Junliang Han

Research and implementation of a single phase stand-alone photovoltaic inverter with parallel topology

A system scheme of the stand-alone photovoltaic inverter based on parallel charge topology for the purpose of improving the energy conversion efficiency and optimizing the battery management was introduced. A novel circuit topology of the DC-AC inverter with the soft switching property using IGBTs and MOSFETs was presented. A modified P&O algorithm for better tracking performance with adaptive step length adjustment was proposed. And a comprehensive strategy for maximum power point tracking (MPPT) with the Constant Voltage Tracking (CVT) algorithm and the modified adaptive Perturbation and Observation (P&O) algorithm was developed. A prototype was implemented to very the feasibility of the proposed scheme.

Study and implementation of grounding insulation resistance detection system for the solar inverter

Grounding insulation resistance detection is of great importance for the solar inverter. A novel scheme of grounding insulation resistance detection system based on switch-controlled bridge circuit for the solar inverter was proposed in the paper. By controlling the bridge circuit, linear equations in respect of insulation resistances can be established, and the values of insulation resistances can be obtained by solving the equations. The hardware circuits and the software algorithm were designed and implemented. The experimental results show that the detection system worked well and the detection result was accurate.