Double-current loop control method of LCL (Inductor Capacitor Inductor) filtering grid-connected inverter

The invention relates to a double-current loop control method of an LCL (Inductor Capacitor Inductor) filtering grid-connected inverter, belonging to the field of inserter control. The method comprises the steps of: respectively sampling inductive currents at a grid side and inductive currents at an inverter bridge side by using two groups of current sensors; respectively converting the inductive currents ia1, b1 and c1 at the grid side and the inductive currents ia2, b2 and c2 at the inverter bridge side under a stationary coordinate system into currents id1 and q1 as well as id2 and q2 under a two-phase rotating coordinate system; and then by taking id1 and id2 as feedback variables of an active current control loop and taking iq1 and iq2 as feedback variables of the active current control loop, sending output signals of the two control loops and phase signals of a power grid voltage to a SVPWM (Space Vector Pulse Width Modulation) module, wherein the SVPWM module is used for outputting corresponding switch driving signals so as to control the quality of grid current waveform of the inverter. The method disclosed by the invention has the advantages of high control precision, high power factor, convenience for protecting a bridge-arm switching tube and the like.