Adaptive Control of DC-DC Power Converter: Design and Experimental Investigation with Constant Power Load

Constant power load (CPL) is a representation of dynamic loads such as power converters and electric motor drives to the DC-DC converter. Precise voltage regulation is necessary for such a combination of loads in a DC microgrid setup. In contrast to typical resistive loads, these loads exhibit negative impedance characteristics, which can cause instability in the DC microgrid system. The proposed adaptive backstepping control methodology effectively solves stability problems while yielding a smooth and fast response of the output voltage and inductor current to changes in load conditions. The success of the proposed method is confirmed by extensive real-time experiments carried out on the prototype of 120W converter using the dSpace DS1104 platform. Additionally, to demonstrate the strength of the proposed technique, a thorough comparison is made with the systematically designed cascade-proportional-integral (PI) and the sliding mode based control systems, which clearly indicate the proposed control is found to be 46% and 60% faster compared to cascade PI and sliding mode control methods respectively. Thus showcasing the potential of proposed control technique for real-time CPL applications.