电气电子教学学报
電氣電子教學學報
전기전자교학학보
Journal of Electrical & Electronic Education
2015年
5期
77-80
,共4页
标幺值系统%电机%磁通不变性%基本物理量
標幺值繫統%電機%磁通不變性%基本物理量
표요치계통%전궤%자통불변성%기본물리량
per unit system%electric machines%invariance of flux%fundamental physic quantities
标幺值是“电机学”课程的重要内容之一。本文提出以频率、容量、电压、绕组有效串联匝数和每极电枢表面积为电机基本物理量来定义基值,从而导出电枢相关各物理量的基值以及基于磁通不变性的直流励磁和异步转子回路各物理量基值的确定方法,从而形成完整的电机标幺值系统。该标幺值系统具有与相数和绕组连接方式无关的特点,保持基本方程形式的不变性,并简化了电机特性表达式,凸现了电机的本质特征,有助于激发学生研究电机的兴趣。
標幺值是“電機學”課程的重要內容之一。本文提齣以頻率、容量、電壓、繞組有效串聯匝數和每極電樞錶麵積為電機基本物理量來定義基值,從而導齣電樞相關各物理量的基值以及基于磁通不變性的直流勵磁和異步轉子迴路各物理量基值的確定方法,從而形成完整的電機標幺值繫統。該標幺值繫統具有與相數和繞組連接方式無關的特點,保持基本方程形式的不變性,併簡化瞭電機特性錶達式,凸現瞭電機的本質特徵,有助于激髮學生研究電機的興趣。
표요치시“전궤학”과정적중요내용지일。본문제출이빈솔、용량、전압、요조유효천련잡수화매겁전추표면적위전궤기본물리량래정의기치,종이도출전추상관각물리량적기치이급기우자통불변성적직류려자화이보전자회로각물리량기치적학정방법,종이형성완정적전궤표요치계통。해표요치계통구유여상수화요조련접방식무관적특점,보지기본방정형식적불변성,병간화료전궤특성표체식,철현료전궤적본질특정,유조우격발학생연구전궤적흥취。
Per-unit concept is one of key contents of Electric Machinery course. Frequency,capacity,voltage,ef-fective series turns and area of armature per pole defined as fundamental quantities are proposed in this paper. Their base values are defined as the rated values or structure parameters of electric machines. Other quantities re-lated to armature windings are further determined. Based on invariance of the main flux,the base values of quanti-ties for the windings like DC excitation and asynchronous rotor with different frequencies are obtained. Therefore,a set of per unit system is completely built up,which is independent of phase number and connection modes,keeps invariance of equations,reduces the expressions of characteristics of electric machines,such that the nature of elec-tric machines is outstanding and the students are interested in this phase.