Inverter design trade-off for photovoltaic power generation

Abstract

Photovoltaic (PV) power generation is a very important way of energy conversion. It can convert solar energy into electricity. As the core photovoltaic power generation device, the microinverter design has many challenges. Limitations that need to be considered include high-frequency leakage current generated by parasitic capacitance, the front DC voltage gain of the inverter, and switch components’ number and power consumption. In many cases, these limitations are difficult to solve perfectly simultaneously in a standard H-bridge or three-phase inverters. A front boost converter requires a high DC voltage gain with fewer switches, and Z-source or split-source structures can be applied. But these structures can lead to high leakage current. A traditional half-bridge inverter can solve the problem but with low efficiency. H5 or HERIC full-bridge inverter for PV can eliminate leakage current while more switches are used. A dual-boost common-grounded H-bridge topology can remove the leakage current and achieve a high DC voltage gain with only four switches. However, the power consumption of different switches varies greatly, which may cause an imbalance in heating and damage the device.