Design and development of solar photovoltaic fed modular multilevel inverter with improved performance parameters

Abstract

The requirement for renewable energy has grown up significantly over the years due to the fast depletion of fossil fuel and also due to the greenhouse effect. The solar Photovoltaic (PV) system has the benefit of directly converting the solar radiations to electricity and also it is well suited for most of the regions. Therefore, it is highly preferred in comparison with other Renewable Energy Systems (RES). However, it is necessary to improve the quality of the energy from these sources to safeguard the loads attached to the system and also to ensure pure form of power to the consumers. To fulfill the goal, it is necessary to connect a modular power electronic module (Modular Multilevel Inverter), which enables the Power Quality (PQ) improvement in between the DC source and loads. The proposed research work investigates a solar PV fed single phase Modular Multilevel Inverter (MMI). The proposed structure operates with symmetric and asymmetric DC sources. Possibly different levels of output voltage can be obtained from the suggested structure. The suggested structure has the capability to produce output voltage without using any extra or auxiliary circuit(H-bridge) and it doesn t require filters and transformers at its output. Switch reduction, harmonic reduction and grid synchronization are the performance parameters considered in the proposed work. The major drawback in multilevel inverter is that, it requires more switching components as the level increases. Increase in switching devices increases the complexity in production of gate pulses to the switches. Moreover, as the switch count increases the switching losses also increase. newline