一种应用于光伏并网系统的新型数字锁相方法

A Digital Phase-Locked Method Applied to Photovoltaic Grid-Connected System

基于DSP和现场可编辑门阵列(FGPA)提出了一种适合于单极三相光伏并网系统的控制方案,基于FPGA提出了一种新型数字锁相方法。不仅通过MATIAB/Simulink验证了数字锁相方法的有效性,而且将锁相方法和基于DSP和FPGA的整套控制方案,实际应用于某3kW单极三相光伏并网逆变器中,并网运行实验表明:所提出的数字锁相方法能确保逆变器输出电流与电网电压同频与同相,并网运行效果良好。

Based on DSP and FPGA（Field-Programmable Gate Array）,this paper proposes a control scheme suitable for the single-stage three-phase photovoltaic grid-connected system and a novel digital phase-locked method based on FPGA.Not only the validity of this phase-locked method is verified through Matlab/Simulink,but also the phase-locked method and the entire control scheme based on DSP and FPGA are applied to a 3 kW single-stage three-phase photovoltaic grid-connected inverter.The integrated operation experimental results show that the proposed phase-locked method could keep the current＇s frequency and phase synchronous to the grid voltage and the grid-connected operating performance is excellent.