines and the conditions for maximum efficiency. It defines efficiency as the ratio of output power to input power. For a DC machine, efficiency is calculated as the output divided by the input power, multiplied by 100. The maximum efficiency typically occurs at around 80% of maximum speed when the load is approximately 20% of the maximum stall torque, though exact details vary between machines. Losses that reduce efficiency include armature losses, field losses, copper losses, brush losses, core losses, and stray load losses.
The document discusses a hybrid inverter system that combines solar power and conventional electric power. A hybrid inverter allows energy from solar panels to charge batteries, and includes an AC/DC converter to charge the batteries from a 220VAC supply. The system includes a microcontroller, solar panel, battery storage, relay, switching circuit, and control circuit. It can provide power to multiple loads from both solar energy and the 220VAC supply.
This document discusses the construction and working principle of a permanent magnet DC (PMDC) motor. It begins with an introduction stating that a DC motor converts direct current into mechanical energy. It then describes the key components of a PMDC motor: the stator, which contains permanent magnets; the rotor or armature, made of wound coils; and how each conductor on the armature experiences a force when inside the magnetic field based on Fleming's left hand rule, causing the armature to rotate. Advantages are listed as reduced size, cost and increased efficiency over traditional DC motors requiring field excitation coils. Applications include toys, drills and automatic doors.
The document discusses AC motor drives and induction motor drives. It provides details on:
1. AC motor drives are commonly used in industrial and domestic applications due to their light weight, low cost, and low maintenance requirements. Their power control is relatively complex.
2. There are two main types of AC motor drives - induction motor drives and synchronous motor drives. Induction motors are commonly used in adjustable speed drives.
3. Speed control of induction motors can be achieved by varying the stator voltage and frequency. Rotor resistance control using an external resistor is also described for wound rotor induction motors.
- The document discusses strongly interacting atoms in optical lattices and lattice-induced Feshbach resonances.
- It presents exact calculations of two atoms in a 1D lattice and finds avoided crossings between molecular bands and continuum states that depend on the lattice quasimomentum.
- An effective Hamiltonian is constructed that qualitatively captures these effects and introduces a momentum-dependent atom-dimer coupling parameter.
This document provides an overview of solar tracking systems. It discusses how solar trackers orient solar panels toward the sun to minimize the angle of incidence and maximize energy production. Single-axis and dual-axis trackers are described, as well as the components and control systems used. Historical developments are reviewed and recent trends showing that tracking is less cost-effective as panel prices decline. Future research directions could improve dual-axis closed-loop control systems to further increase energy harvesting from solar installations.
An inverter is a device that converts DC power from batteries into AC power. It allows appliances that run on AC power to operate from a DC power source. There are different types of inverters based on their output waveform: square wave, modified sine wave, and pure sine wave. Square wave inverters are the cheapest but produce a less stable output. Modified sine wave inverters produce a three-step waveform and are suitable for basic appliances. Pure sine wave inverters have the best waveform quality but are the most expensive. Inverters are commonly used in UPS systems, with solar panels, for backup power, and in HVDC transmission.
This presentation discusses brushless DC motors. It explains that brushless DC motors do not have brushes, instead using electronics for commutation. This makes them highly efficient over a wide speed range with smooth operation and holding torque when stationary. The presentation describes the basic working principles of brushless DC motors, including their rotor, stator, and electronic control of electromagnets. It discusses how brushless DC motors eliminate the need for commutators through electronic position sensing and switching. Examples of applications are provided, along with advantages like increased efficiency and high performance. Disadvantages include higher cost compared to brushed DC motors and limited high power capabilities.
Efficiency Of A DC Machine And Condition For Maximum EfficiencyMuhammadFazilMemon
The document discusses the efficiency of DC machines and the conditions for maximum efficiency. It defines efficiency as the ratio of output power to input power. For a DC machine, efficiency is calculated as the output divided by the input power, multiplied by 100. The maximum efficiency typically occurs at around 80% of maximum speed when the load is approximately 20% of the maximum stall torque, though exact details vary between machines. Losses that reduce efficiency include armature losses, field losses, copper losses, brush losses, core losses, and stray load losses.
The document discusses a hybrid inverter system that combines solar power and conventional electric power. A hybrid inverter allows energy from solar panels to charge batteries, and includes an AC/DC converter to charge the batteries from a 220VAC supply. The system includes a microcontroller, solar panel, battery storage, relay, switching circuit, and control circuit. It can provide power to multiple loads from both solar energy and the 220VAC supply.
This document discusses the construction and working principle of a permanent magnet DC (PMDC) motor. It begins with an introduction stating that a DC motor converts direct current into mechanical energy. It then describes the key components of a PMDC motor: the stator, which contains permanent magnets; the rotor or armature, made of wound coils; and how each conductor on the armature experiences a force when inside the magnetic field based on Fleming's left hand rule, causing the armature to rotate. Advantages are listed as reduced size, cost and increased efficiency over traditional DC motors requiring field excitation coils. Applications include toys, drills and automatic doors.
The document discusses AC motor drives and induction motor drives. It provides details on:
1. AC motor drives are commonly used in industrial and domestic applications due to their light weight, low cost, and low maintenance requirements. Their power control is relatively complex.
2. There are two main types of AC motor drives - induction motor drives and synchronous motor drives. Induction motors are commonly used in adjustable speed drives.
3. Speed control of induction motors can be achieved by varying the stator voltage and frequency. Rotor resistance control using an external resistor is also described for wound rotor induction motors.
- The document discusses strongly interacting atoms in optical lattices and lattice-induced Feshbach resonances.
- It presents exact calculations of two atoms in a 1D lattice and finds avoided crossings between molecular bands and continuum states that depend on the lattice quasimomentum.
- An effective Hamiltonian is constructed that qualitatively captures these effects and introduces a momentum-dependent atom-dimer coupling parameter.
This document provides an overview of solar tracking systems. It discusses how solar trackers orient solar panels toward the sun to minimize the angle of incidence and maximize energy production. Single-axis and dual-axis trackers are described, as well as the components and control systems used. Historical developments are reviewed and recent trends showing that tracking is less cost-effective as panel prices decline. Future research directions could improve dual-axis closed-loop control systems to further increase energy harvesting from solar installations.
An inverter is a device that converts DC power from batteries into AC power. It allows appliances that run on AC power to operate from a DC power source. There are different types of inverters based on their output waveform: square wave, modified sine wave, and pure sine wave. Square wave inverters are the cheapest but produce a less stable output. Modified sine wave inverters produce a three-step waveform and are suitable for basic appliances. Pure sine wave inverters have the best waveform quality but are the most expensive. Inverters are commonly used in UPS systems, with solar panels, for backup power, and in HVDC transmission.
This document describes a solar tracker device that orients solar panels towards the sun for maximum efficiency. It discusses the need for solar trackers to increase solar panel output. The working principle is that light sensors detect sunlight intensity on the panel and a motor rotates the panel towards the stronger light to maintain optimal alignment with the sun throughout the day. Key components are the solar panel, sensors, microcontroller and motor. Benefits are maximizing solar energy capture while disadvantages include reliance on weather conditions.
Automatic solar tracker is a system which helps to boost the energy production of solar panel. The whole system even does not need any external power source,
basic principles of electrical machines,faraday's laws of electro magnetic induction principle.dynamically induced Emf statically induced emf applications to electrical machines
Type 1 superconductors exhibit complete expulsion of magnetic fields and have low critical magnetic field values, while type 2 superconductors exhibit partial expulsion and have two critical field values between which they are in a mixed or vortex state. Type 1 superconductors like aluminum and lead are called "soft" while type 2 like yttrium barium copper oxide are called "hard" due to their higher critical fields. Magnetic resonance imaging uses the type 2 superconductor niobium-titanium which is superconducting below 9.4 Kelvin, while higher field devices use niobium-tin or emerging magnesium diboride.
The document provides information on various types of electric motors, including DC motors, AC motors, and stepper motors. It discusses the fundamental characteristics and classifications of different motor types. For DC motors specifically, it describes the basic functions, types, wiring topologies, and modeling of series, shunt, compound, and permanent magnet DC motors. It also covers motor control using an H-bridge and brushless DC motor designs. For AC motors, it summarizes fractional horsepower designs as well as induction motors, synchronous motors, squirrel cage rotors, torque/speed characteristics, and NEMA standards.
In today circumstance, rapid development of power system network cause the fault current of the system increased greatly .
The levels of fault current in many places have often exceeded the withstand capacity of existing power system equipment.
As implication to this matter ; security , stability and reliability of power system will be negatively affected .
Thus , limiting the fault current of the power system to a safe level can greatly reduce the risk of failure to the power system equipment due to high fault current flowing through the system. Because of that, there is no surprise to fault current limiter (FCL) become a most favourite research since this technology can limit the fault current .
1. The magnetic potential represents the magnetic field B using a scalar quantity φm or vector quantity A instead of B directly. 2. φm is called the magnetic scalar potential and satisfies Laplace's equation, allowing calculation of B outside of current sources. 3. A is the magnetic vector potential and is defined such that the curl of A is equal to B, satisfying both Ampere's law and Gauss's law for magnetism. 4. Both φm and A are not uniquely defined, as adding the gradient of an arbitrary scalar does not change B; this freedom is known as gauge transformation.
An electric generator converts mechanical energy into electrical energy using the principles of electromagnetic induction. It consists of a conductor that rotates inside a magnetic field, inducing currents to flow. As the conductor rotates, the direction of current changes, producing alternating current. For direct current, the generator has a separate metal slip ring and brushes attached to each end of the coil to allow current to flow in only one direction through the external circuit. Most power stations generate alternating current because it can be transmitted over long distances with little energy loss.
A sensor that utilizes the piezoelectric effect, to measure changes in acceleration, strain, pressure, and force by converting them into electrical charge is called as a piezoelectric sensor. Piezo is a Greek word which means ‘press’ or ‘squeeze’. Piezoelectric effect causes the occurrence of electric dipole moments in solids due to the pressure applied to certain solid materials such as piezoelectric crystals, ceramics, bone, DNA, and some proteins that generates electric charge. This generated piezoelectricity is proportional to the pressure applied to the solid piezoelectric crystal materials and last the generated electic charge shoud be stored to the capacitor.
The magnetically sensitive transistor (also known as the spin transistor or spintronic transistor—named for spintronics, the technology which this development spawned), originally proposed in 1990 and currently still being developed, is an improved design on the common transistor invented in the 1940s. The spin transistor comes about as a result of research on the ability of electrons (and other fermions) to naturally exhibit one of two (and only two) states of spin: known as "spin up" and "spin down". Unlike its namesake predecessor, which operates on an electric current, spin transistors operate on electrons on a more fundamental level; it is essentially the application of electrons set in particular states of spin to store information.
This document discusses buck converters, which are dc-to-dc converters that step down voltage from a constant dc source. It describes two modes of operation for buck converters: continuous conduction mode (CCM) and discontinuous conduction mode (DCM). CCM occurs when inductor current flows continuously, while DCM occurs when inductor current falls to zero for a period during each switching cycle. The document provides equations to calculate operating characteristics like output voltage and efficiency based on component values and switching duty cycle.
In this slide show I have explained how magnetic dipole moment is formed and classification of different magnetic materials. I have also explained how B-H curve is plotted, I explained why B-H Curve is also called as Hysteresis loss.
The inverter is a static device. It can convert one form of electrical power into other forms of electrical power. But it cannot generate electrical power. Hence the inverter is a converter, not a generator.
This document contains sample questions and solutions for a basic electronics course on diodes. It includes 6 questions about calculating diode currents and voltages given saturation currents, applied voltages, and temperatures. The questions cover both forward and reverse bias conditions. Dr. Piyush Charan of Integral University authored the document to provide open educational resources for understanding diode characteristics and basic diode circuit analysis.
This document discusses the topic of superconductivity. It begins by introducing superconductivity as a phenomenon where certain materials conduct electricity without resistance below a critical temperature. It then describes the general properties of superconductors such as critical temperature, magnetic field effect, and persistent current. The document goes on to classify superconductors into two types and discusses their different behaviors in magnetic fields. It concludes by outlining several applications that utilize the unique properties of superconductors, such as Maglev trains, SQUIDs, and efficient power transmission.
This document provides information about diffusion and drift currents. It includes the topic, which is diffusion and drift currents. It also lists the degree, which is a BS(Hons) in Physics from the University of Education Township in Lahore. Finally, it provides references for additional reading on the topics of solid state physics, concepts of modern physics, solid state electronic devices, and the differences between diffusion current and drift current.
The document discusses how to build a simple electromagnet using copper wire wrapped around an iron nail, connected to a battery. When electric current flows through the wire, it creates a magnetic field that allows the nail to attract iron filings. The strength of an electromagnet depends on factors like the number of wire turns and amount of electric current. Electromagnets are found in many devices and have various applications because they can be switched on and off using electricity unlike permanent magnets.
A detailed presentation explaining the principles of electromagnetism. It covers the fundamental laws given by Faraday regarding electromagnetic induction.
This document describes a simulation project of a space vector PWM inverter. It provides details of the system configuration including IGBT switches, DC link voltage, frequencies, and load components. It then provides an in-depth explanation of space vector PWM technique, including the principle of PWM, representation of voltage vectors in the dq reference frame, and algorithm for determining switching times. State-space equations for the L-C output filter are also derived. The overall purpose is to simulate and analyze a three-phase PWM inverter using space vector modulation in MATLAB/Simulink.
This document describes a solar tracker device that orients solar panels towards the sun for maximum efficiency. It discusses the need for solar trackers to increase solar panel output. The working principle is that light sensors detect sunlight intensity on the panel and a motor rotates the panel towards the stronger light to maintain optimal alignment with the sun throughout the day. Key components are the solar panel, sensors, microcontroller and motor. Benefits are maximizing solar energy capture while disadvantages include reliance on weather conditions.
Automatic solar tracker is a system which helps to boost the energy production of solar panel. The whole system even does not need any external power source,
basic principles of electrical machines,faraday's laws of electro magnetic induction principle.dynamically induced Emf statically induced emf applications to electrical machines
Type 1 superconductors exhibit complete expulsion of magnetic fields and have low critical magnetic field values, while type 2 superconductors exhibit partial expulsion and have two critical field values between which they are in a mixed or vortex state. Type 1 superconductors like aluminum and lead are called "soft" while type 2 like yttrium barium copper oxide are called "hard" due to their higher critical fields. Magnetic resonance imaging uses the type 2 superconductor niobium-titanium which is superconducting below 9.4 Kelvin, while higher field devices use niobium-tin or emerging magnesium diboride.
The document provides information on various types of electric motors, including DC motors, AC motors, and stepper motors. It discusses the fundamental characteristics and classifications of different motor types. For DC motors specifically, it describes the basic functions, types, wiring topologies, and modeling of series, shunt, compound, and permanent magnet DC motors. It also covers motor control using an H-bridge and brushless DC motor designs. For AC motors, it summarizes fractional horsepower designs as well as induction motors, synchronous motors, squirrel cage rotors, torque/speed characteristics, and NEMA standards.
In today circumstance, rapid development of power system network cause the fault current of the system increased greatly .
The levels of fault current in many places have often exceeded the withstand capacity of existing power system equipment.
As implication to this matter ; security , stability and reliability of power system will be negatively affected .
Thus , limiting the fault current of the power system to a safe level can greatly reduce the risk of failure to the power system equipment due to high fault current flowing through the system. Because of that, there is no surprise to fault current limiter (FCL) become a most favourite research since this technology can limit the fault current .
1. The magnetic potential represents the magnetic field B using a scalar quantity φm or vector quantity A instead of B directly. 2. φm is called the magnetic scalar potential and satisfies Laplace's equation, allowing calculation of B outside of current sources. 3. A is the magnetic vector potential and is defined such that the curl of A is equal to B, satisfying both Ampere's law and Gauss's law for magnetism. 4. Both φm and A are not uniquely defined, as adding the gradient of an arbitrary scalar does not change B; this freedom is known as gauge transformation.
An electric generator converts mechanical energy into electrical energy using the principles of electromagnetic induction. It consists of a conductor that rotates inside a magnetic field, inducing currents to flow. As the conductor rotates, the direction of current changes, producing alternating current. For direct current, the generator has a separate metal slip ring and brushes attached to each end of the coil to allow current to flow in only one direction through the external circuit. Most power stations generate alternating current because it can be transmitted over long distances with little energy loss.
A sensor that utilizes the piezoelectric effect, to measure changes in acceleration, strain, pressure, and force by converting them into electrical charge is called as a piezoelectric sensor. Piezo is a Greek word which means ‘press’ or ‘squeeze’. Piezoelectric effect causes the occurrence of electric dipole moments in solids due to the pressure applied to certain solid materials such as piezoelectric crystals, ceramics, bone, DNA, and some proteins that generates electric charge. This generated piezoelectricity is proportional to the pressure applied to the solid piezoelectric crystal materials and last the generated electic charge shoud be stored to the capacitor.
The magnetically sensitive transistor (also known as the spin transistor or spintronic transistor—named for spintronics, the technology which this development spawned), originally proposed in 1990 and currently still being developed, is an improved design on the common transistor invented in the 1940s. The spin transistor comes about as a result of research on the ability of electrons (and other fermions) to naturally exhibit one of two (and only two) states of spin: known as "spin up" and "spin down". Unlike its namesake predecessor, which operates on an electric current, spin transistors operate on electrons on a more fundamental level; it is essentially the application of electrons set in particular states of spin to store information.
This document discusses buck converters, which are dc-to-dc converters that step down voltage from a constant dc source. It describes two modes of operation for buck converters: continuous conduction mode (CCM) and discontinuous conduction mode (DCM). CCM occurs when inductor current flows continuously, while DCM occurs when inductor current falls to zero for a period during each switching cycle. The document provides equations to calculate operating characteristics like output voltage and efficiency based on component values and switching duty cycle.
In this slide show I have explained how magnetic dipole moment is formed and classification of different magnetic materials. I have also explained how B-H curve is plotted, I explained why B-H Curve is also called as Hysteresis loss.
The inverter is a static device. It can convert one form of electrical power into other forms of electrical power. But it cannot generate electrical power. Hence the inverter is a converter, not a generator.
This document contains sample questions and solutions for a basic electronics course on diodes. It includes 6 questions about calculating diode currents and voltages given saturation currents, applied voltages, and temperatures. The questions cover both forward and reverse bias conditions. Dr. Piyush Charan of Integral University authored the document to provide open educational resources for understanding diode characteristics and basic diode circuit analysis.
This document discusses the topic of superconductivity. It begins by introducing superconductivity as a phenomenon where certain materials conduct electricity without resistance below a critical temperature. It then describes the general properties of superconductors such as critical temperature, magnetic field effect, and persistent current. The document goes on to classify superconductors into two types and discusses their different behaviors in magnetic fields. It concludes by outlining several applications that utilize the unique properties of superconductors, such as Maglev trains, SQUIDs, and efficient power transmission.
This document provides information about diffusion and drift currents. It includes the topic, which is diffusion and drift currents. It also lists the degree, which is a BS(Hons) in Physics from the University of Education Township in Lahore. Finally, it provides references for additional reading on the topics of solid state physics, concepts of modern physics, solid state electronic devices, and the differences between diffusion current and drift current.
The document discusses how to build a simple electromagnet using copper wire wrapped around an iron nail, connected to a battery. When electric current flows through the wire, it creates a magnetic field that allows the nail to attract iron filings. The strength of an electromagnet depends on factors like the number of wire turns and amount of electric current. Electromagnets are found in many devices and have various applications because they can be switched on and off using electricity unlike permanent magnets.
A detailed presentation explaining the principles of electromagnetism. It covers the fundamental laws given by Faraday regarding electromagnetic induction.
This document describes a simulation project of a space vector PWM inverter. It provides details of the system configuration including IGBT switches, DC link voltage, frequencies, and load components. It then provides an in-depth explanation of space vector PWM technique, including the principle of PWM, representation of voltage vectors in the dq reference frame, and algorithm for determining switching times. State-space equations for the L-C output filter are also derived. The overall purpose is to simulate and analyze a three-phase PWM inverter using space vector modulation in MATLAB/Simulink.