Transient Simulation of the AC/DC System Based on the New-type Converter Transformer

For announcing the electromagnetic transient course of the auto-compensator and harmonic shielding converter transformer, simulating the new-type converter transformer´s voltage, current´s input and output characteristics in the HVDC system and the interaction of the AC/DC system, This paper establishes the new-type converter transformer´s transient simulation mathematic model using the synthetic companion method and the controlled source theory, and the simulation experiment is carried on by applying this model into the HVDC transient simulation. The experimental results show that the new-type converter transformer optimizes the system´s structure in the certain degree. Through the zero impedance design of the third winding and the filter parameters reasonable setting, it not only can greatly reduce the harmonics in the AC side and the loss to the converter transformer, but also improve the converter bridge AC side´s voltage and current wave, which is advantageous to the converter´s normally moves.