Bidirectional Quasi-Z-Source Inverter with Hybrid Energy Storage for IM Drive System

The energy storage system of many commercially available hybrid electric vehicle or pure electric vehicle is composed of only battery packs with a bidirectional dc-dc converter connected to the high voltage dc bus. In order to further improve fuel consumption efficiency, topologies to hybridize energy storage system for electrical vehicle have been developed. With these various combinations of energy storage, one common feature can be seen; which is to efficiently combine one fast response energy storage device with high power density and slow response device with high energy density. In relation to this, the Quasi Z-source inverter (qZSI) topology has gained attention as an alternative to the conventional voltage source inverter in many applications such as the electrical motor drive system. Apart from offering a single stage DC-DC-AC conversion, it offers a flexible way on how the hybrid energy storage can be introduced to the system. In this research, a new combination of battery/supercapacitor as HES with qZSI applied for the induction motor drive system is investigated. The effectiveness of proposed hybrid energy storage method in qZSI for the induction motor drive system is verified and validated via simulation and hardware experiment results where it is shown the battery current stress is reduced to approximately more than 50%.