Energy storage inverter PQ control method under grid-connected state

The invention relates to a three-phase inverter control technology, and provides an energy storage inverter PQ control method under a grid-connected state. The method mainly includes the steps of collecting three-phase output voltage and output current of an LCL output port of an energy storage inverter, and carrying out closed loop control on the output voltage and the output current of the energy storage inverter by means of an obtained inner-loop voltage reference value d-axis component, an inner-loop voltage reference value q-axis component and a phase angle, so that output active power and reactive power are equal to an instruction value and a power instruction can be tracked through output power of the inverter. The method integrates island droop control and grid-connected PQ control, and simplifies control of the energy storage inverter. In the control mode switching process, the probability of failed switching is beneficially lowered, and overvoltage and overcurrent phenomena can be obviously reduced. When a microgrid is disconnected with a power grid abnormally and the energy storage inverter enters an island to operate, the energy storage inverter can operate according to a preset rated point, and stability of the microgrid can be improved.