数字控制单相六开关并网逆变器的设计研究

Designation and Research on Digital Control of Six Switches Single-phase Grid-connected Inverter

提出在单相六开关管逆变器中使用双电流环控制方法,能有效减小LCL滤波器产生的稳态误差和波形失真,其中闭环控制器采用增量式积分分离比例积分微分(PID)算法。根据该控制原理使用TMS320F2812型数字信号处理器(DSP)、编写了双电流环控制程序和数字锁相等程序,并制作300 W实验样机,并将软件和样机进行联合调试。实验结果表明输出电流波形较好,能快速跟踪电网电压相位实现并网功能。

To improve the steady-state error and waveform distortion of LCL filter in six switches single-phase grid- connected inverter, the method of digital double-current loop is adopted in the six switches single-phase inverter, and the closed-loop controller adopts incremental separated integral proportional integral distortion （PID） algorithm.A 300 W prototype is built and the programs of digital phase locked and PID control are wrote with the digital signal proce- ssor（DSP） TMS320F2812.The software and prototype joint debug are completed in the experiment.Experimental results indicate the waveform of output current is good and the phase of output current can track the grid phase rapidly.