电动车辆磁悬浮飞轮储能双向变换器的死区补偿

Dead time compensation for bidirectional PWM converter of the electric vehicle maglev flywheel battery

电动车辆磁悬浮飞轮储能电池的充放电过渡态很快,其双向PWM变换器的死区会给飞轮电动机带来输入谐波、脉动转矩等负面作用,采用适宜的变换器死区补偿控制是实现飞轮高速稳定运行和能量有效转化的关键。在对车载磁浮飞轮装置的系统构成、功率匹配和死区机理的分析基础上,通过对其双向变换器的过渡时态、死区系数和补偿方法的研究,提出一种优化的动态对称死区补偿法。该方案基于变换器在旋转坐标系下的电流矢量方向判断,确定补偿方向并使指令PWM波形对称于开关周期的中心;得出基本电压矢量作用时间的算式并进行试验。研究结果表明:调整补偿深度可优化飞轮双向变换器的补偿效果;该方法解决了相电流波形的交越失真问题,抑制电动机的转矩脉动,有助于磁浮飞轮变换器实现可靠的能量转换。

Electric vehicle＇s magnetic suspension flywheel energy storage battery has quick charge and discharge transition state.The dead time of bidirectional PWM converter could bring about some negative effects to the flywheel motor such as the input harmonic and pulsating torque,etc.Therefore,the converter＇s dead time compensation control technique is a key point for the steady running and energy conversion of the flywheel.Based on the analysis of the system composition,power matching and dead time mechanism,and the research on transition state,dead time coefficient and compensation method,an optimized dynamic symmetrical compensation strategy was put forward.The strategy judged current vector orientation on rotating coordinate system,determined the direction of compensation,mode the instruction PWM waveform symmetry in the center of the switching cycle,and achieved the basic equation of voltage vector action time.The results show that the adjustment of compensation depth could optimize the compesation effect.The method can solve the problem of the distortion on the phase current wave-form and contribute to the inhibition of torque ripple of the drive motor and to reliable energy transfer of the flywheel converter.1tab,7figs,16 refs.