JP2020002859A - Wind power generation device and control method for wind power generation device - Google Patents

Abstract

To provide a high-efficiency wind power generation device capable of performing a power generating operation sufficiently until being stopped completely by reducing sudden load fluctuation to a power system even when stopping the wind power generation device, and a control method therefor.SOLUTION: The present invention relates to a wind power generation device connected to a power system. The wind power generation device comprises: a rotor which is rotated by receiving a wind; a generator which generates power by the rotation of the rotor; and a control device which controls the rotation of the rotor. The control device starts an operation for stopping the rotation of the rotor in the case where a wind velocity being measured by a windmill exceeds a predetermined threshold, and the rotation of the rotor is stopped within 30 minutes or longer after the start of the stopping operation.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a wind turbine generator and a control method thereof, and more particularly to a technique that is effective when applied to a method of stopping a wind turbine generator.

  By selecting and installing a place where the wind conditions such as the wind direction and wind speed are stable, the wind power generator can generate power relatively stably both day and night. The operating range of the wind power generator is determined by design with respect to the wind speed. This is for the purpose of protecting the equipment, since the load acting on the windmill generally increases when the wind speed is high. In addition, since the scale and number of wind power generators have been expanding recently, consideration for system stability is also desired.

  In such a situation, the problem is that when many wind turbines are introduced into an area where the wind speed is almost uniformly distributed, such as on the ocean, the wind speed exceeds the wind speed in the operation range and simultaneous stop operation is performed. And it will cause excessive disturbance to the system.

  When the wind speed exceeds the operating range of the windmill, the windmill stops operating at the normal stop. Normal stop means that the output is reduced to zero in a relatively short time. Therefore, when this occurs in a large-scale wind farm, a large load change occurs in a short time, causing a sudden change in the power system.

  As a background art in this technical field, for example, there is a technique as disclosed in Patent Document 1. Patent Literature 1 discloses a technique that suppresses unnecessary stop processing of a wind power generation system that does not need to be stopped originally, and that reduces unnecessary reduction in generated power.

JP 2011-127461 A

  As described above, in the conventional stop operation (normal stop), a sudden change is given to the power system, so that stable power supply is difficult.

  In addition, when the operation is continued with the power generation output lowered, when a large-scale wind farm occurs, a large load fluctuation similarly occurs in a short period of time.

  On the other hand, if the power generation operation is continued without performing the shutdown operation, a large load is applied to the wind power generator (wind turbine). Therefore, it is necessary to suppress the load on the wind power generator (wind turbine). For example, when controlling the output of a windmill in a large-scale wind farm as a whole, a windmill waiting for a stop operation will continue to receive a large load, and there is a concern about an accident such as breakage of a blade or collapse of the windmill.

  Alternatively, there is an idea to prepare a monitoring and control device for the entire wind farm and stop the windmills in order to minimize the influence on the system. However, in this case, the above-described overall monitoring and control device is required, and the power plant system is complicated.

  In addition, a state such as a power generation operation near the upper limit of the operation range wind speed (cutout value) is also an opportunity for the power generation company to increase profits by generating power, and thus it is unavoidable to shift to the shutdown operation. However, there is also a demand that the power generation operation be continued as long as possible until the operation is completely stopped.

  Therefore, an object of the present invention is to provide a high-efficiency wind power generator capable of sufficiently performing a power generation operation until the wind power generator is completely stopped even when the wind power generator is stopped. And a control method therefor.

  In order to solve the above problems, the present invention is a wind power generator connected to an electric power system, wherein a rotor that rotates by receiving wind, a generator that generates power by rotation of the rotor, and a rotation of the rotor A control device that controls the rotation of the rotor, when the wind speed measured by the windmill exceeds a predetermined threshold, starts the operation of stopping the rotation of the rotor, and 30 minutes from the start of the stop operation. The rotation of the rotor is stopped by the above operation.

  Further, the present invention is a method for controlling a wind power generator connected to an electric power system, wherein an operation of stopping rotation of a rotor when a wind speed measured by a wind turbine of the wind power generator exceeds a predetermined threshold value. Is started, and the rotation of the rotor is stopped over 30 minutes or more from the start of the stop operation.

  ADVANTAGE OF THE INVENTION According to the present invention, even when the wind power generator is stopped, a rapid change in the load on the power system is small, and a high-efficiency wind power generator capable of performing a sufficient power generation operation until the wind power generator is completely stopped is provided. A control method can be realized.

  Further, even in a wind farm in which a large number of wind turbines are introduced, the overall monitoring and control for controlling the individual wind turbines is not required, so that a highly reliable power plant with a simple system can be constructed.

  Problems, configurations, and effects other than those described above will be apparent from the following description of the embodiments.

It is a schematic structure figure of a wind power generator concerning one embodiment of the present invention. It is a figure which shows notionally the method of stopping the conventional wind power generator. It is a figure which shows notionally the stopping method of the wind power generator which concerns on one Embodiment of this invention. It is a schematic structure figure of a wind farm concerning one embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each of the drawings, the same components are denoted by the same reference numerals, and detailed description of overlapping portions will be omitted.

  First, a configuration of a wind turbine generator (windmill) to which the present invention is applied and an example of a device to be controlled will be described with reference to FIG. As shown in FIG. 1, a rotating part of a wind power generator (windmill) 10 includes a rotor 1 including a plurality of blades 1 a and a hub 1 b connecting the blades 1a at a center thereof, and a drive for transmitting a rotating torque (power) of the rotor 1. A train (rotating shaft) 2 and a rotating unit of a generator 3 that extracts energy from the power of a drive train (rotating shaft) 2 are provided.

  A rotor 1 composed of a plurality of blades 1a and a hub 1b rotates in response to wind, and a rotational torque (power) of the rotor 1 is transmitted to a generator 3 by a drive train (rotary shaft) 2 to perform a power generation operation. . The generator 3 has a structure in which the generator torque is variable.

  Although FIG. 1 shows only the rotating shaft as the drive train 2, the present invention can be applied to a case where a speed increaser (gear box) is provided. The drive train 2 is provided with a brake 4 for braking a rotational torque (power) and a rotational speed sensor 5 for detecting a rotational speed.

  The control device 6 can issue an ON / OFF command to the brake 4 and a torque command to the generator 3 based on a read value of the rotation speed sensor 5 and the like. Further, the control device 6 sends an ON / OFF command to the brake 4 and a timing to send a torque command to the generator 3 based on the read value (rotation speed) of the rotation speed sensor 5 and the rotation acceleration calculated based on the reading value. Can be controlled.

  In other words, the control device 6 controls the braking force applied to the drive train 2 and the timing of adding the braking force to the ON / OFF command to the brake 4 and the torque command to the generator 3 based on the read value of the rotation speed sensor 5 and the like. can do. In addition, the braking force here includes the generator torque (load) of the generator 3 in addition to the braking force by the brake 4.

  The generator 3 is connected to a power system and transmits generated power to the power system. The rotating part is provided in the nacelle 7, and the nacelle 7 is supported by a tower 8 so as to be rotatable in a horizontal plane according to a change in wind direction.

  Although not shown in FIG. 1, a pitch control mechanism that can change the angle (pitch angle) of the blade 1 a with respect to the hub 1 b is provided, and the angle (pitch angle) of the blade 1 a of the wind turbine is adjusted. It is also possible to control the rotation speed of the windmill (rotor 1) by adjusting the amount of wind received by (rotor 1).

  Next, a control method of the wind turbine generator according to the present embodiment will be described with reference to FIGS. FIG. 2 shows a conventional general method of stopping a wind turbine generator shown as a comparative example for easy understanding of the present invention.

  In a conventional wind turbine generator (windmill), after the windmill reaches the upper limit of operation range wind speed (cutout value), the windmill is stopped by a normal shutdown operation shown in FIG. When the rotation speed of the rotor 1 (drive train 2) read by the rotation speed sensor 5 approaches or exceeds a predetermined operation range wind speed upper limit (cutout value), the control device 6 Starts the stop operation of the windmill. After the start of the stop operation, the rotation of the windmill (rotor 1) is completely stopped, usually in about 15 seconds to one minute, and the wind turbine is brought into an idling state. In the conventional normal shutdown shown in FIG. 2, the rotation of the wind turbine (rotor 1) is suddenly stopped in a short time of 15 seconds to 1 minute, so that the power generation in the generator 3 is also suddenly stopped, and the power system is suddenly stopped. It may cause fluctuation.

Therefore, in this embodiment, as shown in FIG. 3, after the start of the stop operation, control is performed to gradually decrease the rotation speed of the wind turbine (rotor 1) over a much longer time than in the past. Specifically, as shown in FIG. 3, the rotation speed is reduced over 30 minutes or more from the start of the stop operation to the complete stoppage of the windmill (rotor 1). (Hereafter, it is also called slow shutdown.)
That is, when the wind speed (or the rotation speed of the rotor 1) measured by the windmill (wind direction anemometer 9) exceeds a predetermined threshold value (upper limit of the operating range wind speed: cutout value), the controller 4 The operation of stopping the rotation of the rotor 1 is started by braking the drive train (rotary shaft) 2 by the drive train and adjusting the pitch angle of the blade 1a by the pitch control mechanism. Stop the rotation of.

  The stop time depends on the wind conditions and the scale of the wind power generator (windmill), but the longer the stop time, the more the sudden influence on the power system can be suppressed. Therefore, for example, the stop operation may be performed for one hour, six hours, or more.

  Also, in FIG. 3, immediately after the start of the stop operation, the inclination θ1 (first inclination / rotational speed decrease rate) of the change (decrease amount) of the rotation speed with respect to time (t) is changed to the inclination θ2 (the The stop operation is controlled so as to be greater than (2 inclination / rotational rate decrease rate). That is, immediately after the start of the stop operation, the output and the torque are slightly increased first, and then the output and the number of revolutions are gradually reduced.

  After the stop operation is started, the control device 6 reduces the rotation speed of the rotor 1 at a first rotation speed reduction rate (θ1 in FIG. 3), and after a lapse of a fixed (predetermined) time, the first rotation speed reduction. The rotation speed of the rotor 1 is reduced at a second rotation speed reduction rate (θ2 in FIG. 3) lower than the rate (θ1).

  Thereby, after the windmill reaches the upper limit of the operating range wind speed (cutout value), the stress applied to the windmill (rotor 1) is rapidly reduced by rapidly reducing the rotation speed of the windmill (rotor 1) to a certain rotation speed. And the possibility of an accident such as breakage of a blade or collapse of a windmill can be reduced.

  As described above, according to the wind turbine generator and the control method thereof of the present embodiment, when the wind turbine reaches the upper limit of the operating range wind speed (cutout value) and is forced to stop the wind turbine generator (wind turbine) Even in this case, a rapid change in load on the power system is small, and the power generation operation can be sufficiently performed until the power system is completely stopped.

  In FIG. 3, when the wind speed falls below the operation range wind speed upper limit (cutout value) during or after the stop operation of the wind turbine (rotor 1), the control device 6 controls the brake 4 or the generator of the generator 3. Control may be performed so that the braking of the drive train (rotating shaft) 2 by the torque (load) is released, and the power generation operation of the wind turbine (rotor 1) is restarted.

  Second Embodiment A method for controlling a wind farm according to a second embodiment will be described with reference to FIG. FIG. 4 shows a wind farm 11 including a plurality of wind power generators 10. Each of the wind power generators 10 constituting the wind farm 11 is monitored and monitored by a central monitoring building (monitoring system) 12.

  As described above, in the conventional shutdown operation (normal shutdown), since the rotation of the windmill (rotor 1) is rapidly stopped in a short time of 15 seconds to 1 minute, the power generation in the generator 3 is also rapidly stopped. It causes a sudden change in the power system. In particular, in the case of a large-scale wind farm having a large number of wind power generators 10 as shown in FIG. 4, when a plurality of wind power generators 10 constituting the wind farm start a stop operation at once due to a sudden change in wind conditions, the wind farm may be turned off. The whole may cause sudden fluctuations in the power system.

  Therefore, even in a large-scale wind farm as shown in FIG. 4, each of the plurality of wind power generators 10 constituting the wind farm performs the stop operation by the slow shutdown shown in FIG.

  Thus, even if there is an obstacle in the control of the wind farm by the central monitoring building (monitoring system) 12, it is possible to suppress a rapid change in the power generation output for each unit (one unit). The stop operation of the entire wind farm 11 or a part of the wind power generator 10 can be performed while minimizing the influence on the connected power system.

  Note that the present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. In addition, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of one embodiment can be added to the configuration of another embodiment. Further, for a part of the configuration of each embodiment, it is possible to add, delete, or replace another configuration.

  DESCRIPTION OF SYMBOLS 1 ... Rotor, 1a ... Blade, 1b ... Hub, 2 ... Drive train (rotating shaft), 3 ... Generator, 4 ... Brake, 5 ... Rotation speed sensor, 6 ... Control device, 7 ... Nacelle, 8 ... Tower, 9 ... wind direction anemometer, 10 ... wind power generator (windmill), 11 ... wind farm, 12 ... central monitoring building (monitoring system).

Claims (12)

A wind power generator connected to a power system,
A rotor that rotates in response to the wind,
A generator that generates electricity by rotation of the rotor,
A control device for controlling the rotation of the rotor,
When the wind speed measured by the windmill exceeds a predetermined threshold, the control device starts an operation of stopping the rotation of the rotor, and stops the rotation of the rotor over 30 minutes or more from the start of the stop operation. A wind power generator, characterized in that: The wind power generator according to claim 1,
The wind turbine generator, wherein the control device stops the rotation of the rotor over one hour or more from the start of the stop operation. The wind power generator according to claim 1,
The wind turbine generator, wherein the control device stops the rotation of the rotor over 6 hours or more from the start of the stop operation. The wind power generator according to claim 1,
The control device decreases the rotation speed of the rotor at a first rotation speed reduction rate after the start of the stop operation, and after a predetermined time elapses, a second rotation speed lower than the first rotation speed reduction ratio. A wind power generator, wherein the rotation speed of the rotor is reduced at a decreasing rate. The wind power generator according to claim 1,
A drive train for transmitting the rotation of the rotor to the generator;
A braking device for braking the drive train,
A wind power generator, wherein the rotation of the rotor is stopped by braking the drive train by the braking device. The wind power generator according to claim 1,
With a pitch control device that changes the pitch angle of the blades constituting the rotor,
A wind power generator, wherein rotation of the rotor is stopped by changing a pitch angle of the blade by the pitch control device. A method for controlling a wind power generator connected to a power system,
When the wind speed measured by the wind turbine of the wind power generator exceeds a predetermined threshold, the operation of stopping the rotation of the rotor is started, and the rotation of the rotor is stopped over 30 minutes or more from the start of the stop operation. A method for controlling a wind turbine generator. It is a control method of the wind power generator of Claim 7, Comprising:
A method for controlling a wind power generator, wherein the rotation of the rotor is stopped over one hour or more from the start of the stop operation. It is a control method of the wind power generator of Claim 7, Comprising:
A method for controlling a wind turbine generator, wherein the rotation of the rotor is stopped for at least six hours from the start of the stop operation. It is a control method of the wind power generator of Claim 7, Comprising:
After the start of the stop operation, the rotation speed of the rotor is reduced at a first rotation speed reduction ratio, and after a predetermined time, the rotor rotation speed is reduced at a second rotation speed reduction ratio lower than the first rotation speed reduction ratio. A method for controlling a wind power generator, comprising: It is a control method of the wind power generator of Claim 7, Comprising:
A method for controlling a wind turbine generator, wherein the rotation of the rotor is stopped by braking a drive train that transmits the rotation of the rotor to a generator. It is a control method of the wind power generator of Claim 7, Comprising:
A method for controlling a wind power generator, wherein the rotation of the rotor is stopped by changing a pitch angle of blades constituting the rotor.

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