Optimized Diode-Bridge DC/DC Converter for HVDC Tapping: Analytical Modeling and Parameter Optimization

HVDC tapping is a technology designed to transmit a controlled, small amount of power either unidirectionally or bidirectionally from an HVDC transmission line to a local power system. This serves the purposes of supporting, forming, or collecting renewable energy within the local power infrastructure. Despite its benefits, designing a DC/DC converter for HVDC tapping encounters significant challenges due to specific requirements. This paper introduces a cost-effective, easily controllable, and straightforward DC/DC converter utilizing a diode-bridge rectifier. The analytical model of the diode-bridge rectifier is established, and a parameter optimization method is proposed. Through this method, the characteristics of the proposed converter are thoroughly investigated. The findings of this study indicate that the output voltage drop characteristic of the diode-bridge is primarily influenced by the series inductor, while the voltage ripple is mainly determined by the output capacitor. Additionally, the droop characteristic may enhance the power balance of the DC distribution system in HVDC tapping. The proposed analytical model and parameter optimization method are validated through simulation and experimental results.