Grid integration of hybrid renewable energy source using Aligned Multilevel Inverter

Abstract

Abstract Grid connected hybrid renewable energy sources (RES) are main challenges nowadays. Interconnecting of two or more RES is called hybrid system and battery is optional in this kind of systems where grid is in active. The normal inverters are unable to produce sinusoidal voltages and this will cause many problems in grid connected system. Hence, many topologies of multilevel inverters are proposed which can able to produce sinusoidal output voltage. However, the cost and operational complexity will increase due to increasing number of switches. In order to reduce total number of switches, an Aligned Multilevel Inverter (AMI) configuration of three phase is implemented in this paper. Wind energy-based electrical power generation system and solar energy based electrical power generation systems are considered for interconnection. Energy storage devices such as batteries are not incorporated to system since considered grid is in active mode. Maximum power point tracker (MPPT) devices are available to extract maximum power from photovoltaic arrays and wind turbines, hence a boost converter is considered as MPPT converter for wind turbine and proposed AMI also works as MPPT converter for PV by using proposed controller. Hence extra DC–DC converters are not essential for PV system for MPPT, resulting in reduction of overall system cost. Also, the modified invasive weed optimization (MIWO) based algorithm is proposed for PV system to harvest maximum energy under partial shading conditions. The proposed MIWO is compared with particle swarm optimization (PSO) and grey wolf optimization (GWO) to enhance the performance of proposed algorithm. Extensive results are validated with Hardware-in-Loop (HIL) designed on OPAL-RT platform.