JP2000166117A - Solar battery power generation module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the maximum output of a power conversion circuit by having only to control the input voltage of the circuit by using a solar battery cell for reference. SOLUTION: A solar battery cell 40 for reference having both open terminals is incorporated in the main body of a panel, together with a group of solar battery cells 4 and the open-circuit voltage Voc of the cell 40 is monitored by means of a voltage detector 41. Then a reference voltage generating circuit 42 finds a reference input voltage Vref at which the output power becomes maximum, based on the both-terminal open-circuit voltage of the cell 40 through prescribed computation. In addition, control circuits 61 and 62 control the duty of the switching element 52 of the power conversion circuit 5 so that the input voltage Vin from the group of solar battery cells 4 may become the target input voltage value Vref.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photovoltaic power generation module provided with a power conversion circuit for performing maximum power output control.

[0002]

2. Description of the Related Art Conventionally, there has been proposed a photovoltaic power generation module in which a large number of photovoltaic cells are incorporated in a tile-like panel body so that roofing can be performed in place of a normal roof tile for use in a photovoltaic power generation system. (June 6
3-111747).

[0003] Such a solar cell power generation module 101
The circuit configuration shown in FIG. 13 is as shown in FIG. 13, in which DC power at both ends of a group of a large number of solar cells 102 connected in series is input to a DC / DC converter 103, and the control circuit 1
04 so that the maximum output power can be obtained based on the output voltage Vout, the output current Iout, and the input voltage Vin.
The gate of the switching element of the converter 103 is controlled.

[0004]

However, in such a conventional solar cell power generation module, the arithmetic processing for obtaining the maximum power output in the control circuit 104 is complicated, and the power consumed by the control circuit 104 increases. There was a problem.

The present invention has been made in view of such a conventional problem, and simplifies the operation of calculating the maximum power output.
An object of the present invention is to provide a solar cell power generation module capable of reducing a load applied to a control unit of a power conversion circuit.

[0006]

According to a first aspect of the present invention, there is provided a photovoltaic power generation module which is incorporated in a panel main body and which is connected in series or in parallel to a photovoltaic cell group, and generates power from the photovoltaic cell group. A power conversion circuit for converting the output into a DC or AC power of a predetermined voltage as a DC input; a solar cell for reference having both ends open; incorporated in the panel main body together with the solar cell group; and the reference Reference voltage detecting means for detecting an open-circuit voltage at both ends of a solar cell for use, and input voltage target value calculating means for calculating a predetermined calculated value as an input voltage target value based on the open-circuit voltage detected by the reference voltage detecting means And a control circuit that controls the power conversion circuit so that the input voltage from the solar cell group matches the input voltage target value.

In the solar cell power generation module according to the first aspect of the present invention, a reference solar cell having both ends open is incorporated in the panel body together with the solar cell group, and the open-end voltage of the reference solar cell is detected by a reference voltage detecting means. The input voltage target value calculation means calculates the input voltage target value by a predetermined calculation based on the open-circuit voltage at both ends of the reference solar cell. Then, the control circuit controls the power conversion circuit so that the input voltage from the solar cell group matches the input voltage target value.

[0008] With this, the open-circuit voltage of both ends of the reference solar cell and the input voltage from the solar cell group are monitored, and almost maximum output control can be performed only by performing relatively simple arithmetic processing.

A solar cell power generation module according to a second aspect of the present invention is a solar cell power generation module which is incorporated in a panel main body and connected in series or in parallel, and the generated power of the solar cell group is used as a DC input, and is provided with a predetermined power. A power conversion circuit that converts voltage into DC or AC power and outputs the input voltage; an input voltage detection unit that detects an input voltage input from the solar cell group to the power conversion circuit; and a detection unit that detects the input voltage. An input voltage target value calculating means for calculating an input voltage value as an input voltage target value by a predetermined calculation with respect to an input voltage from the solar cell group; and an input from the solar cell group to the input voltage target value. A control circuit for controlling the power conversion circuit so that the voltages match.

In the solar cell power generation module according to the second aspect of the present invention, the input voltage from the solar cell group is monitored by the input voltage detecting means, and the input voltage target value calculating means performs a predetermined calculation on the input voltage. Calculate the input voltage target value. Then, the control circuit controls the power conversion circuit so that the input voltage from the solar cell group matches the input voltage target value.

[0011] Thus, only the input voltage from the photovoltaic cell group is monitored, and almost maximum output control can be performed only by performing relatively simple arithmetic processing.

According to a third aspect of the present invention, there is provided a solar cell power generation module which is incorporated in a panel main body and connected in series or in parallel to each other, and the power generation of the solar cell group is set as a DC input, and a predetermined power is applied to the solar cell. A power conversion circuit that converts the voltage into direct current or alternating current power and outputs the same, and the photovoltaic cell group is incorporated in the panel main body, and both ends of the reference solar cell open at both ends; and both ends of the reference solar cell. Reference voltage detection means for detecting an open-circuit voltage; and a first input voltage target for calculating an input voltage value as a first input voltage target value by a predetermined calculation based on the open-circuit voltage detected by the reference voltage detection means. Value calculation means,
An input voltage detection unit that detects an input voltage input to the power conversion circuit from the solar cell group, and an input voltage from the solar cell group detected by the input voltage detection unit, by a predetermined calculation. A second input voltage target value calculating means for calculating an input voltage value as a second input voltage target value; and the first input voltage target value as a control target target value, wherein the input voltage matches the target voltage. A control circuit that controls a power conversion circuit, and a diagnosis unit that diagnoses the soundness of the reference solar cell based on a comparison between the first input voltage target value and the second input voltage target value,
When the diagnostic unit denies the soundness of the reference solar cell, a target value that sets the second input voltage target value instead of the first input voltage target value as a control target target value of the control circuit. Switching means.

In the solar cell power generation module according to the third aspect of the invention, the open-circuit voltage of both ends of the reference solar cell is normally monitored as in the first aspect of the invention, and the input voltage of the power conversion circuit is controlled based on the voltage. As a result, almost maximum output control is performed.

When the diagnostic means diagnoses that the reference solar cell has lost its soundness,
As in the second aspect of the invention, only the input voltage from the photovoltaic cell group to the power conversion circuit is monitored, and the maximum output control is performed by controlling the input voltage of the power conversion circuit based on the monitored voltage.

In this way, the reliability of long-term use is enhanced by providing the circuit with redundancy.

According to a fourth aspect of the present invention, in the solar cell power generation module of the second or third aspect, the control circuit performs constant current control while the input voltage from the solar cell group is lower than a predetermined value. After the input voltage reaches a predetermined value, constant voltage control is performed, and a simple operation of controlling the input voltage from the photovoltaic cell group to the power conversion circuit to match the predetermined value is performed. By the processing, almost maximum output control can be performed.

According to a fifth aspect of the present invention, in the solar cell power generation module of the second or third aspect, the control circuit performs the constant current control and the constant voltage control by duty control of a power conversion element of the power conversion circuit. The maximum output control can be simplified. Further, the constant current output operation can be replaced with, for example, the lowest duty output of the switching circuit.

According to a sixth aspect of the present invention, in the solar cell power generation module of the first to fifth aspects, the power conversion circuit includes a D
It uses a C / DC converter and can extract the maximum output of DC power.

According to a seventh aspect of the present invention, in the solar cell power generation module of the first to fifth aspects, the power conversion circuit includes a D
It uses a C / AC converter and can extract the maximum output of the alternating current.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 3 show the structure of a solar cell power generation module 1 according to a first embodiment of the present invention. The solar cell power generation module 1 of this embodiment has a large number of solar cells and a power conversion circuit in a lower half working allowance 2D in which sunlight is applied in the state of roofing in a slate tile-like panel main body 2. This is a structure incorporating a power generation unit 3 composed of a DC / DC converter. Then, in each of the four corners overlapping with the other panel main body of the panel main body 2, in the lower half working allowance 2D that is overlapped from the upper side with the upper half of the other panel main bodies 2-1 and 2-2,
A pair of a minus terminal and a plus terminal of the power generation unit 3 are provided at each of the two left and right corners on the lower surface side, and conversely, the working allowance of the lower half of the other panels 2-3 and 2-4 is from the upper side. In the overlapping margin 2U of the upper half to be overlapped, a pair of a minus terminal and a plus terminal of the power generation unit 3 are provided at each of two left and right corners on the upper surface side.

The positions of the negative terminal and the positive terminal provided at each of the four corners of the panel body 2 are almost at the upper or lower side in the staggered grid arrangement, which is a usual slate tile roofing construction method. This is a position facing the minus terminal and the plus terminal of the power generation unit 3 provided in the overlapping portion of another panel body that overlaps by ４.

Thus, when the roofing is performed in the same manner as the normal roofing construction of the slate tile, each of the solar cell power generation modules 1 is connected to the panel body of another solar cell power generation module 1 overlapping the front, rear, left and right. In between, the minus terminal and the plus terminal of the power generation unit 3 incorporated in each of the panels naturally come into contact with each other from above and below, and the large number of power generation units 3 incorporated in each panel body 2 cover the entire roof or some of them. The solar cell power generation system can be configured such that all of the divided regions are connected in parallel.

Next, the circuit configuration of the power generation unit 3 will be described. FIG. 4 shows a circuit of the power generation unit 3 incorporated in the solar cell power generation module 1. The power generation unit 3 connects a large number of solar cells 4 in series or in parallel, connects a current-type DC / DC converter 5 to each of its negative and positive output terminals, and takes out DC power of a predetermined voltage. Since the negative terminal and the positive terminal that are branched out from the negative output and the positive output of the DC / DC converter 5 are arranged in pairs at each of the four corners of the solar cell power generation module 1 described above. is there. Further, as a feature of this embodiment, apart from the solar cells 4 that contribute to a large number of power generations, a reference solar cell 40 whose both ends are open is incorporated in the panel main body 1. From the detector 41 of the open-circuit voltage at both ends of the battery cell 40 to the DC / DC converter 5
The detection signal is input to the.

FIG. 5 shows a connection relationship when roofing is performed by the solar cell power generation module 1 incorporating the power generation unit 3. In FIG. 5, the same applies to FIGS. 1 to 3, but the entire power generation unit 3 is indicated by one battery symbol, but this shows the entire circuit configuration shown in FIG. 4. .

As shown in FIG. 6, a DC / AC conversion circuit (inverter) 8 converts indoor power to 50 Hz or 60 Hz, 100 V or 2
The connection to convert the AC power to 00V and supply the load 9 to the load 9 is performed, thereby configuring a solar cell power generation system.

In such a photovoltaic power generation system, when a poor connection occurs between the negative pole and the positive pole in the hatched portion A in FIG. 5, a bypass path indicated by a chain line B and a broken line C is provided. As a result, the negative electrode and the positive electrode are connected at the same potential, and the power generated by the power generation unit 3 at the portion where the contact failure has occurred can be taken out without waste.

Next, based on FIG. 7 and FIG.
A detailed circuit configuration of the DC / DC converter 5 (including both the power conversion unit and the control unit) as the power conversion circuit will be described. The DC / DC converter 5 includes a capacitor 51 provided in parallel with a large number of solar cells 4 incorporated in the panel main body 2 and a switching element for switching a DC input voltage Vin generated at both ends of the capacitor 51. 52, a step-up transformer 53 for stepping up the AC obtained by the switching element 52, a diode 54 for rectifying the output of the step-up transformer 53, and a smoothing capacitor 55.

Further, as a control system for controlling the switching operation of the switching element 52, it is incorporated in the panel body together with a large number of solar cells 4 contributing to power generation,
A maximum output is obtained based on the reference solar cell 40 having both ends open, a voltage detector 41 for monitoring the open-end voltage Voc of the reference solar cell 40, and an open-end voltage Voc output from the voltage detector 41. A reference voltage generation circuit 42 that calculates an input voltage target value Vref from the combination of the input voltage and the input current by the following equation (1):
A detection value Vin from a voltage detector 56 for detecting an input voltage Vin from the group of solar cells 4 to the DC converter 5;
A comparator 61 for comparing the input voltage target value Vref from the reference voltage generation circuit 42;
1, a control circuit 62 that performs duty control of the switching element 52 of the DC / DC converter 5 based on the comparison result.
It has.

[0029]

Vref = kVoc Here, k is a preset constant, and the voltage at the time of the maximum specified power Vpmspec of one solar cell and the specification open voltage Voc
Assuming that spec is the number of series stages ncM in the module of the photovoltaic cells 4 contributing to power generation and the number ncref of cell series stages of the reference photovoltaic cells 40, it is given by the following equation (2).

[0030]

(Equation 2) For example, assuming that the solar cell group is 10 stages in series, the solar cell for reference is 1 stage in series, the voltage at the maximum specification power in the module is 5V, and the maximum specification open voltage is 6V, the following is determined.

[0031]

(Equation 3) Therefore,

Vref = 8.3 × Voc

Next, the operation of the DC / DC converter 5 having the above configuration will be described. In each solar cell power generation module 1, the DC / DC converter 5 of the power generation unit 3 performs maximum output power control.

FIG. 8 shows a VI curve of the solar cell. Note that ST1, ST2,... Correspond to the light receiving state of the solar cell. As a characteristic of the solar cell, when the operating point moves to a direction higher than the optimum operating voltage Vpm, the current sharply decreases, and when the operating voltage becomes lower than Vpm, the output power decreases substantially in proportion to the voltage. That is, the output is greatly reduced by moving the operating point. Therefore, the maximum output power of the solar cell in a certain sunshine state STi (this is the input power to the DC / DC converter 5)
(These are the input voltage Vin and the input current Iin for the DC / DC converter 5 and correspond to the points P1max, P2max,...), Which are determined almost fixedly. is there.

As described above, the sunshine state STi can be estimated from the power generation state of the reference solar cell 40, and the relationship between the open-ended voltage Voc and the output voltage Vpm at the maximum power in the sunshine state is almost fixed. Therefore, the input voltage Vin input to the DC / DC converter 5 to extract the maximum power Pimax based on the above equation
Is controlled, the input current is defined by Iin = Pimax / Vin, and the output of the DC / DC converter 5 is also determined.

Therefore, in the first embodiment, maximum output control is simulated by the following control. That is, the open-circuit voltage Voc at both ends of the reference solar cell 40 is monitored by the voltage detector 41, and the input voltage Vin of the DC / DC converter 5 is monitored by the voltage detector 56.
The open-circuit voltage Voc at both ends of the reference solar cell 40 is input to the reference voltage generation circuit 42, where the input voltage reference value Vref is calculated by the above equation (1) and input to the comparator 61. The input voltage Vin detected by the voltage detector 56 is directly input to the comparator 61.

In the comparator 61, these Vref, V
is compared, and the comparison result is supplied to the control circuit 62. The control circuit 62 generates a gate signal required to make the input voltage Vin equal to Vref, thereby causing the switching element 52 to perform a switching operation.

In this switching control, (1) Vin>
In the case of Vref, the output current is increased by increasing the on-duty of the switching element 52, and the input current Iin is also increased to control Vin in reverse. (2) When Vin <Vref Is
The output current is reduced by lowering the on-duty of the switching element 52, and the input current Iin is correspondingly reduced to control Vin to increase. (3) When Vin = Vref, the control of the switching element 52 is performed. Maintain on-duty.

As a result, the input voltage Vin to the DC / DC converter 5 is changed to the reference solar cell 40.
Voltage at maximum power determined from open-circuit voltage Voc
, The output maximum control can be realized only by the control on the input voltage Vin side, and the circuit configuration and arithmetic processing can be simplified.

In the above embodiment, a DC / AC converter is used as a power conversion circuit instead of a DC / DC converter.
The same can be applied to a solar cell module provided with a converter.

Next, a second embodiment of the present invention will be described with reference to FIGS.
A description will be given based on FIG. The solar cell power generation module according to the second embodiment is structurally similar to the first embodiment illustrated in FIGS. 1 to 3, but the power generation unit 3 has the circuit configuration illustrated in FIG. 9. It is characterized by having done.

The power generation unit 3 of the second embodiment detects a voltage Vin, which is a voltage generated by the solar cell group 4 and an input voltage to the DC / DC converter 5 as a power conversion circuit, by a voltage detector 56. The current command calculator 63 calculates the switching duty of the switching element 52 based on this, and the control circuit 62 performs the switching operation of the switching element 52 based on the switching duty. Vin is controlled to perform pseudo maximum output control.

That is, as shown in FIGS. 10 and 11, immediately after the solar cell group 4 starts generating power, its output voltage (input voltage to the converter 5) Vin starts to rise. Switching control of the DC / DC converter 5 is stopped until the voltage value reaches the voltage value V2 of 2 (here, the voltage Vpmspec / 2 at the specification maximum power) (steps S1 to S3).

At timing t0 when the second voltage value V2 (= Vpm / 2) is reached, the control circuit 62 starts constant current control and starts switching control with a fixed switching duty (steps S4 and S5). .

If the input voltage Vin rises by the constant current control and reaches the third voltage value V3 (here, the voltage Vpmspec at the time of the specified maximum power) at the timing t1, the input voltage Vin is thereafter increased by the constant voltage control. Almost V3 (= Vpmspec)
(Steps S6 to S810).

In this constant voltage control, strictly speaking, DC / DC
Instead of monitoring the output voltage Vout of the converter 5 and performing control using the feedback value, constant voltage control is performed by means of feedforward control. That is, the input voltage Vin detected by the voltage detector 56
Is compared with a third voltage value V3 (= Vpmspec), and if Vin substantially matches V3, the previous switching duty is maintained again this time (steps S6 and S7).

However, the current input voltage Vin is the third
If it is higher than the voltage value V3, the on-duty is changed by one step from the previous switching duty (for example,
If the change step width of the duty is 0.1, it is decreased by 0.1), and the switching element 52 is switched by the new duty (steps S8 and S9).

Conversely, if the current input voltage Vin is lower than the third voltage value V3, the on-duty is increased by one step from the previous switching duty, and the switching element 52 is switched by the new duty. Are switched (step S10).

This control is continued, and the sun is overcast,
At timing t3 when the power generation of the group of photovoltaic cells 4 is reduced, the input current Iin is reduced by the constant voltage control, and the on-duty in the switching duty of the control circuit 62 is reduced to the value at the time of the constant current control, the constant current control is performed again. (Steps S1, S3 to S5). Then, at timing t4 when the input voltage Iin decreases to the first voltage value V1 (here, the voltage Vpmspec / 3 at the specified maximum power), the switching operation is stopped and the output of the DC / DC converter 5 is stopped (step S1). , S2).

By controlling in this way, DC / D
The maximum output of the C converter 5 can be artificially controlled only by monitoring the input voltage Vin, so that the arithmetic processing is simplified, the energy consumption inside the module is reduced, and more power is output. Will be able to

In the above-described embodiment, the first voltage value V1, the second voltage value V2, and the third voltage value V3 are not limited to Vpmspec / 3, Vpmspec / 2, and Vpmspec, respectively. However, it is preferable in terms of control that these values be determined based on the specified maximum power voltage Vpmspec as characteristics of solar cell power generation.

In the duty control, the on-duty is changed in increments of 0.1, but this can be controlled more finely in accordance with the resolution of the control circuit 62, and is not particularly limited.

Further, the present invention can be equally applied to a solar cell power generation module employing a DC / AC converter instead of a DC / DC converter as a power conversion circuit.

Next, a solar cell power generation module according to a third embodiment of the present invention will be described with reference to FIG. The third embodiment has a circuit configuration in which the first embodiment and the second embodiment are combined, and constantly monitors the soundness of the reference solar cell 40. The maximum output control is performed by the same control as that of the second embodiment, and when the reference solar cell 40 loses its soundness, the control is switched to the same control as that of the second embodiment to perform the maximum output control. I do. Therefore, the structure of the solar cell power generation module is common to the first embodiment shown in FIGS. The power generation unit 3 has a circuit configuration in FIG.

The power generation section 3 of the third embodiment is incorporated in a panel body together with a large number of solar cells 4 contributing to power generation, and is open at both ends as a control system for controlling the switching operation of the switching element 52. The reference solar cell 40, a voltage detector 41 for monitoring the open-circuit voltage Voc across the reference solar cell 40, an input voltage at which a maximum output is obtained based on the open-circuit voltage Voc output from the voltage detector 41, A reference voltage generation circuit 42 for calculating an input voltage target value Vref from the combination of input currents by the above-described equation (1), a diagnosis section 43 for diagnosing soundness of an output of the reference voltage generation circuit 42, and a diagnosis section 43
Switches the control operation when the control unit diagnoses the loss of soundness of the reference photovoltaic cell 40. The switching command of the switching unit 44 causes the same operation as the comparator of the first embodiment and the second embodiment Command operation unit 65 that operates by switching the same operation as the current command operation unit of the embodiment.
And a control circuit 62 that gate-controls the switching element 52 based on the switching duty command of the current command calculation unit 65.

Next, the operation of the solar cell power generation module according to the third embodiment will be described. The power generation unit 3 performs the maximum output control in the initial state, and at normal times, by the same operation as that of the first embodiment. That is, based on the open-circuit voltage Voc at both ends of the reference solar cell 40 detected by the voltage detector 41, the reference voltage generation circuit 42
Is calculated by the above equation (1), and this is output to the diagnosis unit 43 and the current command calculation unit 63.

The diagnosis unit 43 determines whether the reference voltage Vref indicates an abnormal value. If the reference voltage Vref outputs an extremely high value or a continuously low voltage value, it diagnoses that a failure has occurred. Otherwise, it is diagnosed as sound and output to the switching unit 44.

If the diagnostic unit 43 has output a diagnostic result indicating that the unit is sound, the switching unit 44 instructs the current command computing unit 65 to perform the same control operation (normal operation) as in the first embodiment, If 43 outputs the diagnosis result of the loss of soundness, it issues a control operation (alternative operation) similar to that of the second embodiment to the current command calculation unit 65.

In the current command calculation section 65, when the switching section 44 gives a normal operation command, the reference voltage Vref output from the reference voltage generation circuit 42 is applied to the input of the DC / DC converter 5 as in the first embodiment. The switching duty is calculated so that the voltage Vin matches, and the calculated switching duty is applied to the control circuit 62. The control circuit 62 controls the switching of the switching element 52.

On the other hand, the current command calculating section 65
Gives an alternative operation command, the switching duty is obtained by the arithmetic processing of FIGS. 10 and 11 based on only the input voltage Vin of the DC / DC converter 5 and given to the control circuit 62, as in the second embodiment. , The control circuit 62 controls the switching of the switching element 52.

Thus, the solar cell power generation module is provided with redundancy, and even if a failure occurs in the reference solar cell 40, efficient solar cell power generation can be performed for a long time.

It should be noted that also in the third embodiment, the first
Modifications similar to those of the embodiment and the second embodiment are possible.

[0062]

As described above, according to the first aspect of the present invention,
By monitoring the open-circuit voltage at both ends of the reference solar battery cell and the input voltage from the solar battery cell group, it is possible to control the maximum output almost by performing relatively simple arithmetic processing.

According to the second aspect of the present invention, almost the maximum output control can be performed by monitoring only the input voltage from the solar cell group and performing relatively simple arithmetic processing.

According to the third aspect of the invention, in addition to the effects of the first and second aspects, the reliability of long-term use is high by providing the circuit with redundancy.

According to a fourth aspect of the present invention, in the solar cell power generation module according to the second or third aspect, the control circuit performs constant current control while the input voltage from the solar cell group is lower than a predetermined value. After reaching the predetermined value, the constant voltage control is performed, so the input voltage from the photovoltaic cell group to the power conversion circuit is controlled by a simple arithmetic process of controlling the input voltage to a value at which the maximum output can be obtained. Maximum output control can be performed.

According to the invention of claim 5, in the solar cell power generation module of claim 2 or 3, the control circuit performs constant current control and constant voltage control by duty control of the power conversion element of the power conversion circuit. Therefore, the maximum output control can be simplified.

According to the sixth aspect of the present invention, in the solar cell power generation module of the first to fifth aspects, the DC / DC converter is used as the power conversion circuit, so that the maximum output of the DC power can be obtained.

According to the invention of claim 7, in the solar cell power generation module of claims 1 to 5, since a DC / AC converter is used as a power conversion circuit, a maximum output of an alternating current can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view of a solar cell power generation module according to a first embodiment of the present invention.

FIG. 2 is an exploded plan view of a solar cell power generation system using the solar cell power generation module of the embodiment.

FIG. 3 is an exploded perspective view of a solar cell power generation system using the solar cell power generation module of the embodiment.

FIG. 4 is a circuit diagram of the solar cell power generation module according to the embodiment.

FIG. 5 is a circuit diagram of a solar cell power generation system configured using the solar cell power generation module according to the embodiment.

FIG. 6 is a circuit diagram showing a connection state between the solar cell power generation module of the embodiment and a distribution line system.

FIG. 7 is a circuit diagram of a power generation unit in the embodiment.

FIG. 8 is a graph showing V− of the solar cell in the above embodiment.
I curve.

FIG. 9 is a circuit diagram of a power generation unit according to a second embodiment of the present invention.

FIG. 10 is a flowchart of a control operation of the DC / DC converter in the embodiment.

FIG. 11 is a timing chart of a control operation of the DC / DC converter in the embodiment.

FIG. 12 is a circuit diagram of a power generation unit according to a third embodiment of the present invention.

FIG. 13 is a circuit diagram of a conventional solar cell power generation module.

[Explanation of symbols]

 Reference Signs List 1 solar cell power generation module 3 power generation unit 4 solar cell 5 DC / DC converter 40 reference solar cell 41 voltage detector 42 reference voltage generation circuit 43 diagnostic unit 44 switching unit 51 capacitor 52 switching element 53 step-up transformer 54 diode 55 smoothing Capacitor 56 Voltage detector 61 Comparator 62 Control circuit 63 Current command calculator 65 Current command calculator

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tsuneka Tsuchiya 1-1-1, Shibaura, Minato-ku, Tokyo Inside Toshiba Corporation Head Office (72) Inventor Yukinobu Takahashi 1-1-1, Shibaura, Minato-ku, Tokyo Toshiba Corporation Head Office (72) Inventor Nobuo Matsui 1-1-1, Shibaura, Minato-ku, Tokyo Toshiba Corporation Head Office (72) Inventor Eiichiro Fujii 336 Tatehara, Fuji City, Shizuoka Prefecture Toshiba Fuji Factory ( 72) Inventor Yutaka Sada 1 Toshiba-cho, Komukai-Toshiba-cho, Yuki-ku, Kawasaki-shi, Kanagawa Prefecture (72) Inventor Tatsuaki Security Inc. 5F051 BA03 JA06 KA02 KA03 KA04 KA05 5G003 AA06 GB04 GB06 5H730 AA14 AS04 BB43 DD04 EE02 EE07 FD11 FG05

Claims (7)

[Claims] 1. A solar cell group incorporated in a panel main body and connected in series or in parallel, and the generated power of the solar cell group is input as a DC input, and is converted into DC or AC power of a predetermined voltage. A power conversion circuit to be output, a solar cell for reference, both ends open, incorporated in the panel main body together with the solar cell group, and a reference voltage detecting means for detecting an open-end voltage at both ends of the reference solar cell. An input voltage target value calculating means for calculating an input voltage value as an input voltage target value by a predetermined calculation based on the open-circuit voltage detected by the reference voltage detecting means; and the solar cell group in the input voltage target value. And a control circuit that controls the power conversion circuit so that the input voltages from the modules match. 2. A photovoltaic cell group incorporated in a panel body and connected in series or in parallel, and the generated power of the photovoltaic cell group is used as a DC input and converted into a DC or AC power of a predetermined voltage. A power conversion circuit that outputs, an input voltage detection unit that detects an input voltage input from the solar cell group to the power conversion circuit, and an input voltage from the solar cell group detected by the input voltage detection unit. On the other hand, input voltage target value calculating means for calculating an input voltage value as an input voltage target value by a predetermined calculation, and the power conversion circuit so that an input voltage from the solar cell group matches the input voltage target value. And a control circuit for controlling the solar cell. 3. A photovoltaic cell group incorporated in a panel body and connected in series or in parallel, and the generated power of the photovoltaic cell group is used as a DC input and converted into a DC or AC power of a predetermined voltage. A power conversion circuit to be output, a solar cell for reference, both ends open, incorporated in the panel main body together with the solar cell group, and a reference voltage detecting means for detecting an open-end voltage at both ends of the reference solar cell. A first input voltage target value calculating means for calculating an input voltage value as a first input voltage target value by a predetermined calculation based on the open-circuit voltage detected by the reference voltage detecting means; and the solar cell group Input voltage detection means for detecting an input voltage input to the power conversion circuit from the above, and for the input voltage from the solar cell group detected by the input voltage detection means A second input voltage target value calculating means for calculating the input voltage value as a second input voltage target value by a predetermined calculation; and the first input voltage target value as a control target target value. And a control circuit that controls the power conversion circuit so that the two are equal to each other. Based on a comparison between the first input voltage target value and the second input voltage target value, diagnoses the soundness of the reference solar cell. Diagnosing means for performing, when the diagnosing means denies the soundness of the reference solar cell, the second input voltage target value in place of the first input voltage target value and the control target of the control circuit. A solar cell power generation module comprising: target value switching means for setting a value. 4. The control circuit performs constant current control while an input voltage from the solar cell group is lower than a predetermined value, and performs constant voltage control after the input voltage reaches a predetermined value. The solar cell power generation module according to claim 2 or 3, wherein: 5. The solar cell power generation module according to claim 2, wherein the control circuit performs the constant current control and the constant voltage control by duty control of a power conversion element of the power conversion circuit. 6. The solar cell power generation module according to claim 1, wherein the power conversion circuit is a DC / DC converter. 7. The solar cell power generation module according to claim 1, wherein the power conversion circuit is a DC / AC converter.