考虑储能系统控保协同体系的光伏场站送出线路突变量选相能力恢复策略OA北大核心CSTPCD

After the new energy is connected to the power grid,the operating performance of the phase selection element of difference abrupt change is significantly deteriorated.Especially in the weak power supply side,it is difficult to ensure the correctness of the phase selection.Therefore,a recovery of the phase selection ability based on the control and protection coordination of energy storage system is proposed.Through theoretical analysis,it can be concluded that the negative-sequence impedance of the inverter power supply side is basically constant,which is the precondition for implementing the recovery measures of phase selection capability.On this basis,it is recommended to shield the negative sequence suppression short-term in the control strategy of the inverter power supply on the energy storage side in the photovoltaic power station,and to ensure that the positive sequence distribution coefficient on both sides of the fault line is equal to the negative sequence distribution coefficient.The most ideal conditions for the traditional sudden change phase selection element are created to realize the action.This control can be achieved by controlling the d-axis and q-axis currents in the current inner loop of the energy storage device.The simulation results based on PSCAD/EMTDC show that under the action of this control strategy,the distribution coefficient of positive sequence on both sides of the line is almost equal to the distribution coefficient of negative sequence,which greatly restores the phase selection characteristics of the weak power supply side.It has good adaptability under the system,and will not interfere with the normal operation of the phase selection element on the system side,with high reliability.