A photovoltaic power station monitoring system

Abstract

A photovoltaic power station monitoring system includes: a component control end, which is used to collect the output voltage of photovoltaic components and control the on and off of photovoltaic components; a communication collection device, which is used to receive the output voltage transmitted by the component control end and send component control signals to the component control end; the communication collection device is also used to connect to the photovoltaic inverter and receive the loop current of the photovoltaic string collected by the photovoltaic inverter and control the photovoltaic inverter to turn on and off the current switch of the photovoltaic inverter itself; a monitoring end, which is used to send the string control signal to the communication collection device and receive the output voltage and loop current transmitted by the communication collection device. The embodiment of the present invention realizes the measurement of the photovoltaic component voltage through the component control end, and can also realize the control of the on and off of the photovoltaic component. Through the communication collection device, through communication with the photovoltaic inverter, the current data of each photovoltaic component is known by cleverly utilizing the equal current characteristic in the loop.

Description

Technical Field

[0001] The invention belongs to the field of photovoltaic power generation, and in particular relates to a photovoltaic power station monitoring system. Background Art

[0002] With the development and maturity of photovoltaic power generation technology, photovoltaic power generation has become one of the important components in the field of new energy.

[0003] At present, the main problem in the photovoltaic industry is the lack of devices or systems that can simultaneously meet the requirements of low-cost monitoring and low-cost safety shutdown of photovoltaic modules. In the existing market, the main solution to the problem of photovoltaic module monitoring is to use high-cost micro-inverters to collect voltage and current. As a result, only a very small number of photovoltaic power stations that can accept high costs can realize automatic monitoring. However, at present, almost no one uses it in China. There are only a small number of markets in foreign countries where high costs can be accepted. The market application rate of micro-inverters is actually less than 1%. Therefore, in order to reduce costs, domestic mainstream inverter manufacturers have chosen to abandon the use of micro-inverter monitoring and instead use sensors for monitoring. However, the current method of using sensors to monitor photovoltaic modules requires the collection of voltage and current for each photovoltaic module, resulting in very high costs, which the industry cannot accept. At the same time, the safety shutdown problem caused by DC high voltage is mainly solved by connecting a high-current switch in series with the photovoltaic module. Because when shutting down, the module shutdown switch in series with the photovoltaic module also has high voltage and high current, so the module shutdown switch needs to be a switch that can withstand high voltage and high current. Such switches generally have the disadvantages of large size, high cost and short life. The above-mentioned single collection device or single control device can only solve one of the problems, and the cost is high, making it difficult to achieve industrialization.

[0004] Professional terms: Photovoltaic module: A power generation device that converts solar energy into direct current, also called a solar panel. Photovoltaic string: In a photovoltaic power generation system, a circuit unit composed of several or even dozens of photovoltaic modules connected in series. DC high voltage: In a photovoltaic power generation system composed of several or even dozens of photovoltaic modules connected in series, there is a DC high voltage of 500V to 1500V. Photovoltaic inverter: A device that converts the direct current generated by a photovoltaic module into an alternating current output. Micro inverter: A micro inverter that converts the power of a photovoltaic module. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a photovoltaic power station monitoring system, which has a simple structure and solves the problem that the photovoltaic inverter cannot perform photovoltaic module-level monitoring.

[0006] The photovoltaic power station monitoring system according to the embodiment of the present invention includes: a component control end, which is used to collect the output voltage of the photovoltaic component and control the on and off of the photovoltaic component; a communication collection device, which is used to receive the output voltage transmitted by the component control end and send a component control signal to the component control end; the communication collection device is also used to connect to the photovoltaic inverter and receive the loop current of the photovoltaic string collected by the photovoltaic inverter and control the photovoltaic inverter to turn on and off the current switch of the photovoltaic inverter itself; the monitoring end is used to send the string control signal to the communication collection device and receive the output voltage and loop current transmitted by the communication collection device.

[0007] The photovoltaic power station monitoring system according to the embodiment of the present invention has at least the following technical effects: the measurement of the photovoltaic module voltage is realized through the component control end, and the control of the photovoltaic module on and off can be realized at the same time. The communication and collection device can realize the communication with the photovoltaic inverter, and then the photovoltaic string loop current data collected by the photovoltaic inverter can be obtained. The current data of each photovoltaic module can be known by cleverly using the equal current characteristics in the loop. Therefore, it is no longer necessary to repeatedly arrange the current collection unit for each photovoltaic module, which greatly reduces the cost. In addition, the current switch of the photovoltaic inverter itself can be disconnected first through the communication and collection device, so that the component control end can no longer face the impact of large current when the component shutdown switch is subsequently turned off, so that the component shutdown switch can choose a small and low-cost switch. Compared with the traditional data acquisition and shutdown control system, the embodiment of the present invention not only combines the two major functions of data acquisition and shutdown, but also greatly reduces the cost of data acquisition and shutdown control.

[0008] According to some embodiments of the present invention, the component control end includes: a voltage collection unit, used to collect the output voltage of the photovoltaic component; a component shutdown switch, connected in series with the output end of the photovoltaic component, used to connect or disconnect the connection between the photovoltaic component and the photovoltaic string; a component microcontroller, connected to the voltage collection unit, used to receive the output voltage and transmit it to the communication collection device, and the component microcontroller is also used to control the connection and disconnection of the component shutdown switch according to the received component control signal.

[0009] According to some embodiments of the present invention, the component shutoff switch is connected in series with the output terminal of the photovoltaic component using a normally closed contact.

[0010] According to some embodiments of the present invention, the component microcontroller employs a processor having an internal temperature sensor.

[0011] According to some embodiments of the present invention, the component control end further includes a temperature acquisition unit connected to the component microcontroller, and the temperature acquisition unit is used to acquire the temperature of the photovoltaic component.

[0012] According to some embodiments of the present invention, the voltage acquisition unit includes: a reference voltage unit, used to adjust the range of voltage acquisition; a first operational amplifier unit, whose negative input terminal is connected to the output terminal of the reference voltage unit, and whose positive input terminal is used to access the output voltage of the photovoltaic component; a voltage regulating unit, whose input terminal is connected to the output terminal of the first operational amplifier unit, and is used to adjust the output voltage to a range that can be input into the component microcontroller; a voltage follower, whose input terminal is connected to the output terminal of the voltage regulating unit, and whose output terminal is connected to the string microcontroller.

[0013] According to some embodiments of the present invention, the communication and collection device includes: a first communication module, connected to the component control end; a second communication module, connected to the monitoring end; a string microcontroller, connected to the photovoltaic inverter and receiving the loop current collected by the photovoltaic inverter; the string microcontroller is also connected to the first communication module and the second communication module, respectively, for receiving the output voltage and sending the component control signal to the component control end through the first communication module, and for receiving the string control signal transmitted by the monitoring end through the second communication module and transmitting the loop current and output voltage to the monitoring end.

[0014] According to some embodiments of the present invention, the second communication module is a GSM / GPRS module.

[0015] According to some embodiments of the present invention, the component control terminal and the communication collection device and / or the communication collection device and the monitoring terminal communicate with each other by wireless communication.

[0016] According to some embodiments of the present invention, the component control terminal communicates with the communication collection device using a power carrier.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0019] Figure 1 is a system block diagram of an embodiment of the present invention;

[0020] Figure 2 is a schematic diagram of the components control end of an embodiment of the present invention;

[0021] Figure 3 It is a schematic diagram of the principle of the communication collection device according to an embodiment of the present invention;

[0022] Figure 4 is a schematic diagram of the principle of a voltage acquisition unit according to an embodiment of the present invention;

[0023] Figure 5 1 is a schematic diagram of the temperature acquisition unit according to an embodiment of the present invention.

[0024] Reference numerals:

[0025] Component control terminal 100, voltage acquisition unit 110, reference voltage unit 111, first operational amplifier unit 112, voltage adjustment unit 113, voltage follower 114, component shutdown switch 120, component microcontroller 130, temperature acquisition unit 140, local wireless communication module 150,

[0026] Communication collection device 200, first communication module 210, second communication module 220, string microcontroller 230,

[0027] Monitoring terminal 300,

[0028] Photovoltaic modules 400,

[0029] Photovoltaic inverter 500. DETAILED DESCRIPTION

[0030] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0031] In the description of the present invention, if there is a description of first, second, third, fourth, etc., it is only for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the sequence of the indicated technical features.

[0032] In the description of the present invention, unless otherwise clearly defined, words such as setting and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0033] Reference below Figures 1 to 5 A photovoltaic power station monitoring system according to an embodiment of the present invention is described.

[0034] The photovoltaic power station monitoring system according to the embodiment of the present invention includes: a component control terminal 100, a communication collection device 200, and a monitoring terminal 300. The component control terminal 100 is used to collect the output voltage of the photovoltaic component 400 and control the on and off of the photovoltaic component 400; the communication collection device 200 is used to receive the output voltage transmitted by the component control terminal 100 and send a component control signal to the component control terminal 100; the communication collection device 200 is also used to connect to the photovoltaic inverter 500 and receive the loop current of the photovoltaic string collected by the photovoltaic inverter 500 and control the photovoltaic inverter 500 to turn on and off the current switch of the photovoltaic inverter 500 itself; the monitoring terminal 300 is used to send the string control signal to the communication collection device 200 and receive the output voltage and loop current transmitted by the communication collection device 200.

[0035] refer to Figures 1 to 3 , the output voltage of the photovoltaic component 400 is collected through the component control terminal 100, and the collected output voltage is transmitted to the communication collection device 200. The photovoltaic inverter 500 itself has the ability to collect the loop current of the photovoltaic string. The communication collection device 200 obtains the loop circuit data collected by the photovoltaic inverter 500 by communicating with the photovoltaic inverter 500. The communication collection device 200 is connected to the photovoltaic inverter 500 to obtain the loop circuit data. The communication collection device 200 transmits the received output voltage and loop current data to the monitoring terminal 300, completing the data collection process of the photovoltaic component 400.

[0036] In addition, it should be noted that the component control end 100 in some embodiments of the present invention does not include a current acquisition unit, because the photovoltaic components 400 in the photovoltaic string are connected in series, so the current at each point in the loop of the photovoltaic string is equal, so the current data of each photovoltaic component 400 in the loop is also the same. By utilizing this point, there is no need to repeatedly arrange the current acquisition unit, which can greatly reduce the cost. Of course, some embodiments of the present invention can also add a current acquisition unit to the component control end 100 to collect the current of the photovoltaic component 400, so that when the current acquisition function of the photovoltaic inverter connected in series with the photovoltaic string fails, the current data of the photovoltaic component 400 can continue to be collected.

[0037] refer to Figures 1 to 3 , the monitoring terminal 300 sends a string control signal to the communication collection device 200, and the communication collection device 200 controls the photovoltaic inverter 500 to turn off the current switch of the photovoltaic inverter 500 by communicating with the photovoltaic inverter 500. Then the communication collection device 200 sends a component control signal to the component control terminal 100, and the component control terminal 100 disconnects the photovoltaic component 400 from the photovoltaic string, completing the shutdown process of the photovoltaic component 400.

[0038] In addition, it should be noted that the communication collection device 200 first controls the photovoltaic inverter 500 to turn off the current switch of the photovoltaic inverter 500 itself, so that the photovoltaic string circuit can be disconnected first, and then the subsequent component shutdown switch 120 no longer needs to face the impact of large current when it is turned off. Therefore, the component shutdown switch 120 can choose a switch with small size, low cost, and no need to withstand large current impact.

[0039] According to the photovoltaic power station monitoring system of the embodiment of the present invention, the voltage of the photovoltaic module 400 is measured through the component control terminal 100, and the on-off control of the photovoltaic module 400 can be realized at the same time. The communication acquisition device 200 can realize communication with the photovoltaic inverter 500, and then the photovoltaic string loop current data collected by the photovoltaic inverter 500 can be obtained, and then the current data of each photovoltaic module 400 can be known by cleverly using the equal characteristics of the current in the loop, so it is no longer necessary to repeatedly arrange the current acquisition unit for each photovoltaic module 400, which greatly reduces the cost. In addition, the current switch of the photovoltaic inverter 500 itself can be disconnected first through the communication acquisition device 200, so that the component control terminal 100 can no longer face the impact of large current when the component shutdown switch 120 is subsequently turned off, so that the component shutdown switch 120 can choose a small size and low cost switch. Compared with the traditional data acquisition and shutdown control system, the embodiment of the present invention not only combines the two major functions of data acquisition and shutdown, but also greatly reduces the cost of data acquisition and shutdown control. In addition, since a large number of current sensors are reduced, the amount of data transmission can be reduced, and the reliability and speed of data transmission will be higher.

[0040] In some embodiments of the present invention, the component control terminal 100 includes: a voltage collection unit 110, a component shutdown switch 120, and a component microcontroller 130. The voltage collection unit 110 is used to collect the output voltage of the photovoltaic component 400; the component shutdown switch 120 is connected in series with the output end of the photovoltaic component 400, and is used to connect or disconnect the photovoltaic component 400 and the photovoltaic string; the component microcontroller 130 is connected to the voltage collection unit 110, and is used to receive the output voltage and transmit it to the communication collection device 200. The component microcontroller 130 is also used to control the connection and disconnection of the component shutdown switch 120 according to the received component control signal.

[0041] refer to Figures 1 to 3 The voltage collection unit 110 is connected to the output end of the photovoltaic component 400, and can collect the output voltage of the photovoltaic component 400 and convert it to a range that can be received by the component microcontroller 130. After the component microcontroller 130 receives the output voltage of the photovoltaic component 400 transmitted by the voltage collection unit 110, it will transmit the output voltage signal to the communication collection device 200, and finally transmit it to the monitoring end 300 through the communication collection device 200, thereby realizing remote monitoring.

[0042] refer to Figures 1 to 3 , the component shutoff switch 120 is connected in series at the output end of the photovoltaic component 400, and the component microcontroller 130 realizes the on-off control of the photovoltaic component 400 through the component shutoff switch 120. When the component microcontroller 130 receives the component control signal sent by the communication acquisition device 200, it will control the relay K1 to be energized, and then control the component shutoff switch 120 to be disconnected. In addition, by setting the voltage acquisition unit 110 at the output end of the component shutoff switch 120, it can be used to monitor the disconnection of the component shutoff switch 120. For example, when the component shutoff switch 120 fails to disconnect, because the component shutoff switch 120 is still connected in series with the photovoltaic component 400, the voltage acquisition unit 110 can still collect voltage data. At this time, a shutdown failure signal can be sent through the component microcontroller 130, which can further ensure safety and prevent people from being electrocuted after entering.

[0043] In some embodiments of the present invention, the component shutoff switch 120 is connected in series with the output end of the photovoltaic component 400 using a normally closed contact. There are two ways to connect the component shutoff switch 120 to the output end of the photovoltaic component 400, one is that the normally open contact of the component shutoff switch 120 is connected in series with the output end of the photovoltaic component 400, and the other is that the normally closed contact of the component shutoff switch 120 is connected in series with the output end of the photovoltaic component 400. When using the normally open contact connection, the control coil of the component shutoff switch 120 needs to be kept in an energized state, but too long a power-on time will easily cause the control coil to age faster, thereby causing the closure of the component shutoff switch 120 to fail, and ultimately causing the circuit of the entire photovoltaic string to fail. The use of a normally closed contact can effectively avoid this problem. Usually, the control coil of the component shutoff switch 120 is in an unpowered state. When it needs to be disconnected, it can be energized for a short time, which can effectively improve the service life of the entire component shutoff switch 120.

[0044] In some embodiments of the present invention, the component microcontroller 130 uses a processor with an internal temperature sensor. Temperature acquisition is completed by the temperature sensor inside the component microcontroller 130. After the temperature acquisition is completed, it is transmitted to the communication acquisition device 200. Directly using the internal temperature sensor of the component microcontroller 130 to complete temperature acquisition can effectively save costs. In actual engineering, taking some single-chip microcomputers with internal temperature sensors as an example, most of the internal temperature sensors have poor accuracy in collecting temperature, large errors, and are easily affected by the environment. However, in the temperature acquisition of the photovoltaic component 400, in most cases, accurate temperature acquisition is not required, only the overall temperature change needs to be collected. When the overall temperature of the photovoltaic component 400 changes greatly in a short period of time, it can be determined that a fault has occurred.

[0045] In some embodiments of the present invention, the component microcontroller 130 uses an MSP430 series single-chip microcomputer. The internal temperature sensor of the MSP430 series single-chip microcomputer has relatively accurate data acquisition and low cost, and is suitable for large-scale applications.

[0046] In some embodiments of the present invention, the component control terminal 100 further includes a temperature acquisition unit 140 connected to the component microcontroller 130, and the temperature acquisition unit 140 is used to collect the temperature of the photovoltaic component 400. By adding the temperature acquisition unit 140, a part of the component microcontroller 130 that does not have an internal temperature sensor can also be used for temperature acquisition. At the same time, by adding the temperature acquisition unit 140, the location of temperature acquisition can be made more flexible, and the temperature data can be relatively more accurate. The temperature acquisition unit 140 can directly adopt an existing temperature acquisition module.

[0047] In some embodiments of the present invention, the temperature acquisition unit 140 uses a resistive temperature sensor for temperature acquisition. The resistive temperature sensor is relatively low in cost, which can further reduce the cost and facilitate subsequent replacement. When the temperature acquisition unit 140 uses a resistive temperature sensor for temperature acquisition, its application circuit can refer to Figure 5 The voltage divider circuit can directly and effectively feed back temperature data in the form of voltage changes, and after further isolation and protection through the voltage follower 114 and the clamping protection circuit, it is input to the component microcontroller 130. Resistors R5, R6, and R7 can be variable resistors, which can improve the application range of the temperature acquisition unit 140. In addition, some components in the circuit may have slight errors due to aging, and the errors can also be corrected by adjusting the variable resistors to further extend the service life.

[0048] It should be noted that temperature acquisition is also an important link for the photovoltaic module 400. The change in temperature can usually effectively reflect the working status of the photovoltaic module 400. When faults such as short circuit, overvoltage, overcurrent, etc. occur, they are usually accompanied by a rise in temperature. By monitoring the temperature of the photovoltaic module 400, these problems can be discovered in advance. At this time, if the faulty photovoltaic string is shut down in time, and all the component shut-off switches 120 of the photovoltaic string are disconnected, or the component shut-off switch 120 connected to the faulty photovoltaic module 400 is disconnected, further damage to the photovoltaic inverter 500 and other photovoltaic modules 400 in the photovoltaic string can be avoided, thereby reducing losses.

[0049] In some embodiments of the present invention, the voltage acquisition unit 110 uses a DC voltage sensor. The use of a DC voltage sensor can realize the acquisition of the DC output voltage, and is also convenient for troubleshooting when the voltage acquisition fails in the future. If there is a problem with the DC voltage sensor itself, the problem can be quickly solved by replacing the DC voltage sensor. At present, the technology of DC voltage sensors on the market is relatively mature, and can provide high stability and high-precision data acquisition, which can provide users with a better user experience.

[0050] In some embodiments of the present invention, the voltage acquisition unit 110 includes: a reference voltage unit 111, a first operational amplifier unit 112, a voltage adjustment unit 113, and a voltage follower 114. The reference voltage unit 111 is used to adjust the range of voltage acquisition; the first operational amplifier unit 112, whose negative input terminal is connected to the output terminal of the reference voltage unit 111, and whose positive input terminal is used to access the output voltage of the photovoltaic module 400; the voltage adjustment unit 113, whose input terminal is connected to the output terminal of the first operational amplifier unit 112, is used to adjust the output voltage to a range that can be input to the module microcontroller 130; the voltage follower 114, whose input terminal is connected to the output terminal of the voltage adjustment unit 113, and whose output terminal is connected to the string microcontroller 230.

[0051] refer to Figure 4 When using the voltage acquisition unit 110 in some embodiments of the present invention for acquisition, it is necessary to first use the reference voltage unit 111 to set the voltage acquisition range, because in many cases, the output voltage of the photovoltaic module 400 only fluctuates in a small range. Therefore, if the lowest voltage to the highest voltage output by the entire photovoltaic module 400 is used as the voltage acquisition range of the voltage acquisition unit 110, it is obviously not reasonable, which will cause inaccurate voltage acquisition of the photovoltaic module 400. The reference voltage unit 111 and the first operational amplifier unit 112 can adjust the voltage acquisition range. For example, when the reference voltage unit 111 is not added, the acquisition range is 0V to 24V, then it can be changed to 20V to 24V after the addition. Reference Figure 4 In order to improve the application range of the voltage acquisition unit 110, Figure 4 One or both of R1 and R2 in the circuit are set as variable resistors, so that the error can be adjusted on the one hand, and the applicable range of the entire voltage collection unit 110 can also be adjusted at the same time, so that more models of photovoltaic modules 400 can be matched.

[0052] refer to Figure 4The voltage output by the reference voltage unit 111 and the first operational amplifier unit 112 is usually not guaranteed to be within the acquisition range of the component microcontroller 130, so it is necessary to pass through the voltage adjustment unit 113 for voltage division adjustment to ensure that the voltage input into the component microcontroller 130 is within the acceptable range of the component microcontroller 130. In some embodiments of the present invention, the voltage adjustment unit 113 can use a voltage division circuit. In order to improve the application range of the voltage adjustment unit 113, one or both of R4 and R3 can be set as variable resistors.

[0053] In addition, after a long period of operation, the voltage acquisition unit 110 may have measurement errors due to aging of some components. At the same time, if one or two of R1 and R2 are set as variable resistors, and one or two of R4 and R3 are set as variable resistors, this problem can be solved by slightly adjusting the resistance value of the variable resistor when a measurement error occurs.

[0054] refer to Figure 4 After the voltage regulating unit 113 outputs the voltage, it is not directly input to the component microcontroller 130. At this time, further protection is provided by the voltage follower 114. The voltage follower 114 directly utilizes the characteristics of the operational amplifier to increase the impedance without changing the voltage, thereby making the connection with the component microcontroller 130 safer.

[0055] In some embodiments of the present invention, reference Figure 4 A clamping protection circuit is also provided after the voltage follower 114. The clamping protection circuit is composed of two diodes, which can further ensure the safety of the connection with the microcontroller.

[0056] In some embodiments of the present invention, the communication collection device 200 includes: a first communication module 210, a second communication module 220, and a string microcontroller 230. The first communication module 210 is connected to the component control terminal 100; the second communication module 220 is connected to the monitoring terminal 300; the string microcontroller 230 is connected to the photovoltaic inverter 500 and receives the loop current collected by the photovoltaic inverter 500; the string microcontroller 230 is also connected to the first communication module 210 and the second communication module 220 respectively, and is used to receive the output voltage through the first communication module 210 and send the component control signal to the component control terminal 100, and is also used to receive the string control signal transmitted by the monitoring terminal 300 through the second communication module 220 and transmit the loop current and output voltage to the monitoring terminal 300.

[0057] refer to Figures 1 to 3The string microcontroller 230 exchanges data with the component control terminal 100 through the first communication module 210 to obtain the output voltage data collected by the component control terminal 100. The string microcontroller 230 communicates with the photovoltaic inverter 500 to obtain the loop current of the photovoltaic string collected by the photovoltaic inverter 500. Then the string microcontroller 230 sends the monitoring terminal 300 through the second communication module 220.

[0058] refer to Figures 1 to 3 , the control of the assembly control terminal 100 can be realized by directly using the group string microcontroller 230 and the first communication module 210, and the assembly control terminal 100 can complete the control of the assembly shutoff switch 120 according to the assembly control signal sent by the group string microcontroller 230. Here is a brief description of the process of shutting down the photovoltaic assembly 400: the monitoring terminal 300 sends a group string control signal, and the second communication module 220 transmits the group string control signal to the group string microcontroller 230 after receiving it, and the group string microcontroller 230 controls the photovoltaic inverter 500 to shut down the current switch of the photovoltaic inverter 500 itself. After the shutdown is completed, the group string microcontroller 230 sends a component control signal to the assembly control terminal 100, and the assembly control terminal 100 shuts down the photovoltaic assembly 400.

[0059] In some embodiments of the present invention, the string microcontroller 230 uses a processor with an internal temperature sensor. The temperature of the photovoltaic inverter 500 can be detected by the internal temperature sensor. The temperature of the photovoltaic inverter 500 can effectively feedback the working state of the photovoltaic inverter 500 to a certain extent. When the temperature of the photovoltaic inverter 500 rises sharply or the temperature of the photovoltaic inverter 500 exceeds the normal temperature, an alarm can be promptly sent to the monitoring terminal 300. In some embodiments of the present invention, the string microcontroller 230 also uses an MSP430 series single-chip microcomputer. The internal temperature sensor of the MSP430 series single-chip microcomputer is relatively accurate in acquisition and has a low cost, which is suitable for large-scale applications.

[0060] In some embodiments of the present invention, the communication collection device 200 also includes an inverter temperature collection unit connected to the string microcontroller 230, and the inverter temperature collection unit is used to collect the temperature of the photovoltaic inverter 500. By adding an inverter temperature collection unit, a part of the string microcontroller 230 that does not have an internal temperature sensor can also be used for temperature collection. At the same time, by adding an inverter temperature collection unit, the location of temperature collection can be made more flexible, and the collected temperature data will be relatively more accurate. In some embodiments of the present invention, the inverter temperature collection unit uses a resistive temperature sensor for temperature collection. The cost of resistive temperature sensors is relatively low, which can further reduce costs and facilitate subsequent replacement. When the inverter temperature collection unit uses a resistive temperature sensor for temperature collection, its application circuit can also refer to Figure 5 .

[0061] In some embodiments of the present invention, the second communication module 220 uses a GSM / GPRS module. After using the GSM / GPRS module, ultra-long-distance wireless communication can be achieved by means of a built-in SIM card, and data transmission can be completed directly through an existing mobile communication base station, without the need to arrange another wireless communication system to achieve ultra-long-distance communication.

[0062] In some embodiments of the present invention, the control terminal 100 and the communication collection device 200 and / or the communication collection device 200 and the monitoring terminal 300 communicate by wireless communication. In order to realize wireless communication, the first communication module 210 and the second communication module 220 directly use wireless communication modules, and the component microcontroller 130 is connected to the local wireless communication module 150, so that wireless communication can be realized between the control terminal 100 and the communication collection device 200, and between the communication collection device 200 and the monitoring terminal 300. By realizing data transmission by wireless communication, the number of communication lines in the photovoltaic power generation system can be greatly reduced, and because the photovoltaic power generation system itself is in a relatively open environment, there is less interference during wireless communication, and the distance of wireless transmission can be effectively guaranteed, thereby effectively controlling the cost of wireless communication. Compared with the traditional wired communication method, it can not only control the increase in cost but also reduce the wiring on site, thereby improving the safety and stability of the entire photovoltaic power generation system.

[0063] In some embodiments of the present invention, the first communication module 210, the second communication module 220 and the local wireless communication module 150 can all use WIFI modules, Bluetooth modules or ZigBee modules. There are many ways of wireless communication, so WIFI, Bluetooth, ZigBee and other wireless transmission methods can be selected for communication according to the use requirements and the size of the site. In some embodiments of the present invention, the first communication module 210, the second communication module 220 and the local wireless communication module 150 can all choose to use ZigBee modules for communication. ZigBee modules are cheap and have a long communication distance, which is sufficient to meet the needs of photovoltaic power generation systems.

[0064] In some embodiments of the present invention, the component control terminal 100 and the communication collection device 200 communicate with each other by means of a power carrier. By means of a power carrier, the existing lines are directly used for data communication, which can effectively reduce the wiring. At the same time, compared with the wireless communication method, the influence of electromagnetic waves can also be reduced.

[0065] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0066] Although the embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, the present invention is not limited to the above embodiments. Those skilled in the art will understand that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and purpose of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A photovoltaic power station monitoring system, characterized in that: include: A component control terminal (100) is used to collect the output voltage of the photovoltaic component (400) and control the on and off of the photovoltaic component (400); A communication collection device (200) is used to receive the output voltage transmitted by the component control end (100) and send a component control signal to the component control end (100); the communication collection device (200) is also used to connect to the photovoltaic inverter (500) and receive the loop current of the photovoltaic string collected by the photovoltaic inverter (500) and control the photovoltaic inverter (500) to turn on and off the current switch of the photovoltaic inverter (500) itself; A monitoring terminal (300) is used to send a string control signal to the communication collection device (200) and receive the output voltage and loop current transmitted by the communication collection device (200); The component control end (100) and the communication collection device (200), and the communication collection device (200) and the monitoring end (300) communicate with each other using wireless communication; The component control terminal (100) comprises: A voltage collection unit (110) is used to collect the output voltage of the photovoltaic component (400); the voltage collection unit (110) is arranged at the output end of the component shutoff switch (120), and is also used to monitor the disconnection status of the component shutoff switch (120); A component shutoff switch (120) connected in series with the output end of the photovoltaic component (400) and used to connect or disconnect the photovoltaic component (400) from the photovoltaic string; A component microcontroller (130) is connected to the voltage collection unit (110) and is used to receive the output voltage and transmit it to the communication collection device (200); the component microcontroller (130) is also used to control the connection and disconnection of the component off switch (120) according to the received component control signal.

2. The photovoltaic power station monitoring system according to claim 1, characterized in that: The component shutoff switch (120) is connected in series with the output end of the photovoltaic component (400) using a normally closed contact.

3. The photovoltaic power station monitoring system according to claim 1, characterized in that: The component microcontroller (130) employs a processor with an internal temperature sensor.

4. The photovoltaic power station monitoring system according to claim 1, characterized in that: The component control end (100) further comprises a temperature acquisition unit (140) connected to the component microcontroller (130), wherein the temperature acquisition unit (140) is used to acquire the temperature of the photovoltaic component (400).

5. The photovoltaic power station monitoring system according to claim 1, characterized in that: The voltage acquisition unit (110) comprises: A reference voltage unit (111), used for adjusting the range of voltage acquisition; A first operational amplifier unit (112), whose negative input terminal is connected to the output terminal of the reference voltage unit (111), and whose positive input terminal is used to access the output voltage of the photovoltaic module (400); A voltage regulating unit (113), whose input end is connected to the output end of the first operational amplifier unit (112), and is used to adjust the output voltage to a range that can be input into the component microcontroller (130); A voltage follower (114) has an input end connected to the output end of the voltage regulating unit (113), and an output end connected to the component microcontroller (130).

6. The photovoltaic power station monitoring system according to claim 1, characterized in that: The communication collection device (200) comprises: A first communication module (210) connected to the component control terminal (100); A second communication module (220) connected to the monitoring terminal (300); A string microcontroller (230) is connected to the photovoltaic inverter (500) and receives the loop current collected by the photovoltaic inverter (500); the string microcontroller (230) is also connected to the first communication module (210) and the second communication module (220), respectively, and is used to receive the output voltage through the first communication module (210) and send the component control signal to the component control terminal (100), and is also used to receive the string control signal transmitted by the monitoring terminal (300) through the second communication module (220) and transmit the loop current and output voltage to the monitoring terminal (300).

7. The photovoltaic power station monitoring system according to claim 6, characterized in that: The second communication module (220) adopts a GSM / GPRS module.

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