光伏并网系统以MSP430F169 单片机为核心，单片机输出SPWM 波形经IR2110驱动H桥，实现DC-AC 逆变。最大功率点跟（MPPT）绝对误差小于1 ，利用430单片机软件实现锁相环，用参考频率作为基准频率，对MSP430单片机的外中断和定时器测定相位，当反馈的电压信号相位滞后（超前）于参考信号的相位时，就增大（减小）SPWM的频率；达到相位和频率同步。包括阻性负载，以及非阻性负载，实现了频率跟踪，相位跟踪。DC-AC 转换效率达88 ，人机接口LCD液晶显示器，界面直观、简洁，显示输出电压、电流，具有良好的人机交互性能。-Photovoltaic (pv) grid system to MSP430F169 microcontroller as the core, the microcontroller output SPWM waveform by IR2110 driver H bridge, realize DC- AC inverter. Maximum power point (MPPT) with absolute error less than 1 , using 430 single chip microcomputer software phase-locked loop, with the reference frequency as a benchmark, external interrupt and timer of MSP430 single chip microcomputer phase, when the voltage feedback signal phase lag (advanced) in the phase of reference signal, will increase (decrease) of SPWM frequency　To achieve phase and frequency synchronization. Including impedance load, as well as non resistance load, has realized the frequency tracking and phase tracking. DC- AC conversion efficiency up to 88 , and the man-machine interface LCD liquid crystal display, intuitive interface, concise, shows that the output voltage, current, has the good man-machine interactive performance.