不对称双叠异槽绕组直流电机换向片间电压抑制

Suppression the Segment Voltage of DC Motor with Asymmetrical Duplex Lap Split Winding

不对称双叠异槽绕组直流电机换向片间电压中除基波电压外,还含有丰富的谐波电压,过高的换向片间电压会使片间的气隙击穿而产生电位差火花,容易与电刷下的换向火花汇合在一起扩展成环火,造成严重后果。为了控制电位差火花,避免电机在运行时出现换向火花偏大的问题,有必要对换向片间电压开展研究。依据双叠绕组理论,采用复域内电压向量相叠加的方法,研究了换向片间电压,并给出了精确的计算表达式,结合直流电机二维有限元磁场分析计算,计算出了空载和负载下换向片间电压,提出了换向片间电压抑制措施。计算结果表明,电枢电压相等时,采用主极偏心气隙和电枢斜1倍槽距的措施,可抑制换向片间电压。

In addition to the fundamental voltage,there are also abundant harmonic voltages in the segment voltage of the asymmetric duplex lap split winding DC motor.Excessive segment voltage will break down the air gap between the commutator segments and produce potential difference spark,which is easy to merge with the commutation spark under the brush and expand into a circle spark,causing serious consequences.In order to control the potential difference spark and avoid the problem that the commutation spark is too large when the motor is running,it is necessary to study the segment voltage.According to the theory of duplex lap winding,the segment voltage is studied by using the method of superposition of voltage vectors in complex domain,and the accurate calculation expression is given.Combined with the two-dimensional finite element magnetic field analysis and calculation of DC motor,the segment voltage under no-load and load is calculated,and the segment voltage suppression measures are proposed.The calculation results show that when the armature voltage is equal,the segment voltage can be suppressed by adopting the measures of eccentric air gap of main pole and one time slot pitch of armature.