不对称电机效率及能量守恒法测量

目前各国都在积极研究电机效率,重点放在研究电机定子、转子损耗、铁损耗,空气阻力和摩擦力损耗以及附加负荷损耗方面。研究这些损耗都是在电机额定条件下进行的。很少有人介入研究三相不平衡引起的损耗和效率。三相不平衡是指电机的三相供电和负荷不对称,这种不对称引起三相磁势不对称,使运行中的电机产生制动力,一部分功率转化为热能,使电机效率降低。提出能量守恒法来测定电机的不对称度λ与效率η的关系,并做了多次试验,基本与理论吻合。

Asymmetric Motor Efficiency and Measurement in the Energy Conservation Method

Motor efficiency is a subject under active study in various countries,focusing on stator and rotor loss,iron loss,air resistance and friction loss,as well as additional load loss.All these researches are made under rated conditions of the motor.Few people are engaged in the research of the loss caused by three-phase imbalance and the efficiency.Three-phase imbalance refers to the asymmetry between three-phase power supply of the motor and itsload,which gives rise to the asymmetry of three-phase magnetic potential,so that the operating motor generates abraking force and part of the power is converted to heat,resulting in reduction of motor efficiency.In this paper,wepropose an energy conservation method to measure the relationship between motor asymmetry degree λ and efficiency η.Tests results are basically consistent with the theory.