在MG 1-2021 Motors and Generators中關(guān)于電動(dòng)機(jī)沖擊電流inrush current的描述如下:The values in the previous tables are rms symmetrical values, i.e., average of the three phases. There will be a one-half cycle instantaneous peak value which may range from 1.8 to 2.8 times the above values as a function of the motor design and switching angle. This is based upon an ambient temperature of 25°C.
同樣的在IEC60034-12-2016 Starting performance of single”speed three”phase cage induction motors標(biāo)準(zhǔn)中關(guān)于沖擊電流inrush current的描述如下:The values tabled for locked rotorapparent power are based on r.m.s.symmetricalsteady state locked rotor currents ; at motor switch on there will be a one-half cycleasymmetrical instantaneous peak current which may range from 1,8 to 2,8 times the steady state locked rotor value. The current peak and decay time are a function ofthe motor design and switching angle。
IEC60034-12-2016標(biāo)準(zhǔn)對(duì)應(yīng)的國(guó)標(biāo)為GBT 21210-2016單速三相籠型感應(yīng)電動(dòng)機(jī)起動(dòng)性能,原文翻譯如下:附表中列出的轉(zhuǎn)子堵轉(zhuǎn)視在功率相應(yīng)于轉(zhuǎn)子堵轉(zhuǎn)時(shí)對(duì)稱的穩(wěn)態(tài)電流有效值。電動(dòng)機(jī)接通電流時(shí)會(huì)有一個(gè)0.5周的不對(duì)稱瞬時(shí)峰值電流,為穩(wěn)態(tài)值的1.8倍~2.8倍,此電流的峰值和衰變時(shí)間與電動(dòng)機(jī)的設(shè)計(jì)及合閘相角呈函數(shù)關(guān)系。
總結(jié)下來就一句話:電動(dòng)機(jī)起動(dòng)瞬間第一個(gè)半波的沖擊電流(瞬時(shí)值)是起動(dòng)電流(有效值)的1.8~2.8倍。電動(dòng)機(jī)保護(hù)斷路器的磁脫扣力與電流瞬時(shí)值的平方成正比,但是斷路器磁脫扣電流一般以有效值表達(dá),如下圖: