【摘要】 针对使用三相电压源型逆变器的直流母线电流传感器信息,重构电机相电流方法中存在非可测量区域的问题,在分析相电流重构基本原则和现有脉冲宽度调制(PWM)信号修整方法的基础上,提出了通过平移桥臂开关状态波形来修整PWM信号的方法,该方法不增加功率器件的开关损耗,且满足非零电压空间矢量最小作用时间的要求。应用空间电压矢量分析方法证明了修整后的PWM信号在一个开关周期内不改变参考电压的幅值及相位,从而保证了电机相电流具有低的谐波畸变率。以交流永磁电机驱动系统为例进行了实验研究,结果表明采用该方法在稳态和瞬态的情况下都能够精确重构电机相电流。更多还原

【Abstract】 There are some immeasurable regions in the voltage vector plane while reconstructing motor phase currents from the information of a single dc-link current sensor in the 3-phase voltage source inverter.After having analyzed the principle of phase current reconstruction,as well as some existent pulse width modulation(PWM) signal modification approaches,this paper presented a novel PWM signals modification method by moving the switching state waveform of the inverter’s 3 legs along the axis.The method met the request of minimum applying time of active voltage space vectors,and the inverter losses were unaltered comparison with traditional strategy.Using space vector analysis method,it was revealed that,after modification,the reference voltage vectors maintain its amplitude and orientation in a PWM switching interval,so that the waveform distortion of the phase current caused by modification was quite low.Experimental results obtained from the test drive system using a permanent magnet ac motor show that the reconstructed phase current faithfully represents the actual one during both steady state and transient conditions.更多还原