Research on high voltage shore power supply based on DC bias suppression strategy

Abstract

DC bias of transformer will lead to large distortion of excitation current. For the high voltage shore power supply with fundamental frequency isolated output, its output characteristics are greatly affected by the DC bias of the transformer, so the DC component of the high-high cascade H-bridge inverter current must be eliminated in the design of control strategy. Firstly, the main circuit topology of high voltage shore power supply is given, and the DC bias phenomenon of transformer is analyzed. Then, a DC bias suppression method of high voltage shore power supply is proposed. The positive feedback of DC component is introduced to affect the output voltage of the converter chain of shore power supply. By adjusting the PWM pulse width in real time, the DC voltage component is used to compensate the DC current, which fundamentally realizes the compensation and suppression of DC bias. Finally, the test platform of high voltage shore power supply is built, and the experimental results show that the proposed control strategy is correct and effective.