微电网双模式组网逆变器运行控制研究

Research on Micro-grid Double Mode Grid-forming Inverter Control

针对微电网中既可以并网运行,也可以独立运行的三相组网逆变器研究了其双模式运行的控制方法。双模式逆变器在并网模式时起理想电流源作用,采用结构简单且能满足要求的单电流环控制;离网模式时起理想电压源作用,采用能兼顾控制精度和动态响应的基于滤波电感电流的双闭环控制。在此进一步针对双模式逆变器独立运行时满足带不平衡负载的要求,运用正序、负序分别控制的方法。最后通过实验验证了所设计的双模式逆变器具有带不平衡阻性、感性负载的能力,并且能够实现并网/离网双模式运行的快速切换。

This paper proposes a way to design three-phase double mode inverter used in micro-grid which can run in grid-connected and stand-along modes.Double mode inverter plays a role of ideal current source in grid-connected and adopts qualified single current loop control with simple structure.But double mode inverter plays a role of ideal voltage source in standalone mode and adopts double closed loop control based on filtering inductance current to meet the requirement of controlling accuracy and dynamic response.In order to meet the requirements of unbalanced loads, the control of positive sequence and negative sequence is designed respectively.Finally,through the experiment,this paper shows that double mode inverter designed in this way has the capacity to carry unbalance impedance load and inductive load and can be transferred quickly between stand-along mode and grid-connect mode.