KR102666832B1 - Switching Device and Control Method for Solar Photovoltaic System - Google Patents

Abstract

The present invention is an invention to reduce the loss of power efficiency of a solar power generation system through selective step-by-step measures in response to arc occurrence, and includes an arc detection unit for detecting arcs occurring between solar module strings and an inverter, and a solar module. A temperature sensing unit for detecting the temperature of the lines between the strings and the inverter, a switching unit with switches for controlling the lines between the solar module strings and the inverter, according to the sensing information from the arc sensing unit and the temperature sensing unit. It includes a control unit that determines whether an arc has occurred and controls the switching unit according to the determined result, and the control unit analyzes the detection information from the arc detection unit to determine whether an arc has occurred, and the detection information from the temperature detection unit. A temperature analysis means that analyzes which temperature section the line temperature is located in among the three preset temperature sections, and the temperature location of the line analyzed by the temperature analysis means is located in the switch blocking section among the three temperature sections. Provided is a switching device for a photovoltaic system that includes a switch control means that blocks a line by controlling a switching unit and a method of controlling the device.

Description

Switching device and control method for solar photovoltaic system. {Switching Device and Control Method for Solar Photovoltaic System}

The present invention relates to a switching device for detecting arcs occurring in a photovoltaic system and taking action against them, and a control method for the device.

A grid-connected solar power generation system includes a solar cell array unit including a plurality of solar cell strings in which a plurality of solar modules are connected in series, a connection box for merging and outputting direct current power output from the solar cell strings, and the connection. It includes an inverter that converts direct current power output from the box into alternating current power and supplies it to the load or commercial system.

Meanwhile, arc is one of the main causes of electrical fires and is a phenomenon that continuously emits light and heat while being discharged through the gas between two electrodes due to poor contact, connection defect, insulation breakdown, improper installation, aging and damage. Arc defects occur when the connection part of the connector connecting solar panels becomes unsafe due to deterioration or vibration, or when the wire connection becomes loose (when the loose wire is not supported and puts a strain on the connector). It may be caused by etc.

Due to the rapid increase in grid-connected photovoltaic systems and poor management, fire occurrences in photovoltaic systems are increasing, so countermeasures are needed, and the specifications of DC relays and power semiconductor switches for disconnecting electrical connections are improving. there is. In particular, the performance of microprocessors for direct current arc detection has improved sufficiently, so there are no major problems in performing FFT.

Registered Patent Publication No. 10-2166324 discloses an arc detection device based on direct current produced from a solar power generation device. Specifically, the direct current is subjected to Fast Fourier Transform (FFT) and based on the conversion result. A method is disclosed to extract fundamental wave components and harmonic components, and determine that an arc has been detected when the ratio of a specific harmonic component is greater than a preset ratio to the fundamental wave component based on the extraction results. In addition, noise in direct current is removed, the direct current signal is converted into a decoding signal that can be processed by a DSP (Digital Signal Processor) or MPU (Micro Processor Unit), the decoding signal is divided into preset time sections, and the decoding signal that occurs in each time section is divided. A method of determining that an arc has been detected based on a pulse number pattern is also disclosed.

Existing arc detection systems, including the above invention, prevent fire or electric shock caused by the arc by automatically blocking the switch between the string and the junction box or inverter when the arc is detected as described above.

However, in the case of direct current arc, the arc current is limited by the impedance of the circuit and the impedance of the load, so the energy level is low, so it does not fall within the protection level range of existing earth leakage circuit breakers, making detection difficult. (Wan sung Kwon "A Study on the Effect of Arc Fault on Switched Mode Power Supply" , ICPE 2011, 1, June, 2011.) For this reason, the sensitivity of arc detection is set high, so arc may occur due to non-arc frequencies such as inverter noise. There are many cases where it is mistakenly perceived as having occurred. In the case of such misdetection, there is a problem that the power of the solar power system that is operating normally is turned off, thereby reducing the power generation efficiency of the entire solar power generation system.

In addition, even if an arc occurs in a line connected to some strings or arrays, if the power of the entire solar power generation system is turned off, even the power generation of strings or arrays that can operate normally is stopped, which is a problem that greatly reduces the power generation efficiency of the entire power generation system. There is.

In addition, the arc accident blocking technique, which unconditionally turns off the power of the system without considering the risk even if an arc occurs, also causes the above problems.

For arc detection, the temperature of the line is sensed to increase accuracy, and even when an arc occurs, only the relevant line is selectively blocked to maintain power generation on the line and solar array in normal operation, thereby increasing the power generation efficiency of the entire solar power system. In addition, we provide a solar power system switching device and its control method that contribute to increasing the power generation efficiency of the entire solar power system by evaluating the risk and taking step-by-step measures even when an arc occurs.

In order to solve the above problem, the present invention provides an arc detection unit for detecting arcs occurring in each line between solar module strings and an inverter by electrically detecting the characteristics of the arc - the arc detection unit detects arcs occurring in each line. It is a set of arc detectors that can detect information about distinct arcs. A temperature detection unit for detecting the temperature of each line between the solar module strings and the connection box - the temperature detection unit is a set of temperature sensors capable of detecting the temperature of each line -; a switching unit having switches for controlling each line between the photovoltaic module strings and the connection box - the switching unit is a set of switches capable of controlling each line; and a control unit that determines whether or not an arc occurs in each line according to the detection information received from the arc detection unit and the temperature detection unit, and controls the switching unit according to the determined result. Includes, the control unit analyzes the detection information from the arc detection unit and determines whether an arc occurs in the line based on the electrical characteristic information about the arc, and determines whether the arc occurs in the frequency band caused by the switching operation of the inverter and the arc caused by the arc. Arc occurrence determination means for determining whether or not an arc occurs in a line by distinguishing frequency bands; Temperature analysis means for analyzing the sensing information received from the temperature sensing unit to determine which of three preset temperature sections the temperature of the line is located in; and switch control means for controlling the switching unit to block the line when the temperature position of the line analyzed by the temperature analysis means is located in the switch blocking section among the three temperature sections. It includes, wherein the arc occurrence determination means transmits information about whether an arc occurs to the switch control means, the temperature analysis means transmits information about the temperature of the line to the switch control means, and the switch control means Based on the received information, if an arc occurs on a specific line among the plurality of lines, and the temperature of the specific line among the multiple lines is determined to be located in the switch cut-off section, only the switch located on the specific line is selectively selected. Blocking, each of the lines provides a switching device for a solar power system in parallel with each other.

Another solar system switching device provided by the present invention includes a warning light for notifying the site of the occurrence of an arc; It further includes a control unit, a warning light control means for controlling the warning light; and a notification means for notifying the monitoring system of the occurrence of an arc. It further includes, and the three temperature sections further include a first line maintenance section and a second line maintenance section in addition to the switch blocking section, where the first line maintenance section is a temperature section lower than the first critical temperature, and the second line maintenance section is the temperature section between the first critical temperature and the second critical temperature higher than the first critical temperature, and the switch blocking section is the temperature section higher than the second critical temperature. If it is determined that an arc has occurred by the arc occurrence judgment means, the line If the temperature of When in the second line maintenance section, the switch control means maintains the connection of the line, the warning light control means turns on the warning light, the notification means notifies the monitoring system of the occurrence of an arc, and the temperature of the line is maintained within the first line maintenance section. If present, the switch control means maintains the connection of the line, the warning light control means ensures that the warning light is kept OFF, and the notification means may be a switching device of the solar power system that notifies the monitoring system of the occurrence of an arc. there is.

Another embodiment provided by the present invention, a switching device for a solar power system, includes a temperature sensor for measuring the temperature of the outside air; It further includes, and the control unit further includes setting means for setting the first critical temperature and the second critical temperature, wherein the setting means determines the temperature of the outside air measured by the temperature sensor and a device other than the setting means. Based on the measured humidity and power amount, the switching device of the photovoltaic system can set the first critical temperature and the second critical temperature lower as the humidity is low and the temperature and power amount are high.

In order to solve the above problem, the present invention provides a method for controlling a switching device of a photovoltaic system, including an arc occurrence determination step of determining the occurrence of an arc in the line between the photovoltaic module string and the inverter by electrically detecting the characteristics of the arc; A temperature analysis step of analyzing the temperature of the line if it is determined that an arc has occurred in the arc occurrence determination step; In the temperature analysis step, if the temperature of the line is in the switch cut-off section, a first action step of blocking the line, generating an alarm on site, and notifying the monitoring system of the occurrence of an arc; In the temperature analysis step, if the temperature of the line is in the second line maintenance section lower than the switch cutoff section, the second action step is to maintain the line, generate an alarm at the site, and notify the monitoring system of the occurrence of an arc; And in the temperature analysis step, if the temperature of the line is in the first line maintenance section lower than the second line maintenance section, the line is maintained, an alarm is not generated at the site, and the third action step is to notify the monitoring system of the occurrence of an arc. ; Includes, the first line maintenance section is a temperature section lower than the first critical temperature, the second line maintenance section is a temperature section between the first critical temperature and the second critical temperature higher than the first critical temperature, and the switch blocking section is a temperature section higher than the second critical temperature, and the first action step, second action step, and third action step are selectively performed according to the temperature of the line analyzed in the temperature analysis step, and the arc occurrence judgment step is the inverter switching step. It is also possible to provide a switching device control method for a photovoltaic system that determines whether an arc occurs in a line by distinguishing between the frequency band generated by operation and the frequency band generated by arc.

Another embodiment of the switching device control method of the photovoltaic system provided by the present invention is that the arc occurrence determination step, temperature analysis step, first action step, second action step, and third action step are individually controlled for each of a plurality of lines. It can be a method of controlling the switching device of a solar power system.

Another embodiment of the switching device control method of the solar power system provided by the present invention is that the first critical temperature is set at a temperature in the range of 20°C to 30°C higher than the outside air temperature, and the second critical temperature is set at 90°C higher than the outside air temperature. It may be a method of controlling the switching device of a photovoltaic system, set at a temperature in the high range of 100°C.

First, the accuracy of arc detection is improved by utilizing the temperature information of the line to detect the arc.

Second, when an arc occurs, only the connection to the corresponding line is blocked, allowing power generation to be maintained on lines where no arc occurred.

Third, when an arc occurs, the power generation efficiency of the solar power system is increased by evaluating the risk of the arc and taking step-by-step measures rather than uniformly blocking the line.

Figure 1 is a switching device for a solar power system according to the present invention.
Figure 2 is a solar power generation system to which the solar power system switching device of the present invention is applied.
Figure 3 shows three temperature sections necessary for practicing the present invention.
Figure 4 is a method of controlling a switching device of a photovoltaic system according to the present invention.

Below, with reference to the attached drawings, embodiments of the present application will be described in detail so that those skilled in the art can easily implement them. However, the present application may be implemented in various different forms and is not limited to the embodiments described herein. In order to clearly explain the present application in the drawings, parts that are not related to the description are omitted, and similar parts are given similar reference numerals throughout the specification.

Throughout this specification, when a part is said to be “connected” to another part, this means not only “directly connected” but also “electrically connected” or “indirectly connected” with another element in between. "Includes cases where it is.

Throughout the specification of the present application, when a part "includes" a certain component, this means that it may further include other components rather than excluding other components unless specifically stated to the contrary.

Referring to FIG. 2, the solar power generation system in which the present invention is installed includes a plurality of strings 210 in series connecting solar modules that receive sunlight and generate direct current power, and a line 220 individually connected to each string 210. ) and a junction box 240 or inverter 240 connected to the other end of the line 220. The junction box 240 collects the power generated from several strings 210 and transfers it to the inverter 240, and in the process prevents collisions or reverse currents between modules due to power differences in each string 210 or module. It plays a role. The inverter 240 serves to convert direct current power generated by the solar string 210 into commercial alternating current power. In general, power is transmitted by connecting the string 210 - the connection box 240 - the inverter 240 through the line 220 in the order, but there are cases where the connection box 240 is not present.

Hereinafter, it will be described with reference to FIGS. 1 and 2.

One embodiment of the present invention includes an arc detection unit 120 for detecting an arc occurring between the solar module strings 210 and the inverter 240, and an arc detection unit 120 between the solar module strings 210 and the inverter 240. A switching unit ( 140), a control unit 110 that determines whether an arc has occurred according to the detection information received from the arc detection unit 120 and the temperature detection unit 130, and controls the switching unit 140 according to the determined result. Includes.

Here, the inverter 240 may include a connection box 240 or may be a connection box 240 depending on the case. In addition, the line 220 refers to lines 220 in a parallel relationship that connect the individual string 210 to the inverter 240 or the connection box 240.

In addition, the arc detection unit 120 is a set of arc detectors 121 that can detect information about separate arcs occurring in each line 220 or lines 220.

Meanwhile, general arc detection is accomplished by detecting the physical and electrical characteristics of the arc. Physical detection methods include detecting light generated during an arc accident using a video sensor, and detecting harmonic noise and heat energy during an arc accident. Electrical detection methods include a method of detecting through changes in the shoulder, peak value, and effective value caused by the current waveform during an arc accident, and a method of detecting by extracting harmonic components generated by the arc. Each arc detector 121 constituting the arc detection unit 120 is a device for detecting the characteristics of the arc necessary for the above arc detection, and may have any configuration that can be adopted by a person skilled in the art. You can.

Meanwhile, the temperature sensing unit 130 is a set of temperature sensors 131 that can detect the temperature of each line 220 or lines 220. Each temperature sensor 131 constituting the temperature detection unit 130 may have any configuration that can be adopted by a person skilled in the art to measure the temperature of the line 220.

Additionally, the switching unit 140 is a set of switches 141 that can control each line 220 or lines 220. Each switch 141 constituting the switching unit 140 may preferably be a DC relay, but it is understood that it can be any configuration that can be adopted by a person skilled in the art who can control the line 220. It has to be.

Meanwhile, the control unit 110 processes and processes the information collected by the temperature detection unit 130 and the arc detection unit 120, and derives commands for controlling the switching unit 140 based on it. It includes all computing devices that can be employed by a person skilled in the art and have the ability to perform the necessary calculations to achieve the purpose of the invention.

Meanwhile, the control unit 110 of the present invention analyzes the detection information from the arc detection unit 120 and analyzes the detection information from the arc occurrence determination means 112 and the temperature detection unit 130 to determine whether an arc has occurred. Temperature analysis means 113 for analyzing which of the three preset temperature sections the temperature of the line 220 is located in, and the temperature of the line 220 analyzed by the temperature analysis means 113. It includes a switch 141 control means 114 that controls the switching unit 140 to block the line 220 when the position is located in the switch 141 blocking section among the three temperature sections.

The arc generation determination means 112 determines whether an arc has occurred based on the physical and electrical characteristic information about the arc from the arc detection unit 120, and uses all methods that a person skilled in the art can employ for arc generation. It must be understood as meaning. Preferably, it may be a power spectrum analysis method using Fast Fourier Transform (FFT) (Patent Registration No. 10-2166324), but it is not necessarily limited thereto.

Meanwhile, the temperature analysis means 113 determines a more accurate temperature of the line 220 by performing correction to obtain an accurate temperature of the line 220 based on the information received from the temperature sensing unit 130 described above.

Referring to FIG. 3, the three temperature sections are divided into a high temperature section, a switch 141 blocking section, a second line 220 maintenance section, and a first line 220 maintenance section. The higher the temperature, the higher the risk of an arc occurring.

Here, the switch 141 blocking section refers to a temperature section where the temperature of the line 220 is so high that a fire occurs if the line 220 is not immediately blocked due to the occurrence of an arc.

The arc occurrence determination means 112 and the temperature analysis means 113 transmit the above information on whether an arc occurs and the above information on the temperature of the line 220 to the switch 141 control means 114.

The switch 141 control means 114 controls the switching unit 140 by generating an arc in any of the several lines 220 based on information received by the switch 141 control means 114. If it is determined that the temperature of a certain line 220 among several lines 220 is located in the blocking section of the switch 141, this means that only the switch 141 located on the corresponding line 220 is selectively blocked.

These measures prevent accidents such as fires due to the occurrence of arcs, while maintaining power generation status on the line 220 where no arcs have occurred or where arcs that pose a risk of fire have not occurred even if arcs have occurred. This alleviates the decrease in power generation efficiency of the entire solar power system.

Another embodiment of the present invention may further include a warning light 150 to notify the site of the occurrence of an arc.

The warning light 150 is located at a site where a solar power generation system is installed and is configured to exert an alarm function to the extent that site managers can easily recognize the arc occurrence alarm. The warning light 150 for practicing the present invention includes all configurations that can be employed by a person skilled in the art. Additionally, the warning light 150 may be located in the inverter 240 or the connection box 240.

In addition, the warning light 150 is controlled to take appropriate action by the warning light 150 control means 115 located in the control unit 110, which will be described later.

Meanwhile, another embodiment of the present invention includes a warning light 150 control means 115 for controlling the warning light 150 in the control unit 110 and a notification means 111 for notifying the monitoring system 230 of the occurrence of an arc. More may be included.

As will be described later, the warning light 150 control means 115 operates the warning light 150 when necessary according to the conclusion drawn by the arc generation determination means 112 and the temperature analysis means 113 to generate arc at the site. Controls to sound an alarm for fire and electric shock.

The notification means 111 is connected to the monitoring system 230 and, as will be described later, notifies the monitoring system 230 of the occurrence of an arc when necessary based on the conclusions drawn by the arc occurrence judgment means and the temperature analysis means 113. It is possible to inspect the relevant line (220) in the control room, etc., when the power generation system is not in operation.

Meanwhile, in another embodiment of the present invention, the three temperature sections further include a first line 220 maintenance section and a second line 220 maintenance section in addition to the switch 141 blocking section, as described above. The maintenance section of the line 220 is a temperature section lower than the first critical temperature, and the maintenance section of the second line 220 is a temperature section between the first critical temperature and a second critical temperature higher than the first critical temperature, The switch 141 blocking section may mean a temperature section higher than the second critical temperature.

According to FIG. 3, as described above, the temperature of each section is high in the order of the switch 141 blocking section, the second line 220 maintenance section, and the first line 220 maintenance section. This section is divided based on sequential evaluation of the risk of fire and electric shock caused by arc generation according to standards that can be adopted by ordinary technicians. In other words, it should be understood that the risk of fire and electric shock due to arc generation is higher in the order of the switch 141 blocking section, the second line 220 maintenance section, and the first line 220 maintenance section.

As described above, the switch 141 blocking section corresponds to a case in which there is a significant possibility that a fire will immediately occur in the corresponding line 220 due to the occurrence of an arc. In the second line 220 maintenance section, an arc occurs and the temperature of the line 220 increases, so if left as is, there is a possibility that a fire may occur within a considerable period of time. However, other than taking measures to block the line 220, the operation of the power generation system is maintained. This is a case where the risk of fire and electric shock can be eliminated by preventing the occurrence of arc or lowering the temperature of the line 220 through appropriate measures. In the first line 220 maintenance section, it is confirmed that a weak arc has occurred, but the risk does not reach a significant level, so there is no possibility of fire or electric shock. In this case, there is only a need to check the cause of the weak arc to prevent fire and electric shock accidents due to larger arcs in the future.

Hereinafter, the operating method of an embodiment of the present invention will be introduced with reference to FIGS. 3 and 4.

The switching device 100 of a photovoltaic system, which is another embodiment of the present invention, operates when the arc occurrence determination means 112 determines that an arc has occurred and the temperature of the line 220 is in the switch 141 blocking section. The switch 141 control means 114 controls the switch 141 to block the line 220, and the warning light 150 control means 115 turns on the warning light 150, The notification means 111 notifies the monitoring system 230 of the occurrence of an arc.

In this case, since the occurrence of an arc has the risk of immediately leading to a fire accident, the relevant line 220 is blocked and the alarm and monitoring system 230 is notified.

In addition, the switching device 100 of the photovoltaic system operates the switch ( 141) The control means 114 maintains the connection of the line 220, the warning light 150 control means 115 turns on the warning light 150, and the notification means 111 monitors the system 230. ) notifies the occurrence of an arc.

In this case, since an arc that has the risk of causing a fire does not occur immediately, the line 220 is maintained, but the site is notified so that progress to an accident can be prevented through immediate action and the monitoring system 230 is notified to prevent the arc from occurring. Ensure that the cause of the occurrence can be eliminated afterwards.

In addition, the switching device 100 of the photovoltaic system operates the switch ( 141) The control means 114 maintains the connection of the line 220, the warning light 150 control means 115 maintains the warning light 150 in OFF, and the notification means 111 ) notifies the monitoring system 230 of the occurrence of an arc.

In this case, even if an arc occurs, the risk is low enough that there is no possibility of fire and no need for immediate action on site, so the line 220 is maintained as is and no alarm is sounded through the warning light 150. However, the occurrence of even a weak arc can be an indicator predicting arcs that will lead to fire and electric shock accidents in the future. To prevent this, the string 210 or line 220 must be inspected when the solar power generation system is not in operation. Notifies the monitoring system 230 so that it can be done.

The above three measures have the effect of mitigating the decrease in power generation efficiency of the solar power generation system by allowing step-by-step measures to be taken in response to the risk of the arc that has occurred and stopping power generation of the string 210 only when absolutely necessary.

Another embodiment of the present invention further includes a temperature sensor 160 for detecting the temperature of the outside air 300, and the control unit 110 includes setting means 116 for setting the first critical temperature and the second critical temperature. ), wherein the first critical temperature is set at a temperature in the range of 20°C to 30°C higher than the temperature of the outside air (300), and the second critical temperature is 90°C to 100°C higher than the temperature of the outside air (300). It may be a switching device 100 of a photovoltaic system set at a temperature range.

The temperature sensor 160 can be any device that can be adopted by a person skilled in the art to measure the temperature of the outside air 300 in the area where the line 220 is located. In order to increase the accuracy of measuring the temperature of the outside air (300), it is desirable to be located close to the line 220. However, it is avoidable that the temperature of the outside air (300) is measured higher than the actual temperature due to the influence of heat generation from the line 220 by being located too close. It should be located in a place where it can be accessed.

In addition, the setting means 116 takes into account the measured outside air 300 temperature as well as information on humidity, power, weather, etc. measured or recorded by other devices, and sets the first critical temperature to 20°C lower than the outside air 300 temperature. This refers to the principle of setting the second critical temperature higher than any temperature between 90°C and 100°C above the temperature of the outside air (300) or an algorithm designed using such principles. It must be understood. For example, in determining the first and second critical temperatures that determine the risk of arc according to temperature, 'the lower the humidity, the higher the temperature, and the higher the power, the higher the possibility of fire when the same arc occurs, so in these cases, the first and second critical temperatures are and 2 It is desirable to set the critical temperature low.' Principles such as 'or an algorithm designed using this principle may fall under this category. However, this setting means 116 should be understood to mean all means that a person skilled in the art can employ to practice the present invention.

Also, referring to FIG. 4, in another embodiment of the present invention, an arc occurrence determination step 510 determines the occurrence of an arc between the solar module string 210 and the inverter 240. In the arc occurrence determination step 510, an arc occurs. If it is determined that an occurrence occurs, the temperature analysis step 520 analyzes the temperature of the line 220. In the temperature analysis step 520, if the temperature of the line 220 is in the switch 141 blocking section, the line 220 is blocked. In the temperature analysis step 520, the temperature of the line 220 is lower than that of the switch 141 blocking section. If it is in the low second line 220 maintenance section, the line 220 is maintained, an alarm is generated at the site, and the second action step 532 of notifying the monitoring system 230 of the occurrence of an arc and the temperature analysis are performed. In step 520, if the temperature of the line 220 is in the first line 220 maintenance section lower than the second line 220 maintenance section, the line 220 is maintained and an alarm is not generated at the site, It includes a third action step 533 for notifying the monitoring system 230 of the occurrence of an arc, wherein the first line 220 maintenance section is a temperature section lower than the first critical temperature, and the second line 220 The holding section is a temperature section between the first critical temperature and a second critical temperature higher than the first critical temperature, and the switch 141 blocking section is a temperature section higher than the second critical temperature, and the first action step (531), the second action step (532), and the third action step (533) are a switching device of a photovoltaic system that is selectively performed according to the temperature of the line 220 analyzed in the temperature analysis step (520). (100) A control method may be disclosed.

At this time, the arc occurrence determination step 510 applies a technology that can distinguish between the frequency band generated by the switching operation of the solar inverter 240 and the frequency band generated by the arc, so that the solar inverter 240 is detected in the arc detection unit. It is possible to prevent the solar power generation itself from being stopped due to malfunction due to arc generation due to frequency components generated in the switching operation.

Such step-by-step selective measures according to risk can mitigate the decline in power efficiency of the solar power generation system due to blocking of the line 220 by blocking the line 220 only when absolutely necessary.

In addition, in a preferred embodiment of the present invention, the arc occurrence determination step 510, the temperature analysis step 520, the first action step 531, the second action step 532, and the third action step 533 A method of controlling the switching device 100 of a solar power system that is individually performed for each of the plurality of lines 220 may be disclosed.

In this way, by individually controlling the switches 141 of each line 220, the operation of only the string 210 that may cause problems can be stopped, thereby mitigating a decrease in the efficiency of the solar power generation system.

In addition, in another embodiment of the present invention, the first critical temperature is set at a temperature in the range of 20°C to 30°C higher than the temperature of the outside air (300), and the second critical temperature is 90°C higher than the temperature of the outside air (300). It may be a method of controlling the switching device 100 of a photovoltaic system, which is set at a temperature ranging from 100°C to higher.

The first and second critical temperatures can be set by the setting means 116.

As described above, although the present invention has been described using limited embodiments and drawings, the present invention is not limited to the above embodiments, and various modifications and variations can be made from these descriptions by those skilled in the art. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the claims and equivalents thereof as well as the claims described later.

100: Switching device of solar power system
110: control unit
111: Notification means
112: Arc occurrence judgment means
113: Temperature analysis means
114: Switch control means
115: warning light control means
116: Setting means
120: Arc detection unit 121: Arc detector
130: Temperature sensing unit 131: Temperature sensor
140: switching unit 141: switch
150: warning light
160: Temperature sensor
210: string
220: track
230: monitoring system
240: Inverter or connection box
300: Outside air
400: Commercial system
510: Arc occurrence judgment unit
520: Temperature analysis step
531: First action step
532: Second action step
533: Third action step

Claims (6)

An arc detection unit for detecting arcs occurring in each line between solar module strings and the inverter by electrically detecting the characteristics of the arc - the arc detection unit provides information on separate arcs occurring in each line. It is a set of arc detectors that can detect ―;
A temperature detection unit for detecting the temperature of each line between the solar module strings and the inverter - the temperature detection unit is a set of temperature sensors capable of detecting the temperature of each line -;
a switching unit having switches for controlling each line between the photovoltaic module strings and the inverter - the switching unit is a set of switches capable of controlling each line; and
a control unit that determines whether an arc occurs in each line according to detection information received from the arc detection unit and the temperature detection unit, and controls the switching unit according to the determined result; Including,
The control unit
By analyzing the detection information from the arc detection unit, it is determined whether an arc has occurred in the line based on the electrical characteristics information about the arc, and the frequency band that occurs due to the switching operation of the inverter and the frequency band that occurs due to the arc are distinguished from the line. Arc occurrence determination means for determining whether an arc occurs;
Temperature analysis means for analyzing the sensing information received from the temperature sensing unit to determine which of three preset temperature sections the temperature of the line is located in; and
Switch control means for controlling the switching unit to block the line when the temperature position of the line analyzed by the temperature analysis means is located in a switch blocking section among three temperature sections; Including,
The arc occurrence determination means transmits information on whether an arc occurs to the switch control means,
The temperature analysis means transmits information about the temperature of the line to the switch control means,
Based on the received information, the switch control means determines that an arc has occurred on a certain line among the plurality of lines and that the temperature of the specific line among the plurality of lines is located in the switch cutoff section, and the switch control means is located on the specific line. Selectively blocks only the above switch and
Each of the above lines is in parallel with each other.
Switching device for solar power system. According to claim 1,
A warning light to notify the site of the occurrence of an arc; It further includes,
The control unit,
A warning light control means for controlling the warning light; and
Notification means for notifying the monitoring system of the occurrence of an arc; It further includes,
The three temperature sections further include a first line maintenance section and a second line maintenance section in addition to the switch blocking section,
The first line maintenance section is a temperature section lower than the first critical temperature,
The second line maintenance section is a temperature section between the first critical temperature and a second critical temperature higher than the first critical temperature,
The switch blocking section is a temperature section higher than the second critical temperature,
If it is determined that an arc has occurred by the arc occurrence determination means,
When the temperature of the line is in the switch blocking section, the switch control means controls the switch to cut off the line, the warning light control means turns on the warning light, and the notification means indicates that an arc occurs in the monitoring system. informing you of
When the temperature of the line is in the second line maintenance section, the switch control means maintains the connection of the line, the warning light control means turns on the warning light, and the notification means notifies the monitoring system of the occurrence of an arc,
When the temperature of the line is in the first line maintenance section, the switch control means maintains the connection of the line, the warning light control means maintains the warning light as OFF, and the notification means maintains the connection of the line to the monitoring system. Notifies the occurrence of arc
Switching device for solar power system. According to claim 2,
A temperature sensor to measure the temperature of the outside air; It further includes,
The control unit further includes setting means for setting the first critical temperature and the second critical temperature,
The setting means is based on the temperature of the outside air measured by the temperature sensor and the humidity and power amount measured by a device other than the setting means, and as the humidity is low and the temperature and power amount are high, the first threshold temperature and the second threshold temperature are set. Setting the critical temperature low
Switching device for solar power system. In the method of controlling a switching device for a solar power system according to any one of claims 1 to 3,
An arc occurrence determination step of determining arc occurrence in the line between the solar module string and the inverter by electrically detecting the characteristics of the arc;
A temperature analysis step of analyzing the temperature of the line if it is determined that an arc has occurred in the arc occurrence determination step;
In the temperature analysis step, if the temperature of the line is in the switch cut-off section, a first action step of blocking the line, generating an alarm at the site, and notifying the monitoring system of the occurrence of an arc;
In the temperature analysis step, if the temperature of the line is in the second line maintenance section lower than the switch cutoff section, the line is maintained, an alarm is generated at the site, and the second action step is to notify the monitoring system of the occurrence of an arc. ; and
In the temperature analysis step, if the temperature of the line is in the first line maintenance section lower than the second line maintenance section, the line is maintained, an alarm is not generated at the site, and the monitoring system is notified of the occurrence of an arc. 3 Action steps; Includes,
The first line maintenance section is a temperature section lower than the first critical temperature,
The second line maintenance section is a temperature section between the first critical temperature and a second critical temperature higher than the first critical temperature,
The switch blocking section is a temperature section higher than the second critical temperature,
The first action step, the second action step, and the third action step are selectively performed according to the temperature of the line analyzed in the temperature analysis step,
The arc occurrence determination step determines whether an arc occurs in the line by distinguishing between the frequency band generated by the switching operation of the inverter and the frequency band generated by the arc.
Switching device control method for solar power system. According to claim 4,
The arc occurrence determination step, the temperature analysis step, the first action step, the second action step, and the third action step are performed individually for each of a plurality of lines.
Switching device control method for solar power system. According to claim 4,
The first critical temperature is set at a temperature in the range of 20°C to 30°C higher than the outdoor temperature, and the second critical temperature is set at a temperature in the range of 90°C to 100°C higher than the outdoor temperature.
Switching device control method for solar power system.