Power generation control device

Abstract

To provide a power generation control device capable of obtaining power generation characteristics capable of efficiently generating power while stably supplying power.SOLUTION: A power generation control device 1 controls driving of a power generation device which generates power by using sound waves having a natural frequency. The power generation control device 1 includes: a power generation characteristic change detecting portion 11 for detecting whether or not the power generation characteristic of the power generation device S has changed; and a power generation characteristic acquisition portion 12 for acquiring a power generation characteristic of the power generation device S when the power generation characteristic change detection portion 11 detects that the power generation characteristic of the power generation device S has changed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power generation control device for controlling the operation of a power generation device. [Background technology]

[0002] There is known a power generation control device that controls the operation of a power generation device. For example, Patent Document 1 discloses a power generation control device that changes a load based on a result of comparing power before and after the load is changed.

[0003] The power generation control device has a load changing unit, a power comparing unit, and a load determining unit. The load changing unit changes the load related to the power generated by the generator. The power comparing unit compares the power before the load changing unit changes the load with the power after the load changing unit changes the load. The load determining unit determines whether to cause the load changing unit to change the load based on the result of the comparison by the power comparing unit.

[0004] The power generation control device automatically changes the load related to the power generated by the wind power generator while the wind power generator is in operation, and detects the control characteristics of the wind power generator that will allow high power to be obtained. This makes it possible to extract high power according to a characteristic curve that indicates the control characteristics detected by the power generation control device during operation, without having to design a dedicated power generation control device for each wind power generator. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2016-19351 A Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, in the configuration disclosed in the above-mentioned Patent Document 1, the load related to the power generated by the wind power generator is changed to detect the control characteristics of the wind power generator. However, in such a configuration, the load related to the power generated by the wind power generator is frequently changed, which may cause a problem of unstable power supply.

[0007] In response to this, there is a demand for a power generation control device that can obtain power generation characteristics that enable efficient power generation while stably supplying power.

[0008] An object of the present invention is to provide a power generation control device that can obtain power generation characteristics that enable efficient power generation while stably supplying power. [Means for solving the problem]

[0009] A power generation control device according to one embodiment of the present invention is a power generation control device that controls the driving of a power generation device that generates power by utilizing an energy wave having a natural frequency. The power generation control device includes a power generation characteristic change detection unit that detects whether or not the power generation characteristics of the power generation device have changed, and a power generation characteristic acquisition unit that acquires the power generation characteristics of the power generation device when the power generation characteristic change detection unit detects that the power generation characteristics of the power generation device have changed (first configuration).

[0010] In this way, in the case of a power generation device that generates power by utilizing an energy wave having a natural frequency, the power generation control device drives the generator of the power generation device in accordance with the natural frequency of the energy wave. Therefore, when driving the power generation device to obtain electric power, the power generation control device grasps the electric power that can be output from the power generation device from the power generation characteristics of the power generation device that are matched to the natural frequency of the energy wave.

[0011] However, when the natural frequency of at least one of the device that generates the energy wave and the generator, etc. in the power generation device changes due to aging, the power generation characteristics of the power generation device change and the amount of power that can be output from the power generation device also changes.

[0012] In contrast, as configured above, when the power generation characteristics of the power generation device change, the power generation control device acquires the power generation characteristics of the power generation device, and can control the operation of the power generation device by grasping the changed power generation characteristics of the power generation device even if the natural frequency of the devices that constitute the power generation device has changed due to aging or the like as described above and the power generation characteristics of the power generation device have changed.

[0013] Furthermore, when the power generation characteristic change detection unit detects that the power generation characteristics of the power generation device have changed, the power generation characteristic acquisition unit acquires the power generation characteristics of the power generation device, so there is no need to frequently change the power generation characteristics of the power generation device as in the conventional technology.

[0014] Therefore, a power generation control device can be obtained that can obtain power generation characteristics that enable efficient power generation while stably supplying power.

[0015] In the first configuration, the power generation device has a linear generator that generates power by utilizing vibrations caused by the energy wave, and the power generation characteristic change detection unit detects that the power generation characteristics of the power generation device have changed based on a vibration frequency and a reference vibration frequency when the linear generator is operating (second configuration).

[0016] As a result, when the power generation device has a linear generator, the power generation characteristic change detection unit can detect a change in the power generation characteristics of the power generation device based on the vibration frequency and the reference vibration frequency when the linear generator is operating, and therefore the power generation control device can easily detect a change in the power generation characteristics of the power generation device.

[0017] In the second configuration, the power generation characteristic change detection unit detects that the power generation characteristics of the power generation device have changed when the difference between the vibration frequency when the linear generator is operating and the reference vibration frequency exceeds a threshold value. The threshold value is determined based on the reference vibration frequency and a drive stop frequency at which the drive of the linear generator is stopped (third configuration).

[0018] As a result, even if the vibration frequency of the linear generator differs from the reference vibration frequency, the power generation characteristic change detection unit does not detect a change in the power generation characteristics of the power generation device until the difference between the vibration frequency and the reference vibration frequency exceeds a threshold value, thereby preventing the power generation control device from frequently acquiring the power generation characteristics of the power generation device due to changes in the vibration frequency of the linear generator.

[0019] Moreover, the threshold value is determined based on the reference vibration frequency and a drive stop frequency at which the drive of the linear generator is stopped, and therefore the threshold value can be determined within a range in which the drive of the linear generator is not stopped, while taking into consideration disturbances and the like.

[0020] Therefore, the power generation control device can acquire the power generation characteristics of the power generation device while taking into account external disturbances, etc., while preventing the power generation control device from frequently acquiring the power generation characteristics of the power generation device to the extent that the operation of the linear generator is not stopped.

[0021] In the second or third configuration, a reference vibration frequency update unit is further provided which, when the power generation characteristics acquisition unit acquires the power generation characteristics of the power generation device, sets the vibration frequency when the linear generator is operating as the reference vibration frequency (fourth configuration).

[0022] This allows the reference vibration frequency to be changed when the power generation characteristics of the power generation device change and the power generation characteristics acquisition unit acquires the changed power generation characteristics. Therefore, the reference for acquiring the power generation characteristics can be changed in response to aging of the power generation device, etc. Therefore, the power generation characteristics of the power generation device that are grasped by the power generation control device can be changed at an appropriate timing.

[0023] In any one of the first to fourth configurations, the energy wave is a sound wave obtained by a thermoacoustic phenomenon (a fifth configuration).

[0024] As a result, if the power generation characteristics of a power generation device that generates electricity using sound waves change, the power generation control device can grasp the power generation characteristics of the power generation device after the change and control the operation of the power generation device. Effect of the Invention

[0025] According to an embodiment of the present invention, a power generation control device includes a power generation characteristic change detection unit that detects a change in the power generation characteristics of a power generation device, and a power generation characteristic acquisition unit that acquires the power generation characteristics of the power generation device when the power generation characteristic change detection unit detects a change in the power generation characteristics of the power generation device. This provides a power generation control device that can obtain power generation characteristics that enable efficient power generation while stably supplying electric power. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a block diagram showing a schematic configuration of a power generation device including a power generation control device according to an embodiment. [Diagram 2] FIG. 2 is a circuit diagram showing a schematic configuration of the power conversion unit. [Diagram 3] FIG. 3 is a diagram showing an example in which the relationship between the moving speed of a mover of a linear generator and the generated power changes depending on the temperature. [Figure 4] FIG. 4 is a diagram showing an example of the relationship between the moving speed of a mover of a linear generator and generated power at a predetermined temperature. [Diagram 5] FIG. 5 is a diagram showing a schematic diagram of a method for determining the maximum power point. [Figure 6] FIG. 6 is a diagram showing a schematic diagram of a method for determining the power generation characteristic curve. [Figure 7] FIG. 7 is a flowchart showing the operation of the power generation control device for acquiring the power generation characteristics of the linear generator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and the description thereof will not be repeated.

[0028] (Power generation equipment) 1 is a block diagram showing a schematic configuration of a power generation device S including a power generation control device 1 according to an embodiment of the present invention. The power generation device S obtains electric power by driving a linear generator with vibrations obtained by utilizing a thermoacoustic phenomenon. Specifically, the power generation device S has the power generation control device 1, a sound wave conversion unit 2, a vibration conversion unit 3, a linear generator 4, and a power conversion unit 5.

[0029] The sonic conversion unit 2 generates sound waves by utilizing the thermoacoustic phenomenon. The thermoacoustic phenomenon occurs when one of the capillaries is heated to a predetermined temperature or higher while the other of the capillaries is cooled, causing the gas in the capillaries to become unstable and start vibrating, and this vibration acts as a piston to convert heat and work energy. The principle of generating sound waves by utilizing the thermoacoustic phenomenon is the same as the principle of a commonly known thermoacoustic engine, so a detailed explanation will be omitted.

[0030] The sonic conversion unit 2 is a device that converts thermal energy into acoustic energy. Although not shown in the figure, the sonic conversion unit 2 has a plurality of capillaries, a heating unit that heats the plurality of capillaries, and a cooling unit that cools the plurality of capillaries. The configuration of the sonic conversion unit 2 is the same as a conventional configuration that can realize the thermoacoustic phenomenon. Therefore, a detailed description of the configuration of the sonic conversion unit 2 is omitted.

[0031] The vibration conversion unit 3 generates vibrations from the sound waves generated by the sound wave conversion unit 2. The vibration conversion unit 3 has a vibration drive unit (not shown) that vibrates due to the sound waves. The vibration drive unit vibrates by receiving the acoustic energy and moving back and forth.

[0032] The linear generator 4 generates electricity by utilizing the vibrations generated by the vibration conversion unit 3. Although not specifically shown, the linear generator 4 has, for example, a mover having a magnet and a cylindrical stator having a coil. The mover is located inside the cylindrical stator and moves back and forth in the axial direction inside the stator due to the vibration. As a result, a magnetic field generated by the magnet of the mover moves relative to the coil of the stator, so that an induced current flows in the coil, and electric power is output from the linear generator 4.

[0033] The power conversion unit 5 converts the AC power generated by the linear generator 4 into a predetermined power and outputs it to the power grid. In detail, the power conversion unit 5 converts the AC power output from the linear generator 4 into DC power, and then converts the DC power into the predetermined AC power.

[0034] Fig. 2 is a circuit diagram showing a schematic configuration of the power conversion unit 5. As shown in Fig. 2, the power conversion unit 5 has a DC conversion unit 51, a smoothing capacitor 52, and an AC conversion unit 53. The DC conversion unit 51 converts the AC power output from the linear generator 4 into DC power. The smoothing capacitor 52 smoothes the DC power output from the DC conversion unit 51. The AC conversion unit 53 converts the DC power output from the DC conversion unit 51 into AC power. The DC conversion unit 51 and the AC conversion unit 53 each have a plurality of switching elements SW.

[0035] In this embodiment, the DC converter 51 has, for example, four switching elements SW that configure a single-phase bridge circuit, and the AC converter 53 has, for example, six switching elements SW that configure a three-phase bridge circuit.

[0036] In response to a request from the power grid, the AC converter 53 converts the DC power output from the DC converter 51 into AC power of the requested frequency and power, and outputs the AC power.

[0037] (Power generation control device) Next, the configuration of the power generation control device 1 will be described below.

[0038] The power generation control device 1 controls the driving of the power conversion unit 5. Specifically, the power generation control device 1 controls the driving of each of the DC conversion unit 51 and the AC conversion unit 53 of the power conversion unit 5 in response to a request from the power grid.

[0039] Incidentally, the characteristics of at least a part of the sound wave conversion unit 2, the vibration conversion unit 3, and the linear generator 4 in the power generation device S change due to aging. Therefore, the power generation characteristics of the power generation device S may change gradually.

[0040] Fig. 3 is a diagram showing an example in which the relationship between the moving speed of the mover of the linear generator 4 and the generated power changes with temperature. As shown in Fig. 3, the generated power of the linear generator 4 changes according to the moving speed of the mover of the linear generator 4. And at each temperature, there exists a moving speed of the mover of the linear generator 4 at which the generated power of the linear generator 4 is maximum. By connecting such maximum power points, a power generation characteristic curve of the linear generator 4 as shown in Fig. 3 is obtained.

[0041] 4 is a diagram showing an example of the relationship between the moving speed of the mover of the linear generator 4 and the generated power at a predetermined temperature. At the beginning of operation of the power generation device S, the power generation characteristic curve of the linear generator 4 is an initial power generation characteristic curve as shown by the solid line. When the relationship between the moving speed of the mover of the linear generator 4 at the predetermined temperature and the generated power changes as shown by the dashed line due to aging of the power generation device S, the generator characteristic curve of the linear generator 4 also changes to a post-change power generation characteristic curve as shown by the dashed line.

[0042] As shown in Fig. 4, when the speed of the mover of the linear generator 4 is V1, the linear generator 4 can generate power up to P1 at the beginning of operation of the power generation device S, but when the power generation characteristic curve changes as shown by the dashed line, the linear generator 4 can only generate power up to P2. In other words, the power generation capacity of the linear generator 4 is reduced due to aging of the power generation device S, etc.

[0043] If the power generation control device 1 does not recognize the decrease in the power generation capacity of the linear generator 4 as described above, and assumes that the linear generator 4 is capable of outputting the power of the initial power generation characteristic curve shown in Figure 4, and converts the power generated by the linear generator 4, there is a possibility that an excessive load will be placed on the linear generator 4.

[0044] In contrast, the power generation control device 1 of this embodiment also has a function of grasping the power generation characteristics of the power generation device S, including changes in the power generation characteristic curve of the linear generator 4 as described above. Specifically, the power generation control device 1 detects changes in the power generation characteristics of the power generation device S, and acquires the power generation characteristics when the power generation characteristics have changed by a predetermined amount or more. Furthermore, when new power generation characteristics are acquired, the power generation control device 1 updates the reference vibration frequency used when determining whether the power generation characteristics have changed.

[0045] In detail, the power generation control device 1 includes a power generation characteristic change detection unit 11, a power generation characteristic acquisition unit 12, and a reference vibration frequency update unit 13.

[0046] The power generation characteristic change detection unit 11 detects a change in the power generation characteristics of the power generation device S. The power generation characteristic change detection unit 11 detects a change in the power generation characteristics by comparing the vibration frequency of the linear generator 4 with a reference vibration frequency. Specifically, the power generation characteristic change detection unit 11 detects that the power generation characteristics of the power generation device S have changed when the difference between the vibration frequency and the reference vibration frequency is greater than a frequency threshold value (threshold value). In other words, the power generation characteristic change detection unit 11 detects that the power generation characteristics of the power generation device S have changed when the following formula is satisfied. Δfth<Δf=f-fr

[0047] Here, Δfth is a frequency threshold value, and Δf is the difference between the vibration frequency f of the linear generator 4 and the reference vibration frequency fr.

[0048] The frequency threshold Δfth is determined based on the reference vibration frequency fr and a drive stop frequency fc at which the drive of the linear generator 4 stops. Specifically, the lower limit value of the frequency threshold Δfth is determined in consideration of a range f1 that is susceptible to the effects of detection errors, disturbances, etc., with respect to the reference vibration frequency fr. Also, the upper limit value of the frequency threshold Δfth is determined in consideration of a range f2 in which the drive of the linear generator 4 may stop due to detection errors, disturbances, etc., with respect to the drive stop frequency fc of the linear generator 4. The frequency threshold Δfth is set so as to satisfy, for example, the following relationship. (fr+f1)<(Δf+fr)<(fc-f2)

[0049] Here, the reference vibration frequency fr is set to the vibration frequency of the linear generator 4 when the initial power generation characteristic curve is obtained. The vibration frequency is a theoretical value including a design value or an actual measurement value including a vibration frequency at the time of adjusting the acoustic impedance when the power generation device S is installed.

[0050] When the power generation characteristic change detection unit 11 detects that the power generation characteristics of the power generation device S have changed, the power generation characteristic acquisition unit 12 reacquires the power generation characteristics of the power generation device S. Specifically, when the power generation characteristic change detection unit 11 detects that the power generation characteristics of the power generation device S have changed, the power generation characteristic acquisition unit 12 reacquires the power generation characteristic curve of the linear generator 4. The power generation characteristic acquisition unit 12 reacquires the power generation characteristic curve, for example, as follows.

[0051] Fig. 5 is a diagram showing a schematic diagram of a method for determining the maximum power point. Under the condition that the speed of the mover of the linear generator 4 is constant, the power generation characteristic acquisition unit 12 detects the maximum power point PA of the linear generator 4 by changing the output current of the linear generator 4 within a range R as shown in Fig. 5. At this time, the power generation characteristic acquisition unit 12 detects, for example, the current input to the DC conversion unit 51 of the power conversion unit 5 as the output current, and increases or decreases the output current of the linear generator 4 by a hill-climbing method.

[0052] When detecting the maximum power point PA, the power generation characteristic acquisition unit 12 may determine the maximum power point PA using a moving average or may determine the maximum power point PA using multiple detection results so as not to be affected by detection errors or momentary fluctuations due to disturbances.

[0053] The method by which the power generation characteristics acquisition unit 12 detects the maximum power point PA of the linear generator 4 may be a method other than the above.

[0054] Fig. 6 is a diagram showing a schematic diagram of a method for obtaining a power generation characteristic curve. The power generation characteristic obtaining unit 12 obtains a new power generation characteristic curve (dashed line in Fig. 6) for a known power generation characteristic curve (solid line in Fig. 6) by using the maximum power point PA detected as described above. For example, when the moving speed of the mover of the linear generator 4 is B, the power generation characteristic obtaining unit 12 may obtain a proportionality constant by using the ratio between the power P obtained from the known power generation characteristic curve and the maximum power point PA detected as described above, and may obtain a new power generation characteristic curve by correcting the known power generation characteristic curve by using this proportionality constant.

[0055] The power generation characteristic acquisition unit 12 may obtain a new power generation characteristic curve by determining maximum power points in a plurality of operating states of the linear generator 4.

[0056] The reference vibration frequency update unit 13 updates the reference vibration frequency when the power generation characteristic change detection unit 11 detects a change in the power generation characteristics of the power generation device S. This makes it possible to change the standard for detecting a change in the power generation characteristics of the power generation device S after the change in the power generation characteristics of the power generation device S. Therefore, the power generation characteristics of the power generation device S can be changed according to the aging of the power generation device S.

[0057] (How to obtain power generation characteristics) Next, the operation of the power generation control device 1 having the above-mentioned configuration for acquiring the power generation characteristics of the linear generator 4 will be described with reference to Fig. 7. Fig. 7 is a flowchart showing the operation of the power generation control device 1 for acquiring the power generation characteristics of the linear generator 4.

[0058] 7 starts (START), the power generation control device 1 first controls the drive of the power generation device S in accordance with the power required from the power grid in step S1. At this time, the power generation control device 1 drives the power generation device S so that the generated power of the power generation device S becomes an optimal value in accordance with a power generation characteristic curve stored in a storage unit (not shown).

[0059] In the next step S2, the power generation characteristic change detection unit 11 of the power generation control device 1 acquires the vibration frequency of the linear generator 4. The power generation characteristic change detection unit 11 measures the vibration frequency using a position sensor (not shown) or the like provided in the linear generator 4. In step S3, the power generation characteristic change detection unit 11 determines whether the difference Δf between the vibration frequency f of the linear generator 4 and the reference vibration frequency fr is greater than a frequency threshold value (threshold value) Δfth.

[0060] If the power generation characteristic change detection unit 11 determines in step S3 that Δf>Δfth (if YES), the process proceeds to step S4, where the power generation characteristic acquisition unit 12 acquires the power generation characteristic curve of the linear generator 4. On the other hand, if the power generation characteristic change detection unit 11 determines in step S3 that Δf>Δfth is not true (if NO), the process returns to step S2 and the vibration frequency of the linear generator 4 is acquired again.

[0061] In step S4, the power generation characteristic acquisition unit 12 detects the maximum power point and then obtains a new power generation characteristic curve by using the maximum power point for the known power generation characteristic curve. Then, in step S5, the reference vibration frequency update unit 13 updates the vibration frequency f of the linear generator 4 to a new reference vibration frequency fr.

[0062] Then, this flow ends (END).

[0063] As described above, the power generation control device 1 of this embodiment controls the driving of a power generation device that generates power by using sound waves having a natural frequency. The power generation control device 1 includes a power generation characteristic change detection unit 11 that detects whether the power generation characteristics of the power generation device S have changed, and a power generation characteristic acquisition unit 12 that acquires the power generation characteristics of the power generation device S when the power generation characteristic change detection unit 11 detects that the power generation characteristics of the power generation device S have changed.

[0064] In this way, in the case of a power generation device that generates power using sound waves having a natural frequency, the power generation control device drives the generator of the power generation device in accordance with the natural frequency of the sound waves. Therefore, when driving the power generation device to obtain power, the power generation control device grasps the power that can be output from the power generation device from the power generation characteristics of the power generation device S that are matched to the natural frequency of the sound waves.

[0065] However, when the natural frequency of at least one of the sound wave conversion unit 2, the vibration conversion unit 3, and the linear generator 4 that generate the sound waves changes due to aging of the power generation device S, the power generation characteristics of the power generation device S change, and the power that can be output from the power generation device S also changes.

[0066] In contrast, as configured above, when the power generation characteristics of the power generation device S change, the power generation control device 1 acquires the power generation characteristics of the power generation device S, and can control the operation of the power generation device S by grasping the changed power generation characteristics of the power generation device S even if the natural frequency of the devices that constitute the power generation device S has changed due to aging or the like as described above.

[0067] Furthermore, when the power generation characteristic change detection unit 11 detects that the power generation characteristics of the power generation unit S have changed, the power generation characteristic acquisition unit 12 acquires the power generation characteristics of the power generation unit S, so there is no need to frequently change the power generation characteristics of the power generation unit S as in the conventional technology.

[0068] Therefore, the power generation control device 1 can be obtained that can obtain power generation characteristics that enable efficient power generation while stably supplying power.

[0069] In this embodiment, the power generation device S has a linear generator 4 that generates power by utilizing vibrations caused by the sound waves. The power generation characteristic change detection unit 11 detects a change in the power generation characteristics of the power generation device S based on the vibration frequency f and the reference vibration frequency fr when the linear generator 4 is operating.

[0070] This allows the power generation characteristic change detection unit 11 to detect a change in the power generation characteristics of the power generation device S based on the vibration frequency f and the reference vibration frequency fr when the linear generator 4 is operating. Therefore, the power generation control device 1 can easily detect a change in the power generation characteristics of the power generation device S.

[0071] In this embodiment, the power generation characteristic change detection unit 11 detects a change in the power generation characteristics of the power generation device S when the difference Δf between the vibration frequency f when the linear generator 4 is operating and the reference vibration frequency fr exceeds a frequency threshold Δfth. The frequency threshold Δfth is determined based on the reference vibration frequency fr and a drive stop frequency fc at which the drive of the linear generator 4 is stopped.

[0072] As a result, even if the vibration frequency of the linear generator 4 differs from the reference vibration frequency fr, the power generation characteristic change detection unit 11 does not detect a change in the power generation characteristics of the power generation device S until the difference between them exceeds the frequency threshold value Δfth. This prevents the power generation control device 1 from frequently acquiring the power generation characteristics of the power generation device S due to changes in the vibration frequency of the linear generator 4.

[0073] Moreover, the frequency threshold value Δfth is determined based on the reference vibration frequency fr and a drive stop frequency at which the drive of the linear generator 4 is stopped. Therefore, the frequency threshold value Δfth can be determined within a range in which the drive of the linear generator 4 is not stopped, while taking into consideration disturbances and the like.

[0074] Therefore, the power generation control device 1 can acquire the power generation characteristics of the power generation unit S while taking into account disturbances, etc., while preventing the power generation control device 1 from frequently acquiring the power generation characteristics of the power generation unit S to the extent that the operation of the linear generator 4 is not stopped.

[0075] In this embodiment, the power generation control device 1 further includes a reference vibration frequency update unit 13 that sets the vibration frequency f when the linear generator 4 is operating as the reference vibration frequency fr when the power generation characteristics acquisition unit 12 acquires the power generation characteristics of the power generation device S.

[0076] This allows the reference vibration frequency fr to be changed when the power generation characteristics of the power generation device S change and the power generation characteristics acquisition unit 12 acquires the changed power generation characteristics. Therefore, the reference for acquiring the power generation characteristics can be changed in response to aging or the like of the power generation device S. Therefore, the power generation characteristics of the power generation device S grasped by the power generation control device 1 can be changed at an appropriate timing.

[0077] (Other embodiments) Although the embodiment of the present invention has been described above, the above-mentioned embodiment is merely an example for carrying out the present invention. Therefore, the present invention is not limited to the above-mentioned embodiment, and it is possible to carry out the above-mentioned embodiment by appropriately modifying it within the scope of the gist of the present invention.

[0078] In the embodiment, the power generation device S generates power by utilizing sound waves obtained by the thermoacoustic phenomenon. However, the power generation device may generate power by utilizing energy waves other than the sound waves obtained by the thermoacoustic phenomenon as long as the energy waves have a natural frequency.

[0079] In addition, when the power generation device generates power by utilizing energy waves other than sound waves, the power generation device has another device for transmitting the energy waves to the generator, rather than the sound wave conversion unit and the vibration conversion unit.

[0080] In the embodiment, the power generation device S includes a linear generator 4. However, the power generation device may include a generator other than a linear generator as long as the generator is capable of generating power by utilizing an energy wave having a natural frequency.

[0081] In the embodiment, the power generation characteristic change detection unit 11 of the power generation control device 1 detects a change in the power generation characteristics of the power generation device, including the power generation characteristics of the linear generator 4, by using a change in the vibration frequency of the linear generator 4. However, the power generation characteristic change detection unit may detect a change in the power generation characteristics of the power generation device by using the frequency of sound waves obtained by a thermoacoustic phenomenon or the frequency of the current output from the linear generator. The power generation characteristic change detection unit may also compare the power obtained from the power generation characteristic curve with the power actually generated by the linear generator, and detect that the power generation characteristics of the power generation device have changed when the difference exceeds a threshold value.

[0082] In addition, the power generation characteristic change detection unit may detect a change in the power generation characteristics of the power generation device based on at least one of the vibration frequency of the linear generator, the frequency of sound waves, the frequency of the current output from the linear generator, and the difference between the power obtained from the power generation characteristic curve and the actual generated power.

[0083] In the embodiment, the power generation control device 1 has a reference vibration frequency update unit 13. However, the power generation control device may not have a reference vibration frequency update unit. That is, the power generation control device may not update the reference vibration frequency. For example, in a case where the difference between the initial power generation characteristics and the power generation characteristics after the change is small, and therefore the power generation characteristics of the power generation device are hardly affected even if the reference vibration frequency is not updated, or in a case where the setting width of the frequency threshold value Δfth is small, and therefore updating the reference vibration frequency may cause the power generation control of the power generation device to become unstable, the reference vibration frequency may not be updated as described above. [Industrial Applicability]

[0084] INDUSTRIAL APPLICABILITY The present invention can be used in a power generation control device that controls the operation of a power generation device that generates power by utilizing an energy wave having a natural frequency. [Explanation of symbols]

[0085] 1 Power generation control device 2. Sound wave conversion unit 3. Vibration converter 4. Linear generator 5 Power conversion section 11 Power generation characteristic change detection section 12 Power generation characteristics acquisition section 13. Normal vibration frequency update unit 51 DC conversion section 52 Smoothing capacitor 53 AC conversion unit SW Switching element S Power Generation Equipment

Claims

1. A power generation control device that controls the operation of a power generation device that generates power by utilizing an energy wave having a natural frequency, a power generation characteristic change detection unit for detecting whether or not the power generation characteristics of the power generation device have changed; a power generation characteristics acquisition unit that acquires the power generation characteristics of the power generation device when the power generation characteristics change detection unit detects that the power generation characteristics of the power generation device have changed; Equipped with the power generation device has a linear generator that generates power by utilizing vibrations caused by the energy wave, the power generation characteristic change detection unit detects a change in the power generation characteristics of the power generation device based on a vibration frequency and a reference vibration frequency when the linear generator is operating. Power generation control device.

2. 2. The power generation control device according to claim 1, the power generation characteristic change detection unit detects a change in the power generation characteristics of the power generation device when a difference between the vibration frequency when the linear generator is operating and the reference vibration frequency exceeds a threshold value; The threshold value is determined based on the reference vibration frequency and a drive stop frequency at which the drive of the linear generator is stopped. Power generation control device.

3. The power generation control device according to claim 1 or 2, a reference vibration frequency update unit that sets the vibration frequency when the linear generator is operating as the reference vibration frequency when the power generation characteristic acquisition unit acquires the power generation characteristics of the power generation device, Power generation control device.

4. The power generation control device according to any one of claims 1 to 3, A power generation control device, wherein the energy wave is a sound wave obtained by a thermoacoustic phenomenon.

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