基于空间矢量滞环控制的Z源光伏并网逆变器

摘要

提出了一种适用于Z源三相光伏系统的定频电流滞环并网控制新方法.该方法首先基于电网电压空间矢量将复平面分为6个区域以实现线电流的解耦控制,再对线电流进行固定次数的定时比较以实现定频控制,解决了直通时间插入问题.该方法能实现单位功率因数运行,具有响应快速、精度高、抗干扰能力强、开关次数少、易于数字化实现等优点.与传统滞环控制相比,该方法对系统干扰及控制误差有较好的抑制能力,保持开关频率固定.通过仿真和样机上的实验验证,证明了该方法的可行性.%The gird-connection control with fixed frequency current-hysteresis is proposed for Z-source three-phase photovoltaic power system. The complex plane is divided into six sectors based on grid voltage space vectors to realize the decoupling control of line currents. The fixed frequency control is realized by the periodic comparison of line current with a fixed times,which avoids the problem of conducting time interposition. It runs with unity power factor,quick response,high accuracy,less switching times and simpler digital implementation. Compared with the traditional hysteresis control,it has less control error and better anti-interference ability. Its feasibility is proved by simulation and experiment.