基于变直流母线电压的磁耦合式励磁系统控制策略研究

Research on Magnetic Coupling Excitation System Control Strategy Based on Variable DC Bus Voltage

磁耦合式无线励磁系统是电励磁同步电机无刷化研究的热点之一。该励磁系统包括原边能量发射装置和副边接收装置,其中副边固定在电机转子上,并与之同步转动。为实现副边无通讯并减轻转子质量,在电励磁同步电机无线励磁系统中提出一种变直流母线电压的原边控制策略。考虑到原边补偿电感电流受逆变器高次谐波电压影响,导致励磁电流估算存在误差,采用卡尔曼滤波,滤除高次谐波,提高系统励磁电流估算精度;利用发射线圈电流和滤波后的原边补偿电感电流,得到磁耦合式无线励磁电机的励磁电流估算值;基于该励磁电流估算模型调节原边侧DC-DC变换器的母线电压,实现原边侧对副边侧励磁电流的无通讯调节。仿真结果表明,所提方法在励磁绕组阻抗变化及励磁电流突变工况下,能有效提高励磁电流估算精度及控制精度。

Magnetic-coupled wireless excitation(MCWE),one of the research hotspots of the alternative brushless solutions of the electrically excited synchronous motor(EESM),contains the transmitting device in the primary side and the receiving device in the secondary side that fixed on the rotor.To enable secondary-side communication-free operation and reduce rotor weight,this study introduces a variable DC bus voltage primary-side control strategy in the wireless excitation system of EESM.Initially addressing the impact of inverter-induced high-order harmonic voltages on primary compensating inductor currents and consequent excitation current estimation errors,a Kalman filter approach was employed to suppress these harmonics,enhancing excitation current estimation accuracy.Subsequently,magnetic coupling wireless excitation motor excitation current estimates are derived from filtered primary compensating inductor and transmitter coil currents.The primary-side DC-DC converter's bus voltage was then modulated based on this excitation current model,facilitating secondary-side excitation current control without communication.Simulation validates the method's efficacy in improving excitation current estimation and control precision amid excitation winding impedance variations and sudden excitation current shifts.