基于数字移相器的逆变器系统相位跟踪控制

　　针对光伏分布式电源并网系统中的相位跟踪控制问题，分析了数字锁相环控制技术存在的缺点，提出一种基于数字移相器的相位跟踪控制方法。实验利用MSP430产生SPWM信号合成正弦波模拟光伏逆变电源系统。采用基于数字移相器思想的开环控制方式，实现了无误差频率跟踪，高精度的相位跟踪。实验结果表明，该方法控制速度快、精度高。

　　Abstract:

　　To solve the phase tracking in grid-connection system of solar distributed power supply， the shortage of digital phase locked loop(DPLL) technology is analyzed， also a control method of phase tracking based on digital phase-shifter is proposed. In the experiment， SPWM was produced to synthesize sine wave with MSP430， which is aimed at simulating solar inverter system. In this system， the open loop control method， which is based on the principle of digital phase-shifter， realized zero-error frequency tracking and precise phase tracking. The results show that this method has speedy control and high precision.