The Research On Control Strategy For750kV Controllable High Voltage Shunt Reactor

With the super/ultra high voltage, long-distance power grid construction anddevelopment, especially in Xinjiang and northwest750kV Interconnection Projectconstruction and put into operation, which will bring power system stabilizeroperation and flexible control requirements increasing, relative to new powerelectronics technology the combination of equipment is gradually increased, and havebeen used widely as effective means to improve the transmission control, the shuntreactor is one of the important part of these.As an important device in the high voltage long distance transmission system,the controllable high voltage shunt reactor to reduce the line of power loss, the effectsof compensation for long-term capacitor, to prevent resonance over-voltage, reducingthe arc current, limiting the power frequency voltage rise, inhibit the operation ofover-voltage and other function. Compared with the traditional uncontrollable shuntreactor controlled shunt reactor and flexible control that can automatically adjust itsown capacity according to changes in the line of transmission power, to smoothadjustment to the grid system of reactive power, disturbance on the grid systemresponsive, to improve the stability of the grid system, increasing the transmissioncapacity of the grid, reducing the financial burden of grid operation.In this paper, on the basis of analysis of controlled high resistance to theprinciple and characteristics, According to the actual situation of the Hexi750kVTransmission Project, combined with the China Electric Power Research Institute andthe Gansu Electric Power Research Institute’s research results, through750kVstepped switching controllable high voltage shunt reactor control principle of themethod of comparison, determine the750kV stepped switching controllable highvoltage shunt reactor based on the incremental demand and bus boundary voltageinside and outside the double-layer control strategy. This control strategy based onthe incremental demand of reactive power control method and based on the busboundary voltage combination of inner control based on the increment of reactivepower demand, the outer control bus boundary voltage, the outer layer of the controlof a higher priority than the inner control, the inner and outer layers control thecombination of both good followed the principle of reactive power balance and takeinto account the voltage characteristics of the global, can be high-precision andefficient control of switching750kV stepped switching controllable high voltage shuntreactor. Through the control strategy BPA stability program simulation analysis anddynamic simulation, verified the correctness and feasibility of the proposed controlstrategy.