EP-4310324-B1 - CONTROL DEVICE FOR POWER GENERATION SYSTEM

Inventors

• ONO, KOUHEI

Dates

Publication Date

20260506

Application Date

20220310

Claims (4)

1. A power generation system (100) that supplies power to a supply target, the power generation system (100) comprising: a rotating body (1); a generator (3) that is rotated by the rotating body (1) and generates three-phase AC power; a brake circuit (4) that is connected to the generator (3) and configured to generate braking force on the rotating body (1) by short-circuiting phases; a control device (5) having a voltage sensor (VS) and a control unit (52), the voltage sensor (VS) detecting a value of a generated voltage of the generator (3), the control unit (52) obtaining a value of the generated voltage detected by the voltage sensor (VS), wherein the control unit (52) is configured to perform a brake operation by the brake circuit (4) when rotation speed of the rotating body (1) exceeds a first threshold, and stop the brake operation by the brake circuit (4) when a release condition determined based on at least one of the value of the generated voltage detected by the voltage sensor (VS) and the rotation speed is satisfied after the rotation speed is lower than the first threshold, characterized in that the power generation system (100) further comprises a temperature sensor (41) that detects temperature around the brake circuit (4) and in that the release condition is a condition that the value of the generated voltage falls below a second threshold, and wherein the control unit (52) is configured to determine the second threshold according to the temperature detected by the temperature sensor (41).
2. The power generation system (100) according to claim 1, wherein the rotating body (1) is rotated by wind, and the control unit (52) is configured to estimate the second threshold based on learning data in which a wind speed at a place where the rotating body (1) is installed is associated with the generated voltage.
3. The power generation system (100) according to claim 1, wherein the release condition is a condition that the value of the rotation speed falls below a third threshold.
4. The power generation system (100) according to claim 3, wherein the rotating body (1) is rotated by wind, and the control unit (52) is configured to estimate the third threshold based on learning data in which a wind speed at a place where the rotating body (1) is installed is associated with the rotation speed.

Description

TECHNICAL FIELD The present disclosure relates to a power generation system, particularly to brake control in wind power and hydraulic power generation systems. BACKGROUND ART Conventionally, in a wind power generation system, when a strong wind is generated due to a typhoon or the like to become a rotation speed of a wind turbine too fast, a brake operation is started on the wind turbine from the viewpoint of mechanical protection, and the brake operation is continued until the wind speed is weakened. In such the wind power generation system, an anemometer may be used to determine whether the wind speed is sufficiently weakened to enable safe power generation. When the measurement value of the anemometer falls below a standard, the wind power generation system stops the brake operation from the state of continuously executing the brake operation, and rotates the wind turbine to execute normal power generation control. Hereinafter, stopping the brake operation from the state where the brake operation is continuously executed may be referred to as "releasing the brake". When the wind power generation system not including the anemometer, the wind power generation system stops the brake operation on a condition that a predetermined period elapses from a start of the brake operation. The same applies to the hydraulic power generation system. In a wind turbine generator described in WO 2012/164637 A1 (PTL 1), timing at which the electric brake operation is stopped is determined based on temperature of a main body surface of the wind turbine generator, temperature of a resistor, temperature of a cable, and the like after the electric brake operation is started when a strong wind is generated. Thus, in the wind turbine generator of PTL 1, frequent switching between the start and stop of the operation of the electric brake is efficiently prevented. Furthermore, EP 1 734 650 A1 (PTL 2) discloses a generator including a wind turbine rotated by wind power to generate a driving force, a dynamo operated by the driving force of the wind turbine to generate electricity, a short-circuit brake for switching the output side of the dynamo between an output state and a short-circuit state, a rotational speed input unit or an arithmetic processing part for recognizing the magnitude of the wind power in both of the output and short-circuit states based on the rotational speeds of the wind turbine in both of the output and short-circuit states, and an arithmetic processing part for determining which state the dynamo should be changed over to between the output and short-circuit states based on the rotational speed of the wind turbine and controlling the switching of the short-circuit brake based on the determination result. From JP 2011 127480 A (PTL 3) a rotation state detecting means for detecting the rotation state of a wind turbine, a load means connected to a generator and consuming electric power, an electric current detecting means for detecting an electric current outputted from the generator, a selecting switch arranged in series in the load means and capable of switching the connecting state of electrically connecting the load means to the generator and the releasing state of releasing the load means from the generator and a control means for controlling the braking operation of the wind turbine by operating the selecting switch based on a detecting result of the rotation state detecting means and the electric current detecting means are known. CN 104 791 192 A (PTL 4) discloses a wind turbine speed limiting and braking protection and control device and method. The method comprises the steps that data presenting the environment wind speed are obtained, and data presenting the environment wind speed are also obtained in braking protection, wherein the data presenting the environment wind speed comprise any one of wind speed, wind wheel rotating speed and direct voltage output by a wind driven generator or direct current output by the wind driven generator; whether the data presenting the environment wind speed are larger than a first threshold value or not is judged, if the data are larger than the first threshold value, an instruction of executing short circuit braking is sent, and the data presenting the environment wind speed are obtained in the braking protection; whether the data presenting the environment wind speed are larger than the data of the current environment wind speed in the wind speed scope of normal electricity generating or not is judged, and if the data presenting the environment wind speed are beyond the wind speed scope of the normal electricity generating, the braking state is maintained. According to the embodiment of the wind turbine speed limiting and braking protection and control device and method, the environment wind speed is judged in the braking protection, when the environment wind speed is beyond the wind speed scope of the normal electricity generating, the braking state is maintained,