2、 the liberalization of electricity market, economical benefits, the grid has to be operated with maximized transfers physical constrains; outage, partially black-out, complete black-out; available transmission capacity(ATC) 突然损失发电机或线路：sudden loss of a generator or transmission l
3、ine. 负荷突然增加或减少：sudden load increases or decreases 短路和开关操作：short circuits and switching operations. 三相和对地短路：three-phase and line-to-ground faults 短路器：circuit breaker 暂态过电压和电流：transient overvoltages and currents 雷击：lightning strikes 电涌放电器：surge arrester 相量：phasor，通常用复数phasors 瞬时功率：i
4、nstantaneous power 特别地：In particular, 正弦电压或电流：A sinusoidal voltage or current at constant frequency 最大值：maximum value 有效值：effective value 平均值：average value 坐标系实轴：real axis 坐标系虚轴：imaginary axis 相量图：phasor diagram for 无源元件：passive elements 电阻、电感、电容、电抗：resistor, inductor, and capa
5、citor, reactance, 感性、容性：inductive, capacitive 有功功率：real power or active power 无功功率：reactive power 功率因数：power factor 功率因数角：power factor angle A single-phase source delivers 100kW to a load operating at a power factor of 0.8 lagging. 物理意义：The physical significance of 与…同相位：…be in p
6、hase with…Example：For a purely resistive load, the current into the load is in phase with the load voltage. 如式（2.1）所示：As indicated by (2.1), ……落后(超前)…多少相位：The current lags（leads…the voltage by 90. 正弦稳态：sinusoidal-steady-state 让a＝b，得到：Letting a=b gives 按照惯例（通常）：By convention, the
7、power factor cos(a-b) is positive. 时间区间：a time interval T. Example: The total energy absorbed by a load during a time interval T. 额定值：rating. 例：额定功率－power rating；发电机额定功率－power rating of electric generator；额定电压：voltage rating. 基尔霍夫电流（电压）方程：Kirchhoff’s current(voltage) law。节点方程：nod
