Single-phase dual-input split-source inverter for photovoltaic systems

Abstract

This paper proposes dual-input configuration of split-source inverter (abbreviated as DSSI) to transfer the power of two photovoltaic (PV) modules simultaneously or individually. The proposed DSSI keeps the continuity of the input current and the voltage boosting capability offered by the conventional split-source inverter (SSI). Thus, independent as well as efficient tracking of the maximum power points (MPPs) is realized. In addition, low capacitance is utilized for power decoupling in single-phase circuits. Compared to using one SSI per PV source to feed a common load, the proposed DSSI uses lower number of switches at reduced total volt-ampere stresses. Therefore, decreased cost, size, and control circuitry are realized. Simple unipolar modulation technique is presented. Accordingly, the modes of operation and the Volt-ampere stresses of the switches are explained. A closed loop control system is explained to fulfill operation at MPP along with regulation of DC-link voltage and load current. Comparative study with other dual-input topologies is presented. Experimental results as well as real-time simulation results for dual- and single-input scenarios are presented. Also, the dynamic performance under step change in the radiation is investigated. Finally, the capability of operation under different power factors is verified.