JP2003124492A - Solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a compact designing and a higher production efficiency of a solar cell module without lowering the photovoltaic energy conversion efficiency thereof. SOLUTION: The solar cell module 1 has a plurality of solar cell elements 2 and a converter 3 formed on a photodetecting surface of a base plate. The solar cell elements 2 are arranged in a matrix to be connected in series and parallel on the photodetecting surface of the base plate. The converter 3 with a circuit structure comprising semiconductor elements directly formed using the semiconductor production technology has the maximum power follow-up function of performing control for always obtaining the maximum generating current by flexibly responding to changes in the quantity of solar radiation and in the temperature or the like of the solar cell elements 2. Thus, the DC voltage which is outputted from the solar cell elements 2 connected in series and parallel is produced dropped down to a certain level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell module, and more particularly to miniaturization and cost reduction of the solar cell module.

[0002]

2. Description of the Related Art A so-called system interconnection system is widely known as a solar cell system that converts direct current output generated by a solar cell upon receiving sunlight into alternating current and supplies the alternating current to electric appliances.

This system interconnection system comprises a solar cell module having a structure in which a plurality of solar cell elements are connected in series or in parallel to a glass plate or the like, and an interconnection inverter.

The interconnection inverter comprises a DC / DC converter that boosts the DC voltage generated by the solar cell module, and a DC / AC inverter that converts the DC voltage boosted by the DC / DC converter to AC. The output of the DC / AC inverter is linked with the commercial power system.

As a technique for reducing the size of the statistical interconnection system having such a configuration, a DC / DC converter and a DC / AC are disclosed in Japanese Patent Laid-Open No. 2001-189476.
It is known that an inverter is arranged on the non-light-receiving surface side of a solar cell module.

[0006]

However, in the system interconnection system as described above, the DC / DC converter and the DC / AC inverter must be provided for each solar cell module on the non-light-receiving surface of the solar cell module. Therefore, there is a problem that the number of manufacturing steps increases and the production efficiency decreases.

[0007] Therefore, an object of the present invention is to provide a solar cell module which is compact and whose manufacturing efficiency can be improved without lowering the light / electric energy conversion efficiency.

[0008]

In order to solve the above problems, a solar cell module according to the present invention is provided with a plurality of solar cell elements mounted on an element mounting surface of a substrate and connected in series and parallel, and an element of the substrate. A converter provided on the mounting surface for reducing the DC voltage generated by the plurality of solar cell elements.

According to such an invention, the interconnection system is constructed by using the solar cell module,
The system can be significantly downsized without reducing the conversion efficiency of electric energy.

Since the converter and the solar cell element can be integrally manufactured, the production efficiency of the solar cell module can be greatly improved and the cost can be reduced.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described more specifically with reference to the drawings. Here, in the accompanying drawings, the same reference numerals are given to the same members,
Moreover, the duplicate description is omitted. It should be noted that the embodiment of the present invention is a particularly useful embodiment for carrying out the present invention, and the present invention is not limited to the embodiment.

FIG. 1 is an explanatory view showing the structure of a solar cell module, FIG. 2 is a circuit diagram of a converter provided in the solar cell module of FIG. 1, and FIG. 3 is a timing of voltage / current waveforms of respective parts in the converter of FIG. Chart, Figure 4 is Figure 1
5 is a connection explanatory view showing an example when the solar cell modules of 1 are connected in parallel, and FIG. 5 is a connection explanatory view showing an example when the solar cell modules of FIG. 1 are connected in series.

In the present embodiment, the solar cell module 1 receives sunlight to generate power and outputs DC power. The solar cell module 1 is used, for example, as a system interconnection system that operates by connecting to a commercial power source.

As shown in FIG. 1, the solar cell module 1 is provided with a plurality of solar cell elements 2. These solar cell elements 2 are arranged in a matrix on the light receiving surface (element mounting surface) of a transparent substrate such as a glass plate, and the respective solar cell elements 2 are connected in series and parallel.

A converter 3 is formed on the light receiving surface of the substrate on which the solar cell element 2 is arranged. Converter 3
Has a circuit configuration in which a semiconductor element is directly formed using a semiconductor manufacturing technique.

This converter 3 flexibly responds to changes in the amount of solar radiation of the solar cell element 2, changes in temperature, etc., and has a maximum power follow-up function for controlling so as to always obtain the maximum generated current. The DC voltage EPV output from the solar cell element 2 is stepped down to a certain voltage level to output a DC voltage.

The circuit configuration of the converter 3 will be described.

As shown in FIG. 2, the converter 3 includes a capacitor 4, semiconductor switch elements 5 and 6, and voltage detecting means 7.
9 to 9, diodes 10, 11, a control circuit 12, a gate generation circuit 13, a drive circuit 14, and a power supply circuit 15.

The output parts of the series-parallel solar cell elements 2 are connected to the input parts IN1 and IN2 of the converter 3, respectively, and the DC voltage E generated by the solar cell elements 2 is connected.
PV is input.

The input portions IN1 and IN2 of the converter 3 are connected in parallel with the capacitor 4 and the input portion of the voltage detecting means 7, respectively. The capacitor 4 is for smoothing the DC voltage EPV, and the voltage detecting means 7 detects the voltage level of the DC voltage EPV generated by the solar cell element 2.

Further, the input portion IN1 of the converter 3 is
One connection portion of the semiconductor switch element 5 is connected, and one connection portion of the semiconductor switch element 6 is connected to the other connection portion of the semiconductor switch element 5.

The semiconductor switch elements 5 and 6 are FET (F
It is composed of a transistor element such as a Field Effect Transistor. To one connection portion of the semiconductor switch element 5, one input portion of the voltage detection means 8 and the cathode of the diode 10 are connected. The other connecting portion of the semiconductor switch element 5 is connected to the other input portion of the voltage detecting means 8 and the anode of the diode 10.

Similarly, one input portion of the voltage detecting means 9 and the cathode of the diode 11 are connected to one connection portion of the semiconductor switching element 6, respectively, and the other connection portion of the semiconductor switching element 6 is connected. The other input portion of the voltage detection means 9 and the anode of the diode 11 are connected to the.

Then, the other connecting portion of the semiconductor switching element 5 and the other connecting portion of the semiconductor switching element 6 serve as the output portions OUT1 and OUT2 of the converter 3, and the DC voltage converted to a certain voltage level is output. .

A control circuit 12 is connected to the output sections of the voltage detecting means 7-9. The control circuit 12 calculates electric power from the voltage / current detected by the voltage detection means 7 to 9 and measures whether the electric power is decreased or increased, and determines whether the electric power is close to or far from the maximum generated power, so-called hill climbing. The gate generation circuit 13 and the like are controlled so as to obtain the maximum power by control according to the method.

The gate generation circuit 13 includes a drive circuit 1
4 is connected. The gate generation circuit 13 generates a gate signal based on the control signal of the control circuit 12. The gate signal generated by the gate generation circuit 13 is connected so as to be input to the input section of the drive circuit 14, and the semiconductor switch element 5, 5 is connected to the output section of the drive circuit 14.
6 are connected to control terminals (gates) for controlling ON / OFF.

The drive circuit 14 is a gate generation circuit 13
The gate signal generated by is amplified so that the semiconductor switch elements 5 and 6 can be ON / OFF controlled. Power supply circuit 15
Supplies the operating power supply voltage of the control circuit 12, the gate generation circuit 13, and the drive circuit 14.

In FIG. 3, the output current iM1 output from the converter 3, the voltage V1 between the cathode and the anode of the diode 10, and the voltage V2 between the cathode and the anode of the diode 11 are shown from the upper side to the lower side.
The current / voltage waveforms of each part are shown.

As shown in the figure, the semiconductor switch element 5,
6 is controlled to be turned on / off alternately,
The output current iM1 is detected by combining the voltages when the semiconductor switch elements 5 and 6 are ON.

Therefore, the control circuit 12 controls the ON / OFF time of these semiconductor switch elements 5 and 6, so that the DC voltage of maximum power is stably output from the converter 3.

Next, a configuration example of the grid interconnection system SS using the solar cell module 1 according to the present embodiment will be described with reference to FIGS.
As shown in FIG.

FIG. 4 shows a system interconnection system SS in which the solar cell modules 1 are connected in parallel.

In this case, the smoothing coil L is connected to the output section OUT1 of the converter 3 provided in each solar cell module 1. These solar cell modules 1 are connected in parallel to the input section of the interconnection inverter Iv via the respective coils L. Further, the smoothing capacitor C is provided at the input of the interconnection inverter Iv.
Are connected.

The interconnection inverter Iv is the solar cell module 1 stepped down to a certain voltage level by the converter 3.
The direct current voltage EM is controlled so as to be a constant voltage, converted into alternating current and output, and is connected to the commercial power system.

Although the interconnection inverter Iv is connected to the subsequent stage of the solar cell module 1 in FIG. 4, as shown in FIG. 5, the solar cell module 1 and the interconnection inverter Iv connected in parallel are connected. A configuration may be provided in which a boost converter CV that boosts the DC voltage output from the solar cell module 1 to a certain voltage level is connected between and.

Further, FIG. 6 shows a system interconnection system SS configured by connecting the solar cell modules 1 in series.

Also in this case, each solar cell module 1
The smoothing coil L is connected to the output portion OUT1 of the converter 3 provided in the converter 3, and the smoothing capacitor C is connected to the input portion of the interconnection inverter Iv.

As a result, according to the present embodiment, the solar cell element 2 and the converter 3 are provided on the light receiving surface of the substrate, so that the grid interconnection system SS can be downsized.

Further, by forming the converter 3 on the light receiving surface of the substrate by the semiconductor manufacturing technique, the converter 3 can be manufactured integrally with the solar cell element 2, so that the production efficiency of the solar cell module 1 can be greatly improved and the cost can be reduced. Down is possible.

[0040]

As is apparent from the above description, according to the present invention, the following effects can be obtained. (1). Since the solar cell element and the converter are respectively provided on the light receiving surface of the substrate, the grid interconnection system can be downsized. (2). Further, since the converter is directly formed on the light receiving surface of the substrate by the semiconductor manufacturing technology, the production efficiency of the solar cell module can be significantly improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a solar cell module according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of a converter provided in the solar cell module of FIG.

FIG. 3 is a timing chart of voltage / current waveforms of various parts in the converter of FIG.

FIG. 4 is a connection explanatory view showing an example when the solar cell modules of FIG. 1 are connected in parallel.

FIG. 5 is a connection explanatory view showing another example when the solar cell modules of FIG. 1 are connected in parallel.

FIG. 6 is a connection explanatory view showing an example in which the solar cell modules of FIG. 1 are connected in series.

[Explanation of symbols]

1 solar cell module 2 Solar cell element 3 converter 4 capacitors 5,6 Semiconductor switch element 7-9 Voltage detection means 10,11 diode 12 Control circuit 13 Gate generation circuit 14 Drive circuit 15 power supply circuit IN1, IN2 input section OUT1, OUT2 output section SS system interconnection system CV boost converter L coil Iv interconnection inverter C capacitor

Claims (3)

[Claims] 1. A plurality of solar cell elements mounted on an element mounting surface of a substrate and connected in series and parallel, and a DC voltage generated by the plurality of solar cell elements provided on the element mounting surface of the substrate, is stepped down. A solar cell module comprising a converter. 2. The solar cell module according to claim 1, wherein the converter has a maximum power tracking control function. 3. The converter according to claim 1, wherein the converter is composed of a semiconductor integrated circuit, and the semiconductor integrated circuit element is directly formed on the element mounting surface of the substrate by a semiconductor manufacturing technique. Solar cell module.