Adaptive Sampling Frequency based Phase Locking Scheme for Single-phase Grid Converters

An adaptive phase locking scheme (PLL) is proposed for single-phase systems based on sampling frequency control. The proposed PLL has been designed to synchronize reference signal with the incoming signal by adaptively adjusting the sampling frequency. The efficiency of the proposed adaptive phase locking scheme has been validated through simulation results. The phase locking scheme is also tested for normal as well as polluted frequency environment such as the presence of harmonics. The PLL exhibits the quick acquisition behavior while tracking the wide variation in the frequency and phase of the incoming signal. The PLL parameters like lock-in-range, pull-in-range, and hold-in-range are determined for the proposed scheme which demonstrates the application of the scheme also in demodulation techniques.