论文部分内容阅读
微电泵电机大部分是单相异步电动机,烧毁的原因主要是电机端电压偏低、电机内部短路、电机堵转、环境温度高散热不良等。损毁电机中大部分是由于端电压偏低而烧毁的。从电机学知,电动机的输入电功率P_1=P_2η,P_2是电动机的轴功率,也称输出功率,即铭牌功率;η是电动机的效率,单相电动机效率一般在0.75～0.85之间,有的更低。在电动机稳定运行区内,异步电动机属于硬机械特性,端电压降低后,转速下降不多。根据水泵特性可知,转速下降不多时,水泵所需轴功率也变化不大。当电泵正常工作时,电动机的轴功率应和水泵轴功率相等。即电压降低后,电动机的输出功率P_2变化不大。电动机的输入电功率P_1也变化不大。而P_1=UIcosφ,假定电动机功率因数cosφ
Most of the micro-pump motor is a single-phase asynchronous motor, burned mainly due to the motor terminal voltage is low, the motor internal short circuit, the motor stalls, poor heat dissipation and other environmental temperature. Most of the damaged motor is burned due to the low terminal voltage. From motor learning, the motor input power P_1 = P_2η, P_2 is the motor shaft power, also known as the output power, that is, nameplate power; η is the motor efficiency, single-phase motor efficiency is generally between 0.75 ~ 0.85, and some more low. In the motor stable operation area, the asynchronous motor belongs to the hard mechanical characteristic, after the terminal voltage reduces, the rotational speed drops not much. According to the pump characteristics we can see that when the speed dropped little, the pump required shaft power also changed little. When the pump is working properly, the shaft power of the motor should be equal to the pump shaft power. That is, the voltage decreases, the motor output power P_2 little change. Motor input power P_1 also changed little. P_1 = UIcosφ, assuming the motor power factor cosφ