Linear Quadratic Integrator Control Design for Battery-Supercapacitor Hybrid Energy Storage System

Battery-supercapacitor is one of the hybrid energy storage systems (HESS) that recently develops for environmental-friendly energy systems. In its design, a control system is required to generate the desired current for the load and manage the use between the battery and the supercapacitor to supply the load. This research aims to design a current control system for the HESS battery-supercapacitor using the Linear Quadratic Integrator (LQI) control approach. This controller is used due to its ability to optimize state variables and the control signal by adjusting the weighting matrices Q and R. We use the Bryson method to get the matrices Q and R to minimize the states and the control signal. The LQI control then generates a duty cycle signal to control the active topology DC/DC boost converter. The simulation results demonstrate the successful operation of the LQI control and achieving optimal performance. Battery-supercapacitor current can supply the load according to the load current demand. The resulting IAE value is less than 0.8 and the duty cycle is less than 0.6 for the load change testing scenario.