Design and Analysis of Multilevel Inverter for Standalone Power Supply System with Improved Power Quality for Rural Electrification

Abstract

newline As energy demand around the world increases, the need for renewable energy sources that will not harm the environment increases. Renewable energy, such as wind and solar energy, is desirable for power generation due to its unlimited existence and environmental friendly nature. However wind and solar sources are not reliable in terms of sustainability and power quality due to their intermittent nature. A management system is required for supplying the continuous load power demand. The main objective of designing SAPS system is to fulfill the electrical load demand and maximizing the utilization of renewable energy sources while optimizing the use of battery and diesel generator. This thesis presents a control strategy for power management in a standalone solar photovoltaic, wind and diesel hybrid power system based on hybrid controller, power management strategy is developed to manage the power flow to the system. The controller chooses the optimal operating mode of power sources ensuring continuous supply of the load and maintaining the battery state of charge (SOC) at acceptable levels. The proposed system and its control strategy was assessed using a hybrid system comprising of PV panels, wind turbine and battery storage. In addition to that, a backup stand-by diesel engine is used to supply power only when there is a shortage in the power supply due to solar and wind turbines. There are two main advantages of the proposed system as compared to others. Firstly, the energy of the proposed system is used wisely and efficiently by monitoring the load power and the available renewable energy to define the quantity of needed power and to select the best available source. newlineSecondly, a hybrid energy storage system is also developed aiming towards proving the potential of ultra- capacitors (UC) to cater sudden power demand placed by inductive loads particularly at the time of starting. The specialty of UC lies in the fact that it is capable of charging and discharging at very high rate. Therefore, UC is e