一种新型光伏逆变器及其控制方法

Control Scheme for a Novel Photovoltaic Inverter

介绍了一种新型的光伏逆变器,可以工作在独立负载和并网运行两种模式。在两种模式下分别建立了逆变器简化的数学模型。独立负载模式下,主要考虑电压环控制,逆变器主电路的数学模型相当于一个二阶系统。并网运行模式下,主要考虑电流环控制,逆变器主电路可以简化成一个一阶系统。在两种模式下分别设计了相应的控制器,并给出了详细的控制方法。频域仿真结果证明了控制系统的稳定性。在实验室建立了3 kW的样机,运用DSP完成了环路运算及控制,获得了较好的实验结果。

A novel photovoltaic inverter is introduced.The inverter can work in local load mode and grid-connected mode.Mathematical models of the inverter are built in the two modes.When working in local load mode,the main circuit of in-verter can be considered as a two-order system and the voltage loop control should be mainly considered.When working in grid-connected mode,the main circuit of inverter can be simplified to a one-order system and current loop control should be mainly considered.The controllers are designed and the control schemes are described respectively in the two modes.The frequency field simulation results prove the stability of the control system.A 3 kW inverter is set up in the laboratory,the loop algorithm and control are accomplished by a DSP.A good experimental result is achieved.