Three-phase double-grounded buck-boost PV inverter without shoot-through problem

Abstract

The conventional transformerless photovoltaic(PV) inverter has the common mode leakage current and shoot-through problems. In addition, the output voltage of the PV module is low under the shading condition, resulting in the inverter not working properly. A three-phase double-grounded buck-boost PV inverter without shoot-through problem is proposed. The front-end converter of this inverter is composed of two boost converters, which can realize boost conversion. The rear-end inverter consists of three dual-buck half-bridge inverters, which solves the shoot-through problem. In this topology, the load ground is connected to the negative ground of the PV module, eliminating the common mode leakage current. The operating principle and mode analysis are described in detail. Finally, a simulation circuit is built to verify the theoretical analysis.

Keywords

• PV inverter
• Common mode leakage current
• Shoot-through problem
• Buck-boost
• Double-grounded