Application of second-order generalized integral PLL method when inverter connecting with grid under harmonic background

In case of large number of distributed generation (DG) connected to grid, harmonic pollution becomes more seriously. DGs and grid-connected inverters are expected to participate in grid operation and management responsibly. Especially when the grid meets serious harmonic pollution, inverter’s grid connecting manipulation requires very high-precision phase angle detection. In these years, as a novel phase locked loop (PLL) method, second-order generalized integral (SOGI) PLL attracts more and more attentions. For inverter grid connecting manipulation purpose, in this paper, relationship between SOGI controller parameters and its dynamic performance are analyzed firstly. Then via SOGI, positive sequence components are extracted accurately and rapidly from the seriously polluted grid voltage. Using this information, inverter grid connecting controller can be designed. Through Matlab/Simulink simulation tool, above proposed method is justified and simulation results show its effectiveness when inverter connecting with grid under serious harmonic pollution.