Читать книгу Handbook of Large Hydro Generators - Geoff Klempner - Страница 36

Current flows through the machines conductors generating heat (a loss). However, there are a number of other sources within a working synchronous generator that produce heat and, thus, losses. The following is a list of some of those sources of losses:

 I2R losses of stator winding

 I2R losses of rotor winding

 Core loss

 Stray load loss

 Excitation system lossFigure 1.7-8 Steady‐state equivalent circuit and vector diagram. (a) Generator operation and (b) motor operation.

 Windage and Friction loss

 Ventilation and cooling loss

In determining I²R losses, the resistance of windings should be corrected to the reference temperature. During the commissioning tests for a generator, the OEM may use a common reference temperature of 75 °C. When calculating the actual losses at a specific temperature, then the resistance at 75 °C must be converted to the resistance at the desired temperature.