| 摘要 |
PURPOSE:To improve the operability and the reliability, by providing a switching circuit, which makes a load current continuous, between a generator, which is used as a damping machine of the expansion turbine, and a load to control the turbine in accordance with the difference between the real speed and a set speed of the turbine. CONSTITUTION:An AC output generated from a synchronous generator 2 by an expansion turbine 1 is rectified in a part 7 and is absorbed through a transistor (TR) 10 by a load 3. The frequency of the output of the synchronous generator 2 is converted to a voltage signal by an F/V converter 19, and a speed set by a speed setting equipment 5 is converted to a voltage signal also, and the difference between both voltages is amplified in a part 18 as the difference between the real speed and the set speed. When the actual rotational frequency of the expansion turbine 1 is larger than the set value, the difference between the output voltage of the F/V converter 19 and the voltage of the setting equipment becomes positive and is amplified in a part 18 to turn on a TR 24, and the turn- on time of a TR 23 and the TR 10 of the switching circuit is longer, and the time of the load state of the synchronous generator 2 is longer; and when the actual rotational frequency of the expansion turbine 1 is smaller than the set value, the time of this load state is shorter. Thus, the rotational frequency is controlled. |
