大功率电弧加热器电源的设计研究

Study on High Power Converter for Arc Heater Applications

研究了63MW大功率电弧加热器交直流电源的主电路设计和控制策略。提出了一种相移叠桥组合晶闸管整流主电路结构,使该电源在输出直流电压1～21kV的不同工况下,其输入端功率因数不小于0.9,且高功率时THD<5%。根据主电路相移叠桥结构的特点,提出了一种非线性反馈控制器与前馈控制器相结合的复合稳流控制策略,稳流精度能够达到0.1%。实验结果表明,相移叠桥组合晶闸管主电路结构达到了电源电能质量设计指标;采用复合稳流控制策略后,稳流精度不仅能够达到设计指标,而且省去主电路中的稳流电阻,从而减小了电源系统1.8MW的电阻热耗。

An AC/DC converter and its control strategy for 63 MW high power arc heater is investigated.A new main circuit configuration named phase-shift bridge cascaded multiplex is proposed.This new configuration enables the power factor more than 0.9 and the total harmonic distorsion （THD） less than 5% at high power condition for AC side of the converter at various conditions from DC 1 kV to DC 21 kV output vohages.A kind of CUlTent stabilizing control scheme combined nonlinear feedback and feedforward is proposed based on characteristic of the proposed AC/DC converter configuration. Upon this control scheme, the stabilized current precision reaches 0. 1%.The experimental results indicate that the phase- shift bridge cascaded multiplex AC/DC converter satisfies the requirements of the power quality and current stabilized precision.As the benefit of the current stabilizing control scheme for the AC/DC, the stabilizing resistor in the main circuit could be saved which will dissipate 1.8 MW power loss in thermal conversion.