The electrical power cannot be stored in large quantities and consequently, it has to be generated at the same time as the consumers’ needs it. The generation of electrical energy is performed by means of high-power synchronous machines or alternators, whose construction design depends on the type of drive/prime movers i.e., gas, steam, water or by any motor AC/DC. Then the synchronous generator must be connected in parallel with a constant voltage and frequency, on reaching its nominal speed, excitation voltage and current may be increased from zero until the stator voltage is brought up to the same level as that of the network. To obtain this situation the magnitude, the phase rotation and the rotational direction of the two voltages may be achieved. This procedure is termed as synchronization.
Experiments:
- Alternator and Parallel Operation Experiments:
- Determination of the effective resistance of stator and exciter windings of the alternator.
- Determination of the mechanical and iron losses of the alternator.
- Recording the open-circuit curve at various speeds.
- Determination of the ohmic and stray losses of the alternator.
- Recording the short-circuit curve at various speeds.
- Parallel operation using a synchronous
- Response of the alternator on a constant-voltage constant-frequency system.
- Calculating the synchronous reactance.
- Recording the regulation characteristics at different power factors.
- Determination of the conventional efficiency of the alternator using the open-and short-circuit test results.
- Becoming familiar with various lamp circuits used to connect an alternator in parallel to a constant voltage constant-frequency system.
- Recording the response of the alternator operating with the excitation and speed kept constant under different types of load.
