Abstract
This paper highlights the controller of a bidirectional converter to interface an ultracapacitor as storage device to renewable energy systems. Ultracapacitors are typically used in renewable energy systems to improve the system's reliability and energy conversion efficiency. The controller of the converter system has been designed and simulated based on the integration of both Current Mode Control and Linear Quadratic Regulator methods. The controller performance is tested under different modes of operating conditions in bidirectional converter using MATLAB/Simulink simulation package. The simulation results show that a good DC bus voltage regulation is achieved in the tested conditions. In addition to that, the controller ensures smooth transition between the buck and boost modes of the bidirectional converter operation.