WO2022130457A1 - Power control device, thermoelectric power generation system, and power control method - Google Patents

Abstract

The purpose of the present invention is to increase the power extracted from a thermoelectric conversion device. This power control device is provided with a power measurement unit which measures power outputted from the thermoelectric conversion device, and a control unit which controls the power outputted from the thermoelectric conversion device. The power measurement unit measures the power outputted from the thermoelectric conversion device after the load relative to the output of the thermoelectric conversion device has fluctuated and further after a time corresponding to the thermal time constant of the thermoelectric conversion device has elapsed.

Description

Power control device, thermoelectric power generation system, and power control method

The technique disclosed in the specification of the present application relates to a thermoelectric power generation technique.

As a control method of the conventional thermoelectric converter, in order to maximize the output from the thermoelectric converter, the output current of the thermoelectric converter is fluctuated at an arbitrary control cycle using the mountain climbing method to search for the optimum operating point. (For example, refer to Japanese Patent Application Laid-Open No. 2013-055769, which is Patent Document 1).

Japanese Unexamined Patent Publication No. 2013-055769

In such a control method of a thermoelectric conversion device, if the control cycle is shorter than the thermal time constant of the thermoelectric conversion device, it becomes difficult to obtain an accurate maximum power point of the thermoelectric conversion device. As a result, there is a problem that the extraction power is lower than the maximum output power of the thermoelectric conversion device.

The technique disclosed in the present specification has been made in view of the above-mentioned problems, and is a technique for increasing the extraction power of the thermoelectric conversion device.

The electric power control device according to the first aspect of the technique disclosed in the present specification is a power control device that controls the electric power of the thermoelectric conversion device that outputs the electric power generated based on heat, and is from the thermoelectric conversion device. A power measuring unit for measuring the output power and a control unit for controlling the power output from the thermoelectric conversion device are provided, and the power measuring unit has a load on the output of the thermoelectric conversion device after the load is changed. Further, after the time corresponding to the thermal time constant of the thermoelectric conversion device has elapsed, the electric power output from the thermoelectric conversion device is measured.

According to at least the first aspect of the technique disclosed in the present specification, it is possible to increase the electric power (extracted electric power) output from the thermoelectric conversion device.

Further, the objectives, features, aspects, and advantages associated with the techniques disclosed herein will be further clarified by the detailed description and accompanying drawings shown below.

It is a figure which shows the example of the structure of the thermoelectric power generation system which concerns on embodiment. It is a flowchart which shows the example of the operation (maximum output control) of a power control device. It is a figure which shows the example of the value of the electric power (take-out electric power) output from a thermoelectric conversion apparatus in the electric power control apparatus which concerns on embodiment, when the control cycle which is the waiting time of control is changed. It is a figure which shows typically the thermal circuit of a thermoelectric conversion apparatus. It is a figure which shows the example of the transient characteristic of the electric power output from a thermoelectric conversion apparatus when the current of a thermoelectric conversion apparatus is increased by ΔI (when the current is perturbed by + ΔI by a hill climbing method). It is a figure which shows the example of the current-voltage characteristic at the time of thermal equilibrium of a thermoelectric conversion apparatus. It is a figure which shows the example of the voltage characteristic of a thermoelectric conversion apparatus when the current of a thermoelectric conversion apparatus is increased by ΔI (when the current is perturbed by + ΔI by a hill climbing method). It is a figure which shows the example of the transient characteristic of the electric power P output from a thermoelectric conversion apparatus when the current of a thermoelectric conversion apparatus is decreased by ΔI (when the current is perturbed by −ΔI by a hill climbing method). It is a figure which shows the example of the current-voltage characteristic at the time of thermal equilibrium of a thermoelectric conversion apparatus. It is a figure which shows the example of the voltage characteristic of a thermoelectric conversion apparatus when the current of a thermoelectric conversion apparatus is decreased by ΔI (when the current is perturbed by −ΔI by a hill climbing method). It is a figure which shows the example of the structure of the thermoelectric power generation system which concerns on embodiment. It is a flowchart which shows the example of the operation for acquiring the thermal time constant of a power control device. It is a figure which shows the example of the transient characteristic of the voltage of a thermoelectric conversion apparatus at the time of changing from a short circuit state to an open state. It is a flowchart which shows the example of the operation (maximum output control) of a power control device. It is a figure which schematically exemplifies the hardware configuration in the case of actually operating the thermoelectric power generation system whose example is shown in FIGS. 1 and 11. It is a figure which schematically exemplifies the hardware configuration in the case of actually operating the thermoelectric power generation system whose example is shown in FIGS. 1 and 11.

Hereinafter, embodiments will be described with reference to the attached drawings. In the following embodiments, detailed features and the like are also shown for illustration purposes, but they are exemplary and not all of them are essential features for the embodiments to be feasible.

It should be noted that the drawings are shown schematically, and for convenience of explanation, the configuration is omitted or the configuration is simplified as appropriate in the drawings. Further, the interrelationship between the sizes and positions of the configurations and the like shown in different drawings is not always accurately described and can be changed as appropriate. Further, even in a drawing such as a plan view which is not a sectional view, hatching may be added to facilitate understanding of the contents of the embodiment.

Further, in the explanation shown below, similar components are illustrated with the same reference numerals, and their names and functions are the same. Therefore, detailed description of them may be omitted to avoid duplication.

Further, in the description described below, when a certain component is described as "providing", "including", "having", etc., the existence of the other component is excluded unless otherwise specified. Not an expression.

Also, even if ordinal numbers such as "first" or "second" may be used in the description described below, these terms facilitate the understanding of the content of the embodiments. It is used for convenience, and is not limited to the order that can be generated by these ordinal numbers.

Further, in the description described below, expressions indicating equality, such as "same", "equal", "uniform" or "homogeneous", are strictly equal unless otherwise specified. It shall include the case where it indicates that there is, and the case where there is a difference within the range where tolerance or similar function can be obtained.

<First Embodiment>
Hereinafter, the electric power control device, the thermoelectric power generation system, and the electric power control method according to the present embodiment will be described.

<About the configuration of the thermoelectric power generation system>
FIG. 1 is a diagram showing an example of a configuration of a thermoelectric power generation system according to the present embodiment. As an example shown in FIG. 1, the thermoelectric power generation system 100 includes a thermoelectric conversion device 11, a power control device 12 for controlling electric power output from the thermoelectric conversion device 11, and a load 13. The load 13 is composed of a constant voltage source such as a storage battery.

The thermoelectric conversion device 11 includes a thermoelectric conversion module 11a, a high temperature side heat exchanger 11b and a low temperature side heat exchanger 11c provided with the thermoelectric conversion module 11a interposed therebetween.

The thermoelectric conversion module 11a is composed of, for example, a thermoelectric conversion element. When a temperature difference is applied to both ends of the thermoelectric conversion module 11a, an electromotive force is generated by the Seebeck effect. When the thermoelectric conversion module 11a is composed of a thermoelectric conversion element, the thermoelectric conversion element is connected in series or in parallel in the thermoelectric conversion module 11a. Then, the electromotive force generated in the thermoelectric conversion module 11a is taken out from the positive electrode and the negative electrode of the thermoelectric conversion module 11a.

The high temperature side heat exchanger 11b has a fin structure made of, for example, aluminum or SUS. The high temperature side heat exchanger 11b transfers the heat of a high temperature fluid such as exhaust gas to the surface on the high temperature side of the thermoelectric conversion module 11a.

On the other hand, the low temperature side heat exchanger 11c has a structure in which cooling water flows in a block made of, for example, aluminum or copper. The low temperature side heat exchanger 11c takes heat transferred from the low temperature side surface of the thermoelectric conversion module 11a.

With these configurations, heat is transferred (penetrated) from the surface on the high temperature side of the thermoelectric conversion module 11a to the surface on the low temperature side.

The power control device 12 includes a thermal time constant acquisition unit 12a, a power measurement unit 12b, a power conversion control unit 12c, and a power conversion unit 12d.

The positive electrode and the negative electrode of the thermoelectric conversion device 11 are connected to the power control device 12. Then, the electric power generated by the thermoelectric conversion device 11 is input to the power control device 12.

The load 13 is also connected to the power control device 12. Then, the electric power converted by the electric power conversion unit 12d is output to the load 13.

The power conversion unit 12d is provided with a positive electrode and a negative electrode on the input side, and each is connected to the positive electrode and the negative electrode of the thermoelectric conversion device 11. Then, the electric power generated by the thermoelectric conversion device 11 is input to the electric power conversion unit 12d.

Similarly, the power conversion unit 12d is provided with a positive electrode and a negative electrode on the output side, and each is connected to the positive electrode and the negative electrode of the load 13. Then, the electric power converted by the electric power conversion unit 12d is output to the load 13.

The power conversion unit 12d is composed of, for example, a step-up type, step-down type or buck-boost type DC-DC converter. The load of the power conversion unit 12d as seen from the terminal on the input side of the power conversion unit 12d can be changed by controlling the time ratio (duty ratio) of opening and closing the switching element of the power conversion unit 12d.

In the control by opening and closing of the switching element, a switching signal which is a periodic rectangular wave (for example, a PWM (Pulse Width Modulation) wave or a PFM (Pulse Frequency Modulation) wave) for opening and closing is a power conversion control unit. This is done by sending from 12c to the switching element.

The thermal time constant acquisition unit 12a, the power measurement unit 12b, and the power conversion unit 12d are connected to the power conversion control unit 12c.

The thermal time constant acquisition unit 12a detects and acquires the temperature of the surface on the high temperature side and the temperature of the surface on the low temperature side of the thermoelectric conversion module 11a using a thermoelectric pair or the like. Then, the thermal time constant acquisition unit 12a calculates the thermal time constant based on the temperature of the surface on the high temperature side and the temperature of the surface on the low temperature side of the thermoelectric conversion module 11a, and transmits the thermal time constant to the power conversion control unit 12c. do.

The power measuring unit 12b measures the power output from the thermoelectric conversion device 11 by measuring the current and voltage output from the thermoelectric conversion device 11. Further, the internal resistance of the thermoelectric conversion device 11 is acquired based on the current value and the voltage value output from the thermoelectric conversion device 11. Then, the power measuring unit 12b transmits the measured power as power data to the power conversion control unit 12c.

The power conversion control unit 12c controls the maximum output of the power output from the thermoelectric conversion device 11 based on the input thermal time constant and the power data.

<About the operation of the power control device in the thermoelectric power generation system>
FIG. 2 is a flowchart showing an example of the operation of the power control device 12 (mainly, maximum output control by the power conversion control unit 12c). Here, as an example of the maximum power point search, the maximum power point search algorithm by the mountain climbing method is used.

First, in step ST10, the thermal time constant acquisition unit 12a calculates and acquires the thermal time constant T of the thermoelectric conversion device 11. The thermal time constant T is obtained as follows.

When the value of the current output from the thermoelectric conversion device 11 is changed from I to I + ΔI, the temperature _{Th on the high temperature side of the thermoelectric conversion module 11a changes to Th + ΔT h0 , and} the temperature on the low temperature side of the thermoelectric conversion module 11a changes. The temperature T _c changes to T _c + ΔT _{c 0} . At this time, the temperature difference given to the thermoelectric conversion module 11a changes as shown in the following equation (1).

Then, after a certain period of time (t seconds), the temperature on the high temperature side of the thermoelectric conversion module 11a becomes _{Th + ΔT h1 ,} and the temperature on the low temperature side of the thermoelectric conversion module 11a becomes T _c + ΔT _c1 . Therefore, the change in the temperature difference of the thermoelectric conversion module 11a in t seconds is as shown in the following equation (2).

The thermal time constant T is calculated from the transient characteristics of the temperature difference obtained as described above with respect to the time t.

Next, in step ST11, the duty ratio of the switching signal input from the power conversion control unit 12c to the power conversion unit 12d is changed. Then, the value of the current output from the thermoelectric conversion device 11 to the power conversion unit 12d is changed from I to I + ΔI.

Next, in step ST12, wait for a time corresponding to the thermal time constant T acquired in step ST10. Since the value of the current output from the thermoelectric conversion device 11 to the power conversion unit 12d in step ST11 is changed from I to I + ΔI, a Pelche effect is generated in the thermoelectric conversion module 11a and the thermal resistance is lowered. Then, the heat balance of the thermoelectric conversion device 11 is temporarily lost.

Therefore, depending on the system, the system is thermally stabilized by waiting for an arbitrary constant multiple time such as T or 3T with respect to the time T of the thermal time constant.

Next, in step ST13, the power measuring unit 12b measures the power P (take-out power) output from the thermoelectric conversion device 11. The power measuring unit 12b measures the voltage V output from the thermoelectric conversion device 11 and the current I output from the thermoelectric conversion device 11, respectively, and calculates the power as power P = voltage V × current I.

Next, in step ST14, the power P measured in step ST13 and the power P'similarly measured in step ST13 of the previous loop (that is, the power before the current value changes in step ST11) are combined. compare. When step ST14 is the first time in the loop, the comparison is performed with the power P'set to 0.

Then, if P> P', that is, if it corresponds to "YES" branching from step ST14 shown in FIG. 2, the process proceeds to step ST15. On the other hand, if P> P', that is, if it corresponds to "NO" branching from step ST14 shown in FIG. 2, the process proceeds to step ST16.

In step ST15, it is determined that the current value ΔI to be changed in step ST11 in the next loop is ΔI, which is the same value as in the previous step ST11. Then, the process proceeds to step ST17.

In step ST16, it is determined that the value ΔI of the current to be changed in step ST11 in the next loop is −ΔI, which is the value of the opposite sign (the absolute value is the same) as in the case of the previous step ST11. Then, the process proceeds to step ST17.

Next, in step ST17, the power P measured in step ST13 is updated to the value used as the power P'in step ST14 of the next loop. Then, the process returns to step ST11.

By these processes, the power control device 12 controls to repeat the loop near the current value at which the power output from the thermoelectric conversion device 11 is maximized. In this way, the power control device 12 searches for the maximum value of the power output from the thermoelectric conversion device 11.

Although the maximum power point search by the mountain climbing method is shown in the present embodiment, another power search method may be adopted as long as the maximum power point is searched by changing the current value.

Next, the optimum value of the control cycle of the thermoelectric conversion device 11 will be examined. FIG. 3 shows an example of the value of the power P (take-out power) output from the thermoelectric conversion device 11 when the control cycle t, which is the waiting time for control, is changed in the power control device 12 according to the present embodiment. It is a figure which shows. In FIG. 3, the vertical axis shows the value of the electric power P, and the horizontal axis shows the control cycle of the thermoelectric conversion device 11.

As an example is shown in FIG. 3, there is a point X where the electric power P output from the thermoelectric conversion device 11 is maximized in the control cycle t. The point X is near the thermal time constant T of the thermoelectric conversion device 11. The reason for this will be described below.

When the control cycle t is shorter than the thermal time constant T, the thermoelectric conversion is performed when measuring the power P output from the thermoelectric conversion device 11 after changing the current I output from the thermoelectric conversion device 11 in step ST11. The temperature of the device 11 has not yet reached the equilibrium state. Therefore, the output has not reached the equilibrium state, and the true maximum power point cannot be obtained.

FIG. 4 is a diagram schematically showing a thermal circuit of the thermoelectric conversion device 11. In the thermoelectric conversion device 11, the thermal resistance R _h and the heat capacity _Ch mainly by the high temperature side heat exchanger 11b are formed between the surface _Th of the high temperature side of the thermoelectric conversion module 11a and the temperature fixing point _Th on the high temperature side. It exists in parallel. Similarly, between the surface T _cs on the low temperature side of the thermoelectric conversion module 11a and the temperature fixing point T _c on the low temperature side (here, the temperature of the cooling water), the heat resistance R _c mainly due to the low temperature side heat exchanger 11 c. The heat capacity C _c exists in parallel.

In the thermoelectric conversion module 11a, by varying the flowing current I, the amount of heat transferred from the high temperature side to the low temperature side of the thermoelectric conversion element increases from Q to Q + ΔQ due to the Pelche effect, and the thermal resistance _RTEG changes. At this time, assuming that the thermal resistance of the thermoelectric conversion module 11a when the current is 0 is r _TEG0 and the Perche coefficient is Π, the amount of heat Q flowing through the thermoelectric conversion module 11a is expressed by the following equation (3).

Therefore, the thermal resistance R _TEG of the thermoelectric conversion module 11a is expressed by the following equation (4).

That is, when the current is increased by ΔI, the thermal resistance R _TEG decreases according to the above equation (4).

As described above, the thermal resistance _RTEG of the thermoelectric conversion module 11a changes due to the current fluctuation, and the high temperature side heat exchanger 11b and the low temperature side heat exchanger 11c each have a heat capacity, so that the thermoelectric conversion element There is a delay before the temperature difference between the two reaches the equilibrium state. Along with this, the response of the thermoelectromotive force of the thermoelectric conversion module 11a also becomes delayed.

FIG. 5 is a diagram showing an example of the transient characteristics of the electric power P output from the thermoelectric conversion device 11 when the current of the thermoelectric conversion device 11 is increased by ΔI (when the current is perturbed by + ΔI by the hill climbing method). .. In FIG. 5, the vertical axis shows the value of electric power, and the horizontal axis shows the value of current.

Further, FIG. 6 is a diagram showing an example of the current-voltage characteristics of the thermoelectric conversion device 11 at the time of thermal equilibrium. In FIG. 6, the vertical axis represents the voltage value and the horizontal axis represents the current value.

Further, FIG. 7 is a diagram showing an example of the voltage characteristics of the thermoelectric conversion device 11 when the current of the thermoelectric conversion device 11 is increased by ΔI (when the current is perturbed by + ΔI by the mountain climbing method). In FIG. 7, the vertical axis represents the voltage value and the horizontal axis represents time.

Assuming that the power P _max (see FIG. 5), which is the maximum power at the time of thermal equilibrium, is indicated by V _pmax I _pmax , when the current I is increased by ΔI from I _pmax to I _pmax + ΔI, the voltage V increases the current. From the moment of, it gradually approaches V _pmax -ΔV according to the current-voltage characteristics at the time of thermal equilibrium of the thermoelectric conversion device 11 (see FIGS. 6 and 7). Here, the time constant at the time of asymptote is the thermal time constant T.

In this case, when the time (control cycle t) to wait in step ST12 of the flowchart shown in FIG. 2 is shorter than the thermal time constant T, the voltage V measured in step ST13 of the flowchart shown in FIG. 2 is shown in FIG. It becomes V1 shown in 6 and FIG. 7, and becomes a value higher than the value V _pmax − ΔV of the voltage V at the time of thermal equilibrium.

The value of the voltage V when the current I is increased from I _pmax to I _pmax + ΔI by ΔI can be expressed by the following equation (5) which approaches V _pmax − ΔV with the thermal time constant T.

For example, when the control cycle t is 1/100 of the thermal time constant T, substituting 1/100 for t / T in the equation (5), the voltage V is shown as follows.

Therefore, the voltage V becomes almost the same value as V _pmax , and a value higher than V _pmax − ΔV at the time of thermal equilibrium is measured as the voltage V. In this case, the power P calculated in step ST13 of the flowchart shown in FIG. 2 is shown as follows.

As described above, the calculated power P is higher than V _pmax I _pmax , which is the maximum power at the time of thermal equilibrium. Then, in step ST14 of the flowchart shown in FIG. 2, P>P'(that is, corresponding to “YES” branching from step ST14 shown in FIG. 2), and the step of the flowchart shown in FIG. Proceed to ST15.

Then, in step ST15 of the flowchart shown in FIG. 2, the value ΔI of the current to be changed in step ST11 in the next loop is ΔI, which is the same value as in the previous step ST11. When returning to step ST11 of the flowchart shown in 2, the value of the current output from the thermoelectric conversion device 11 to the power conversion unit 12d is changed from I _pmax + ΔI to I _pmax + 2ΔI, which is higher than I _pmax . Further, the current I becomes large.

Further, while repeating the loop from step ST11 to step ST17 in the flowchart shown in FIG. 2, the temperature difference applied to the thermoelectric conversion module 11a (thermoelectric conversion element) becomes smaller with the passage of time, and the electromotive force decreases. do. Then, in step ST14 of the flowchart shown in FIG. 2, P> P'is no longer present (that is, corresponding to “NO” branching from step ST14 shown in FIG. 2), and the flowchart shown in FIG. 2 is shown. Proceed to step ST16.

Then, in step ST16 of the flowchart shown in FIG. 2, the value ΔI of the current to be changed in step ST11 in the next loop is a value having a sign opposite to that in the previous step ST11 (the absolute value is the same). In order to set ΔI, when returning to step ST11 of the flowchart shown in FIG. 2 in a later step, the value of the current output from the thermoelectric conversion device 11 to the power conversion unit 12d is changed from I _pmax + ΔI to I _pmax . It will change.

As described above, the value of the current output from the thermoelectric conversion device 11 to the power conversion unit 12d repeats the loop in the vicinity of a value that is ΔI larger than I _pmax . Therefore, step ST13 of the flowchart shown in FIG. The power P measured in is smaller than the power P _max , which is the maximum power at the time of thermal equilibrium.

On the other hand, the case where the current of the thermoelectric conversion device 11 is reduced by ΔI will also be described below.

FIG. 8 is a diagram showing an example of the transient characteristics of the power P output from the thermoelectric conversion device 11 when the current of the thermoelectric conversion device 11 is reduced by ΔI (when the current is perturbed by −ΔI by the hill climbing method). be. In FIG. 8, the vertical axis shows the value of electric power, and the horizontal axis shows the value of current.

Further, FIG. 9 is a diagram showing an example of the current-voltage characteristics of the thermoelectric conversion device 11 at the time of thermal equilibrium. In FIG. 9, the vertical axis shows the voltage value and the horizontal axis shows the current value.

Further, FIG. 10 is a diagram showing an example of the voltage characteristics of the thermoelectric conversion device 11 when the current of the thermoelectric conversion device 11 is reduced by ΔI (when the current is perturbed by −ΔI by the hill climbing method). In FIG. 10, the vertical axis represents the voltage value and the horizontal axis represents time.

Assuming that the power P _max (see FIG. 8), which is the maximum power at the time of thermal equilibrium, is indicated by V _pmax I _pmax , when the current I is reduced by ΔI from I _pmax + ΔI to I _pmax , the voltage V decreases. From the moment of, the voltage gradually approaches V _pmax according to the current-voltage characteristics (see FIG. 9) at the time of thermal equilibrium of the thermoelectric conversion device 11. Here, the time constant at the time of asymptote is the thermal time constant T.

In this case, when the time (control cycle t) to wait in step ST12 of the flowchart shown in FIG. 2 is shorter than the thermal time constant T, the voltage V measured in step ST13 of the flowchart shown in FIG. 2 is shown in FIG. It becomes V1 shown in 9 and FIG. 10, and becomes a value lower than the value V _pmax of the voltage V at the time of thermal equilibrium.

For example, when the control cycle t is 1/100 of the thermal time constant T, the voltage V becomes almost the same value as V _pmax − ΔV, and a value lower than V _pmax at the time of thermal equilibrium is measured as the voltage V. .. In this case, the power P calculated in step ST13 of the flowchart shown in FIG. 2 is shown as follows.

As described above, the calculated power P is lower than V _pmax I _pmax , which is the maximum power at the time of thermal equilibrium. Then, in step ST14 of the flowchart shown in FIG. 2, P>P'is no longer present (that is, corresponding to “NO” branching from step ST14 shown in FIG. 2), and the flowchart shown in FIG. 2 is shown. Proceed to step ST16.

Then, in step ST16 of the flowchart shown in FIG. 2, the value ΔI of the current to be changed in step ST11 in the next loop is a value having a sign opposite to that in the previous step ST11 (absolute value is the same) + ΔI. Therefore, when returning to step ST11 of the flowchart shown in FIG. 2 in a later step, the value of the current output from the thermoelectric conversion device 11 to the power conversion unit 12d is changed from I _pmax to I _pmax + ΔI. Will be made to.

Further, while repeating the loop from step ST11 to step ST17 in the flowchart shown in FIG. 2, the temperature difference applied to the thermoelectric conversion module 11a (thermoelectric conversion element) becomes smaller with the passage of time, and the electromotive force decreases. do.

Then, the value of the current output from the thermoelectric conversion device 11 to the power conversion unit 12d repeats the loop in the vicinity of a value ΔI larger than I _pmax , so that it is measured in step ST13 of the flowchart shown in FIG. The power P is smaller than the power P _max , which is the maximum power at the time of thermal equilibrium.

As described above, when the control cycle t is shorter than the thermal time constant T of the thermoelectric conversion device 11, the power P (take-out power) output from the thermoelectric conversion device 11 is higher than the maximum output during thermal equilibrium (steady state). Also declines.

Therefore, by setting the control cycle t to a value near the thermal time constant T, power characteristics close to those at the time of thermal equilibrium (steady state) of the thermoelectric conversion device 11 can be obtained, and the power P (extracted) output from the thermoelectric conversion device 11 can be obtained. Power) can be maximized.

On the other hand, when the control cycle t is sufficiently larger than the thermal time constant T, if the high temperature side heat source or the low temperature side heat source fluctuates in a cycle longer than the thermal time constant T and shorter than the control cycle t, the temperature fluctuation can be followed. Instead, the power P output from the thermoelectric conversion device 11 may stay at a value deviating from the maximum power P _max . Then, the electric power P output from the thermoelectric conversion device 11 becomes lower than the electric power P _max .

Therefore, in order to maximize the electric power P output from the thermoelectric conversion device 11, it is desirable that the control cycle t is a value near the thermal time constant T of the thermoelectric conversion device 11. By setting the control cycle t to a value near the thermal time constant T, the electric power P output from the thermoelectric conversion device 11 can be maximized even for a heat source in which the temperature difference fluctuates.

<Second embodiment>
A power control device, a thermoelectric power generation system, and a power control method according to the present embodiment will be described. In the following description, components similar to the components described in the above-described embodiments will be illustrated with the same reference numerals, and detailed description thereof will be omitted as appropriate. ..

<About the configuration of the thermoelectric power generation system>
FIG. 11 is a diagram showing an example of the configuration of the thermoelectric power generation system according to the present embodiment. As an example shown in FIG. 11, the thermoelectric power generation system 101 includes a thermoelectric conversion device 11, a power control device 22 for controlling electric power output from the thermoelectric conversion device 11, and a load 13. The load 13 is composed of a constant voltage source such as a storage battery.

The power control device 22 includes a thermal time constant acquisition unit 22a, a power measurement unit 22b, a power conversion control unit 22c, and a power conversion unit 22d.

The positive electrode and the negative electrode of the thermoelectric conversion device 11 are connected to the power control device 22. Then, the electric power generated by the thermoelectric conversion device 11 is input to the power control device 22.

The load 13 is also connected to the power control device 22. Then, the electric power converted by the electric power conversion unit 22d is output to the load 13.

The power conversion unit 22d is provided with a positive electrode and a negative electrode on the input side, and each is connected to the positive electrode and the negative electrode of the thermoelectric conversion device 11. Then, the electric power generated by the thermoelectric conversion device 11 is input to the electric power conversion unit 22d.

Similarly, the power conversion unit 22d is provided with a positive electrode and a negative electrode on the output side, and each is connected to the positive electrode and the negative electrode of the load 13. Then, the electric power converted by the electric power conversion unit 22d is output to the load 13.

The load of the power conversion unit 22d as seen from the terminal on the input side of the power conversion unit 22d can be changed by controlling the time ratio (duty ratio) of opening and closing the switching element of the power conversion unit 22d.

The thermal time constant acquisition unit 22a, the power measurement unit 22b, and the power conversion unit 22d are connected to the power conversion control unit 22c.

The thermal time constant acquisition unit 12a shown in FIG. 1 directly detects the temperature of the surface on the high temperature side and the temperature of the surface on the low temperature side of the thermoelectric conversion module 11a using a thermoelectric pair or the like. On the other hand, the thermal time constant acquisition unit 22a in the present embodiment is connected to the power measurement unit 22b, and the thermal time constant T is calculated only from the power measurement result (power data) transmitted from the power measurement unit 22b. do. Then, the thermal time constant acquisition unit 22a transmits the calculated thermal time constant T to the power conversion control unit 22c.

The power measuring unit 22b measures the power output from the thermoelectric conversion device 11 by measuring the current and voltage output from the thermoelectric conversion device 11. Then, the power measuring unit 22b transmits the measured power as power data to the heat time constant acquisition unit 22a and the power conversion control unit 22c.

The power conversion control unit 22c controls the maximum output of the power output from the thermoelectric conversion device 11 based on the input thermal time constant T and the power data.

<About the operation of the power control device in the thermoelectric power generation system>
The operation of the power control device 22 (mainly the maximum output control by the power conversion control unit 22c) according to the present embodiment is the same as the operation shown in FIG. 2.

However, when acquiring the thermal time constant in step ST10, the power control device 22 acquires the thermal time constant in the following flow.

FIG. 12 is a flowchart showing an example of an operation for acquiring the thermal time constant of the power control device 22.

First, in step ST120, the positive electrode and the negative electrode of the thermoelectric conversion device 11 are short-circuited and wait for a certain period of time. This time may be an arbitrary value set in advance, but it is desirable that the time is longer than or equal to the thermal time constant T in order to obtain an accurate thermal time constant T. If there is a previously measured thermal time constant T, about three times that time may be set as the waiting time in step ST120.

Next, in step ST121, the thermoelectric conversion device 11 is instantly opened and the transient characteristic of the voltage V between the positive electrode and the negative electrode of the thermoelectric conversion device 11 is acquired for a certain period of time.

Next, in step ST122, a time constant is acquired based on the time change of the voltage V of the thermoelectric conversion device 11 after a certain period of time has passed immediately after the thermoelectric conversion device 11 is opened.

FIG. 13 is a diagram showing an example of the transient characteristics of the voltage of the thermoelectric converter 11 when the short-circuited state is changed to the open state. In FIG. 13, the vertical axis represents the voltage value and the horizontal axis represents time.

As an example is shown in FIG. 13, the voltage V immediately after the open state is set as V _oc1 , and the voltage V when the temperature of the thermoelectric converter 11 stabilizes after a sufficient time has passed after the open state is set. Assuming V _oc2 , the theoretical curve of the voltage V with respect to the time t can be expressed by the following equation (6).

Then, the thermal time constant T of the thermoelectric conversion device 11 can be obtained by fitting the time constant to the measured transient characteristic of V by the above equation (6) using the least squares method or the like. ..

The electromotive force of the thermoelectric conversion device 11 is proportional to the temperature difference ΔT between the surface on the high temperature side and the surface on the low temperature side of the thermoelectric conversion device 11 due to the Seebeck effect. Therefore, the time response of the voltage value shows the same behavior as the time response of the temperature difference ΔT.

From this, since the time constant of the voltage value can be regarded as the thermal time constant T as it is, the thermal time constant T can be obtained only by the voltage measurement.

As a result, the thermal time constant T of the thermoelectric conversion device 11 can be acquired only by the power measurement in the power measurement unit 22b without newly adding hardware for heat measurement such as a thermocouple. Therefore, the electric power output from the thermoelectric conversion device 11 can be maximized inexpensively and easily.

In the present embodiment, the thermal time constant T is acquired as a result by changing the thermoelectric conversion device 11 from the short-circuited state to the open state, but the voltage value at that time is changed by changing the current value by ΔI. The thermal time constant T may be acquired based on the transient characteristics.

<Third embodiment>
A power control device, a thermoelectric power generation system, and a power control method according to the present embodiment will be described. In the following description, components similar to the components described in the above-described embodiments will be illustrated with the same reference numerals, and detailed description thereof will be omitted as appropriate. ..

The power control device 12 (or the power control device 22) in the embodiment described above may perform maximum output control by controlling the load 13.

FIG. 14 is a flowchart showing an example of the operation of the power control device (mainly, the maximum output control by the power conversion control unit 12c). Although the control performed by the power control device 12 is described in FIG. 14, it may be replaced with the control performed by the power control device 22.

First, in step ST310, the thermal time constant acquisition unit 12a calculates and acquires the thermal time constant T of the thermoelectric conversion device 11.

Next, in step ST311, the value of the load 13 is changed from R to R + ΔR.

Next, in step ST312, wait for a time corresponding to the thermal time constant T acquired in step ST310. Since the value of the load 13 was changed from R to R + ΔR in step ST311, the thermal balance of the thermoelectric conversion device 11 is temporarily lost.

Therefore, depending on the system, the system is thermally stabilized by waiting for an arbitrary constant multiple time such as T or 3T with respect to the time T of the thermal time constant.

Next, in step ST313, the power measuring unit 12b measures the power P (take-out power) output from the thermoelectric conversion device 11. The power measuring unit 12b measures the voltage V output from the thermoelectric conversion device 11 and the current I output from the thermoelectric conversion device 11, respectively, and calculates the power as power P = voltage V × current I.

Next, in step ST314, the power P measured in step ST313 is compared with the power P'similarly measured in step ST313 of the previous loop. When step ST314 is the first time in the loop, the comparison is performed with the power P'set to 0.

Then, if P> P', that is, if it corresponds to "YES" branching from step ST314 shown in FIG. 14, the process proceeds to step ST315. On the other hand, if P> P', that is, if it corresponds to "NO" branching from step ST314 shown in FIG. 14, the process proceeds to step ST316.

In step ST315, it is determined that the load value ΔR to be changed in step ST311 in the next loop is ΔR, which is the same value as in the previous step ST311. Then, the process proceeds to step ST317.

In step ST316, it is determined that the load value ΔR to be changed in step ST311 in the next loop is −ΔR having the opposite sign value (absolute value is the same) as in the previous step ST311. Then, the process proceeds to step ST317.

Next, in step ST317, the power P measured in step ST313 is updated to the value used as the power P'in step ST314 of the next loop. Then, the process returns to step ST311.

By these processes, the power control device 12 controls to repeat the loop near the current value at which the power output from the thermoelectric conversion device 11 is maximized.

When the value of the load 13 is kept constant, even if the temperature of the heat source or the cooling source fluctuates, the thermoelectric conversion is performed as compared with the case where the current value as in the loop after step ST11 in FIG. 2 is kept constant. The power output from the device 11 can be kept near the maximum power.

If the current value is kept constant when the temperature of the heat source or cooling source fluctuates, the electromotive force changes in proportion to the temperature difference, so the deviation from the maximum power point due to the temperature fluctuation becomes large.

On the other hand, if the value of the load 13 is kept constant, the deviation from the maximum power point does not occur unless the internal resistance of the thermoelectric conversion device 11 changes.

Actually, the internal resistance tends to increase as the temperature of the thermoelectric conversion element rises, but this effect is generally small. Therefore, the power output from the thermoelectric conversion device 11 is larger in the control that keeps the value of the load 13 constant than in the control that keeps the current value constant. As a result, the electric power output from the thermoelectric conversion device 11 can be increased as compared with the case where the current value is kept constant during the control cycle t.

<Hardware configuration of power control device in thermoelectric power generation system>
15 and 16 are diagrams schematically illustrating a hardware configuration in the case of actually operating a thermoelectric power generation system (particularly, a power control device) whose example is shown in FIGS. 1 and 11.

The hardware configurations exemplified in FIGS. 15 and 16 may not match the configurations illustrated in FIGS. 1 and 11, but this may be inconsistent with the configurations illustrated in FIGS. 1 and 11. Is due to the fact that is a conceptual unit.

Thus, at least one configuration exemplified in FIGS. 1 and 11 comprises a plurality of hardware configurations exemplified in FIGS. 15 and 16, and one configuration exemplified in FIGS. 1 and 11 includes. , The case corresponding to a part of the hardware configurations exemplified in FIGS. 15 and 16, and further, the plurality of configurations exemplified in FIGS. 1 and 11 are one exemplified in FIGS. 15 and 16. It can be assumed that it is prepared for a hardware configuration.

In FIG. 15, the thermal time constant acquisition unit 12a, the thermal time constant acquisition unit 22a, the power measurement unit 12b, the power measurement unit 22b, the power conversion control unit 12c, the power conversion control unit 22c, and the power conversion in FIGS. 1 and 11 are shown. As a hardware configuration for realizing the unit 12d and the power conversion unit 22d, a processing circuit 1102A for performing an operation and a storage device 1103 capable of storing information are shown. These configurations are the same in other embodiments.

In FIG. 16, the thermal time constant acquisition unit 12a, the thermal time constant acquisition unit 22a, the power measurement unit 12b, the power measurement unit 22b, the power conversion control unit 12c, the power conversion control unit 22c, and the power conversion unit in FIGS. 1 and 11 are shown. As a hardware configuration for realizing the 12d and the power conversion unit 22d, a processing circuit 1102B for performing an operation is shown. The configuration is the same in other embodiments.

The heat time constant is stored in the heat time constant acquisition unit 12a, the heat time constant is stored in the heat time constant acquisition unit 22a, the power is stored in the power measurement unit 12b, or the power is measured in the power measurement unit 22b. Storage and the like are realized by storage device 1103 or another storage device (not shown here).

The storage device 1103 is, for example, a hard disk drive (Hard disk drive, that is, HDD), a random access memory (random access memory, that is, RAM), a read-only memory (read only memory, that is, ROM), a flash memory, and an erase program. Memory (storage) including volatile or non-volatile semiconductor memory, magnetic disk, flexible disk, optical disk, compact disk, mini disk or DVD such as read only memory (EPROM) and electricalally erasable program read-only memory (EEPROM). It may be a medium) or any storage medium that will be used in the future.

The processing circuit 1102A may execute a program stored in a storage device 1103, an external CD-ROM, an external DVD-ROM, an external flash memory, or the like. That is, for example, it may be a central processing unit (CPU), a microprocessor, a microcomputer, or a digital signal processor (DSP).

When the processing circuit 1102A executes a program stored in a storage device 1103, an external CD-ROM, an external DVD-ROM, an external flash memory, or the like, the thermal time constant acquisition unit 12a, the thermal time constant In the acquisition unit 22a, the power measurement unit 12b, the power measurement unit 22b, the power conversion control unit 12c, the power conversion control unit 22c, the power conversion unit 12d and the power conversion unit 22d, the program stored in the storage device 1103 is stored in the storage device 1103 by the processing circuit 1102A. It is realized by the software to be executed, the firmware, or the combination of the software and the firmware. The functions of the thermal time constant acquisition unit 12a, the thermal time constant acquisition unit 22a, the power measurement unit 12b, the power measurement unit 22b, the power conversion control unit 12c, the power conversion control unit 22c, the power conversion unit 12d, and the power conversion unit 22d are For example, it may be realized by coordinating a plurality of processing circuits.

The software and firmware may be described as a program and stored in the storage device 1103. In that case, the processing circuit 1102A realizes the above function by reading and executing the program stored in the storage device 1103. That is, the storage device 1103 may store a program in which the above functions are eventually realized by being executed by the processing circuit 1102A.

Further, the processing circuit 1102B may be dedicated hardware. That is, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an integrated circuit (application specific integrated circuit, that is, an ASIC), a field-programmable gate array (FPGA), or a combination thereof. It may be a circuit.

When the processing circuit 1102B is dedicated hardware, the thermal time constant acquisition unit 12a, the thermal time constant acquisition unit 22a, the power measurement unit 12b, the power measurement unit 22b, the power conversion control unit 12c, the power conversion control unit 22c, and the power conversion The unit 12d and the power conversion unit 22d are realized by operating the processing circuit 1102B. The functions of the thermal time constant acquisition unit 12a, the thermal time constant acquisition unit 22a, the power measurement unit 12b, the power measurement unit 22b, the power conversion control unit 12c, the power conversion control unit 22c, the power conversion unit 12d, and the power conversion unit 22d are , It may be realized by a separate circuit, or it may be realized by a single circuit.

The functions of the thermal time constant acquisition unit 12a, the thermal time constant acquisition unit 22a, the power measurement unit 12b, the power measurement unit 22b, the power conversion control unit 12c, the power conversion control unit 22c, the power conversion unit 12d, and the power conversion unit 22d are , A part may be realized in the processing circuit 1102A which executes the program stored in the storage device 1103, and a part may be realized in the processing circuit 1102B which is the dedicated hardware.

<Effects caused by the above-described embodiments>
Next, an example of the effect caused by the above-described embodiment will be shown. In the following description, the effect is described based on the specific configuration shown in the embodiment described above, but to the extent that the same effect occurs, the examples are described in the present specification. May be replaced with other specific configurations indicated by. That is, in the following, for convenience, only one of the specific configurations to be associated may be described, but one specific configuration described may be described as another specific configuration to which the specific configuration is associated. May be replaced.

Further, the replacement may be made across a plurality of embodiments. That is, it may be the case that the respective configurations shown in the examples in different embodiments are combined to produce the same effect.

According to the embodiment described above, the power control device is output from the power measuring unit 12b (or the power measuring unit 22b) for measuring the power output from the thermoelectric conversion device 11 and the thermoelectric conversion device 11. It is provided with a control unit that controls the electric power. Here, the control unit corresponds to at least one of, for example, a power conversion control unit 12c, a power conversion control unit 22c, and the like. The thermoelectric conversion device 11 generates electricity based on heat. Then, the thermoelectric conversion device 11 outputs electric power. Here, the power measuring unit 12b is output from the thermoelectric conversion device 11 after the load on the output of the thermoelectric conversion device 11 is changed and after a time corresponding to the thermal time constant of the thermoelectric conversion device 11 has elapsed. Measure the power.

Further, according to the embodiment described above, the power control device includes a processing circuit 1102A for executing a program and a storage device 1103 for storing the program to be executed. Then, when the processing circuit 1102A executes the program, the following operations are realized.

That is, after the load on the output of the thermoelectric conversion device 11 fluctuates, and after the time corresponding to the thermal time constant of the thermoelectric conversion device 11 elapses, the power output from the thermoelectric conversion device 11 is measured.

Further, according to the embodiment described above, the power control device includes a processing circuit 1102B which is dedicated hardware. Then, the processing circuit 1102B, which is dedicated hardware, performs the following operations.

That is, the processing circuit 1102B, which is dedicated hardware, is a thermoelectric conversion device after the load on the output of the thermoelectric conversion device 11 is changed and after a time corresponding to the thermal time constant of the thermoelectric conversion device 11 has elapsed. The power output from 11 is measured.

According to such a configuration, the power P (take-out power) output from the thermoelectric conversion device 11 is measured by measuring the power output from the thermoelectric conversion device 11 after the time corresponding to the thermal time constant T has elapsed. ) Can be increased.

In addition, when other configurations shown in the present specification are appropriately added to the above configurations, that is, when other configurations in the present specification not mentioned as the above configurations are appropriately added. Even if there is, the same effect can be produced.

Further, according to the embodiment described above, the power conversion control unit 12c searches for the maximum value of the power output from the thermoelectric conversion device 11 based on the measured power of the thermoelectric conversion device 11. According to such a configuration, the maximum power output from the thermoelectric conversion device 11 can be found by repeating the search for varying the load on the output of the thermoelectric conversion device 11 such as how to climb a mountain.

Further, according to the embodiment described above, the power conversion control unit 12c fluctuates the current value output from the thermoelectric conversion device 11 by varying the load on the output of the thermoelectric conversion device 11. The current value output from the thermoelectric conversion device 11 is kept constant for the time corresponding to the thermal time constant of the thermoelectric conversion device 11. According to such a configuration, the power P (take-out power) output from the thermoelectric conversion device 11 is measured by measuring the power output from the thermoelectric conversion device 11 after the time corresponding to the thermal time constant T has elapsed. ) Can be maximized.

Further, according to the embodiment described above, the power conversion control unit 12c fluctuates the load on the output of the thermoelectric conversion device 11, and the load corresponds to the thermal time constant of the thermoelectric conversion device 11. Keep it constant. According to such a configuration, even if the temperature of the heat source or the cooling source fluctuates, the electric power output from the thermoelectric conversion device 11 can be kept near the maximum electric power. Then, after the time corresponding to the thermal time constant T has elapsed, the electric power P (extracted electric power) output from the thermoelectric conversion device 11 is maximized by measuring the electric power output from the thermoelectric conversion device 11. Can be done.

Further, according to the embodiment described above, the power control device 22 changes the current value output from the thermoelectric conversion device 11 and changes the voltage value output from the thermoelectric conversion device 11 over time. A thermal time constant acquisition unit 22a for acquiring the thermal time constant of the thermoelectric conversion device 11 is provided. According to such a configuration, the positive electrode and the negative electrode of the thermoelectric conversion device 11 are short-circuited, wait for a certain period of time, and then the thermoelectric conversion device 11 is opened again to output from the thermoelectric conversion device 11. By measuring the time change of the voltage value, the time response of the temperature difference ΔT and the time response of the voltage value have the same behavior. Therefore, the thermal time constant T is not acquired by the thermal measurement of the thermoelectric converter 11. Both can acquire the thermal time constant T.

Further, according to the embodiment described above, the power measuring unit 12b acquires the internal resistance of the thermoelectric conversion device 11 based on the current value and the voltage value output from the thermoelectric conversion device 11. According to such a configuration, the thermoelectric conversion device 11 (including the thermal resistance between the high temperature side (or low temperature side) surface and the high temperature side (or low temperature side) temperature fixing point of the thermoelectric conversion module 11a) is accurate. Since it is possible to measure the internal resistance, it can be utilized for the maximum power control of the thermoelectric conversion device 11.

<About the modified example of the embodiment described above>
In the embodiments described above, the materials, materials, dimensions, shapes, relative arrangement relationships, implementation conditions, etc. of each component may also be described, but these are one example in all aspects. However, it shall not be limited.

Therefore, innumerable variants and equivalents for which examples are not shown are envisioned within the scope of the art disclosed herein. For example, when transforming, adding or omitting at least one component, or when extracting at least one component in at least one embodiment and combining it with the component in another embodiment. Shall be included.

Further, in the above-described embodiment, when the material name or the like is described without being specified, the material contains other additives, for example, an alloy or the like, as long as there is no contradiction. It shall be included.

Further, as long as there is no contradiction, "one or more" components described as being provided in the above-described embodiment may be provided.

Further, each component in the above-described embodiment is a conceptual unit, and within the scope of the technique disclosed in the present specification, one component is composed of a plurality of structures. It is assumed that one component corresponds to a part of a structure, and further, a case where a plurality of components are provided in one structure is included.

Further, each component in the above-described embodiment shall include a structure having another structure or shape as long as it exhibits the same function.

Further, the description in the present specification is referred to for all purposes related to the present art, and none of them is recognized as the prior art.

Further, each component described in the above-described embodiment is assumed to be software or firmware and corresponding hardware, and in both concepts, each component is a "part". Alternatively, it is referred to as a "processing circuit" or the like.

Further, the heat time constant is stored in the heat time constant acquisition unit 12a, the heat time constant is stored in the heat time constant acquisition unit 22a, the power is stored in the power measurement unit 12b, or the power is measured in the power measurement unit 22b. The storage of electric power and the like are shown in FIGS. 1 and 11 as being mounted in the thermoelectric power generation system, but at least one of them may be an external functional unit. In that case, it suffices as long as the other functional parts in the thermoelectric power generation system and the external functional parts interact with each other to fulfill the function of the thermoelectric power generation system as a whole.

11 thermoelectric conversion device, 11a thermoelectric conversion module, 11b high temperature side heat exchanger, 11c low temperature side heat exchanger, 12, 22 power control device, 12a, 22a thermal time constant acquisition unit, 12b, 22b power measurement unit, 12c, 22c Power conversion control unit, 12d, 22d power conversion unit, 13 loads, 100, 101 thermoelectric power generation system, 1102A, 1102B processing circuit, 1103 storage device.

Claims (8)

1. It is a power control device that controls the power of a thermoelectric conversion device that outputs the power generated based on heat.
   A power measuring unit that measures the power output from the thermoelectric conversion device, and
   It is provided with a control unit that controls the electric power output from the thermoelectric conversion device.
   The power measuring unit measures the power output from the thermoelectric conversion device after the load on the output of the thermoelectric conversion device is changed and after a time corresponding to the thermal time constant of the thermoelectric conversion device has elapsed. Measure,
   Power control device.
2. The power control device according to claim 1.
   The control unit searches for the maximum value of the electric power output from the thermoelectric conversion device based on the measured electric power of the thermoelectric conversion device.
   Power control device.
3. The power control device according to claim 1 or 2.
   The control unit fluctuates the current value output from the thermoelectric conversion device by fluctuating the load on the output of the thermoelectric conversion device, and the time corresponding to the thermal time constant of the thermoelectric conversion device is the time. Keeping the current value output from the thermoelectric converter constant,
   Power control device.
4. The power control device according to claim 1 or 2.
   The control unit varies the load on the output of the thermoelectric conversion device, and keeps the load constant for a time corresponding to the thermal time constant of the thermoelectric conversion device.
   Power control device.
5. The power control device according to any one of claims 1 to 4.
   A thermal time constant acquisition unit that fluctuates the current value output from the thermoelectric conversion device and acquires the thermal time constant of the thermoelectric conversion device based on the time change of the voltage value output from the thermoelectric conversion device. Further prepare
   Power control device.
6. The power control device according to any one of claims 1 to 5.
   The power measuring unit acquires the internal resistance of the thermoelectric conversion device based on the current value and the voltage value output from the thermoelectric conversion device.
   Power control device.
7. A thermoelectric converter that generates electricity based on heat and outputs electric power,
   It is provided with a power control device that measures the electric power output from the thermoelectric conversion device and controls the electric power output from the thermoelectric conversion device.
   The power control device changes the load on the output of the thermoelectric conversion device, and after a time corresponding to the thermal time constant of the thermoelectric conversion device has elapsed, the power output from the thermoelectric conversion device is output. Measure,
   Thermoelectric power generation system.
8. It is a power control method that controls the power of a thermoelectric converter that outputs the power generated based on heat.
   The power output from the thermoelectric converter is measured and
   By controlling the power output from the thermoelectric conversion device,
   The measurement of the electric power output from the thermoelectric conversion device is performed after the load on the output of the thermoelectric conversion device is changed and after a time corresponding to the thermal time constant of the thermoelectric conversion device has elapsed. It is to measure the power output from the thermoelectric converter,
   Power control method.

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