Research On Control Method And Digital Triggering Technology Of High Voltage Static Var Compensator

With the rapid development of social economy, power quality problems such as harmonics and reactive power shortfall are more and more serious. The application of high-power impact load, asymmetric load and nonlinear load has being aggravating the matter. The stable and reliable operation of the power system is under a more severe challenge. In resent years, with the expansion of power system scale and capacity, as well as the reform of the power electronic technology, high-voltage AC-DC power transmission and FACTS are gradually becoming a more and more popular subject. The large-scale blackout occurring at home and abroad in these years reminds that sufficient dynamic reactive reserve and voltage support must be installed in modern power grid. In the last 10 years, high-voltage SVC developed by China has performed its role in power transmission and distribution system, but not got a further step in its extension due to technology and cost factors. Therefore, the research in this thesis has its positive significance for the application and extension of high-voltage SVC in our country.At first, vector model of SVC is built according to the phasor relationships of its branch current. A new method for calculating compensating admittance of TCR is put forward. How to use the established model in main circuit parameters optimization plays its part in further studies. Then, the control module of compensating admittance is presented, in company with system voltage control module and power factor correction module containing hysteresis controller with adjustable hysteresis width that presented, a new type of integrated controller is established. Individual phase control and mode switch are set up in the integrated controller. SVC simulation model is built based on PSIM6.0. The simulation shows that the presented controller can fit the regulation requirement well.Research on digital control and high-voltage triggering technology for thyristor valve is drawn up in the following chapter. Two key units of the photoelectric triggering and monitoring system are designed, which are referred as valve based electronics(VBE) and thyristor electronics(TE) in national and power industry standard. In the progress of designing, structures and functions of the system are formulated, according to which hardware and software design of the electronics is described in detail. Besides, insulation scheme and electro magnetic susceptibility (EMS) of the device are programmed and carried out next.A high voltage SVC(TCR&PF) prototype of 6kV/200kvar is developed for the sake of verifying the reliability of presented control strategy and photoelectric system. Then a series of verification and regulation tests are conducted on it. The experiment result proves that the developed triggering and monitoring system can operate steadily without any breakdowns in long-term test,the control system in this paper can meet the requirements of fast and accurate regulation.