Control Strategy of Virtual Synchronous Generator Based on Frequency Control Capability of Charging Station
With the access of many distributed power sources,the inertia level of microgrid decreases significantly,which easily leads to frequency instability.Electric vehicles(EVs)in the charging station(CS)can provide auxiliary frequency control(FC)service for the power grid.Based on this,a virtual synchronous generator(VSG)control strategy based on the FC capability of CS is proposed in this paper.Firstly,VSG control architecture based on CS FC power is proposed,and the FC participation factor calculation method reflecting FC capability is proposed based on user charging demand.Further,the CS FC power controllable boundary evaluation method and the power response model based on EVs classification method are proposed.Secondly,adaptive moment of inertia,damping coefficient and frequency-FC power controller based on CS FC power boundary are designed.Finally,the simulation is carried out on the CS VSG model built on MATLAB/Simulink to verify that the proposed control strategy can reduce the frequency offset,improve the frequency stability and dynamic adjustment ability of the system,and determine the response FC power based on the FC capability of CS and frequency offset.And the FC power can be reasonably distributed among EVs in CS.
charging stationelectric vehiclevirtual synchronous generatorfrequency control capabilityfrequency control participation factorpower response