A Single DC-Source Five-Level Inverter Applied in Stand-Alone Photovoltaic Systems Considering MPPT Capability

摘要

This paper presents a single DC source five-level photovoltaic inverter topology for a stand-alone photovoltaic (PV) system. The proposed PV converter system consists of a five-level inverter and a buck DC-DC converter. The DC-DC converter that embedded in the inverter structure is used to realize the maximum power point tracking (MPPT) in various environmental conditions (temperature and irradiation). Also, as the studied system is stand-alone PV system, a battery energy storage system (BESS) is also included which consists of a bidirectional buck/boost DC-DC converter and a battery energy storage. The BESS is connected to a branch of the DC-link and controls the DC-link voltage while managing the battery energy. One of the main advantages of the proposed converter is that the buck DC-DC converter which is in-charge of MPPT, deals with partial power of the PV and hence the system efficiency would be improved. The simulation results using MATLAB/ SIMULINK confirm the performance of the proposed topology in different scenarios.