KR101216740B1 - Solar electricity generating system and method for controllig thereof and integrated connecting board - Google Patents

Abstract

PURPOSE: A sunlight generation system, control method, and integrated connector band are provided to control a surface polarization phenomenon by transmitting a control signal to a solar battery. CONSTITUTION: One or more solar battery(101) outputs voltages by converting sunlight into the voltages. One or more diode(102) connect to each solar battery. One or more diodes prevent inverse current in the solar battery. One or more blockers(103) are individually connected to one or more diodes. A DC/AC inverter connects to one or more blockers. [Reference numerals] (101, 111, 121) Cell; (160) PV off-set control unit

Description

SOLAR ELECTRICITY GENERATING SYSTEM AND METHOD FOR CONTROLLIG THEREOF AND INTEGRATED CONNECTING BOARD}

The present invention relates to a solar power system and a control method thereof. In addition, the present invention relates to an integrated connection panel for connecting a solar cell and a DC-AC inverter in a solar power generation system.

In recent years, research on alternative energy has been actively conducted to cope with the depletion of fossil fuels and environmental problems. In particular, research on solar power generation is being actively conducted among researches on alternative energy, and the amount of photovoltaic power generation is showing a sharp increase, doubling every two years on average. The increase in solar power generation is one of the fastest growing sectors in energy technology, and is one of the candidates that can replace current major power generation methods.

1 is a conceptual diagram of a conventional solar power system. As shown in FIG. 1, the photovoltaic power generation system may include a plurality of solar cells 101, 111, 121, diodes 102, 104, 112, 114, 122, 124, breakers 103, 105, 113, 115, 123, 125, a DC-AC inverter 140, and a grid 150. Here, the diodes 102, 104, 112, 114, 122, 124 and the breakers 103, 105, 113, 115, 123, 125 may also be referred to as the connection board 130.

The connection panel 130 may prevent the reverse current supplied to the solar cells 101, 111, and 121, or cut off when overpower is applied.

Meanwhile, the solar cells 101, 111, and 121 may include a PN junction semiconductor. In the PN junction semiconductor, sunlight may be incident to the PN junction interface, whereby the positive charge moves toward the negative electric field and the negative charge moves toward the positive electric field. As the incidence of sunlight continues, the shift of the above-mentioned charges may be repeated to generate an electromotive force of 0.6V between both terminals. The generation of electromotive force generates a surface polarization phenomenon in which the movement of positive and negative charges decreases at the PN interface. Due to the surface polarization, charge transfer from the solar cells 101, 111, and 121 may be disturbed, thereby causing a problem that the efficiency of the entire photovoltaic system is lowered.

Patent Application Publication No. 10-0983236
Japanese Laid-Open Patent Publication No. 2003-032897

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a photovoltaic power generation system and an integrated connection panel which suppress occurrence of surface polarization.

In order to achieve the above-described invention the present invention comprises: at least one solar cell that receives sunlight and converts it into electric power; At least one diode connected to each of the solar cells and preventing a reverse current flowing back into the solar cell; At least one breaker connected to each of the at least one diode and blocking the overvoltage from being applied to the solar cell; A DC-AC inverter connected to the at least one breaker and configured to collect DC-AC inverted power output from each of the at least one solar cell; A system for receiving an inverted power output from the DC-AC inverter; And detecting the voltage at an input terminal of the DC-AC inverter to determine whether the DC-AC inverter is operated. When the DC-AC inverter is idle, It includes; PV offset controller for outputting a control signal input from the grid to each of the at least one solar cell.

In addition, the control method of the photovoltaic power generation system including at least one solar cell and a DC-AC inverter according to another aspect of the present invention, detecting the input terminal voltage of the DC-AC inverter; Determining whether the DC-AC inverter is operating based on a detection result of the input terminal voltage of the DC-AC inverter; And outputting a control signal to each of the at least solar cells when the DC-AC inverter is at rest.

Meanwhile, an integrated connection panel connecting at least one solar cell and a DC-AC inverter according to another embodiment of the present invention is connected to each of the solar cells and prevents reverse current flowing back into the solar cell. At least one diode; At least one breaker connected to each of the at least one diode and blocking the overvoltage from being applied to the solar cell; Connected to the DC-AC inverter and the grid, respectively, and detects the voltage of the input terminal of the DC-AC inverter to determine whether the DC-AC inverter is operated. And a PV offset controller for outputting an input control signal to each of the at least one solar cell.

According to various embodiments of the present disclosure, a photovoltaic power generation system and an integrated connection panel may be provided to suppress occurrence of surface polarization. In addition, the influence due to surge or the like introduced into the system can be suppressed. In addition, the burnout of the reverse current prevention diode for preventing the module from being damaged by the reverse current can be prevented.

1 is a conceptual diagram of a conventional solar power system.
2 is a conceptual diagram of a photovoltaic system according to an embodiment of the present invention.
3 is a block diagram of a PV offset controller according to an embodiment of the present invention.
4A and 4B are conceptual views illustrating a solar power system according to another embodiment of the present invention.
5 is a flowchart of a control method of a solar power system according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in more detail. It is to be noted that the same components in the drawings are denoted by the same reference numerals whenever possible. In the following description and the annexed drawings, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

2 is a conceptual diagram of a photovoltaic system according to an embodiment of the present invention.

As shown in FIG. 2, the photovoltaic power generation system includes a plurality of solar cells 101, 111, 121, diodes 102, 104, 112, 114, 122, 124, breakers 103, 105, 113, 115, 123, 125, DC-AC inverter 140, a grid 150, and a PV offset controller 160. ) May be included. Here, the diodes 102, 104, 112, 114, 122, 124, the breakers 103, 105, 113, 115, 123, 125 and the PV offset controller 160 may also be referred to as integrated access panels.

The solar cells 101, 111, and 121 may output incident power by converting incident sunlight. The solar cells 101, 111, and 121 may include, for example, pn junction semiconductors, and sunlight may be incident on the pn junction surface. At the pn junction, incident photons can cause the generation of a pair of electrons and holes. The generated electrons may move to the n-type semiconductor portion, and the generated holes may move to the p-type semiconductor portion. Accordingly, a potential difference may be generated in the pn junction semiconductor, and a current may be generated from the n-type semiconductor to the p-type semiconductor. The solar cells 101, 111, and 121 may be crystalline, amorphous, or the like, and the kind thereof is not limited. In addition, the solar cells 101, 111, and 121 may be implemented as silicon solar cells, gallium arsenide, and gallium antimony double layer condensed tandem solar cells.

The solar cells 101, 111, and 121 may output predetermined power in the presence of sunlight, and may not output the predetermined power in the absence of sunlight. In particular, the solar cells 101, 111, and 121 according to the present invention receive a predetermined control signal when there is no sunlight, more specifically, when the DC-AC inverter 140 does not operate. This can remove residual charges. More specifically, an electric field may be applied to prevent immediate recombination in the solar cells 101, 111 and 121. The residual charge generated in the EVA foil can be removed by the electric field.

Each of the solar cells 101, 111, and 121 may have two input / output terminals. The first input / output terminal of the solar cell 101 may be connected to one end of the diode 102. The other end of the diode 102 may be connected to one end of the breaker 103, and the other end of the breaker 103 may be connected to the DC-AC inverter 140 and the PV offset controller 160. The second input / output terminal of the solar cell 101 may be connected to one end of the diode 104. The other end of the diode 104 may be connected to one end of the breaker 105, and the other end of the breaker 105 may be connected to the DC-AC inverter 140 and the PV offset controller 160.

Meanwhile, the first input / output terminal of the solar cell 111 may be connected to one end of the diode 112. The other end of the diode 112 may be connected to one end of the breaker 113, and the other end of the breaker 113 may be connected to the DC-AC inverter 140 and the PV offset controller 160. In particular, the other end of the breaker 113 may be connected to the other end of the breaker (103). The second input / output terminal of the solar cell 111 may be connected to one end of the diode 114. The other end of the diode 114 may be connected to one end of the breaker 115, and the other end of the breaker 115 may be connected to the DC-AC inverter 140 and the PV offset controller 160. In particular, the other end of the breaker 115 may be connected to the other end of the breaker 105.

In addition, the first input / output terminal of the solar cell 121 may be connected to one end of the diode 122. The other end of the diode 122 may be connected to one end of the breaker 123, and the other end of the breaker 123 may be connected to the DC-AC inverter 140 and the PV offset controller 160. In particular, the other end of the breaker 123 may be connected to the other end of the breaker 103 and the other end of the breaker 113. The second input / output terminal of the solar cell 121 may be connected to one end of the diode 124. The other end of the diode 124 may be connected to one end of the breaker 125, and the other end of the breaker 125 may be connected to the DC-AC inverter 140 and the PV offset controller 160. In particular, the other end of the breaker 125 may be connected to the other end of the breaker 105 and the other end of the breaker 115. On the other hand, those skilled in the art will readily understand that the number of solar cells 101, 111, and 121 is arbitrary.

Each of the diodes 102, 104, 112, 114, 122, and 124 may prevent conduction of reverse current flowing back into the solar cells 101, 111, and 121. In addition, the breakers 103, 105, 113, 115, 123, and 125 may open the conductor when an overvoltage is applied.

The DC-AC inverter 140 may invert the input DC power in the AC shape. For example, the DC-AC inverter 140 may invert power input from the solar cells 101, 111, and 121 when there is sunlight, and when the sunlight is not present, the solar cells 101, 111, and 121. There is a rest period because no power is input from the system. When the DC-AC inverter 140 inverts power, the DC-AC inverter 140 may maintain a predetermined input terminal 414 voltage, for example, a first voltage, and maintain a second voltage during the rest period. Here, the second voltage may be 0V.

The DC-AC inverter 140 may be implemented as, for example, a transformer inverter or may be implemented as a transformerless inverter. When the DC-AC inverter 140 is implemented as a transformer inverter, the solar cells 101, 111, and 121 are insulated from the grid 150.

The DC-AC inverter 140 may collect and invert power input from the respective solar cells 101, 111, and 121, and output the inverted power to the grid 150.

The PV offset controller 160 may be connected to two input terminals of the DC-AC inverter 140, and may be connected to the output terminal and the grid 150 of the DC-AC inverter 140. The PV offset controller 160 may monitor the voltage applied to the input terminal of the DC-AC inverter 140 to determine whether the DC-AC inverter 140 is being driven or in the idle period. For example, when the voltage of the input terminal 141 of the DC-AC inverter 140 is the first voltage, the PV offset controller 160 may determine that the DC-AC inverter 140 is being driven. In addition, when the voltage of the input terminal 141 of the DC-AC inverter 140 is the second voltage, the PV offset controller 160 may determine that the DC-AC inverter 140 is a rest period. Meanwhile, the configuration in which the PV offset controller 160 monitors the voltage at the input terminal 141 of the DC-AC inverter 140 is merely an example, and the PV offset controller 160 monitors the voltage at the other input terminal or the voltage at the output terminal. As a result, it may be determined whether the DC-AC inverter 140 is being driven or idle.

The PV offset controller 160 does not perform any other operation when the DC-AC inverter 140 is being driven. The PV offset controller 160 may input a control signal to each of the solar cells 101, 111, and 121 when the DC-AC inverter 140 is idle. Here, the control signal may be a current having a magnitude of 300 mA, for example, and the waveform is not limited. The control signal may be input to the solar cells 101, 111, and 121. The solar cells 101, 111, and 121 may form a predetermined potential difference within the cell by a control signal, and thus residual charges causing polarization may be removed.

As described above, when the DC-AC inverter 140 is in the idle period, the PV offset controller 160 may apply a control signal to each of the solar cells 101, 111, and 121. By the control signal, residual charges that cause polarization in the solar cells 101, 111, and 121 may be removed, thereby creating an effect of increasing the efficiency of the entire photovoltaic system.

3 is a block diagram of a PV offset controller according to an embodiment of the present invention. Input / output terminals 182 and 183 of the PV offset controller 160 may be connected to input terminals of a DC-AC inverter (not shown). In addition, the input / output terminal 181 of the PV offset controller 160 may be connected to an output terminal and a grid (not shown) of the DC-AC inverter (not shown).

The input / output unit 161 may receive an input signal from an input terminal of a DC-AC inverter (not shown). The input signal input to the input / output unit 161 may be the same as the input terminal voltage of the DC-AC inverter (not shown).

The voltage detector 162 may measure an input terminal voltage of a DC-AC inverter (not shown) by measuring a voltage of an input signal input from the input / output unit 161. The voltage detector 162 may only measure the voltage of the input signal. Alternatively, the voltage detector 162 may determine whether to drive the DC-AC inverter (not shown) based on the voltage of the input signal. In this case, the voltage detector 162 may include a comparator in which a predetermined reference voltage is input to the first input terminal and the input signal is input to the second input terminal. As a result of the comparison of the comparator, when the reference voltage is greater than or equal to the first voltage, the controller 163 may output a determination result that the DC-AC inverter (not shown) is being driven. In addition, when the comparison result of the comparator is less than the reference voltage, for example, the first voltage, the DC-AC inverter (not shown) may output the determination result to the controller 163.

The controller 163 may determine whether to output the control signal to the solar cell based on the voltage detection result of the voltage detector 162. For example, when the DC-AC inverter (not shown) is in the idle period, the controller 163 may receive a predetermined power from the system (not shown), and output it to the amplifier 164 as a control signal. have. On the other hand, when the DC-AC inverter (not shown) is a driving period, the controller 163 may not perform a separate operation.

The amplifier 164 receiving the control signal from the controller 163 may amplify the control signal with a preset gain. Here, the amplifier 164 may be implemented as, for example, an OP-amp, and those skilled in the art will readily understand that there is no limitation as long as the means can amplify a predetermined control signal with a predetermined gain.

The load resistor 165 may generate a potential difference, and a control signal may be applied to the solar cell based on the potential difference generated by the load resistor 165.

Based on the operation of the PV offset controller 160 described above, a control signal capable of removing residual charge when the DC-AC inverter (not shown) is in the idle period may be applied to the solar cell.

4A is a conceptual diagram of a photovoltaic system according to another embodiment of the present invention. The photovoltaic system according to FIG. 4A may further include a surge protect device 190 as compared to the photovoltaic system of FIG. 2. The SPD 190 may be connected to both input terminals of the DC-AC inverter 140. The SPD 190 may minimize the effects of lightning or surges coming from the system 150.

The SPD 190 may be implemented as a general SPD including an raster or a ground terminal, and the type is not particularly limited.

4B is a conceptual diagram of a photovoltaic system according to another embodiment of the present invention.

SPDs 151 to 153, 161 to 163, and 171 to 173, which are installed to protect the solar cells 101, 111 and 121 from lightning or surges, have a continuous operating voltage of DC and are directly exposed to the structure of the solar cells exposed to the outdoors. Class I (10/350 μs) Impulse Current (Iimp) 1 to 25 kA or Class II (8/20 μs) Nominal Discharge Current (In) 5 to 80 kA ) Is configured to 2 to 6 times the output voltage of the solar cell, and evaluates the limit voltage to configure the protection level (Up) within the impulse insulation strength range of the solar cell and DC-AC inverter 140. The installation method consists of protection mode between each pole (+,-) and PE conductor and between each pole.

The SPDs for protecting the DC-AC inverter 140 include DC SPDs 191 to 193 on the DC side of the DC-AC inverter and AC SPDs 194 to 196 on the AC side, respectively. The applied SPDs (191 to 193) are open circuit voltages of class II (8/20 μs) nominal discharge current (In) 1 to 10 kA class or class III (1.2 / 50 μs, 8/20 μs combination wave). Uoc) 1 to 20 kV class, and residual voltage (Ures) is composed 2 ~ 6 times of output voltage of solar cell or using voltage of DC-AC inverter. It is configured to within the DC impulse dielectric strength range of the DC-AC inverter 140.

5 is a flowchart of a control method of a solar power system according to an embodiment of the present invention.

The photovoltaic system may detect a voltage at an input terminal of the DC-AC inverter (S501). The solar power generation system may determine whether the DC-AC inverter is operating based on the detection result of the voltage of the input terminal of the DC-AC inverter (S503). As one embodiment, the solar power generation system may determine that the DC-AC inverter is operating when the input terminal voltage of the DC-AC inverter is greater than or equal to a preset threshold. In addition, the photovoltaic system may determine that the DC-AC inverter is in the idle period when the input terminal voltage of the DC-AC is less than a predetermined threshold.

If it is determined that the DC-AC inverter is in operation (S503-Y), the photovoltaic system may not perform any operation while continuing to detect the voltage at the inverter input terminal. On the other hand, if it is determined that the DC-AC inverter is in the idle period (S503-N), the photovoltaic system may apply a control signal to the solar cell (S505).

As described above, the DC-AC inverter may remove the residual charge by applying a control signal to the solar cell during the idle period.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of illustration, It goes without saying that the example can be variously changed. Therefore, various modifications may be made without departing from the spirit of the invention as claimed in the claims, and such modifications should not be individually understood from the technical spirit or outlook of the invention.

101: solar cell 102: diode
103: breaker 140: DC-AC inverter
150: grid 160: PV-offset controller
161: input and output unit 162: voltage detection unit
163 controller 164 amplifier
165: load resistance 190: SPD

Claims (11)

At least one solar cell that receives sunlight and converts it into electric power;
At least one diode connected to each of the solar cells and preventing a reverse current flowing back into the solar cell;
At least one breaker connected to each of the at least one diode and blocking the overvoltage from being applied to the solar cell;
A DC-AC inverter connected to the at least one breaker and configured to collect DC-AC inverted power output from each of the at least one solar cell;
A system for receiving an inverted power output from the DC-AC inverter; And
Connected to the DC-AC inverter and the grid, respectively, and detecting the voltage of an input terminal of the DC-AC inverter to determine whether to operate the DC-AC inverter, and the system when the DC-AC inverter is idle. And a PV offset controller for outputting a control signal input from each of the at least one solar cell.
The PV offset controller,
An input / output unit connected to an input terminal of the DC-AC inverter to receive an electrical signal from the DC-AC inverter;
A voltage detector detecting a voltage of the input / output unit to detect an input terminal voltage of the DC-AC inverter; And
A controller for determining whether the DC-AC inverter is in operation based on a detection result of the voltage detector and controlling the controller to output the control signal to each of the solar cells when the DC-AC inverter is in the rest period. ;;
And the PV offset controller further comprises an amplifier connected to the controller and amplifying the control signal with a predetermined gain. delete delete The method of claim 1,
The PV offset controller further includes a load resistor connected to the amplifier for generating a potential difference between the amplifier and the solar cell. The method of claim 1,
The voltage detector includes a comparator having a first input terminal connected to a predetermined reference voltage terminal and a second input terminal connected to the input / output unit. The method of claim 5, wherein
The comparator determines that the DC-AC inverter is operating when the input voltage of the second input terminal is greater than or equal to the voltage of the reference voltage terminal, and when the input voltage of the second input terminal is less than the voltage of the reference voltage terminal. A solar power system, characterized in that it is determined that the DC-AC inverter is in the idle period. The method of claim 1,
And a surge protect device (SPD) connected to both input terminals of the DC-AC inverter to suppress lightning or surges flowing from the grid. The method of claim 1,
The control signal is a photovoltaic power generation system, characterized in that to remove the residual charge that exists in the solar cell causing a polarization phenomenon. delete delete An integrated connection panel connecting at least one solar cell and a DC-AC inverter,
At least one diode connected to each of the solar cells and preventing a reverse current flowing back into the solar cell;
At least one breaker connected to each of the at least one diode and blocking the overvoltage from being applied to the solar cell;
It is connected to the grid and the DC-AC inverter, respectively, and detects the voltage of the input terminal of the DC-AC inverter to determine whether the DC-AC inverter is operating, from the system when the DC-AC inverter is in the idle period And a PV offset controller configured to output an input control signal to each of the at least one solar cell.
The PV offset controller,
An input / output unit connected to an input terminal of the DC-AC inverter to receive an electrical signal from the DC-AC inverter;
A voltage detector detecting a voltage of the input / output unit to detect an input terminal voltage of the DC-AC inverter; And
A controller for determining whether the DC-AC inverter is in operation based on a detection result of the voltage detector and controlling the controller to output the control signal to each of the solar cells when the DC-AC inverter is in the rest period. ;;
And the PV offset controller further comprises an amplifier connected to the controller and amplifying the control signal with a predetermined gain.

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