Patent ID: 7092795

Claim:
A turbine apparatus to be driven by a water, comprising a runner rotatable to be rotationally driven by the water, a flow rate adjuster for adjusting a flow rate of the water to change an actual rotational speed of the runner, and a control device for generating a control signal for controlling the flow rate adjuster so that a difference between the actual rotational speed of the runner and a desired rotational speed of the runner is decreased, wherein: the control device includes an input port for receiving a runner speed signal whose value corresponds to the actual rotational speed of the runner so that an input signal whose value corresponds to the difference between the actual rotational speed of the runner and the desired rotational speed of the runner is generated, a derivative calculation element for generating a derivative component of the control signal whose value corresponds to a value obtained by performing differentiation on the value of the input signal with respect to a time proceeding and an integration calculation element for generating an integral component of the control signal whose value corresponds to a value obtained by performing integration on the value of the input signal with respect to the time proceeding, and a ratio of a gain of the derivative calculation element to a gain of the integration calculation element to be applied to the derivative calculation element and the integration calculation element when the difference between the actual rotational speed of the runner and the desired rotational speed of the runner is not more than a predetermined degree is greater than a ratio of the gain of the derivative calculation element to the gain of the integration calculation element to be applied to the derivative calculation element and the integration calculation element when the difference between the actual rotational speed of the runner and the desired rotational speed of the runner is more than the predetermined degree.