WO2018198771A1

WO2018198771A1 - Hydroelectric power generation device and power generation system

Info

Publication number: WO2018198771A1
Application number: PCT/JP2018/015191
Authority: WO
Inventors: 智哉川合
Original assignee: Ntn株式会社
Priority date: 2017-04-28
Filing date: 2018-04-11
Publication date: 2018-11-01
Also published as: JP6885778B2; JP2018188981A

Abstract

A hydroelectric power generation device comprises: a water turbine (1); an electrical or mechanical braking device (12) for causing braking force to act on a rotation shaft that interlocks with the water turbine (1); and a control device (100) for repeating the operation and release of the braking device (12) so as to increase or decrease the braking force. The control device (100) operates the braking device (12) for a first number of times when a reduction amount of generated power of a generator (3) from power corresponding to flow velocity is a first value (for example, the braking device is operated three times when the generated power is 90% after reducing by 10%), and operates the braking device (12) for a second number of times larger than the first number of times when the reduction amount of the generated power is a second value larger than the first value (for example, the braking device is operated four times when the generated power is 70% after reducing by 30%, and is operated six times when the generated power reduces by 50%). As a result, a compact hydroelectric power generation device with easy maintenance against dust and foreign matters can be provided while suppressing cost.

Description

Hydroelectric generator and power generation system

The present invention relates to a hydroelectric generator and a power generation system, and more particularly to control of a small hydroelectric generator.

Hydropower generator is a system that uses the kinetic energy of running water for power generation. The hydroelectric generator includes, as main components, a water turbine that rotates by receiving a flow of water, a generator that is connected to the water turbine and converts rotational energy into electric energy, and a controller that controls the output of the generator and the water turbine. . Since the optimum power to be extracted from the generator varies depending on the flow velocity, the control device measures the flow velocity, the rotation speed of the water turbine, or the generated voltage of the generator, determines the optimum power to be extracted from the generator, and determines the power amount of the generator. And the generator are controlled so that the optimum values match.

ゴミ Garbage, aquatic plants, branches, and strings drifting from the upstream to the generator are entangled with the water wheel and cause a decrease in the amount of power generation. For this reason, countermeasures against garbage are important in hydropower generation. For example, it is preferable to install a device for removing dust upstream of the water wheel.

Japanese Patent Application Laid-Open No. 2013-189837 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2014-202093 (Patent Document 2) disclose techniques for measures against dust generated by hydroelectric power generation.

JP 2013-189837 A JP 2014-202093 A

Japanese Patent Laid-Open No. 2013-189837 (Patent Document 1) discloses an example in which a dust removal facility for removing foreign substances is installed in a water channel upstream from a water turbine installation location. However, in a small hydroelectric generator that is small and can be easily installed in a water channel, it is difficult to use such a large dust removal equipment because it causes an increase in cost. For this reason, it is conceivable to install a simple dust remover such as a comb filter in the small hydroelectric generator.

∙ When a simple dust remover is installed in a small hydroelectric generator, some garbage and aquatic plants may flow into the turbine. Some of the trash that has flown into the water turbine passes through as it is, while others are caught on the water turbine blades (blades). Garbage caught on the turbine blade is pressed against the turbine blade by the water pressure, centrifugal force, and water pressure generated by the rotation of the turbine blade. When the garbage and aquatic plants attached to the water wheel increase, the power generation decreases. Therefore, a simple dust remover is not a complete measure against dust, and it is necessary to periodically remove dust adhering to the water wheel.

On the other hand, Japanese Patent Application Laid-Open No. 2014-202093 (Patent Document 2) proposes a method of crushing and removing dust by using a water turbine blade as a crushing blade for crushing foreign matter by using a generator as a motor. With such a measure, dust can be removed without a significant increase in cost. However, the small hydroelectric generator disclosed in Japanese Patent Application Laid-Open No. 2014-202093 (Patent Document 2) has the following two problems.

First, in order to drive the generator as an electric motor, the control device must have an inverter function. Since a general generator control device has only functions of a rectifier circuit and a DC / DC converter, it is difficult to easily add such functions. Second, using an inverter to make a generator function as an electric motor is not power generation, which is the original purpose, but power consumption. The functioning of the generator as an electric motor that consumes electric power is an operation opposite to the original target power generation, and is not a desired operation. Furthermore, it is necessary to secure a power supply when functioning as an electric motor.

The present invention is for solving the above-described problems, and an object thereof is to provide a small-sized hydroelectric generator that is easy to maintain against dust and foreign matter while suppressing cost.

The present disclosure relates to a hydroelectric power generation apparatus. The hydroelectric power generator includes a water turbine, an electric or mechanical braking device that operates a braking force on a rotating shaft that is linked to the water wheel, and a control device that repeatedly operates and releases the braking device so that the braking force increases or decreases. Prepare. When the amount of decrease from the power corresponding to the flow rate of the generated power of the hydroelectric generator is the first value, the control device operates the brake device a first time, and the amount of decrease in the generated power is the first value. If the second value is greater than the second value, the braking device is operated a second number of times greater than the first number of times.

A hydroelectric generator of another aspect disclosed in the present disclosure includes a water turbine, an electric or mechanical braking device that operates a braking force on a rotating shaft that is linked to the water turbine, and a braking device that increases or decreases the braking force. And a control device that repeats operation and release. The control device operates the braking device so that the braking force exhibits the first increase / decrease pattern when the generated power decreases from the power corresponding to the flow velocity, and when the recovery of the generated power is insufficient, the first The braking device is operated with a second increase / decrease pattern having a larger deceleration than the increase / decrease pattern.

Preferably, the braking device includes a brake that applies a frictional force to a member fixed to the rotating shaft, and the control device increases or decreases the braking force by changing the frictional force.

Preferably, the braking device includes a generator that generates electric power by rotating the water wheel, and the control device increases or decreases the braking force by increasing or decreasing the electric power extracted from the generator.

Preferably, the control device repeats the operation and release of the braking device after increasing the rotational speed of the water turbine by reducing the power generated by the hydroelectric power generation device.

Preferably, the water wheel has a horizontal axis type propeller rotor blade.
Preferably, the water turbine has a vertical axis type rotor blade.

The present disclosure also discloses a power generation system that performs ocean current power generation or tidal power generation that converts kinetic energy of flowing water into electric power using any of the above-described hydroelectric power generation apparatuses.

According to the present invention, in a small hydroelectric generator, it is possible to remove dust and the like adhering to the water turbine while suppressing an increase in cost, and it is possible to prevent a decrease in power generation amount.

In addition, dust and grass are less likely to get entangled in the turbine blade, eliminating the need for a dust remover to remove dust installed in the water channel upstream from the water turbine installation location, or reducing the number of dust removal operations of the dust remover. It is possible to reduce the introduction cost or running cost of the entire hydroelectric power generation system. In addition, the risk of causing damage such as overflow is reduced because the water flow in the channel is not hindered.

It is a front view which shows the structure of the hydraulic power unit which concerns on this Embodiment. It is a side view which shows the structure of the hydraulic power unit which concerns on this Embodiment. It is a block diagram which shows the structure of the hydraulic power unit which concerns on this Embodiment. 4 is a flowchart for explaining control executed by a control unit in the configuration example of FIG. 3. It is a figure which shows the relationship between the generated electric power before a brake, and the generated electric power after a brake recovered | restored after the garbage removal driving | operation. It is a graph for examining the frequency | count of braking by a brake. It is the figure which showed the relationship between the electric power generated before a brake, and the frequency | count of a brake operation of garbage removal driving | operation. It is a block diagram which shows the modification of a structure of a hydroelectric generator. It is a flowchart for demonstrating the control which removes the dust adhering to a water turbine in the structure of FIG. 5 is a flowchart for illustrating control executed by a control unit in the hydroelectric generator of Embodiment 2. It is a wave form diagram showing the 1st example of the 1st braking pattern. It is a wave form diagram showing the 2nd example of the 1st braking pattern. It is a wave form diagram showing the 3rd example of the 1st braking pattern. It is a wave form diagram showing the 4th example of the 1st braking pattern. It is the wave form diagram which showed the example of the 2nd braking pattern. FIG. 6 is a front view showing a schematic shape of a hydroelectric generator according to Embodiment 3.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

[Embodiment 1]
<Configuration of hydroelectric generator>
FIG. 1 is a front view showing the configuration of the hydroelectric generator according to the present embodiment. FIG. 2 is a side view showing the configuration of the hydroelectric generator according to the present embodiment.

The hydroelectric power generation device shown in FIGS. 1 and 2 uses a kinetic energy of a water flow for power generation, and is a small and lightweight hydroelectric power generation that can be installed in a water channel that distributes existing agricultural water, tap water, or industrial water. System.

As shown in FIGS. 1 and 2, the hydroelectric power generation device includes a water turbine 1, a speed increaser 2, a power generator 3, and a support portion 40.

The water turbine 1 has a propeller-type rotor blade having a horizontal axis as a rotation center. The water turbine 1 rotates in response to the force of water flow in the water channel.

The gearbox 2 is connected to the water turbine 1. The speed increaser 2 increases the rotation speed of the water turbine 1 by a predetermined gear ratio, and converts the rotation of the horizontal axis into the rotation of the vertical axis and transmits the rotation to the generator 3.

The generator 3 is, for example, a three-phase synchronous generator. The generator 3 is connected to the water turbine 1 through the speed increaser 2. The generator 3 includes a rotor and a stator (both not shown). The generator 3 generates AC power when the rotor rotates as the water turbine 1 rotates. The power generated by the generator 3 is controlled by the control device 100 (see FIG. 3).

The support unit 40 supports the water turbine 1, the speed increaser 2, and the generator 3. The support portion 40 includes two

beams

40a and 40b, a gantry 40c, a support column 40d, and a base plate 40e.

The two

beams

40a and 40b are arranged so as to have a parallel positional relationship. In the central part of the two

beams

40a and 40b, a gantry 40c is provided so as to be placed on top of both of the two

beams

40a and 40b. The two struts 40d are disposed at one end and the other end of the gantry 40c, respectively. A base plate 40e is disposed so as to connect the upper portions of the two columns 40d.

The generator 3 is disposed between the gantry 40c and the base plate 40e, and is fixed to the base plate 40e. A column for fixing the position of the water turbine 1 and the gearbox 2 with respect to the position of the gantry 40c is provided below the gantry 40c. A rotating shaft that connects the speed increaser 2 and the generator 3 is accommodated inside the column. When the two

beams

40 a and 40 b are arranged above the side wall of the water channel along the width direction of the water channel, the water wheel 1 is fixed to a predetermined position in the water channel by the support portion 40.

<Regarding the control configuration of the hydroelectric generator>
FIG. 3 is a block diagram showing a configuration of the hydroelectric generator according to the present embodiment. Referring to FIG. 3, the hydroelectric power generation device according to the present embodiment includes a water turbine 1, a speed increaser 2, a power generator 3, a rotation speed detector 6, a braking device 12, a current meter 14, Control device 100. Control device 100 includes a control unit 7, a rectifier circuit 4, and a DC / AC converter 10. The control unit 7 controls the braking device 12 as well as the rectifier circuit 4 and the DC / AC converter 10.

The water wheel 1 is rotated by the power of running water. A generator 3 is connected to the water turbine 1 via a speed increaser 2. The generator 3 generates power as the water turbine 1 rotates. The generator 3 is a three-phase synchronous generator, and its output is output as a three-phase alternating current. The three-phase AC output of the generator 3 is converted into a DC output by the rectifier circuit 4, and the DC output is output to the subsequent DC / AC converter 10.

Here, the case where the generator 3 is a three-phase synchronous generator will be described as a specific example. However, the type of the generator is not limited to this, and an arbitrary type such as a three-phase induction generator or a DC generator may be used. The generator can be used in combination with a control device corresponding to the generator type.

As the braking device 12, a mechanical brake that converts kinetic energy into heat by friction can be used. For example, a mechanical brake (electromagnetic brake, disc brake, etc.) and a fluid brake can be used as the braking device 12. By increasing or decreasing the braking force generated by the braking device 12, the rotational speed of the water turbine 1 can be increased or decreased or the rotation can be stopped. Moreover, you may brake and release a water wheel with the electric brake by the short circuit of a generator etc. instead of the braking device 12. FIG.

The control unit 7 measures the state of the generator 3 while measuring the state of the water flow with the velocimeter 14. When the trash is entangled, the control device 100 can observe that the rotational speed of the water turbine 1 has decreased or the amount of power generation has decreased even though the flow rate is sufficient. At this time, the control device 100 controls the braking device 12 to repeat braking (decrease in rotational speed) and release (increase in rotational speed). Garbage and aquatic plants entangled with the water turbine blades float from the water turbine 1 when the rotation speed of the water turbine 1 decreases and the water pressure and centrifugal force due to the rotation of the water turbine blades are weakened. On the other hand, when the rotation speed increases, the rotation of the water turbine 1 accelerates, so that the water pressure and centrifugal force increase, and a stronger force is applied to the dust and aquatic plants. When braking and releasing of the generator 3 are repeated, dust and the like are easily lifted from the water turbine blades, and a force that pushes the water downstream is applied, and the dust and the like are caused to flow downstream.

If the flow rate and the amount of water are not monitored, the above control may be performed every time a certain time has elapsed.

FIG. 4 is a flowchart for explaining the control executed by the control unit in the configuration example of FIG. The process of this flowchart is called and executed at regular intervals from the main routine for generator control. Referring to FIGS. 3 and 4, in step S 1, control unit 7 determines whether or not the dust removal operation condition is satisfied.

The dust removal operation condition is established when the possibility that dust has adhered to the water turbine 1 increases. For example, when any one of the following conditions (1) to (4) is satisfied, the control unit 7 determines that the dust removal operation condition is satisfied. Note that the control unit 7 may determine that the dust removal operation condition is satisfied when a combination of two or more of the conditions (1) to (4) is satisfied.

Condition (1): The average generated power of the hydroelectric generator at a certain time has decreased below the threshold value. Condition (2): The average rotation speed of the water turbine 1 at a certain time has decreased to fall below a threshold value. Condition (3): The average generated voltage of the hydroelectric generator at a certain time has decreased below a threshold value. Condition (4): A predetermined time has elapsed since the last time the dust removal operation condition was satisfied (or released).

In addition, it is preferable to change the threshold value of said electric power generation, rotation speed, and electric power generation voltage with the magnitude | size and flow velocity of a water channel. Even in cases other than (1) to (4) above, the operating conditions may be determined based on the amount of decrease in average generated power, the average current, the average rotational torque, and the like.

When it is determined in step S1 that the dust removal operation condition is not satisfied (NO in S1), the control unit 7 advances the process to step S10. In this case, control is returned to the main routine.

On the other hand, when it is determined in step S1 that the dust removal operation condition is satisfied (YES in S1), the control unit 7 executes the dust removal operation shown in steps S2 to S9.

In the dust removal operation, the control unit 7 increases or decreases the braking force of the braking device 12. For example, the control unit 7 outputs a command signal to the braking device 12 so that the braking force repeats the maximum value and zero when the rotational speed detector 6 detects a decrease in the rotational speed of the generator 3. , The deceleration and acceleration of the water wheel 1 are repeated.

At this time, in order to extend the life of the braking device 12 as much as possible while restoring the generated power, it is desirable to change the number of times of increase / decrease of the braking force according to the state of dust adhesion. The number of increase / decrease of the braking force corresponds to the upper limit value of the counter in the following control for turning on / off the brake. Since the amount of dust attached has a correlation with the amount of decrease in generated power, in step S2, the control unit 7 sets a counter upper limit value corresponding to the amount of decrease in generated power.

Below, how to reduce the amount of power generation and the number of times the braking force increases or decreases will be explained. FIG. 5 is a diagram showing the relationship between the generated power before the dust removal operation and the generated power recovered after the dust removal operation.

As shown in FIG. 5, when the generated power before the dust removal operation is 0 to 30%, the generated power hardly changes even if the dust removal operation is performed. On the other hand, when the generated power before the dust removal operation is 40%, the generated power recovers to 60% when the dust removal operation is performed.

Furthermore, if the power generation before the dust removal operation is 50% and the dust removal operation is performed, the generated power recovers to 90%. Further, if the dust removal operation is performed in a state where the generated power before the dust removal operation is 60% or more, the generated power is recovered to 100%.

In the dust removal control, the larger the amount of dust entangled in the turbine blade, the more difficult it is to remove the dust. This is because garbage is entangled in the turbine blade, and the more the garbage, the lower the rotation speed of the turbine blade, so the inertial force of the dust when braking is not obtained and the dust does not rise This is probably because of this.

From the above results, it can be seen that it is effective to perform the dust removal operation before the generated power drops to 50%. Therefore, the above conditions (1) to (3) should be set to threshold values for the respective conditions so as to correspond to the generated power of 50%, preferably 60%.

FIG. 6 is a graph for examining the number of times of braking by the brake. In FIG. 6, the vertical axis represents the generated power (%) after braking, the horizontal axis represents the number of braking times, and the generated power (%) before braking is 20%, 30%, 40%, 50%, 70%, 90 % Data are plotted.

FIG. 6 shows that when the pre-brake generated power is 20% and 30%, the generated power does not increase and dust is not removed no matter how many times the brake is operated. When the generated power before braking is 40%, the generated power recovers somewhat when the brake is operated, but does not increase more than 60%.

When the generated power before braking is 50%, the generated power increases and recovers up to 4 times when the brake is operated, but it does not increase more than 90% even if it is operated 4 times or more.

When the generated power before braking is 70%, the generated power increases and recovers up to 3 times when the brake is operated, and reaches 100% after 3 times. When the generated power before braking is 90%, when the brake is operated, the generated power increases and recovers up to twice, and becomes 100% after two times.

Since the life of a brake will be shortened if it is operated many times, in equipment that is used continuously for a long period of time, such as a hydroelectric generator, the operation frequency should be set appropriately to balance the recovery of generated power and the maintenance of the brake life. Is desired. Therefore, in the present embodiment, the brake operation frequency is changed according to the decrease rate of the generated power.

FIG. 7 is a diagram showing the relationship between the power generated before braking and the number of brake operations in the dust removal operation. As described with reference to FIG. 5, the dust removal operation is executed when the generated power is 50% or more in order to effectively recover the power. In this case, considering the relationship shown in FIG. 6, when the generated power before the dust removal operation is 90% when the dust removal operation is performed, the number of times of brake operation is three, and when the generated power before the dust removal operation is 70%. The brake operation frequency is set to 4 times, and when the generated power before the dust removal operation is 50%, the brake operation frequency is set to 6 times. Thus, the number of brake actuations is increased as the generated power before the dust removal operation decreases.

Returning to FIG. 4, in step S 2, the control unit 7 determines a counter upper limit value (the number of brakes) as a numerical value corresponding to the amount of decrease in generated power based on the number of removal operations shown in the relationship shown in FIG. Subsequently, in step S3, the control unit 7 clears the built-in counter. This counter is a counter for measuring the number of repetitions. Subsequently, in step S4, the control unit 7 sets the command signal SB so that the braking device 12 generates a braking force (brake ON). Thereafter, in step S5, the control unit 7 waits until a set time (for example, 1 to 10 seconds) elapses in the brake-on state.

Next, in step S6, the control unit 7 sets the command signal SB so that the braking device 12 does not generate a braking force (brake OFF). Thereafter, in step S7, the control unit 7 waits until a set time (for example, 1 to 10 seconds) elapses in the brake OFF state.

Subsequently, the control unit 7 increments the counter in step S8, and in step S9, determines whether or not the count value of the counter has reached an upper limit value (set number of repetitions of increase / decrease). In step S9, if the count value has not yet reached the upper limit value, the control unit 7 returns the process to step S4 and turns on the brake again.

On the other hand, if the count value reaches the upper limit value in step S9, the process proceeds to step S10, and the dust removal operation per time is completed.

In this embodiment, the braking device 12 is installed on the rotating shaft that connects the speed increaser 2 and the generator 3 of the hydroelectric power generation device, and the braking device 12 is repeatedly turned on and off. Thereby, the rotational speed of the water turbine 1 is changed. The foreign matter adhering to the water wheel 1 can be removed by applying a force during acceleration, floating up when decelerating, and flowing downstream with the force of water flow. Therefore, there is an effect of recovering the power generation amount that is reduced due to the foreign matter.

In the present embodiment, the set time in S5 and the set time in S7 are fixed values while being repeated up to the upper limit value of the counter. However, the set time may be changed.

FIG. 8 is a block diagram showing a modification of the configuration of the hydroelectric generator. Referring to FIG. 8, the modified hydroelectric generator includes a water turbine 1, a speed increaser 2, a generator 3, a rotational speed detector 6, a flow meter 14, and a control device 100 A.

The control device 100A includes a control unit 7A, a rectifier circuit 4, a DC / DC converter 9, and a DC / AC converter 10. Since water turbine 1, generator 3, rectifier circuit 4, and rotational speed detector 6 are the same as those shown in FIG. 3, the description thereof will not be repeated.

The control unit 7A outputs a current command signal SA to the DC / DC converter 9. The DC / DC converter 9 takes out power from the output of the rectifier circuit 4 in accordance with the command of the current command signal SA, and outputs a current as commanded to the DC / AC converter 10. Along with this, the output voltage of the DC / DC converter 9 rises. The DC / AC converter 10 outputs power to the subsequent stage. When the output voltage of the DC / DC converter 9 increases, the DC / AC converter 10 is configured to suppress an increase in the output voltage of the DC / DC converter 9 by outputting more power to the subsequent stage.

The optimum power that can be extracted from the water turbine 1 is determined by the flow rate of water received by the water turbine 1. The flow rate and the number of rotations of the generator 3 are substantially proportional. By detecting the rotational speed of the generator 3, the optimum power can be determined. If the electric power that is larger than the optimum electric power is taken out from the generator 3, the rotational speed of the generator 3 is lowered. At this time, the rotational speed of the water turbine 1 connected to the generator 3 also decreases. On the contrary, when the electric power taken out from the generator 3 is less than the optimum value, for example, zero, the rotation speed of the generator increases and increases similarly to the rotation speed of the water turbine 1 connected to the generator 3.

Therefore, the rotational speed of the water turbine 1 can be increased or decreased by increasing or decreasing the electric power extracted from the generator 3.

FIG. 9 is a flowchart for explaining control for removing dust adhering to the water wheel in the configuration of FIG. 8 and 9, in step S11, control unit 7A determines whether or not the dust removal operation condition is satisfied.

The dust removal operation condition is established when the possibility that dust has adhered to the water turbine 1 increases. As specific conditions (conditions (1) to (4) or combinations thereof), those already described can be applied, and therefore description thereof will not be repeated here.

If it is determined in step S11 that the dust removal operation condition is not satisfied (NO in S11), the control unit 7A advances the process to step S20. In this case, control is returned to the main routine.

On the other hand, when it is determined in step S11 that the dust removal operation condition is satisfied (YES in S11), the control unit 7A executes the dust removal operation shown in steps S12 to S19.

In step S12, the control unit 7A determines the counter upper limit value to a numerical value corresponding to the amount of decrease in generated power based on the number of removal operations shown in the relationship shown in FIG. Subsequently, the control unit 7A increases or decreases the current command value to the DC / DC converter 9 as the dust removal operation. For example, when the control unit 7A detects a decrease in the rotational speed of the generator 3 from the rotational speed detector 6, the control unit 7A outputs the current command signal SA so that the output current repeats the maximum value and zero. Repeat the deceleration and acceleration.

Specifically, in step S13, the control unit 7A clears the built-in counter. This counter is a counter for measuring the number of repetitions. Subsequently, in step S14, the control unit 7A sets the current command signal SA so that the DC / DC converter 9 maximizes the output current, and then in step S15, the control unit 7A sets the set time (for example, 1 to Wait 3 seconds). While the output current of the DC / DC converter 9 is maximized, a large amount of electric power is consumed and a large braking force is generated in the generator 3.

Next, in step S16, the control unit 7A sets the current command signal SA so that the DC / DC converter 9 sets the output current to zero, and then in step S17, the control unit 7A sets the set time (for example, 1 to 3). Wait). In this case, since the load on the generator 3 is lighter than when the current command signal SA is set to the maximum current, the rotational speed of the generator 3 increases.

Subsequently, the control unit 7A increments the counter in step S18, and determines in step S19 whether or not the count value of the counter has reached the upper limit value (set number of repetitions of increase / decrease). In step S19, if the count value has not yet reached the upper limit value, control unit 7A returns the process to step S14, and sets current command signal SA to maximize the output current again.

On the other hand, when the count value reaches the upper limit value in step S19, the process proceeds to step S20, and the dust removal operation per time is completed.

In the modification of the first embodiment, the load of the generator 3 that is linked to the water turbine 1 of the hydroelectric generator is varied by increasing or decreasing the current command value of the DC / DC converter 9. Thereby, the rotational speed of the generator 3 is changed, and the rotational speed of the water turbine 1 interlocked with the generator 3 is changed. The foreign matter adhering to the water wheel 1 can be removed by applying a force during acceleration, floating up when decelerating, and flowing downstream with the force of water flow. Therefore, there is an effect of recovering the power generation amount that is reduced due to the foreign matter.

[Embodiment 2]
In the first embodiment, the brake life is extended while effectively removing dust by determining the number of times of increase / decrease in braking force corresponding to the amount of decrease in generated power. On the other hand, in the second embodiment, the pattern for applying the braking force is changed.

FIG. 10 is a flowchart for explaining control executed by the control unit in the hydroelectric generator of the second embodiment. The process of this flowchart is called and executed at regular intervals from the main routine for generator control.

3 and 10, first, in step S51, the control unit 7 determines whether or not the dust removal operation condition is satisfied.

If it is determined in step S51 that the dust removal operation condition is not satisfied (NO in S51), the control unit 7 advances the process to step S55. In this case, control is returned to the main routine.

On the other hand, when it is determined in step S51 that the dust removal operation condition is satisfied (YES in S51), the control unit 7 executes the dust removal operation shown in steps S52 to S54.

In step S52, control is performed to decelerate the water turbine 1 with the first braking pattern. The first braking pattern is a braking pattern in which the load on the braking device 12 is relatively small. Thereafter, if the generated power does not recover to the determination value in step S53, the process proceeds to step S54, and after the control for decelerating the water turbine 1 with the second braking pattern is performed, the control is returned to the main routine. The second braking pattern is a braking pattern in which the load on the braking device is larger than that of the first braking pattern. On the other hand, if the generated power has recovered to the determination value in step S53, the process in step S54 is not executed, the process proceeds to step S55, and the control is returned to the main routine.

FIG. 11 is a waveform diagram showing a first example of the first braking pattern. FIG. 12 is a waveform diagram showing a second example of the first braking pattern. FIG. 13 is a waveform diagram showing a third example of the first braking pattern. FIG. 14 is a waveform diagram showing a fourth example of the first braking pattern. FIG. 15 is a waveform diagram showing an example of the second braking pattern.

The second braking pattern shown in FIG. 15 is a control in which a sudden braking is applied to the rotating water wheel 1 to temporarily stop the rotation and then the brake is released. On the other hand, in the waveforms shown in FIGS. 11 to 14, the brake is applied more slowly than in FIG. 15, or the brake is released before reaching the stop.

When the braking force (negative angular acceleration) at t41 and t44 is increased as shown in the second braking pattern shown in FIG. Can be removed more reliably. In addition, more dust can be removed by increasing the number of times of braking control. However, if the waveform shown in FIG. 15 is repeatedly given, it is necessary to use a large braking device 12 having high durability, and the impact applied to the braking device 12 is great and the life of the braking device 12 is shortened. Further, the generated power decreases during the operation of the braking device 12.

Therefore, first, the control unit 7 tries to remove dust with the first braking pattern with a light load on the braking device 12, and when the electric power still does not recover, the second braking pattern is applied. Various examples of the first braking pattern can be considered and will be described with reference to FIGS.

In the example shown in FIG. 11, the degree of deceleration at time t1 is not different from that in FIG. 15, but when the rotational speed decreases from N1 to N2, the braking force is maintained and released at time t2.

In the example shown in FIG. 12, the degree of deceleration at times t11 to t12 is slower than that in FIG. 15, and the braking torque of the braking device 12 can be small.

In the example shown in FIG. 13, the deceleration degree from time t21 to t22 is slower than that in FIG. 15, and the braking device 12 is released immediately at time t22, so that the amount of power generation can be reduced little.

In the example shown in FIG. 14, during the deceleration period from time t31 to t32, the rotational speed is decreased stepwise from N1 to N2. This is effective when the inertial force of the water turbine is large, it is difficult to apply the brake suddenly, and it is difficult to control the braking force continuously. Thus, by shortening the braking time and performing braking many times, it is possible to reduce the impact load due to the dust removal operation control and prevent the mechanical parts from being damaged.

In the description of the second embodiment, the example applied to the hydroelectric generator shown in FIG. 3 is shown. However, the same control can be applied to the hydroelectric generator shown in FIG.

[Embodiment 3]
In the first and second embodiments described above, the power generation apparatus that generates power by receiving flowing water using the water turbine having the horizontal axis type propeller type rotor blades shown in FIGS. 1 and 2 has been described as an example. In the third embodiment, it will be described that the first or second embodiment can be modified and applied to a power generation apparatus that generates power by receiving flowing water with a water turbine having a vertical axis type rotor blade.

FIG. 16 is a front view showing a schematic shape of the hydroelectric generator according to the third embodiment. Referring to FIG. 16, the hydraulic power generation apparatus according to Embodiment 4 includes a water turbine 1 A and a generator 3. The water turbine 1 A has a vertical axis type rotary blade and rotates by a water flow. The generator 3 is connected to the rotating shaft of the water turbine 1A. When the water wheel 1A rotates, the rotating shaft of the generator 3 also rotates.

3 to 15 can be used in combination in the same manner for the water turbine 1A shown in FIG. Since the control device, flowchart, and braking pattern shown in FIGS. 3 to 15 have been described in the first and second embodiments, description thereof will not be repeated here.

As shown in FIG. 16, the vertical axis type water turbine 1 A is a straight wing type and exemplifies a configuration in which the upper and lower ends of the wing are bent toward the rotation axis, but is not particularly limited thereto. For example, other types such as a Darius type, a gyromill type, a Savonius type, a cross flow type, a paddle type, and an S-type rotor type may be used.

Also in the hydroelectric generator according to Embodiment 3, the rotational speed of the generator 3 can be changed, and the rotational speed of the water turbine 1A connected to the generator 3 can be changed. The foreign matter attached to the water turbine 1A can be removed by applying a force during acceleration, floating up when decelerating, and flowing downstream with the force of water flow. Therefore, there is an effect of recovering the power generation amount that is reduced due to the foreign matter.

Although some parts overlap with the above description, the first to third embodiments are summarized. The hydroelectric generator of the present embodiment includes a hydraulic turbine 1, an electric or mechanical braking device 12 that operates a braking force on a rotating shaft that is linked to the hydraulic turbine 1, and an operation of the braking device 12 so that the braking force increases or decreases. And a control device 100 that repeats release. As shown in FIG. 7, when the amount of decrease from the power corresponding to the flow rate of the generated power of the generator 3 is the first value, the control device 100 operates the braking device 12 a first number of times (for example, If the electric power corresponding to the flow rate is 100% and then 90% is reduced by 10%, the operation is performed three times). If the amount of decrease in the generated power is a second value larger than the first value, braking is performed. The device 12 is activated a second number of times that is greater than the first number of times (eg, activated 4 times for 70% reduced by 30%, and activated 6 times for reduced 50%).

Thus, the rotational speed of the turbine blade is changed by installing the rotational braking device connected to the hydraulic turbine of the hydroelectric generator and repeating the braking (decreasing rotational speed) and releasing (increasing rotational speed) on the turbine blade. Garbage and grass entangled with the turbine blades are lifted from the turbine blades by the inertial force because the water pressure and centrifugal force due to the rotation of the turbine blades are weakened when the rotation speed of the turbine wheels decreases. When braking and releasing are repeated, it becomes easy to float, and the force that pushes downstream by the water flow acts and flows downstream. Note that the reduction amount ΔP of the generated power may be expressed as a percentage (%) or may be expressed as electric power (W).

Preferably, as shown in FIG. 3, the braking device 12 includes a brake (mechanical friction brake) that applies a frictional force to a member fixed to the rotating shaft of the water turbine. The control device 100 increases or decreases the braking force by changing the frictional force.

Preferably, as shown in FIG. 8, the braking device includes a generator 3 that generates power by the rotation of the water wheel. As shown in FIG. 9, the control device 100A increases or decreases the braking force by increasing or decreasing the electric power extracted from the generator.

In addition, it is desirable that the speed fluctuation range of the water turbine 1 is sufficiently obtained by repeatedly increasing / decreasing the braking force from the predetermined rotational speed. The flow rate of water received by the water turbine 1 varies greatly in the long term, and may be greatly reduced in a season with little rainfall. Accordingly, the rotational speed of the water turbine 1 also decreases, and even when the braking force increase / decrease operation is repeated from the state in which the rotational speed of the water turbine 1 decreases, the fluctuation range of the rotational speed of the water turbine 1 is small, and predetermined dust removal The effect may not be obtained. Thus, when the rotational speed of the water turbine 1 is decreasing, the electric power taken out from the generator 3 is decreased (the power generation load is decreased), the rotational speed of the water turbine 1 is increased, and then the braking device 12 is operated. It is desirable to repeat and release.

Preferably, as shown in FIGS. 1 and 2, the water turbine has a horizontal axis type propeller rotor blade.

Preferably, as shown in FIG. 16, the water turbine has a vertical axis type rotor blade.
The hydroelectric generator of another aspect disclosed in the present disclosure includes a water turbine 1, an electric or mechanical brake device 12 that operates a braking force on a rotating shaft that operates in conjunction with the water turbine, and braking so that the braking force increases or decreases. A control device 100 that repeats the operation and release of the device 12 is provided. As shown in FIG. 10, when the generated power is lower than the power corresponding to the flow velocity, the control device 100 performs braking so that the braking force shows the first increase / decrease pattern (any one of FIGS. 12 to 14). When the device 12 is operated and recovery of the generated power is insufficient, the braking device is operated with a second increase / decrease pattern (FIG. 15) having a deceleration larger than that of the first increase / decrease pattern.

By determining the number of times of braking or the braking pattern as described above, it is possible to prevent a significant decrease in the amount of power generated due to adhesion of dust to the turbine blades while protecting the braking device and the like.

The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1, 1A water wheel, 2 speed increaser, 3 generator, 4 rectifier circuit, 6 rotation speed detector, 7, 7A control unit, 9, 10 converter, 12 braking device, 14 current meter, 40 support unit, 40a, 40b Beam, 40c stand, 40d strut, 40e base plate, 100, 100A control device.

Claims

A hydroelectric generator,
With a water wheel,
An electric or mechanical braking device that activates a braking force on a rotating shaft interlocked with the water wheel;
A control device that repeats the operation and release of the braking device so that the braking force increases or decreases,
When the amount of decrease from the power corresponding to the flow rate of the generated power of the hydroelectric generator is the first value, the control device operates the braking device a first time, and the amount of decrease in the generated power is A hydroelectric generator that operates the braking device a second number of times greater than the first number of times when the second value is greater than the first value.
The braking device includes a brake that applies a frictional force to a member fixed to the rotating shaft,
The hydroelectric generator according to claim 1, wherein the control device increases or decreases the braking force by changing the frictional force.
The braking device includes a generator that generates electricity by rotating the water wheel,
The hydroelectric generator according to claim 1, wherein the control device increases or decreases the braking force by increasing or decreasing electric power extracted from the generator.
The hydraulic power generator according to claim 1, wherein the control device repeats the operation and release of the braking device after increasing the rotational speed of the water turbine by reducing the generated power of the hydraulic power generator.
The hydroelectric generator according to any one of claims 1 to 4, wherein the water turbine has a horizontal axis type propeller type rotor blade.
The hydroelectric generator according to any one of claims 1 to 4, wherein the water turbine has a vertical axis type rotor blade.
A power generation system that performs ocean current power generation or tidal power generation that converts kinetic energy of flowing water into electric power using the hydroelectric power generation device according to any one of claims 1 to 4.
A hydroelectric generator,
With a water wheel,
An electric or mechanical braking device that operates a braking force on a rotating shaft interlocking with the water wheel;
A control device that repeats the operation and release of the braking device so that the braking force increases or decreases,
The control device operates the braking device so that the braking force exhibits the first increase / decrease pattern when the generated power is reduced from the power corresponding to the flow velocity, and when the recovery of the generated power is insufficient A hydroelectric generator that operates the braking device with a second increase / decrease pattern having a larger deceleration than the first increase / decrease pattern.
The braking device includes a brake that applies a frictional force to a member fixed to the rotating shaft,
The hydroelectric generator according to claim 8, wherein the control device increases or decreases the braking force by changing the frictional force.
The braking device includes a generator that generates electricity by rotating the water wheel,
The hydroelectric generator according to claim 8, wherein the control device increases or decreases the braking force by increasing or decreasing electric power extracted from the generator.
The hydraulic power generator according to claim 8, wherein the control device repeats the operation and release of the braking device after increasing the rotational speed of the water turbine by decreasing the generated power of the hydraulic power generator.
The hydroelectric generator according to any one of claims 8 to 11, wherein the water turbine has a horizontal axis type propeller type rotor blade.
The hydroelectric generator according to any one of claims 8 to 11, wherein the water turbine has a vertical axis type rotor blade.
A power generation system for performing ocean current power generation or tidal power generation that converts the kinetic energy of flowing water into electric power using the hydroelectric power generation device according to any one of claims 8 to 11.