Harmonics , reactive power , voltage flicker and negative - sequence current of power grids can affect the power quality and harm the power equipment badly 摘要電網(wǎng)中存在諧波、無(wú)功、電壓閃變及負(fù)序電流等問題,嚴(yán)重影響電能質(zhì)量,危害電力設(shè)備。
The device can protect start - up status and running status of asynchronous motors by differential protection , over current protection , negative - sequence current protection , zero - sequence current protection , inverse time current protection , under - voltage protection and so on , can measure every kind of electricity , and can process the function of telecontrol , telemetering and telecommunication 其依靠電流差動(dòng)、速斷、負(fù)序過(guò)流、反時(shí)限、零序過(guò)流和低電壓等保護(hù)方法實(shí)現(xiàn)了片電動(dòng)機(jī)的運(yùn)行、啟動(dòng)和自啟動(dòng)過(guò)程進(jìn)行保護(hù),并實(shí)現(xiàn)各種電量的計(jì)量,同時(shí)具有遙控、遙測(cè)、遙信的功能。
In order to consider the different heating of positive - sequence current and negative - sequence current of the motor stator generally , the equivalent current is adopted instead of the traditional phase current . the way how to gather positive - sequence current and negative - sequence current is brought forward , and the recurrence fourier - algorithm is adopted to calculate the effective value of current and voltage , the effective value of positive - sequence current and negative - sequence current 為了全面考慮感應(yīng)電動(dòng)機(jī)定子正序電流和負(fù)序電流的不同發(fā)熱效應(yīng),提出了正序電流和負(fù)序電流獲取的方法,并采用遞推傅氏算法來(lái)實(shí)現(xiàn)電流、電壓及電流正序和負(fù)序分量的有效值的計(jì)算。