Abstract: As a large number of new energy sources such as photovoltaic and wind power are connected to the power grid,the voltage stability decreases,and reactive power and voltage problems occur in the case of power grid failure.To solve this problem,a new virtual condenser control strategy based on the equivalent circuit model of synchronous generator was proposed.Firstly,taking the photovoltaic inverter with sufficient reactive power regulation capability at night as an object,a distributed renewable energy generation virtual synchronous machine control strategy based on synchronous machine equivalence was designed.Then,the virtual regulator and reactive power control method of inverter were proposed based on the modeling of synchronous generator and the analysis of its subtransient effect.Finally,it was verified in the case of single machine transmission line infinite bus.After the inverters with large-scale new energy access to the region are given the subtransient reactive power response characteristics and inertia of the distributed condenser,the regional transient reactive power support capacity and transient voltage stability are greatly enhanced.