Phase-Locked Loop Technology Research Based on Photovoltaic Grid-Connected Inverter

摘要

In photovoltaic grid-connected system, it is an essential link to inspect frequency, phase position and amplitude of network voltage accurately and rapidly. Using DSP inner capture unit, common timer and comparing element realizes signal capture on network voltage and photovoltaic power generation, so as to reach the purpose of frequency modulation and phase modulation, as well as grid-connection condition. This paper selects network voltage positive zero-cross detection digital phase-locked loop, designs hardware implementation circuit and provides software flow pattern. The experimental result verifies the feasibility and effectiveness of this method.