Applications:
1, power supply and power system
Computer high-efficiency green power supply
High-speed development of computer technology has led mankind into the information society, but also promote the rapid development of power supply technology. In the eighties, the computer fully adopted the switching power supply, the first to complete the computer power supply replacement. Then switching power supply technology has entered the field of electronic and electrical equipment.
The development of computer technology, proposed green computer and green power. Green computer refers to environmentally friendly personal computers and related products, green power supply refers to the green computer related to efficient power saving power supply, according to the U.S. Environmental Protection Agency on June 17, 1992 "Energy Star" program, desktop personal computers or related peripheral equipment, power consumption in the sleep state if less than 30 watts, in line with the requirements of the green computer, improve power supply efficiency is to reduce the power consumption of the computer. Improving power supply efficiency is a fundamental way to reduce power consumption. In the case of a 200-watt switching power supply, which is currently 75% efficient, the power supply itself consumes 50 watts of energy.
High-frequency switching power supply for communications
The rapid development of the communications industry has greatly promoted the development of communications power supplies. High-frequency miniaturized switching power supply and its technology has become the mainstream of modern communication power supply system. In the field of communications, the rectifier is usually referred to as the primary power supply, while the DC-DC (DC/DC) converter is called the secondary power supply. The role of the primary power supply is to single-phase or three-phase AC power grid into a nominal value of 48V DC power. Currently in the primary power supply for program-controlled switches, the traditional phase-controlled voltage regulator has been replaced by a high-frequency switching power supply, high-frequency switching power supply (also known as switching rectifier SMR) through the high-frequency operation of the MOSFETs or IGBTs, the switching frequency is generally controlled in the range of 50-100kHz, to achieve high efficiency and miniaturization. In recent years, the power capacity of the switching rectifier has been expanding, and the stand-alone capacity has been expanded from 48V/12.5A and 48V/20A to 48V/200A and 48V/400A.
Because of the wide variety of integrated circuits used in the communication equipment, their power supply voltages vary, and the use of high-frequency DC-DC isolated power supply modules with a high power density in communication power supply systems, from the Intermediate bus voltage (generally 48V DC) into the required DC voltage, which can greatly reduce losses, easy maintenance, and installation, increase very convenient. Generally can be directly mounted on the standard control board, the requirements of the secondary power supply is high power density. Due to the increasing communication capacity, communication power supply capacity will also continue to increase.
DC-DC (DC/DC) converter
DC/DC converter converts a fixed DC voltage into a variable DC voltage, this technology is widely used in trolley buses, subway trains, electric vehicles, stepless speed change and control, while enabling the above control to obtain the acceleration of a smooth, fast response performance, and at the same time receive the effect of saving power. Using DC chopper instead of varistor can save power (20~30)%. DC chopper can not only play the role of voltage regulation (switching power supply), but also play an effective role in suppressing grid-side harmonic current noise.
Communication power supply DC/DC converter of the secondary power supply has been commercialized, the module using high-frequency PWM technology, switching frequency of about 500kHz, the power density of 5W ~ 20W/in3. With the development of large-scale integrated circuits, the requirements of power supply modules to achieve miniaturization, so it is necessary to continue to improve the switching frequency and the use of new circuit topologies, there are already a number of companies have developed and produced the use of zero-current switching and zero-current switching and zero-current switching. The production of zero-current switching and zero-voltage switching technology of the secondary power supply module, the power density has improved substantially.
Uninterruptible power supply (UPS)
Uninterruptible power supply (UPS) is a highly reliable, high-performance power supply necessary for computers, communication systems and the requirement to provide uninterrupted occasions. AC utility input through the rectifier into DC, part of the energy to the battery pack charging, the other part of the energy through the inverter into AC, through the conversion switch to the load. In order to provide energy to the load even when the inverter fails, the other way back-up power is realized through the power conversion switch.
Modern UPS commonly used pulse width modulation technology and power M0SFET, IGBT and other modern power electronic devices, power supply noise can be reduced, while efficiency and reliability can be improved. The introduction of microprocessor hardware and software technology can realize the intelligent management of UPS, remote maintenance and remote diagnosis.
At present, the maximum capacity of on-line UPS has been made to 600kVA. ultra-small UPS development is also very rapid, has been 0.5kVA, lVA, 2kVA, 3kVA and other specifications of the product.
Inverter power supply
Inverter power supply is mainly used for AC motor frequency conversion speed control, which occupies an increasingly important position in the electrical drive system, has been a huge energy-saving effect. The main circuit of inverter power supply adopts AC-DC-AC program. Industrial frequency power supply through the rectifier into a fixed DC voltage, and then by high-power transistors or IGBT PWM high-frequency converter, the DC voltage will be inverted into voltage, frequency variable AC output, the power supply output waveform approximate sinusoidal waveforms, used to drive AC asynchronous motors to achieve stepless speed regulation.
International 400kVA inverter power supply series products have been introduced. In the early eighties, Japan's Toshiba was the first to AC frequency conversion speed control technology used in air conditioners. By 1997, its share has reached more than 70% of Japan's household air conditioners. Inverter air conditioners have the advantages of comfort and energy saving. Domestic in the early 1990s began to study inverter air conditioning, 96 years the introduction of production lines to produce inverter air conditioners, and gradually formed a hot spot for the development and production of inverter air conditioning. It is expected to form a climax around 2000. In addition to inverter power supply, inverter air conditioner also requires a compressor motor suitable for inverter speed regulation. Optimize the control strategy, selected functional components, is the air conditioning frequency conversion power supply development of further development direction.
High-frequency inverter rectifier welder power supply
High-frequency inverter rectifier welder power supply is a high-performance, high-efficiency, material-saving new type of welder power supply, on behalf of today's welder power development direction. Due to the commercialization of IGBT high-capacity modules, this power supply has a broader application prospect.
Electronic components
Inverter welder power supply mostly AC-DC-AC-DC (AC-DC-AC-DC) conversion method. 50Hz AC rectified by the full-bridge into DC, IGBT composed of PWM high-frequency converter part of the DC inverter into a high-frequency rectangular wave of 20kHz, high-frequency transformer coupling, rectifier filtering into a stable DC, for arc use. DC for arc use.
Because of the harsh working conditions of the welding machine power supply, frequently in the short circuit, arc, open circuit alternating changes, so the reliability of the high-frequency inverter rectifier welding machine power supply has become the most critical issue, but also the user is most concerned about the problem. The use of microprocessors as a pulse width modulation (PWM) of the relevant controller, through the multi-parameter, multi-information extraction and analysis, to achieve the purpose of foreknowledge of a variety of system operating state, and then in advance of the system to make adjustments and processing to solve the current high-power IGBT inverter power supply reliability.
Foreign inverter welder has been able to achieve the rated welding current of 300A, load duration rate of 60%, the full load voltage of 60 ~ 75V, the current adjustment range of 5 ~ 300A, the weight of 29kg.
High-power switching high-voltage DC power supply
High-power switching high-voltage DC power supply is widely used in electrostatic dust removal, water quality improvement, medical X-ray machine and CT machine and other large-scale equipment. The power supply is widely used in electrostatic dust removal, water quality improvement, medical X-ray machine and CT machine and other large equipment. The voltage is as high as 50~l59kV, the current is more than 0.5A, and the power is up to 100kW.
Since the 70's, some Japanese companies started to use the inverter technology, which rectifies the utility power and then inverts it into the medium frequency of about 3kHz, and then boosts the voltage. Into the 80s, high-frequency switching power supply technology developed rapidly. Germany Siemens used power transistors as the main switching element to increase the switching frequency of the power supply to more than 20kHz. And the dry-type transformer technology successfully applied to high-frequency high-voltage power supply, canceled the high-voltage transformer tank, so that the volume of the transformer system is further reduced.
Domestic development of electrostatic precipitation of high voltage DC power supply, utility power rectified to DC, using full bridge zero current switching series resonance inverter circuit will be DC voltage inverter for high frequency voltage, and then by the high-frequency transformer step-up, and finally rectified to DC high voltage. Under resistive load conditions, the output DC voltage reaches 55kV, the current reaches 15mA, and the operating frequency is 25.6kHz.
Power active filter
The traditional alternating current - direct current (AC - DC) converter will inject a large number of harmonic currents into the grid when it is put into operation, which will cause harmonic losses and disturbances, and at the same time there is a deterioration of the power factor on the grid side of the device.
Power active filter is a new type of power electronic device that can dynamically suppress harmonics, and can overcome the shortcomings of traditional LC filter. It can overcome the shortcomings of traditional LC filters, and is a very promising means of harmonic suppression. The filter consists of a bridge-type switching power converter and a specific control circuit. The difference with the traditional switching power supply is: (l) not only feedback output voltage, but also feedback input average current; (2) the current loop reference signal for the voltage loop error signal and the full-wave rectifier voltage sampling signal product.
Distributed switching power supply system
Distributed power supply system using low-power modules and large-scale control integrated circuits as the basic components, the use of the latest theories and technological achievements, the composition of building blocks, intelligent high-power power supply power supply, so that the strong power and the weak power is closely integrated to reduce the development of high-power components, high-power devices (centralized) the pressure to improve the production of efficiency.
In the early eighties, the study of distributed high-frequency switching power supply system is basically focused on the study of converter parallel technology. In the mid-to-late eighties, with the rapid development of high-frequency power conversion technology, a variety of converter topologies have emerged, combined with large-scale integrated circuits and power components technology, so that the integration of small and medium-power devices possible, thus rapidly promoting the research of distributed high-frequency switched-mode power supply system. Since the late eighties, this direction has become the international power electronics research hotspot, the number of papers increased year by year, the field of application continues to expand.
Distributed power supply system circuit
Distributed power supply method has the advantages of energy saving, reliable, efficient, economic and easy maintenance. It has been gradually adopted by large computers, communication equipment, aerospace, industrial control and other systems, and is also the most ideal power supply method for low voltage power supply (3.3V) of ultra-high-speed type integrated circuits. It is also the most ideal low-voltage power supply (3.3V) for ultra-high-speed integrated circuits. It also has broad application prospects in high-power applications such as electroplating, electrolytic power supply, electric locomotive traction power supply, medium-frequency induction heating power supply, and motor drive power supply.
2, industrial applications
In the traditional industrial field, widely used mainly AC and DC motors. DC motor has a strong speed control function, for its power supply can be controlled rectifier power supply or DC power supply most of the power electronic devices. Accompanied by the continuous progress of science and technology, power electronic frequency conversion technology rapid development and maturity, it makes the AC motor speed performance has been greatly improved, and gradually replace the DC motor to occupy the main position in the market.
In industrial production, AC motors are widely used in different loads of rolling mills and CNC machine tools, playing an important role and good performance. In order to avoid the current impact caused in the startup of the equipment, some devices that do not need to use power electronics have also begun to widely take the device equipment. At the same time, in the electroplating device is also installed in the use of rectifier power supply, metallurgical industry in the high-frequency, medium-frequency induction heating power supply is also widely used in power electronics technology. The use of power electronics technology in the expanding scope and scale.
3, the application of the field of transportation
Electronic technology in the field of transportation is mainly used for the application of transportation systems. Electric locomotives are currently being transformed from the traditional DC motor drive to AC motor tradition, mainly using GTO control devices, rectifier and inverter with PWM control, so the input current can be made sinusoidal. At present, many countries in the development of the use of linear synchronous motor-driven maglev train, once the technology is mature and successful application, then, will bring a change for the transportation, not only help to shorten the time but also make an important contribution to energy saving and emission reduction.
Motor technology can also be used in automobile engines. In modern automobiles, mechanical or electromechanical hybrid fuel injection systems have been eliminated, and electronically controlled fuel injection devices are widely used because of their excellent performance. Through the electronic fuel injection device can automatically ensure that the engine is always in the best working condition, so that its output power under certain conditions to maximize fuel saving and air purification. At the same time through the experiment to obtain the best working conditions, and input into the memory, when the engine began to work, according to the sensor measured air flow, oxygen content in the exhaust pipe and other parameters, in accordance with the pre-numbered arithmetic program running, and then control the engine in the best working conditions.
Currently automotive electronics technology has developed to the fourth generation, that is, including electronic technology (including microcomputer technology), optimal control technology, sensor technology, network technology, mechatronics coupling cross technology and other integrated technology of the small system, and has long since entered the stage of scientific research into the maturity of the production of commodities (for example, the centralized control of the brakes, steering and suspension, as well as centralized control of the engine and transmission). At the same time, intelligent integrated sensors and intelligent actuators will be put into practice, digital signal processing methods will be applied to sound recognition, safety collision, timely diagnosis and navigation systems.
4, the application of medicine
Electronic technology in the medical application of electronic medical records, biochips, portable medical electronic detector, remote diagnosis and treatment system. Electronic medical record is a combination of electronic technology and network technology, can provide timely medical information for medical institutions, is a systematic health records of residents, but also can provide evidence of medical liability; the use of sensors of biochips, can be the human body for the detection of DNA, rapid processing of relevant information, paternity testing, etc.; electronic technology applied to portable medical electronic detector can be through the micro-controller, connected to the Medical institutions network, the realization of the doctor to the patient's late diagnosis and treatment observation, conducive to the play of medical effects; at the same time, the use of medicine and network technology, microelectronics technology, etc., can achieve the remote diagnosis and treatment of medicine, to achieve the **** enjoyment of medical resources, and is conducive to the remote areas of the medical diagnosis and treatment.
5, the field of radio and television
Radio and television industry is a technology-intensive industry, it is accompanied by the emergence of modern electronic technology, with the development of modern electronic technology and development. In the past 10 years, new technologies represented by digital technology, satellite technology, optical transmission technology and network technology are revolutionizing the development of radio and television. The development of technology determines the quality of program production, the quality of transmission and the coverage of radio and television, all of which are the means of competitive development of the radio and television industry. Therefore, foreign radio and television groups have already adopted or are planning the large-scale application of new technologies. China's radio and television industry to participate in the competition, the same must take the road of industrialization and development, in full accordance with the industrial operation of the implementation of large-scale technological transformation.
6, the field of national defense
The development of national defense relies heavily on the development of defense electronics enterprises, and the development of defense electronics enterprises rely on the progress of electronic technology. The wave of mergers and reorganization of the global military industry has created a number of mega defense electronics enterprises. These enterprises have catered to the needs of the new military transformation with their advantages in electronics and information technology, and have also changed the layout of the entire defense electronics industry. At present, airborne, satellite-carried, shipborne and land-based sensors (including radio-frequency and optoelectronic sensors) are the main means for many countries to gain an intelligence advantage, while communication network technology and integrated weapon system technology are the basis and necessary conditions for the implementation of joint operations and military transformation. Information network will connect and support a variety of weapons platforms, it is the "network center war" foundation and core, and electronic information equipment in a variety of weapons and equipment in the penetration of the basic realization of the informatization of weapons and equipment, so that the form of war has developed into a system against the system, system against the system of confrontation. For defense electronics companies, according to this change in the military environment and market demand to make adjustments, is its survival based on the necessity of network, information technology will also be the key technology for future military equipment.
7, the field of newspapers
The development of electronic technology so that the newspaper has a new form of electronic newspaper appeared in the newspaper is one of the main sources of information in today's human society, reading the newspaper has become a lifetime of many people do not change the habit of the emergence of the network newspaper will make the habit of reading the newspaper changed. Electronic newspaper is a product of the development of computer technology, it is not only the newspaper, magazine pages on the computer screen, and is a supplement to the existing newspaper. Readers can access relevant background materials, as well as previously published articles in the electronic press; in addition, they can also use the computer to contact the author of the article, the editor, and even the people involved in the article. Electronic newspapers can provide readers with a large amount of information, which is impossible to achieve with the space limitations of the average newspaper. Electronic newspapers can provide the entire content of the day's newspaper, as well as computer games, articles that the newspaper has published in the past, advertisements of all kinds, readers and newsmakers, and reader-to-reader conversations. The development prospects of the emerging electronic newspaper is very attractive.