锁相技术在变频恒压供水系统中的应用

Application of Phase-lock Technique in Variable-frequency Constant-pressure System of Water Supply

文章针对变频恒压供水系统中水泵电机由变频电源供电向工频电源供电切换时,由于水泵电机断电后的电动势与工频电源相位差的不确定性,可能产生的过电流问题,文章进行了数字锁相环同步切换控制的研究。文中主要介绍了以单片机为核心的供水控制器的设计方案及数字锁相环的实现,同时给出了系统实验结果。

In variable-frequency constant-pressure system of water supply, the problem of excessive current may be generated when the system controls the pumps to get power from variable frequency equipment changing to the electricity network,and due to the phenomenon caused by the uncertain phase relationships between back electromotive force of the pump and the power supply. This paper discusses the synchronous switch control based on digital PLL(Phase Lock Loop)to solve the problem. In the paper,the design scheme of water supply controller based on single chip microcomputer and how to actualize digital PLL and result of laboratorial are briefly presented.