摘要
针对方波和正弦波两种驱动方式对永磁无刷电动机损耗及温升的影响进行了研究,其中方波驱动下对比分析了3种等效电压相同,不同PWM占空比情况下电动机损耗及温升的不同。仿真了2种驱动方式下电动机的电流,并对电流波形进行了谐波分析。采用一种精确的损耗模型对电机进行了损耗计算,并在此基础上利用解析集总参数热网络法进行了温度场分析,实验结果验证了分析结果。通过研究发现,正弦波驱动下电动机的电流为平滑的正弦波,而方波驱动下的电流中存在显著的时间谐波以及PWM型逆变器带来的载波谐波,造成方波驱动下电动机的转子涡流损耗远大于正弦波驱动的。正弦波驱动下,电机的定转子温升差异并不明显。方波驱动下,电动机的转子温升明显高于定子的,并且随着PWM占空比的降低,定转子的温升差异加剧。
The effect of two different driving modes, square-wave and sine-wave drive modes, on the losses and temperature rises of permanent magnet brushless motor is researched, and the differences of losses and temperature rises under three square-wave drive conditions with the same equivalent voltage are compared. The currents of motor under two drive modes were simulated and harmonic analyses were performed respectively. An accurate loss model was used to calculate the losses of motor. Thermal field was analyzed using analytical lumped-circuit method based on the obtained losses and the result was validated by experiment. The analysis reveals that the phase current is smooth sinusoidal waves under sine-wave drive mode while significant magnetomotive force（MMF） time harmonics and pulse width modulation（PWM） carder harmonics exist in the phase current under square-wave drive mode, causing larger rotor eddy current losses under square-wave drive mode. The temperature rise difference between rotor and stator is not significant under sine-wave drive mode, while large difference exists in temperature rises of rotor and stator under square-wave drive mode, and the difference becomes more significant with the decrease of PWM duty ratio and increased DC supply voltage.
出处
《电机与控制学报》
EI
CSCD
北大核心
2013年第9期92-98,共7页
Electric Machines and Control
基金
陕西省教育厅自然科学专项项目(2013JK1009)
西安建筑科技大学学科建设重点培育计划专项资金建设项目(XK201223)
西安建筑科技大学青年科技基金(QN1322)
西安建筑科技大学人才科技基金(RC1308)
关键词
永磁无刷电动机
损耗
热场
方波
正弦波
permanent magnet brushless motors
loss
thermal
square wave
sine wave
