Huang Chun

Novel Automatic Synchronizer Based on Dual Principles and Dual Microprocessors

Automatic synchronizers are widely employed to connect synchronous generators to power system. The core task of a synchronizer is to estimate the voltage magnitude, frequency and phase angle difference between the generator terminal and the system bus accurately and rapidly. This paper introduces a novel automatic synchronizer, which consists of two independent CPU modules running under completely different principles, the hardware based one and the software based one respectively. The design of the hardware based CPU module is described, and the new parameter estimating algorithm in the software based CPU module is proposed and detailed. The new algorithm can estimate the parameters precisely with a fixed sampling frequency, even when signal frequency is time varying. The cooperation and coordination between the two CPU modules are discussed. Due to the different working principles and independent hardware circuits, the probability of false synchronization decision that made by both CPU modules at a same time is minimized, therefore, the reliability of the synchronization is improved. The results of both laboratory tests and engineering applications prove the good performance of the developed device.