结合锁相环的原理研究,利用DSPTMS320F240实现高精度锁相的数字锁相环的原理与方法。所给出的锁相方法中利用DSP的捕获中断和周期中断读取市电和逆变输出的相差,经数字PI调节器输出一个载波周期的补偿量,通过动态改变载波周期值实现逆变输出对市电的锁相,理论上相位差分辨率可高达0·72°。分析了相位关系的判断方法,给出了相位跟踪的硬件实现电路及程序流程图。实验结果验证了该方案的可行性和有效性。 Combined with the principle of phase-locked loop, using DSPTMS320F240 phase-locked loop to achieve high-precision digital phase-locked loop principle and method. The lock-in method is given by using DSP capture interrupt and cycle interrupt to read out the difference between mains and inverter output. The digital PI regulator outputs the compensation amount of one carrier cycle, and the inverter output is obtained by dynamically changing the carrier cycle value Phase lock on the mains, in theory, the phase difference resolution up to 0.72 °. The method of judging the phase relationship is analyzed, and the hardware circuit and program flowchart of phase tracking are given. The experimental results verify the feasibility and effectiveness of this scheme.