Power electronics- the science of the interaction of electrons and other charged particles, radiation quanta with electromagnetic fields in vacuum, in various media and at their interfaces - (physical electronics): as well as methods of creating electronic devices and devices in which this interaction is used for processing and storage information and energy conversion - (technical electronics).
Power electronics is one of the areas of electronics and is directly used when converting the type, voltage level, number of phases, the order of their alternation, DC transformation. as well as when converting the energy of power sources into the energy of the control action supplied to managed object(OU) -load.
Electronics is subdivided into:
Control and control electronics (information electronics, low output power);
Process electronics (power electronics, unlimited power);
Communication electronics (radio, television, high frequencies);
At the present time, modern power semiconductor devices and other passive components have been created, which make it possible to implement an ESS at relatively high powers.
The presence of microprocessor technology makes it possible to obtain certain necessary characteristics of the SEP.
Main directions:
Improvement of parameters and characteristics of semiconductor devices;
Development of new types semiconductor devices;
Creation of smart devices;
The use of microcontrollers of computer technology in the control system, control and regulation;
Creation of modules from semiconductor devices or complete circuits.
2. The main tasks and problems arising in the design of power electronic devices (seu).
SEU means large group devices designed to obtain electrical control required power(executive power plant), as well as for the transformation, regulation or stabilization of the parameters of electrical energy (converter power plant).
The main tasks in the design of the power plant is to increase the reliability, efficiency and power factor, which ultimately determines its dimensions, weight, economic efficiency, etc.
3. Generalized structural diagram and main elements of the seu.
Figure shows structural scheme SEU, the main part of which is the power unit (SB), the power circuit.
The output signal SB - SU (Uout) is fed to the controlled object - load (U UO, Zн). Integral parts of the ESS are a control block or circuit (BU), a control block or circuit, protection and regulation (BKiZ). The power unit consists of power active (SAE) and passive (PSE) elements, connected according to a certain scheme and are used to convert and control energy coming from the power source (PS). Power semiconductor devices (PSD) are currently used as the SAE: powerful transistors (bipolar, field, combined), thyristors, triacs, optothyristors and intelligent SPP, modules, etc. conversion function of the input signal x, as well as signals α, β feedback(OS) from the BKiZ block to the control signals of the SAE is performed by the CU. V general case The BKiZ receives signals γ and δ from the sensors (DTS, DTO) for monitoring the operating mode of the SB, UO and generates the necessary control signal for the control unit.
In this article, we'll talk about power electronics. What is power electronics, what is it based on, what are the advantages, and what are its prospects? Let's dwell on constituent parts power electronics, we will briefly consider what they are, how they differ from each other, and for what applications are these or those types of semiconductor switches convenient. Here are some examples of power electronics devices used in Everyday life, at work and at home.
In recent years, power electronics devices have made a major technological breakthrough in energy conservation. Power semiconductors, due to their flexible controllability, allow efficient conversion of electrical energy. The weight and size indicators and efficiency achieved today have already brought the converting devices to a qualitatively new level.
Many industries use soft starters, speed controllers, power supplies uninterruptible power supply operating on a modern semiconductor base, and showing high efficiency. These are all power electronics.
Controlling the flow of electrical energy in power electronics is carried out using semiconductor switches, which replace mechanical switches, and which can be controlled according to the required algorithm in order to obtain the required average power and precise action of the working body of this or that equipment.
So, power electronics is used in transport, in the mining industry, in the field of communications, in many industries, and not a single powerful one household appliance does not do today without power electronic units included in its design.
The main building blocks of power electronics are precisely the semiconductor key components capable of different speed, up to megahertz, open and close the circuit. In the on state, the resistance of the key is units and fractions of an ohm, and in the off state - megaohms.
Key management does not require a lot of power, and the losses on the key arising during the switching process, with a well-designed driver, do not exceed one percent. For this reason, the efficiency of power electronics is high compared to the losing ground of iron transformers and mechanical switches such as conventional relays.
Power electronic devices are devices in which effective current greater than or equal to 10 amperes. In this case, the key semiconductor elements can be: bipolar transistors, field effect transistors, IGBT transistors, thyristors, triacs, latching thyristors, and latching thyristors with integrated control.
Low control power allows you to create power microcircuits in which several blocks are combined at once: the key itself, the control circuit and the control circuit, these are the so-called intelligent circuits.
These electronic building blocks are used both in high-power industrial installations and in household electrical appliances... An induction oven for a couple of megawatts or a home steamer for a couple of kilowatts - both have semiconductor power switches that simply operate at different powers.
So, power thyristors work in converters with a capacity of more than 1 MVA, in electric drive circuits direct current and high voltage drives alternating current are used in compensation installations re active power, in installations of induction melting.
Lockable thyristors are controlled more flexibly, they are used to control compressors, fans, pumps with a capacity of hundreds of KVA, and the potential switching power exceeds 3 MVA. allow the implementation of converters with a capacity of up to MVA units for various purposes, both for controlling motors and for providing uninterruptible power supply and switching high currents in many static installations.
MOSFETs have excellent controllability at frequencies of hundreds of kilohertz, which greatly expands their range of applicability compared to IGBTs.
Triacs are optimal for starting and controlling AC motors, they are capable of operating at frequencies up to 50 kHz, and for control they require less energy than IGBT transistors.
Today, IGBTs have a maximum switching voltage of 3500 volts, and potentially 7000 volts. These components can replace bipolar transistors in the coming years, and they will be used on equipment up to MVA units. For low-power converters, MOSFETs will remain more acceptable, and for more than 3 MVA - lockable thyristors.
According to analysts, most power semiconductors in the future it will have a modular design, when two to six key elements are located in one housing. The use of modules allows you to reduce weight, reduce the size and cost of the equipment in which they will be used.
For IGBT transistors, the progress will be an increase in currents up to 2 kA at a voltage of up to 3.5 kV and an increase in operating frequencies up to 70 kHz with simplified control circuits. One module can contain not only keys and a rectifier, but also a driver and active protection circuits.
Transistors, diodes, thyristors produced in recent years have already significantly improved their parameters, such as current, voltage, speed, and progress does not stand still.
For a better conversion of alternating current into direct current, controlled rectifiers are used, which allow smoothly changing the rectified voltage in the range from zero to nominal.
Today, in the excitation systems of DC electric drives, thyristors are mainly used in synchronous motors. Dual thyristors - triacs, have only one gate electrode for two connected anti-parallel thyristors, which makes control even easier.
To carry out the reverse process, the conversion of direct voltage to alternating voltage is used. Independent inverters on semiconductor switches give the output frequency, shape and amplitude determined by electronic circuit rather than a network. Inverters are made on the basis different types key elements, but for high capacities, more than 1 MVA, again IGBT-based inverters come out on top.
Unlike thyristors, IGBTs provide the ability to more widely and more accurately shape the current and voltage at the output. Low-power car inverters use field-effect transistors in their work, which, with powers of up to 3 kW, do an excellent job of converting the direct current of a 12-volt battery, first into direct current, through a high-frequency pulse converter operating at a frequency from 50 kHz to hundreds of kilohertz, then - to alternating 50 or 60 Hz.
To convert a current of one frequency into a current of another frequency, they are used. Previously, this was done exclusively on the basis of thyristors, which did not have full controllability, it was necessary to design complex circuits forced locking of thyristors.
Using type keys field MOSFET and IGBT transistors facilitates the design and implementation of frequency converters, and it can be predicted that in the future, thyristors, especially in low-power devices, will be abandoned in favor of transistors.
For reversing electric drives, thyristors are still used, it is enough to have two sets of thyristor converters to provide two different directions current without the need for switching. This is how modern non-contact reversing starters work.
We hope that our short article was useful for you, and now you know what power electronics is, what elements of power electronics are used in power electronic devices, and how great the potential of power electronics is for our future.
Power electronics is called the field of science and technology, which solves the problem of creating power electronic devices, as well as the problem of obtaining significant electrical energy, controlling powerful electrical processes and converting electrical energy into a sufficiently large energy of another type when using these devices as the main tool.
Below are considered power electronics devices based on semiconductor devices. It is these devices that are most widely used.
The solar cells discussed above have been used to generate electrical energy for a long time. At present, the share of this energy in the total electricity volume is small. However, many scientists, including the Nobel Prize laureate academician Zh.I. Alferov, consider solar cells to be very promising sources of electrical energy that do not violate the energy balance on Earth.
The control of powerful electrical processes is precisely the problem in solving which power semiconductor devices are already very widely used, and the intensity of their use is rapidly increasing. This is due to the advantages of power semiconductor devices, the main of which are high performance, low drop in the open state and small in the closed state (which ensures low power losses), high reliability, significant current and voltage carrying capacity, small size and weight, easy operation, organic unity with semiconductor devices of informative electronics, which facilitates integration high-current and low-current elements.
In many countries, intensive research and development work on power electronics has been launched and, thanks to this, power semiconductor devices, as well as electronic devices on their basis, they are constantly being improved. This ensures rapid expansion areas of application of power electronics, which, in turn, stimulates scientific research. Here we can talk about a positive feedback on the scale of an entire field of human activity. The result is the rapid penetration of power electronics into a wide variety of technical fields.
A particularly rapid spread of power electronics devices began after the creation of power field-effect transistors and IGBT.
This was preceded by a rather long period when the main power semiconductor device was an unlocked thyristor created in the 50s of the last century. Non-latching thyristors have played an outstanding role in the development of power electronics and are widely used today. But the impossibility of switching off by means of control pulses often complicates their application. Decades for developers power devices I had to come to terms with this drawback, using in a number of cases rather complex nodes of power circuits to turn off thyristors.
The widespread use of thyristors led to the popularity of the term "thyristor technology" that emerged at that time, which was used in the same sense as the term "power electronics".
Power bipolar transistors developed during this period found their field of application, but did not radically change the situation in power electronics.
Only with the advent of power field-effect transistors and 10 W in the hands of engineers were fully controllable electronic switches, approaching in their properties to ideal ones. This greatly facilitated the solution of a variety of tasks for the control of powerful electrical processes. Having sufficiently perfect electronic keys makes it possible not only to instantly connect the load to a DC or AC source and disconnect it, but also to generate very large current signals or practically any required form for it.
The most common typical power electronics devices are:
contactless switching devices alternating and direct current (interrupters) designed to turn on or off the load in the alternating or direct current circuit and, sometimes, to regulate the load power;
rectifiers converting alternating polarity (unidirectional);
inverters converting constant to variable;
frequency converters converting a variable of one frequency to a variable of another frequency;
DC converters(converters), converting a constant of one quantity into a constant of another quantity;
phase converters converting an alternating one with one number of phases into an alternating one with a different number of phases (usually single-phase is converted to three-phase or three-phase - to single-phase);
compensators(power factor correctors), designed to compensate for reactive power in the AC supply network and to compensate for distortions of the current and voltage waveforms.
Essentially, power electronics devices convert powerful electrical signals... For this reason, power electronics is also called converter technology.
Power electronics devices, both standard and specialized, are used in all areas of technology and in almost any fairly complex scientific equipment.
As an illustration, let us indicate some objects in which power electronics devices perform important functions:
Electric drive (regulation of speed and torque, etc.);
Plants for electrolysis (non-ferrous metallurgy, chemical industry);
Electrical equipment for the transmission of electricity to long distances on direct current;
Electrometallurgical equipment (electromagnetic stirring of metal, etc.);
Electrothermal installations (induction heating, etc.);
Electrical equipment for battery charging;
Computers;
Electrical equipment of cars and tractors;
Electrical equipment of aircraft and spacecraft;
Radio communication devices;
Equipment for TV broadcasting;
Devices for electric lighting (power supply fluorescent lamps and etc.);
Medical electrical equipment (ultrasound therapy and surgery, etc.);
Power tool;
Devices consumer electronics.
The development of power electronics is changing the very approaches to solving technical tasks... For example, the creation of power field-effect transistors and IGBTs significantly contributes to the expansion of the field of application of inductor motors, which are replacing collector motors in a number of areas.
A significant factor that has a beneficial effect on the distribution of power electronics devices is the success of informative electronics and, in particular, microprocessor technology. To control powerful electrical processes, more and more complex algorithms are used, which can be rationally implemented only with the use of sufficiently advanced informative electronics devices.
The effective combination of advances in power and power electronics produces truly outstanding results.
Existing devices for converting electrical energy into energy of a different kind with the direct use of semiconductor devices do not yet have a high output power. However, here, too, encouraging results have been obtained.
Semiconductor lasers convert electrical energy into coherent energy in the ultraviolet, visible and infrared ranges. These lasers were proposed in 1959, and were first implemented on the basis of gallium arsenide (GaAs) in 1962. Semiconductor lasers have a high useful action(above 10%) and long service life. They are used, for example, in infrared floodlights.
Super bright LEDs white glow, which appeared in the 90s of the last century, are already used in a number of cases for lighting instead of incandescent lamps. LEDs are significantly more economical and have a significantly longer lifespan. It is assumed that the scope LED lamps will expand rapidly.
Textbook. - Novosibirsk: Publishing house of NSTU, 1999.
Parts: 1.1, 1.2, 2.1, 2.2, 2.3, 2.4
This textbook is intended (at two levels of depth of presentation of the material) for students of the faculties of FES, EMF, who are not "specialists" in power electronics, but who study courses of various names on the use of power electronics devices in electric power, electromechanical, electrical systems. Sections of the textbook, highlighted in chopped type, are intended (also at two levels of depth of presentation) for additional, deeper study of the course, which allows it to be used as a textbook for students of the REF Promelectronics specialty, who are trained “as specialists” in power electronics. Thus, the proposed edition implements the “four in one” principle. The reviews of scientific and technical literature on the relevant sections of the course added to separate sections make it possible to recommend the manual as an information publication for undergraduates and postgraduates.
Foreword.
Scientific, technical and methodological foundations for the study of power electronics devices.
Methodology of a systems approach to the analysis of power electronics devices.
Energy indicators of the quality of energy conversion in valve converters.
Energy indicators of the quality of electromagnetic processes.
Energy indicators of the quality of using the elements of the device and the device as a whole.
Element base of valve converters.
Power semiconductor devices.
Incompletely controlled valves.
Fully controlled valves.
Lockable thyristors, transistors.
Transformers and reactors.
Capacitors.
Types of converters of electrical energy.
Methods for calculating energy indicators.
Mathematical models of valve converters.
Methods for calculating the energy performance of converters.
Integral method.
Spectral method.
Direct method.
Adu method.
Adu method.
Adu's method (1).
Methods Adum1, Adum2, Adum (1).
The theory of projection of alternating current into direct current with ideal parameters of the converter.
Rectifier as a system. Basic definitions and notation.
Mechanism for converting alternating current into rectified current in the base cell Dt / Ot.
Two-phase rectifier single-phase current(m1 = 1, m2 = 2, q = 1).
Single-phase bridge rectifier (m1 = m2 = 1, q = 2).
Rectifier three-phase current with a connection diagram of trans windings.
the triangle formator is a star with zero output (m1 = m2 = 3, q = 1).
A three-phase current rectifier with a star-zigzag-zero transformer winding connection diagram (m1 = m2 = 3, q = 1).
A six-phase three-phase current rectifier with the connection of the secondary windings of the star-reverse star transformer with an equalizing reactor (m1 = 3, m2 = 2 x 3, q = 1).
Three-phase current rectifier in bridge circuit (m1 = m2 = 3, q = 2).
Controlled rectifiers. The control characteristic is the theory of converting alternating current into direct current (with recuperation), taking into account the real parameters of the converter elements.
The switching process in a controlled rectifier with a real transformer. External characteristic.
Theory of operation of the rectifier on the counter-emf at final value inductance Ld.
Intermittent current mode (? 2? / Qm2).
Limiting continuous current mode (? = 2? / Qm2).
Continuous current mode (? 2? / Qm2).
Rectifier operation with a capacitor smoothing filter.
Reversal of the direction of the flow of active power in a valve converter with a back EMF in the DC link - dependent inversion mode.
Dependent single-phase current inverter (m1 = 1, m2 = 2, q = 1).
Dependent three-phase current inverter (m1 = 3, m2 = 3, q = 1).
General dependence of the primary current of the rectifier on the anode and rectified currents (Chernyshev's law).
Spectra of primary currents of rectifier transformers and dependent inverters.
Spectra of rectified and inverted voltages of the valve converter.
Optimization of the number of secondary phases of the rectifier transformer. Equivalent multiphase rectification circuits.
The effect of switching on effective values transformer currents and its typical power.
Efficiency and power factor of the valve converter in the rectification and dependent inversion mode.
Efficiency.
Power factor.
Rectifiers on fully controlled valves.
A rectifier with advanced phase control.
Rectifier with pulse-width control of rectified voltage.
Rectifier with forced shaping of the current drawn from the mains.
Reversible valve converter (reversible rectifier).
Electromagnetic compatibility of the valve converter with the mains supply.
A model example of the electrical design of a rectifier.
Rectifier circuit selection (structural synthesis stage).
Calculation of the parameters of the elements of the controlled rectifier circuit (stage of parametric synthesis).
Conclusion.
Literature.
Subject index.
Power Electronics Fundamentals
The book will allow a novice radio amateur to step by step, with a soldering iron in his hands, go through the thorns to the stars - from comprehending the basics of power electronics to the mountain peaks of professional skill.The information presented in the book is divided into three categories of training levels for a specialist in the field of power electronics. After mastering the next stage of preparation and answering a kind of examination questions, the student is "transferred" to the next level of knowledge.
The book provides practical, theoretical and reference information sufficient for the reader, as he moves through the pages of the book, to independently calculate, collect and configure the one he likes. electronic design... To improve the professional skills of the reader, the book contains numerous proven practice useful tips, and real schemes electronic devices.
The publication may be useful to readers different ages and the level of training interested in the creation, design, improvement and repair of elements and assemblies of power electronics.
Introduction
Chapter I. Mastering the Basics of Power Electronics
1.1. Definitions and laws of electrical engineering
1.2. The main elements of power electronics
1.3. Series-parallel and other connection
elements of radio electronics
Series-parallel connection of resistors
Series-parallel connection of capacitors
Series-parallel connection of inductors
Series-parallel connection of semiconductor diodes
Composite transistors
Darlington and Shiklai-Norton schemes
Parallel connection of transistors
Series connection of transistors
1.4. Transient processes in RLC-circuits
Transients in CR and RC circuits
Transients in LR and RL circuits
Transients in CL and LC circuits
1.5. Linear transformer power supplies
Typical block diagram of a classic secondary power supply
Transformer
1.6. Rectifiers
1.7. Power smoothing filters
Single element single link C-filter
Single element single link L-filter
Dual Element Single Link L-Shape LC Filter
Two-element single-link L-shaped RC filter
Three-element single-stage U-shaped diode anti-aliasing filter
Compensation filter
Multi-tiered smoothing filters
Active filters
Transistor smoothing filter
Series transistor filter
Filter with parallel connection transistor
Comparative characteristics of power supply filters
1.8. Surge Protectors
Parallel voltage regulator
on increased power load
Serial voltage regulator
Serial Compensation Stabilizer
using an operational amplifier
Voltage stabilizers on integrated circuits
1.9. Voltage converters
Capacitor voltage converters
Self-excited voltage converters
Voltage converters with external excitation
Switching voltage converters
1.10. Questions and tasks for self-test of knowledge
Chapter II. Practical Power Electronics Designs
2.1. Rectifiers
Single-phase, two-channel and step-controlled rectifiers
Three-phase (polyphase) rectifier circuits
Half-wave multiphase rectifier
2.2. Voltage multipliers
2.3. Power smoothing filters
2.4. DC stabilizers
Stable current generators
Current mirror
Stable current generators on field effect transistors
Stable current generators on field and bipolar transistors
Stable current generators using operational amplifiers
GTS using specialized microcircuits
2.5. Surge Protectors
Reference voltage sources
Parallel type voltage regulators
on specialized microcircuits
Pulse stabilized voltage regulator
Step-down switching voltage regulator
Laboratory stabilized power supply
Switching voltage regulators
2.6. Voltage converters
Boost DC / DC Converter
Stabilized voltage converter
Voltage converter 1.5 / 9 V for power supply of the multimeter
Simple voltage converter 12/220 V 50 Hz
Voltage converter 12V / 230V 50 Hz
Typical DC / DC converter circuit with galvanic isolation on TOPSwitch
Voltage converter 5/5 V with galvanic isolation
2.7. Voltage converters for power supply of gas-discharge and LED
light sources
Low-voltage power supply of LDS with adjustable brightness
Voltage converter for powering fluorescent lamps
Converter for power supply of LDS on TVS-110LA
Energy-saving lamp power converter
Drivers for powering LED light sources
for power supply of LED light sources from galvanic
finger or rechargeable batteries
Voltage converters on microcircuits
for power supply of LED light sources from the AC mains
2.8. Dimmers
Dimmers for controlling the intensity of the glow of incandescent lamps
Dimmers to control the intensity of radiation
LED light sources
2.9. Batteries and charging device
Comparative characteristics of batteries
Universal chargers
for charging NiCd / NiMH batteries
Li-Pol charge controller battery on a microcircuit
Li-Pol battery charger
LiFePO4 and Li-Ion battery charger
Solar powered automatic chargers
Wireless chargers
2.10. Regulators and stabilizers of frequency of rotation of a shaft of electric motors
Characteristics of electric motors
DC motors
DC motor speed controllers
on integrated circuits
Cooler speed controller for computer
Temperature-dependent fan switch
Stabilizer of the frequency of rotation of the shaft of the electric motor
Regulation and stabilization of the speed of the DC motor
Speed controller for DC motor
PWM speed controllers for DC motors
Reversing motor speed controller
AC motors
Three-phase connection asynchronous motor
to a single-phase network
Three-phase voltage from the electric motor
Single-phase to three-phase converter
Three-phase voltage generators based on
electronic analogue of Scott's transformer
Wide Range Three Phase Voltage Generator
Frequency converters for supplying three-phase asynchronous
electric motors
Usage pulse width modulation
to regulate the speed of the electric motor
Stepper motor speed controller
Motor overload protection device
2.11. Power factor correctors
Power triangle
Power Factor Correction Techniques
Passive power factor correction
Active power factor correction
2.12. Mains voltage stabilizers
Main characteristics of stabilizers
Ferroresonant stabilizers
Electromechanical stabilizers
Electronic stabilizers
Inverter stabilizers
Uninterruptible or backup power supplies
2.13. Repair and adjustment of power electronics units
2.14. Questions and tasks for self-test of knowledge
to go to the next step
Chapter III. Professional technical solutions power electronics issues
3.1. Methodological foundations of engineering and technical creativity in solving
practical tasks radio electronics
3.2. Methods for solving creative problems
Solving creative problems of the first level of complexity
Time or scale magnifying glass method
Solving creative problems of the second level of complexity
Brainstorming (brainstorming, brainstorming)
Solving creative problems of the third level of complexity
Functional cost analysis
Power Electronics Tasks
for the development of creative imagination
3.3. Power Electronics Patents and New Ideas
New patents in the field of power electronics
Compensating constant voltage stabilizer
Constant voltage stabilizer
Buck converter alternating voltage in permanent
Unipolar to bipolar converter
Micropower unipolar to bipolar converter
Barrier resistive elements - baristors and their applications
Induction heating
Current transformer for heating the coolant
3.4. Power electronics unusual phenomena
Paradoxical experiments and their interpretation
Kirlian photography technique
Installation for research of gas-discharge processes
Circuitry of devices for "Kirlianovskaya" photography
Generator for obtaining "Kirlian" photos
Ultratonic therapy devices
Electronic traps of radioactive dust - electronic vacuum cleaner
Ion engine
Ionolet
Ionophone or singing arc
Plasma ball
Simple Linear Accelerator - Gauss Cannon
Railgun
3.5. Features of the use of passive elements in power electronics
Rows of resistors and capacitors
Power Electronics Resistors
Power electronics capacitors
Frequency characteristics of various types of capacitors
Aluminum electrolytic capacitors
Tantalum Electrolytic Capacitors
Inductors for power electronics
Main parameters of inductors
Frequency properties of inductors
3.6. Features of the use of semiconductor devices in power electronics
Properties of p-p-transition
Bipolar transistors
MOSFET and IGBT transistors
3.7 Snubbers
3.8. Cooling of power electronics
Comparative characteristics of cooling systems
Air cooling
Liquid cooling
Thermocoolers with Peltier effect
Piezoelectric active cooling modules
3.9. Questions and tasks for self-test of knowledge
Appendix 1. Methods of winding toroidal transformers
Appendix 2. Safety precautions during manufacture, commissioning
and operation of power electronics devices
List of literature and Internet resources
Pages: 336
Russian language
Format: PDF
Quality: excellent
Size: 21 mb
Download: Shustov M.A. Power Electronics Fundamentals
