Generator model mechanical turbine /mech elec generator electrical energy energy rotational speed a rotational acceleration ■ phase angle of a rotating machine ■ Tnet net accelerating torque in a machine Tmech mechanical torque exerted on the machine by the turbine Telec electrical torque exerted on the machine by the generator Steam The Position of the Throtue Valve is Controlled by the Governor Pnet net accelerating power Turbine Stator Blades Turbine Generator Pmech mechanical power input Pelec electrical power output To 3-Phase /moment of inertia for the machine From Turbine Generator M=angular momentum of the machine all quantities,except for the phase angle,are expressed in per unit on the machine base and/or the standard system frequency base steady-state and nominal values have a "o"subscript added 电力拿镜广城洲量写控制四川省童点实验蜜 国家电网
电力系统广域测量与控制四川省重点实验室 Generator model = rotational speed = rotational acceleration = phase angle of a rotating machine Tnet = net accelerating torque in a machine Tmech = mechanical torque exerted on the machine by the turbine Telec = electrical torque exerted on the machine by the generator Pnet = net accelerating power Pmech = mechanical power input Pelec = electrical power output I = moment of inertia for the machine M = angular momentum of the machine all quantities, except for the phase angle, are expressed in per unit on the machine base and/or the standard system frequency base steady-state and nominal values have a “0” subscript added
Generator model Fundamental relationship Accelerate theory:T =Ia o Momentum theory:M=ol Energy Equation:P=oT=ola=Ma Angle 0=0+0t △6=o,+am)di-∫o,dh deviation: Generator absolute angle Reference angle =0t+5at2-0,1 2 电力拿镜广城洲量写控制四川省重点实验蜜 家电
电力系统广域测量与控制四川省重点实验室 Generator model Fundamental relationship Accelerate theory: Momentum theory: Energy Equation: T I net M I P T I M net Angle deviation: 0 t 0 0 2 0 0 2 ( ) 1 = 2 1 = 2 t dt dt t t t t 机组绝对相角 参考轴相角 Generator absolute angle Reference angle
Generator model Deviation to nominal value: (A8)=A0-at dt Relate to torque: wer Deviation:( )(A) 电力拿镜广城洲量写控制四川省重点实验蜜 家电
电力系统广域测量与控制四川省重点实验室 Generator model Deviation to nominal value: ( ) d t dt Relate to torque: 2 2 ( ) net mech elec d T T T I I dt Power Deviation: 2 2 ( ) net mech elec net d P P P T I dt 2 2 ( ) ( ) mech elec d d P P M M dt dt
Generator model Laplace transform: Tmecho-Telec Tet=Tmech0(-Teeco+ATmech-△Teolec=△mech-△Teec Phet=Tnet=ATmech-ATe=APnech-APslee AP-AP=Md (A@) dt APech-APelee=M(△o） 1 △P ech △0 Ms △Pelec 电力拿镜广城测量与控制四川省重点实验蜜 家电顺
电力系统广域测量与控制四川省重点实验室 Generator model Laplace transform: 0 0 0 0 ( ) ( ) mech elec net mech elec mech elec mech elec net net mech elec mech elec mech elec mech elec T T T T T T T T T P T T T P P d P P M dt P P Ms
Load model Generally we have resistive load and inductive motor load.Load variation comes from variation of load itself and variation caused by frequency variation: APelec APL +D△0 Non-frequency- Frequency-sensitive sensitive load load variation variation Exhibit 2-3 Motor Load and Frequency Dependence Motor Load Total Load 60.0 Characteristic Characteristic 59.8 D= △P.(eg 1% 59.6 △0 59.4 Non-Motor Load 59.2 Characteristic 3% 59.0 960 970 980 990 1000 Load [MW叮 家电
电力系统广域测量与控制四川省重点实验室 Load model Generally we have resistive load and inductive motor load. Load variation comes from variation of load itself and variation caused by frequency variation: P P D elec L 非频率敏感 频率敏感 负荷变化 负荷变化 PL freq ( ) D Non-frequencysensitive load variation Frequency-sensitive load variation