三相逆变电源的锁相环设计

Phase-Locked Loop Designing of Three Phase Inverter Power

电网同步锁相技术是实现电源无扰动切换的一个重要技术。本文介绍了一种备用电源系统的锁相技术,对此锁相技术在供电电源切换中的应用及其锁相原理进行了阐述。针对传统锁相环在电压畸变条件下不能获得准确相位的问题,根据软件锁相环(SPLL)原理,在锁相环的基础上加入低通滤波器来抑制电压畸变对锁相造成的影响。对此锁相环进行了Matlab仿真。通过仿真验证了该锁相环在电压不平衡、电压谐波畸变及电压突降的情况下可实现频率的准确锁定。证明了此锁相环技术可实现由电网供电到不间断电源供电的无扰动切换,响应速度快,稳定性好。最后,通过试验对此锁相环进行了验证。

Grid synchronization phase locking technique is one kind of important technology of power supply switching without disturbances. This paper introduces a sort of phase locking technique used in standby power supply system. Meanwhile, it elaborates the principle and the application of this technology in switching power supply. For the problem of traditional on the condition of voltage distortion, it can not obtain accurate phase. According to the principle, a kind of software phase-locked loop(SPLL) is introduced,on the basis of phase-locked loop(PLL), adding low-pass filter(LPF) to it to suppress the effects of voltage distortion. Through simulation with MATLAB, it shows that accurate frequency locking can be realized under the condition of unbalanced voltage, the voltage with harmonic and voltage dip. Then it proves that the PLL can make it realize undisturbed switching from grid to the uninterrupted power supply,fast response and good stability. Finally,The PLL is proved through tests.