级联固态变压器在SVG模式下的控制策略

A Control Strategy for Cascaded Solid-state Transformer in SVG Mode

基于级联H桥(CHB)拓扑的三相光伏(PV)固态变压器(SST)可以白天工作在PV发电模式,夜晚工作在静止无功发生器(SVG)模式用以补偿整个电站的无功功率消耗。因此,PV电站不需要额外安装无功补偿装置,有助于提高变换器的利用率并降低电站的建设成本。为此,提出一种适用于CHB SST工作在SVG模式下的控制策略,不仅考虑了相间和模块间的功率平衡,且计算较为简单。实验结果验证了所提控制方法的有效性。

The three-phase photovoltaic(PV) solid-state transformer(SST) based on cascaded H-bridge(CHB) topology can operate in PV power generation mode during the day and in static var generator(SVG) mode at night to compensate reactive power consumption of the whole power station.Therefore,there is no need to install additional reactive power compensation devices,which is able to improve the utilization of converter and reduce the construction cost of PV power plants.For this reason,a control strategy for SST working in SVG mode is proposed,which not only considers the inter-phase and inter-module power balance,but also simplifies the calculation.The experimental results verify the effectiveness of the proposed control method.