A High Performance of Three-phase Electrolytic Capacitor-Less LC-Type Grid-connected Inverter System with Multiple PV Arrays

In this paper, a three-phase two-stage LC-type three-level electrolytic capacitor-less grid-connected inverter with multiple PV arrays input is proposed. The multiloop and the interleaved control method was adopted for the three-level boost DC/DC part, and voltage and current double closed-loops were also implemented for the DC/AC part. The logical working strategy of two photovoltaic arrays input and adjustable power factor function of three-phase inverter are analyzed in detail. A single carrier modulation method was also implemented for T-type three-level inverter. The control strategy with electrolytic capacitor-less of the inverter system is introduced. The proposed LC-type inverter has the advantages of low harmonic, low cost and easy implementation. High-performance and power factor adjustment of the system can be achieved based on a 20kW experimental prototype.