PI adaptation based compound control method for active power filter

The invention discloses a PI adaptation based compound control method for an active power filter. According to the method, inductance change of inductors L1 and L2 in an LCL filter is detected in real time, and in combination of the inductance change of the inductors L1 and L2, a control parameter table of a PI controller is inquired, so that control parameters of the PI controller are regulated in real time. The defect that the control effect of the active power filter becomes poorer during inductance change is overcome, and the active power filter is stably controlled and normally works when the inductance changes in a certain range.