自动化英语 专业电力电子技术在电力系统中的应用.doc

Power electronic technology in the power systemAbstract: This paper aims at introducing the power electronic technology in electric power system of all kinds of application, the key is in power transmission link, link, link in the application and saving energy distribution in the link of use. Keywords: DC transmission; Power electronics; generator Introduction:Power electronic technology is a power semiconductor devices, circuit technology, computer technology and modern control technology for support technology platform. After 50 years of development, the traditional industry equipment in it, power quality control, issued new energy development and civil products have been applied more and more. The most successfully applied in the power system of power electronic technology is a high power dc transmission (HVDC). Since the 1980 s, flexible ac power (FACTS) concept is put forward, power electronic technology in power system, the application research was highly focused, a variety of equipment arise. This paper introduces the power electronic technology in power generation, transmission link, link in the application and saving energy distribution in the link of use.Second, the power electronic technology application Power electronic technology applications:Since the 1980 s, flexible ac power (FACTS) concept is put forward, power electronic technology in power system, the application research was highly focused, a variety of equipment arise. Has quite a few paper summarizes the related equipment and the basic principle and application situation. According to the power system of power generation, transmission and distribution and power saving link, the list of power electronic technology research and the application of the status quo. (A) In the power of the application of the linkThe power system of power generation link generator set a variety of equipment involved, the application of the power electronic technology to improve the equipment for the main purpose of the operation characteristic. 1, Large generator excitation control of staticStatic excitation using thyristor rectifier since by way, the structure is simple, high reliability and low cost advantages, is the major world power system widely adopted. Due to tell the exciter among the inertial link, and thus has its unique speed adjustment, the control law to advanced provide fully play their part and produce good control effect of favorable conditions 2, The wind turbine hydraulic VSCF excitationThe hydraulic power effective power depends on the head pressure and flow, as head of the change to a larger extent (especially the pumped-storage unit), units of the best speed will change. Effective power of wind power and wind speed is directly proportional to the three times, the speed of the maximum wind power windmill capture with wind speed and change. In order to gain maximum effective power, can make the operation speed, by adjusting the rotor exciter current frequency, make its and the rotor speed stacked stator frequency output frequency that keep constant. The application of the technology is the key of the frequency conversion power.3, Power plant of variable frequency speed pump fanThe power plant factory electricity rates an average of 8%, and fan pump power consumption accounts for about 65% of total power consumption thermal power equipment, and low operation efficiency. Use the low voltage or high voltage inverter, the implementation of the pump fan variable frequency speed regulation, can achieve the purpose of saving energy. (B) In the application of transmission link Power electronics device used in high voltage transmission system is called caused by the silicon chips second revolution, greatly improved the stable operation of the grid characteristics. 1, DC transmission (HVDC) and Light dc transmission (HVDC Light) technologyHVDC transmission capacity is big, good stability, flexible control regulation etc, and for long-distance transmission, submarine cable transmission and different frequency system networking, HVDC transmission with a unique advantage. The first thyristor change the flow, marking the formal power electronic technology used in dc transmission. From then on the world of the new HVDC project is using thyristor change flow valves. 2, Flexible ac power (FACTS) technology The concept of dry FACTS technology came in the late 1980 s, is a based on power electronic technology and modern control technology for ac transmission system impedance, voltage and phase of the flexible regulate the transmission technology, can be used for communication with the trend of the power transmission flexible control greatly improve the level of the power system stability. (C) In the distribution of the application of the linkThe power distribution system is urgent needs to solve the question of how to strengthen the power supply reliability and improve power quality. Power quality control should not only meet the voltage, frequency, harmonic and asymmetric degree requirements, but also inhibit all kinds of transient fluctuations and interference. Power electronic technology and modern control technology in the distribution system of application, namely the user Power (custom Power) technology or say DFACTS technology, is in the mature technology FACTS developed on the basis of Power quality control of the new technology. DFACTS equipment can be understood as FACTS equipment smaller version, its principle, structure are the same, the function is similar. Due to the huge potential demand, market intervention in relative easy, investments in development and production cost is lower, with power electronics device prices lower, we can expect DFACTS equipment products will enter the rapid development. (D)In the use of energy saving link 1, The variable load motor drive runningMotor power saving potential power saving just dig itself, through the variable load motor speed technology of power saving is another a only both up, motor power saving party more perfect. At present, exchange control in the metallurgy, mining and other departments and social life in a wide range of applications. First is fan and pump variable load in machinery such as the wind speed regulation control instead of board or throttle valve to control the wind flow and the flow of water has the remarkable effect. Foreign variable load of the fans and pumps is used mostly communication speed regulation, our country is the promoted application. Variable frequency speed advantage is wide speed range, high precision, high efficiency, can realize the continuous stepless speed regulation. In the process of poor transfer speed small loss, stator and rotor copper consumption is not large also, energy saving rate generally can reach up to about 30%. 2, Reduce the reactive power loss, improve the power factorAt the electric equipment, transformer and exchange asynchronous motor belong to the perceptual load, the equipment in operation with not only the active power consumption, but also consume reactive power. Therefore, reactive power and active p