DSP-based simple and efficient synchronizer for three-phase grid-connected renewable energy systems

Abstract

The generated power's frequency, rotating sequence, and phase angle must be conditioned corresponding to both of power grid specifications, and energy system needs. This paper proposes a novel DSP-based simple and efficient synchronizer for three-phase grid-connected renewable energy systems. “Efficient” refers to its low-cost, fast response, and immunity to distorted voltage of the power grid. The proposed synchronizer contains two parts: 1. Peripheral hardware part, which employs a conventional simple photocoupler-based zero-crossing detector. 2. Embedded software part, which processes the only single signal-generated by the zero-crossing detector-to safely extract power grid information, and to efficiently synchronize the turning on/off of the power switches. A simulation model is developed in MATLAB Simulink and is implemented using a fixed-point digital signal processor (DSP) TMS320F2812. Moreover, a breadboard circuit is built-up for experimental investigations in a three-phase grid-connected PV system. Both of simulation and experimental results show that proposed synchronizer attains a good performance.