Research On Battery Charge Regulator With Wide Range Of Output Voltage

As the bus to the battery charging path, battery charging regulator(BCR)'sperformance directly affect the battery life. So BCR is an important component ofthe satellite power system. This paper aims to meet the targets required to design anon-isolated, high-efficiency, step-down output voltage of a wide range of batterycharging regulator.In this paper, a variety of commonly used battery charging regulators topologyare analyzed and compared, and taking into account the requirements such asefficiency, size and current ripple, coupled-inductor Superbuck converter is chosenas the BCR main topology. After analyzing the working principle of the coupled-inductor Superbuck converter, zero input current ripple condition of couplinginductance is easily achieved, and the open-loop transfer function of system isdeduced. By two simple assumptions, damping network parameters restrictions thatavoid the existence of the right half plane zeroes are achieved, and is verified byBode diagram. Because the BCR acts as a current source in case of deep dischargeof a battery, and as a voltage source in case of near100%battery state of charge, theaverage current mode control PWM is chosen as the converter control mode, and themode conversion circuit is designed. In the constant current charging stage, thecurrent inner loop controls the average current of inductor, so the converter works asa current source. In the constant voltage charging stage, both loops works, so theconverter works in average current mode as a voltage source. For high stability anddynamic response characteristics, appropriate PI compensation network parametersare achieved. At the same time, the high side current sampling circuit is alsodesigned. The simulation and experiment results verified stability and dynamicresponse of the converter for load mutation. Finally, the efficiency curve of batterycharge regulator is tested under different working conditions.According to the experimental results, the coupled-inductance Superbuckconverter designed input and output current with very small ripple and a wide rangeof output voltage, fully conforming to the requirements of the battery controllerperformance.