610 / 2019-03-14 14:26:35

Harmonic suppression scheme of L-type photovoltaic grid-connected inverter based on harmonic injection method

Photovoltaic Power Generation; Inverter; Low-order Harmonics; Harmonic Injection; Power Quality; Harmonic Distortion Rate

As a new energy generation technology, photovoltaic power generation has been widely used. However, in the process of grid-connected photovoltaic power generation, due to the switching characteristics of the inverters, the output current usually contains low-order harmonics, of which the 5-order and 7-order low-order harmonics are the most serious. In order to restrain low-order harmonics in grid-connected current and reduce power loss in lines and loads, this paper proposes a modulation scheme based on SPWM harmonic injection, that is, to inject 5-order and 7-order harmonic compensation voltage into SPWM sinusoidal signal, so as to reduce the specific sub-harmonic content of output current and improve grid-connected power quality. The simulation and experiment of matlab/Simulink show that the scheme can effectively reduce the specific sub-harmonic content in grid-connected current, reduce the harmonic distortion rate and improve the power quality of grid-connected current of photovoltaic power generation.