同步前馈的光伏逆变系统网侧畸变抑制策略

Grid Side Distortion Suppression Strategy for Photovoltaic Inverter Systems Based on Synchronous Feedforward

为提升分布式光伏逆变系统在畸变电网的谐波抑制能力,提出并研究了一种同步前馈的光伏逆变系统网侧畸变抑制策略。将输出电压变化量叠加在网侧基准电压以获得良好的电压同步前馈响应,借助硬件低通滤波器固有的相位延迟和幅值衰减,将网侧畸变电流分量导出,并基于柯西-施瓦茨不等式和自适应搜索对光伏逆变系统的网侧畸变抑制性能进行优化,并分析截止频率对补偿电压增益和相位角的影响。最后通过搭建3 kW的光伏逆变样机充分验证所提同步前馈网侧畸变抑制策略的有效性和正确性。

To enhance the harmonic suppression capability of distributed photovoltaic inverter systems in distorted power grids,a synchronous feedforward grid side distortion suppression strategy for photovoltaic inverter systems is proposed and studied.The output voltage variation is superimposed on the grid side reference voltage to obtain a good voltage synchronous feedforward response.By utilizing the inherent phase delay and amplitude attenuation of hardware low-pass filters,the grid side distortion current component is derived.Based on the Cauchy Schwarz inequality and adaptive search,the grid side distortion suppression performance of photovoltaic inverter systems is optimized,and the influence of cutoff frequency on compensation voltage gain and phase angle is analyzed.Finally,the effectiveness and correctness of the proposed synchronous feedforward grid side distortion suppression strategy are fully verified by building a 3 kW photovoltaic inverter prototype.