| 摘要 |
<p>PURPOSE:To prevent the trip of a generator due to a field failure relay for insufficient excitation side defect of an AVR by mounting a low excitation limiter and a low excitation protecting unit similar in a hardware. CONSTITUTION:When an automatic voltage regulator 28 is used to control the terminal voltage of a synchronous generator 1 constant, a calculator 10 becomes defective and continuously outputs the maximum drop voltage. In this case, the field current of the generator 1 decreases to lower the terminal voltage of the generator. When the terminal voltage of the generator decreases, a leading phase reactive power flowed from the system side to the generator increases. When the reactive power reaches the prescribed value, a low excitation limiter 9 is operated to output a voltage rise signal. When the leading phase reactive power further increases, a low excitation protecting unit 16 is operated to switch from the regulator 28 to a field current controller 29. Thus, an excitation controller which has high reliability can be obtained.</p> |
