| 摘要 |
PURPOSE: To protect a turbine generator or the like against damage by providing a variation rate limiter for limiting the variation rate of current reference signal within a predetermined range to suppress abrupt variation in the output torque from a synchronous machine. CONSTITUTION: A speed regulator 15 generates a current reference signal serving as a rotational frequency signal of a synchronous machine 6. A current regulator 17 outputs a rectifier phase control signal for delivering a current reference signal from the rectifier 2. A margin angle operating unit 20 operates a commutation overlapping angle which is employed, along with a commutation margin angle from an inverter 4, in the operation of an inverter phase control angle. A variation rate limiter 30 limits the variation rate of current reference signal within a predetermined range thus suppressing abrupt variation in the output torque from the synchronous machine 6. With such constitution, vibration of the shaft system of the synchronous machine 6 is prevented from being enlarged even if the r.p.m. thereof is close to the resonance point thus protecting the rotary system against damage while avoiding fatigue of the shaft system from enlarging. |
