Handbook of Electrical Engineering

3 Synchronous Generators and Motors 3.1 Common Aspects Between Generators and Motors The theoretical operation of synchronous ge ...

62 HANDBOOK OF ELECTRICAL ENGINEERING When a machine is not connected to the three-phase supply but is running at rated speed an ...

SYNCHRONOUS GENERATORS AND MOTORS 63 3.2.2 Transient state armature reaction Assume the generator is loaded and operating in a s ...

64 HANDBOOK OF ELECTRICAL ENGINEERING 3.3 Phasor Diagram of Voltages and Currents The following points apply to the drawing of p ...

SYNCHRONOUS GENERATORS AND MOTORS 65 Figure 3.1 Phasor diagram of a two-axis salient pole generator. Ra= 0. 002 Xd= 2. 5 Xq= 0. ...

66 HANDBOOK OF ELECTRICAL ENGINEERING Quadrative axis: Xq=Xa+Xmq (3.4) X′′q=Xa+ XmqXkd Xmq+Xkd Xa+Xkd (3.5) WhereXmdandXmqare m ...

SYNCHRONOUS GENERATORS AND MOTORS 67 Figure 3.3 D-axis sub-transient reactance versus field leakage reactance. 3.4.1 Sensitivity ...

68 HANDBOOK OF ELECTRICAL ENGINEERING The field leakage reactance is dependent on the shape of the pole yoke, Xf∝ circumference ...

SYNCHRONOUS GENERATORS AND MOTORS 69 To distinguish between the sending-end and the receiving-end the subscripts ‘s’and‘r’are in ...

70 HANDBOOK OF ELECTRICAL ENGINEERING Qs=Imaginary part of(EI∗) =I ( Eqsin(δr+Ø)−Edcos(δr+Ø) ) The active and reactive power los ...

SYNCHRONOUS GENERATORS AND MOTORS 71 Where, Pr 1 =Vsinδ(EqXq)+ V^2 2 sin 2δ(Xd−Xq) Pr 2 =Vcosδ(EqRa)−V^2 Ra Qr 1 =Vcosδ(EqXq) Qr ...

72 HANDBOOK OF ELECTRICAL ENGINEERING Qr 2 =−V^2 (Xdsin^2 δ+Xqcos^2 δ) DEN=XdXq The sending-end variables remain the same. These ...

SYNCHRONOUS GENERATORS AND MOTORS 73 Table 3.1. Preferred rated voltages of generators Generator rating (kVA) Approximate voltag ...

74 HANDBOOK OF ELECTRICAL ENGINEERING Figure 3.5 D-axis synchronous reactance versus generator MVA rating. Figure 3.6 D-axis ope ...

SYNCHRONOUS GENERATORS AND MOTORS 75 Figure 3.7 D-axis transient reactance versus generator MVA rating. Figure 3.8 D-axis short ...

76 HANDBOOK OF ELECTRICAL ENGINEERING Figure 3.9 D-axis sub-transient reactance versus generator MVA rating. Figure 3.10 D-axis ...

SYNCHRONOUS GENERATORS AND MOTORS 77 Figure 3.11 Q-axis synchronous reactance versus generator MVA rating. Figure 3.12 Q-axis su ...

78 HANDBOOK OF ELECTRICAL ENGINEERING of the spread would also give realistic results. It should be remembered that manufacturer ...

SYNCHRONOUS GENERATORS AND MOTORS 79 3.9.2 Reactances Where possible it is most economical to accept the design values of reacta ...

80 HANDBOOK OF ELECTRICAL ENGINEERING 3.9.4 Terminal boxes Motors and generators should be provided with properly designed termi ...