JPH0851230A - Photovoltaic unit and module using this - Google Patents

Abstract

PURPOSE:To provide photovoltaic units, where microrelays are united with each of an integrated photovoltaic elements, and also, provide a photovoltaic module, which can supply each device with required voltage and currents by the combination in series or parallel of the photovoltaic units. CONSTITUTION:Each photovoltaic unit is equipped with an integrated photovoltaic element 2, a microrelay 8, which is united at the rear of the photovoltaic element and contact of which is switched by the application of specified voltage, and a switch 4, which leads the output of the integrated photovoltaic element 2 to the electrode of a microrelay 8 capably of opening and closing. These photovoltaic units are coupled with each other by connection circuits 6. The switch 4 and the connection circuits 6 are switched severally by a control circuit 5, and the combination in series or parallel is materialized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photovoltaic unit in which a photovoltaic element and a micro relay are integrated, and a photovoltaic module using the photovoltaic unit.

[0002]

2. Description of the Related Art In recent years, the size of one functional component is one.
Research and development of a micromachine called a micromachine having a size of mm or less is in progress. Micromachines are classified into fixed micromachines and self-propelled micromachines, but in the self-propelled micromachines, the development of an energy supply system is a major issue.

The method of supplying energy to the micromachine is classified into a wired method and a wireless method. According to the wired method,
Although high-density energy can be supplied, there is a problem in that movement of the micromachine is restricted because the energy source and the micromachine are connected to each other by electric wires. Therefore, a wireless system in which electromagnetic wave energy such as microwaves and light rays is radiated from the outside toward a micromachine has been studied. For example, in the energy supply method using light rays, the surface of the micromachine is covered with a photovoltaic element, and the light applied to the photovoltaic element is directly converted into electric power.

[0004]

By the way, various devices such as sensors and actuators are mounted as functional components in the micromachine. It is necessary to supply power to each of these devices, but in the past, the output of the photovoltaic element was distributed at a fixed ratio to supply a voltage and current of a predetermined magnitude to each device. .

However, generally, all the devices in the micromachine are rarely operated at the same time, and the power consumption of the actuator increases during the movement of the micromachine, for example. On the other hand, the sensor is often used by turning it on and off intermittently. Therefore, it is necessary to preferentially supply energy to the actuator while the micromachine is moving. Further, when the sun is used as the light source of the photovoltaic element, the amount of light changes depending on the weather. Even when a light source other than the sun is used, the light amount changes depending on the relative positional relationship between the micromachine and the light source. If the amount of light decreases, the output current as a whole decreases, so it is necessary to reduce the amount of current supplied to the actuator and supply more current to the sensor.

As described above, in the micromachine, it is appropriate to variably set the output (voltage, current) to each device according to the type of operation and the external situation. However, since the output to each device was fixed in the past,
In some cases, the voltage or current may be insufficient and the function may stop. It should be noted that there is known a technique for matching voltage and current to each device when distributing a constant power to a plurality of devices, but the mounting of such a special electric circuit only makes the micromachine larger. However, when the variable setting range of the voltage is wide (several V to several 100 V), there is a problem that the energy loss of the electric circuit increases.

An object of the present invention is to provide a photovoltaic unit in which a micro-relay is integrated with a photovoltaic element, and by combining the photovoltaic units in series and in parallel, necessary voltage and current can be supplied to each device. It is to provide a photovoltaic module that can be supplied.

[0008]

A photovoltaic unit according to the present invention is constructed by integrating a microrelay whose contacts are switched by applying a predetermined voltage on the back surface of a photovoltaic element. The output of the power element is taken out through the micro relay.

In a specific configuration, the microrelay includes an actuating member formed by sandwiching a piezoelectric element plate (81) between a pair of electrode plates (82) and (83), and one electrode plate of the actuating member in a free state.
The first conductor layer (84) with which the (82) contacts, and the second conductor layer (8) with which the other electrode plate (83) should contact with the deformation of the piezoelectric element plate (81).
5) and are included.

Another photovoltaic unit according to the present invention comprises a photovoltaic element and a back surface of the photovoltaic element,
The photovoltaic device includes a microrelay whose contacts are switched by applying a predetermined voltage, and an opening / closing means for opening / closing the output of the photovoltaic element to the electrode of the microrelay, the photovoltaic element being closed by the closing operation of the opening / closing means. Is led to the micro relay, and thereby the output of the photovoltaic element is taken out to the outside via the micro relay.

Further, the photovoltaic module according to the present invention is
The plurality of photovoltaic units are connected to each other via a connecting means. Each photovoltaic unit includes a photovoltaic element, a micro relay that is integrated on the back surface of the photovoltaic element, and a contact that switches when a predetermined voltage is applied, and a micro output for the photovoltaic element. An opening / closing means for opening / closing the relay electrode is provided. The connecting means and the opening / closing means are switched and controlled by the control means, and among the plurality of photovoltaic units, any number of photovoltaic elements are connected in series with each other and the remaining photovoltaic elements are connected in parallel with each other. It

In a specific configuration, the control means determines the ratio of the photovoltaic elements to be connected in series and the photovoltaic elements to be connected in parallel according to the output of the photovoltaic element, And a command means for generating a switching command for the connecting means and the opening / closing means based on the judgment result.

[0013]

In the above photovoltaic unit, electric power is generated when the photovoltaic element receives light. At this time, by applying a predetermined voltage to the micro-relay, the contact of the micro-relay is switched and turned off.
To ON. As a result, the output of the photovoltaic element is taken out through the micro relay.

In the concrete structure of the micro relay,
By applying a predetermined voltage to both electrode plates (82) (83) of the operating member, the piezoelectric element plate (81) and both electrode plates (82) (83) are simultaneously deformed, and one electrode plate (82) Is separated from the first conductor layer (84), the other electrode plate (83) contacts the second conductor layer (85), and the contacts of the micro relay are switched. According to this configuration, the electrode plate (83) as the operating member,
Since it also has a function as a connection electrode with the second conductor layer (85), the structure is simplified and the manufacturing process is also simplified.

In the photovoltaic unit having the above-mentioned other structure including the opening / closing means, the electric power for driving the micro relay is covered by the output of the photovoltaic element, so that a special power source for driving the micro relay is provided. Is unnecessary,
The configuration is simple.

Further, the photovoltaic module according to the present invention is
The plurality of photovoltaic units are connected to each other via a connecting means. By connecting more photovoltaic elements in series, a high output voltage is obtained from both ends of these photovoltaic elements. On the other hand, by connecting more photovoltaic elements in parallel, a large output current can be taken out from both ends of these photovoltaic elements. Therefore, for each device to be driven by the photovoltaic module, the voltage and current required by each device are determined to determine the number of photovoltaic elements to be connected to each device, and according to the result. The connection means and the opening / closing means are switched.

In the concrete construction of the control means, the output fluctuation of the photovoltaic element is detected to detect the fluctuation of the light quantity or load received by the photovoltaic element, and based on the detection, the connecting means and the opening / closing operation are performed. Switch means. This determines the number of photovoltaic elements that should be connected in series and the photovoltaic elements that should be connected in parallel. For example, when the amount of light decreases, the number of photovoltaic elements to be connected in parallel is increased.

[0018]

According to the photovoltaic unit and the photovoltaic module using the same according to the present invention, the voltage and current required for each device can be changed by simply changing the series-parallel combination of the photovoltaic units. Can be supplied. Therefore, a special electric circuit for matching the voltages and currents of a plurality of devices is unnecessary, and it is particularly suitable for a power supply system such as a micromachine that needs to be compact.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 is a photovoltaic module configured to implement the present invention in a micromachine power supply system.
(1) is shown. The photovoltaic module (1) is shown in FIG.
The photovoltaic units shown in Fig. 1 are arranged in a plurality of rows in the front-rear direction of Fig. 1, and each photovoltaic unit has an integrated photovoltaic element (2) arranged on a micro relay (8). It is configured.

The integrated photovoltaic element (2) comprises a unit cell (22) having a pn junction, as shown in a partially enlarged view of FIG.
3 stack cells (20) are formed by stacking 3 layers in the upper and lower layers, and a large number of 3 stack cells (20) are connected in series on the same surface, and high-precision selective processing using a laser. Manufactured by making full use of technology (see Journal of Precision Engineering, Vol. 56, No. 11, separate volume, issued November 5, 1990, pages 117-122).

According to the photovoltaic module (1) using the integrated photovoltaic element (2), for example, in a region of 1 cm ² ,
Stack cells (20) can be arranged in 19 rows and 5 columns,
If all the integrated photovoltaic elements (2) are connected in series, a high voltage output exceeding 200 V will be obtained from both ends of the photovoltaic module (1). Therefore, the output obtained from the photovoltaic module (1) as shown in FIG.
A plurality of devices (7a) (7b) through the connection circuit (6)
It is distributed to (7c).

The micro relay (8) is an electrostatic type (Proceedin
gs of IEEE “Micro Electro Mechanical Systems” IEEE
Various types such as Catalog Number 94CH3404-1, pp.97-101) and the piezoelectric type described later can be adopted. In either type, a pair of electrodes to which a predetermined voltage should be applied,
It has a contact that is switched by applying a voltage, and in recent years, a particularly small and high-performance one has been developed.

One output terminal of the integrated photovoltaic element (2)
(Eg negative terminal) and one electrode of the micro relay (8) are connected to each other via the first switch (4)
(See Figure 3). The other output terminal (for example, a positive terminal) of the integrated photovoltaic element (2) and the other electrode of the micro relay (8) are connected to each other as described later, and the connection point is the second
Via the switch (41), it is connected in parallel with the connection point of the adjacent photovoltaic unit (see FIG. 5). Incidentally, in FIG. 1, only the first switch (4) and the second switch (41) connected to the integrated photovoltaic element (2) in the front row are shown,
The first switch and the second of the integrated photovoltaic device (2) in the rear row
The switches are not shown in the figure.

The first switch (4) and the second switch (41) of each photovoltaic unit are switched and controlled by the control circuit (5). As will be described later, the plurality of switches built in the connection circuit (6) are also switched and controlled by the control circuit (5).

FIG. 3 shows a pair of integrated photovoltaic elements.
The sectional structure of a photovoltaic unit including (2) and the piezoelectric type micro relay (8) and the connection state of the first switch (4) and the second switch (41) are shown. The micro relay (8) is integrated on the back surface of the integrated photovoltaic element (2), and
A frame composed of an i substrate (80) and an insulating material (90), and an operating member formed by fixing a first electrode plate (82) and a second electrode plate (83) on both surfaces of a piezoelectric element plate (81). It is equipped with Both ends of the actuating member are supported by the frame, and the piezoelectric element plate
By applying the predetermined voltage of (81), it bends like a chain line.

The Si substrate (80) is provided with a first conductor layer (84), one end of which contacts the first electrode plate (82) in a free state. A second conductor layer (85) is provided on the insulating material (90), and a contact (86) to be in contact with the second electrode plate (83) deformed like a chain line is provided at one end thereof. Has been formed.

As described above, the negative terminal of the integrated photovoltaic element (2) and the second electrode plate (83) are connected to each other via the first switch (4). In addition, integrated photovoltaic device (2)
The positive terminal and the first electrode plate (82) are connected to each other as described above, and the second switch (41) is connected to the connection point.

Therefore, when the first switch (4) is opened with the integrated photovoltaic element (2) generating electric power by receiving light, the negative terminal of the integrated photovoltaic element (2) is connected to the negative terminal of the integrated photovoltaic element (2). The generated power can be taken out from the first conductor layer (84). Further, in this state, when the first switch (4) is closed, the output voltage of the integrated photovoltaic element (2) changes from the first electrode plate (82) to the second electrode plate (82).
When applied to the electrode plate (83), the piezoelectric element plate (81) deforms like a chain line together with both electrodes. As a result, the micro relay (8) switches from the first conductor layer (84) side to the second conductor layer (85) side, and the plus terminal of the integrated photovoltaic element (2) and the second conductor layer (85). It is possible to take out the generated power from.

In the above photovoltaic unit, the second electrode plate (83) to which a voltage is to be applied to the piezoelectric element plate (81) is an electrode for connecting and disconnecting with the contact (86) of the second conductor layer (85). It also plays a role of, and sharing the electrode simplifies the structure,
The manufacturing process is also simplified.

FIG. 4 shows another example of the structure of the photovoltaic unit. The negative terminal of the integrated photovoltaic device (2) and the first electrode plate (82) are directly connected, while the positive terminal of the integrated photovoltaic device (2) and the second electrode plate (83) are They are connected to each other via the third switch (42). Therefore, the third
With the switch (42) open, the integrated photovoltaic device
The generated power can be taken out from the positive terminal (2) and the first electrode plate (82).

When the third switch (42) is closed, the piezoelectric element plate
(81) is deformed like a chain line with both electrode plates (82) and (83)
The electrode plate (83) and the second conductor layer (85) are in contact with each other. Therefore, the generated power can be taken out from the first electrode plate (82) and the second conductor layer (85).

FIGS. 5 and 6 show an example in which a photovoltaic module is constructed using the photovoltaic unit having the above-mentioned first configuration. In FIG. 5, a plurality of photovoltaic units are connected in series with each other. Connected, in FIG. 6, a plurality of photovoltaic units are connected in parallel with each other.

That is, as shown in FIG. 5, adjacent photovoltaic units are connected to each other through the second switch (41). Further, the first conductor layer (84) and the second conductor layer (85) of the micro relay (8a) constituting the first row photovoltaic unit are both integrated type constituting the second row photovoltaic unit. It is connected to the negative terminal of the photovoltaic element (2b). Second
Micro-relays (8b) that make up a row of photovoltaic units
Both the first conductor layer (84) and the second conductor layer (85) of the above are integrated type photovoltaic elements (2c) constituting a third row of photovoltaic units.
It is connected to the minus terminal of. The same applies hereinafter.

As shown in FIG. 5, when all the first switch (4) and the second switch (41) are open, the micro relay is
(8a) (8b) (8c) does not operate, and the positive terminal of the integrated photovoltaic element (2a) in the first row is the first electrode plate (82) and the first terminal.
A second row of integrated photovoltaic devices (2
Connected to the negative terminal of b). The plus terminal of the integrated photovoltaic device (2b) in the second row is the integrated photovoltaic device in the third row via the first electrode plate (82) and the first conductor layer (84).
Connected to the negative terminal of (2c). The same applies hereinafter.

Therefore, a plurality of integrated photovoltaic elements (2a)
(2b) and (2c) are connected in series with each other, and a high-voltage output Vs corresponding to the number of connected integrated photovoltaic elements is obtained from both ends of the photovoltaic module.

On the other hand, when all the first switches (4) and the second switches (41) are closed as shown in FIG. 6, the integrated photovoltaic elements (2a) (2b) (2c) are transferred to the micro relays. (8
A voltage is applied to both electrode plates (82) and (83) of a), (8b) and (8c). As a result, the piezoelectric element plate (81) and both electrode plates (82) (83)
Is deformed, and the second electrode plate (83) becomes the second conductor layer (85) as shown in the figure.
Contact the contact (86) of.

As a result, each integrated photovoltaic element (2a)
The positive terminals of (2b) and (2c) are connected to each other. The negative terminals of the integrated photovoltaic elements (2a) (2b) (2c) are the first switch (4), the second electrode plate (83) and the second conductor layer.
They are connected to each other via (85). Therefore, the plurality of integrated photovoltaic elements (2a) (2b) (2c) are connected in parallel with each other, and the voltage Vp corresponding to the performance of the integrated photovoltaic element is connected from both ends thereof. Output is obtained.

FIG. 7 shows a connection circuit shown in FIG. 1 for a photovoltaic module composed of 6 rows of photovoltaic units.
It represents a system in which an actuator (71) and a sensor (72) are connected via (6) to supply power to these devices. As shown in FIG. 7, each integrated photovoltaic device (2
Between the positive terminals of a) to (2f) and each device,
While the fourth switch (43) is interposed, each fourth switch (4
The device-side contacts of 3) are connected to each other via the fifth switch (44) to form the connection circuit (6).

When the actuator (71) and the sensor (72) are in the normal operating state, the second switch (41), the fourth switch (43) and the fifth switch (44) are switched as shown in the figure. , 1st to 3rd rows of micro relays (8a)
(8b) and (8c) remain OFF, and the contacts of the micro-relays (8d) (8e) (8f) in the fourth to sixth rows are switched to O
Let N. Accordingly, the integrated photovoltaic elements (2a) (2b) (2c) of the first to third columns are connected in series with each other,
The voltage generated across the integrated photovoltaic elements (2a) (2b) (2c) is applied to the actuator (71), and the integrated photovoltaic elements (2d) in the fourth to sixth rows are also applied. (8
e) and (8f) are connected in parallel with each other, and the voltage obtained from these integrated photovoltaic devices (2d) (8e) (8f) is applied to the sensor (72).

For example, when the load of the actuator (71) is increased due to the movement of the micromachine and the sensor (72) is in a non-use state, as shown in FIG. 8, the second switch (41),
Switch the fourth switch (43) and the fifth switch (44),
The fourth and fifth rows of microrelays (8d) (8e) are OF
Let it be F. As a result, the integrated photovoltaic elements (2a) to (2e) of the first to fifth columns are connected in series with each other, and are generated at both ends of these integrated photovoltaic elements (2a) to (2e). High voltage is applied to the actuator (71) and
Only the output of the row integrated photovoltaic device (8f) is sensor (72)
Supply to.

If the amount of light decreases and it becomes necessary to increase the amount of current supplied to the sensor (72), as shown in FIG. 9, the second switch (41), the fourth switch (43) and By switching the fifth switch (44), the micro relays (8a) (8b) of the first and second rows are turned off, and the micro relays (8c) (8d) (8e) (8f of the third to sixth rows are turned off. ) Is turned on. Accordingly, the integrated photovoltaic devices (2
a) and (2b) are connected in series with each other to apply a voltage generated across the integrated photovoltaic elements (2a) and (2b) to the actuator (71), and to connect the third to sixth columns. The electric current obtained from the integrated photovoltaic elements (2c) (2d) (2e) (2f) of (1) is supplied to the sensor (72). At this time, the voltage applied to the actuator (71) decreases, but this does not pose a problem when the load is low.

The switching of the above-mentioned second switch (41), fourth switch (43) and fifth switch (44) is controlled by the control circuit (5) shown in FIG. For example, the increase in the load of the device and the decrease in the light amount can be recognized by detecting that the output current of the photovoltaic module (1) decreases accordingly. Further, the decrease in the amount of light can be recognized by using one photovoltaic element that constitutes the photovoltaic module (1) as a light amount sensor, or by providing a dedicated pyranometer separately.

10 to 12 show a manufacturing process of a photovoltaic unit including the integrated photovoltaic element (2) and the micro relay (8). FIG. 10 shows a manufacturing process of the micro relay (8). First, as shown in FIG. 10 (a), on a Si substrate (80) having a thickness of 300 to 500 μm,
The first electrode plate (82) and the piezoelectric element plate (8) each having a thickness of about 1 μm
1) and the second electrode plate (83) are sequentially formed.

Next, as shown in FIG. 10B, the Si substrate 80 is anisotropically etched to selectively remove the central portion thereof. Thereafter, as shown in FIG. 10C, a polysilicon layer (9) having a thickness of several to several tens of μm is formed on the surface of the electrode, and then, as shown in FIG.
In (d), the second conductor layer (85) is formed on the surface of the polysilicon layer (9).
To a thickness of 1 μm or less.

[0045] In FIG. 10 (e), the covering polysilicon layer (9) and the second conductive layer (85), an insulating material such as SiN _x (90) is deposited to a thickness of several [mu] m, followed by FIG. At 10 (f), the polysilicon layer (9) is selectively removed by using a sacrifice layer etching technique to form a cavity between the insulating material (90) and the second electrode plate (83).

On the other hand, in the manufacturing process of the integrated photovoltaic element (2), a glass substrate (24) having a thickness of about 500 μm is prepared as shown in FIG. 11 (a), and then, in FIG. 11 (b), Glass substrate (2
4) The integrated structure (25) of photovoltaic elements is formed on the above through a well-known process using a laser to obtain an integrated photovoltaic element (2). Further, referring to FIG. 11 (c), an integrated photovoltaic device
The first conductor layer (84) is provided on the surface of the glass substrate (24) (2) to a thickness of 300 to 500 μm.

Finally, as shown in FIG. 12, the integrated photovoltaic element (2) and the micro relay (8) are joined together,
Together, they complete a photovoltaic unit with a total thickness of about 2 mm. Where the integrated photovoltaic device
For bonding the (2) and the micro relay (8), a well-known bonding technique for different materials, for example, thermocompression bonding in vacuum can be adopted. The glass substrate (24) that constitutes the integrated photovoltaic element (2)
Although not shown in the integrated photovoltaic device (2) shown in FIGS. 1 and 2, the integrated photovoltaic device (2) is obtained by performing the manufacturing process of FIGS. It is also possible to omit the formation of the glass substrate (24) interposed between the power element (2) and the micro relay (8).

According to the above photovoltaic module, the micro relay (8) is provided to each of the plurality of integrated photovoltaic devices (2).
By providing ON / OFF of each micro relay (8), these integrated photovoltaic elements (2) can be connected in various forms of mixed series and parallel. This makes it possible to select an appropriate connection form according to the requirements of a plurality of devices to which power is to be supplied, and particularly in a power supply system that requires miniaturization such as a micromachine, a suitable energy supply source. Become. Also, by adopting a micro relay (8) with movable contacts,
As described above, it is also possible to combine with an integrated photovoltaic element that outputs a high voltage exceeding 200 V, and thus a sufficient voltage can be distributed to many devices.

The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or limiting the scope. Further, the configuration of each part of the present invention is not limited to the above embodiment, but various modifications can be made within the technical scope described in the claims. For example, it goes without saying that the present invention can be widely applied not only to micromachines but also to various household appliances, automobile appliances, communication appliances and the like.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a photovoltaic module according to the present invention.

FIG. 2 is a partially enlarged perspective view showing the structure of the photovoltaic unit according to the present invention.

FIG. 3 is a sectional view of a photovoltaic unit.

FIG. 4 is a cross-sectional view showing another configuration example of the photovoltaic unit.

FIG. 5 is a cross-sectional view showing a state in which a plurality of photovoltaic units are connected in series.

FIG. 6 is a cross-sectional view showing a state in which a plurality of photovoltaic units are connected in parallel.

FIG. 7 is a diagram showing an example of a switch switching mode of the photovoltaic module in the power supply system.

FIG. 8 is a diagram showing another example of the above-mentioned switch switching mode.

FIG. 9 is a diagram showing still another example of the above-mentioned switch switching mode.

FIG. 10 is a diagram showing a manufacturing process of a micro relay.

FIG. 11 is a diagram showing a manufacturing process of the integrated photovoltaic element.

FIG. 12 is a diagram showing a process of joining an integrated photovoltaic device and a micro relay.

[Explanation of symbols]

 (1) Photovoltaic module (2) Integrated photovoltaic device (8) Micro relay (4) First switch (41) Second switch (5) Control circuit (6) Connection circuit (7) Device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seiichi Kiyama 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd.

Claims (5)

[Claims] 1. A back surface of a photovoltaic element is integrally formed with a micro relay whose contacts are switched by applying a predetermined voltage, and the output of the photovoltaic element is taken out to the outside through the micro relay. Photovoltaic unit characterized by. 2. A microrelay comprises an operating member formed by sandwiching a piezoelectric element plate (81) between a pair of electrode plates (82) (83), and one electrode plate (82) of the operating member in a free state. The first conductor layer (84) in contact with the other electrode plate due to the deformation of the piezoelectric element plate (81)
Photovoltaic unit according to claim 1, characterized in that (83) comprises a second conductor layer (85) to contact. 3. A photovoltaic element, a microrelay integrated on the back surface of the photovoltaic element and having contacts switched by applying a predetermined voltage, and an output of the photovoltaic element of the microrelay. An opening / closing means for opening / closing the electrode is provided, and by the closing operation of the opening / closing means, the output of the photovoltaic element is guided to the micro relay, and thereby the output of the photovoltaic element is taken out through the micro relay. Photovoltaic unit characterized in that 4. A plurality of photovoltaic units are connected to each other via a connecting means, and each photovoltaic unit is integrated with a photovoltaic element and a back surface of the photovoltaic element to a predetermined voltage. A microrelay whose contacts are switched by applying a voltage, and an opening / closing means for opening / closing the output of the photovoltaic element to an electrode of the microrelay, the connecting means and the opening / closing means are switching-controlled by the control means, A photovoltaic module, wherein among a plurality of photovoltaic units, any number of photovoltaic elements are connected in series with each other and the remaining photovoltaic elements are connected in parallel with each other. 5. The control means determines the proportion of the photovoltaic elements to be connected in series and the photovoltaic elements to be connected in parallel in accordance with the output of the photovoltaic element, and the determination result. The photovoltaic module according to claim 4, further comprising command means for generating a switching command for the connection means and the opening / closing means based on the above.