大功率分布式发电系统通常采用三相逆变器并网，由于三相逆变器系统参数耦合，传统方法设计的控制器算法复杂。在d。q坐标系下为双模式三相并网逆变器的独市和并网模式建立了数学模型．采用新的解耦方法，依据独立和并网模式控制系统超调量越小，模式切换过程中被控量的波动越小。切换过程就越平滑的原则。完成了两种模式的控制器设计，即分别应用积分环节、比例环节即可将独立模式和并网模式整定成典型的二阶系统，控制器设计简单．能取得优良的动、静态特性。仿真与实验验证了设计方法的正确性和可行性。-It is necessary to research on three—phase grid-connected inverter which a8 an important part of distributed

generation．The parameters of three—phase inverter are coupling．The traditional design algorithm of the controller is

complicated．The mathematicM models of stand—alone mode and grid—connected mode are established in d，q fhme．

Based on the principle that the lower overshoot of the controller system，the smaller fluctuation of the controlled vailables，

the smoother in transfer，controllers of two modes are designed separately，as integral and proportional regulators

are separately added to stand-alone mode and g而d—connected mode．The controller has good dynamic and static char—

acteristics．Simulation and experimental results varify the correctness and feasibility of the proposed method．