Power Allocation for Energy Stored Quasi-Z-Source Inverter Based on the Power Loss Modelling

In this paper, convertor power loss modelling and its efficiency enhancement control strategies in the hybrid energy stored system (HESS) are studied. The energy stored quasi-Z-source inverter (ES-qZSI) is chosen to demonstrate a detailed power regulation method. According to the current commutation of the converter, the U-type power loss variation trend is found with the power allocation ratio. The expressions of power loss in both the system dc and ac side are presented to derive the loss trajectory mathematically. Both simulation and experimental results verify that within the efficiency enhancement range, more than 40% power loss get saved and the efficiency get increased by 8% with the proposed power allocation method. The analysis about the energy storage units embedding can also be applied for the optimal operation in other energy storage systems.