Direct Load Current Control in Power Supply Based on DC–DC Converter and AC Current-Controlled Converter in Parallel for Electrolytic Hydrogen Production Test

The topology in which a dc–dc converter and an ac current-controlled converter are connected in parallel to output dc current and ac current, respectively, is usually used in the power supply for electrolytic hydrogen production test. The ac current of the current-controlled converter is distributed by the dc–dc converter, which will affect the precision of load current control. This article proposed a novel direct load current control strategy in the ac current-controlled converter, which can provide a high-precision ac current to the load. The added inductor in the output side of the dc–dc converter can effectively reduce the distribution of the ac current. The influence and the design consideration of the added inductor on the output impedance of the dc–dc converter and the current control loop of the ac current-controlled converter are analyzed. Based on the model of the proposed control method, the comparison is made between the proposed control method and the traditional control method, and the proposed control method has higher control precision. The proposed control strategy is more suitable for situations of parallel connection between a voltage-controlled converter and a current-controlled converter.