Electrical Machines

Hunting in Synchronous Machine: So far the operation of the synchronous machine under steady-state conditions at constant (synchronous) speed has been considered. Under these conditions of Hunting in Synchronous Machine where Pe= electrical power output of the machine Pm= mechanical power input to the machine the machine losses having been assumed negligible. These power flows […]

Parallel Operation of Synchronous Generator: We already know that synchronous machine connected to infinite bus-bars. Parallel Operation of Synchronous Generator of two finite size will be considered, which is the way large practical size generators are used. In a power system the generators are connected to the nodes of a grid composed of a network

Slip Test on Synchronous Machine: Direct and quadrature axis reactances of a salient-pole synchronous machine can be estimated by means of a test known as the Slip Test on Synchronous Machine. The machine armature is connected to a 3-phase supply whose voltage is much less than the rated voltage of the machine, while the rotor

Two Reaction Model of Salient Pole Synchronous Machine: In a Two Reaction Model of Salient Pole Synchronous Machine, the flux established by a mmf wave is independent of the spatial position of the wave axis with respect to the field pole axis. On the other hand, in a salient-pole machine as shown in the cross-sectional

Capability Curve of Synchronous Generator: Capability Curve of Synchronous Generator defines the bounds within which it can operate safely. Various bounds imposed on the machine are: MVA-loading cannot exceed the generator rating. This limit is imposed by the stator heating. MW-loading cannot exceed the turbine rating which is given by MVA (rat­ing) x pf (rating).

Power Flow Equation of Synchronous Generator: Power Flow Equation of Synchronous Generator – The flow of active and reactive power in a synchronous link will now be studied. The approach will be analytical and armature resistance will be considered for generality of results. Figure 8.42 shows the schematic diagram of a synchronous generator wherein E̅f leads

Synchronous Machine Operation: The Synchronous Machine Operation are examined here under conditions of variable load and variable excitation. One of these quantities will be assumed to be held constant at a time while the other will be allowed to vary over a wide range. Further, here too the armature resistance will be assumed negligible. This

Synchronous Machine on Infinite Bus Bars: A definite procedure has to be followed in connecting a Synchronous Machine on Infinite Bus Bars which for the present purpose will be assumed to be infinite. Infinite bus-bars means a 3-phase supply of constant voltage and frequency independent of the load exchanged (fed into the bus-bars or drawn

Armature Reaction in Synchronous Generator: The Armature Reaction in Synchronous Generator is dependent on the power factor at which the machine is operating and upon the operating mode generating/motoring. For simplicity of explanation, it will be assumed here that the armature resistance and leakage reactance are negligible so that Figure 8.26 shows the phasor diagrams,

Armature Reaction in Synchronous Motor: The Simple circuit model of the synchronous machine was obtained in Sec. 8.3 by making the assumption that the magnetic circuit of the machine is linear. However, it is known that, under normal operating conditions, the machine operates in a somewhat saturated region. In order to take account of magnetic