Mobile application terminal intelligent photovoltaic component monitoring alarm system and method

Abstract

The present invention provides a mobile application terminal intelligent photovoltaic component monitoring alarm system and method, wherein photovoltaic components and a monitoring system for monitoring and analyzing the power generation performance of the photovoltaic components and an alarm system for warning of abnormal information are installed at the illuminated part of the mobile application terminal, and the monitoring system includes an intelligent junction box and a data acquisition analyzer, the intelligent junction box collects the current, voltage, power, temperature, power generation and cumulative power generation information of each component in real time and transmits it to the data acquisition analyzer, the data acquisition analyzer determines whether each photovoltaic component has a fault through a preset judgment condition, and sends the fault information to the mobile application terminal. The present invention provides a solution for the safe and effective use of photovoltaic components in various mobile application terminals, such as buses, and broadens the application field of solar energy.

Description

Technical Field

[0001] The present invention relates to a monitoring and alarm system for a photovoltaic system, and in particular to a monitoring and alarm system and method for an intelligent photovoltaic component of a mobile application terminal, and belongs to the technical field of photovoltaic system applications. Background Art

[0002] As a clean and renewable energy source, solar energy is being applied in a wide range of scenarios and scopes. For example, it is used in various vehicles with large top areas, such as buses, to provide all or part of the energy for their operation, which is an important application field to effectively alleviate the energy crisis.

[0003] At present, there are no cases of photovoltaic monitoring systems for buses. The main reason is that the application of photovoltaic systems on buses has not yet been developed and promoted. Photovoltaic module monitoring systems are currently mainly used in industry, commerce and power stations. Photovoltaic monitoring systems used in other fields use photovoltaic inverters or controllers as carriers to monitor abnormal conditions in the entire string circuit. The number of monitoring unit components is too large to accurately measure each component. Traditional photovoltaic monitoring systems are installed in fixed buildings, and there is no need to consider vibration issues. In traditional photovoltaic systems, photovoltaic modules are installed in fixed locations and the environment will not change rapidly. In addition, there are meteorological stations as environmental measurement standards. Therefore, the method of judging whether photovoltaic modules are working properly is relatively simple. It only needs to calculate the range of various parameters through lighting conditions, and then judge whether the parameters of each component are within the range.

[0004] But for buses, each component needs to be effectively monitored to ensure vehicle safety. And vehicle vibration is a great test for the monitoring system. In addition, the components are installed on a moving bus, and there are various unknown conditions. The shadows cast by the roadside or buildings will cause each component of the same power to generate different power. Changes in vehicle speed (wind speed) and the location where the components are installed (at the air conditioning exhaust vent, at the front of the car, and at the rear of the car) will have different effects on the temperature of the components. Unlike traditional power stations, there is no condition to install a weather station on the roof, and there is no standard for environmental measurement. Therefore, for the photovoltaic roof of the bus, accurate judgment is extremely difficult. Therefore, the intelligent monitoring and alarm of photovoltaic components on the roof of the bus will become a key technology for the application of photovoltaic systems to moving objects such as buses. Summary of the invention

[0005] The purpose of the present invention is to address the above-mentioned problems and to provide a mobile application terminal intelligent photovoltaic component monitoring and alarm system and method. While applying the photovoltaic system to the roof of a bus, a component monitoring and alarm system is added to meet the needs of vehicle safety. At the same time, the changeable environmental problems during vehicle movement are taken into consideration to avoid affecting judgment and generating false alarms in short-term environmental changes.

[0006] To this end, the present invention adopts the following technical solutions:

[0007] The mobile application terminal intelligent photovoltaic component monitoring and alarm system is characterized in that: photovoltaic components and a monitoring system for monitoring and analyzing the power generation performance of the photovoltaic components and an alarm system for warning of abnormal information are installed on the illuminated part of the mobile application terminal. The monitoring system includes an intelligent junction box and a data acquisition analyzer. The intelligent junction box collects the current, voltage, power, temperature, power generation and cumulative power generation information of each component in real time and transmits it to the data acquisition analyzer. The data acquisition analyzer determines whether there is a fault in each photovoltaic component through preset judgment conditions, and sends the fault information to the mobile application terminal.

[0008] Furthermore, the intelligent junction box transmits the photovoltaic module data every second to the data acquisition analyzer in a wired or wireless manner.

[0009] Furthermore, the intelligent junction box is provided with a microcontroller unit MCU, an A / D sampling circuit, a storage unit, a power conversion module and a wireless communication module ZigbeeANT. The A / D sampling circuit includes a current acquisition module, a voltage acquisition module, a temperature acquisition module, a power acquisition module and a power generation acquisition module. The information collected by the A / D sampling circuit is transmitted to the microcontroller unit MCU, and is transmitted to the data acquisition analyzer through the wireless communication module ZigbeeANT.

[0010] Another aspect of the present invention provides a mobile application terminal intelligent photovoltaic component monitoring and alarm method, wherein the current, voltage, power, temperature, power generation and cumulative power generation information of each component are collected in real time through the intelligent junction box and transmitted to the data acquisition analyzer, and the data acquisition analyzer determines whether each photovoltaic component has a fault according to a preset judgment condition, and sends the fault information to the mobile application terminal in the form of an alarm;

[0011] The preset judgment conditions include:

[0012] Component temperature: Set several temperature monitoring points on each component and calculate the average value of each point. If the temperature of a certain point exceeds the first set ratio of the average value, it is judged as overtemperature A; if the temperature of any point exceeds the set temperature threshold, it is judged as overtemperature B. If any temperature monitoring point on the component is judged as overtemperature A and overtemperature B at the same time and lasts for 3 days, the component will issue an overtemperature alarm;

[0013] Module power generation: divide the PV modules of equal size into a group, calculate the cumulative power generation of each PV module in the same group for N consecutive days and calculate the average value, compare the power generation of each module in the previous N days with the average value, if it is lower than the second set ratio of the average value, it is judged that the module power generation is too low;

[0014] Module voltage: PV modules of equal size are divided into a group. If the voltage of any PV module is higher than the set high voltage threshold and lasts for the first set time, the module is judged as an overvoltage fault; if the voltage of any PV module is higher than the set low voltage threshold and lasts for the second set time, the module is judged as an undervoltage fault; the second set time is greater than the first set time.

[0015] Furthermore, the first setting ratio is 10-40%, preferably 15-25%; the second setting ratio is 10-40%, preferably 15-25%.

[0016] Furthermore, the high pressure threshold is calculated by the following formula:

[0017] Vmax=40.8×[1+(T pv_min -25)×-0.26%]V,

[0018] The first set time T1≥30min, where: T pv_min It is the lowest temperature of the five temperature measurement points of each component; the open circuit voltage temperature coefficient of the component is -0.26% / ℃;

[0019] The low voltage threshold is calculated by the following formula:

[0020] Vmin=11×[1+(T pv_max -25)×-0.26%]V,

[0021] The second set time T2≥3days, where: T pv_max It is the highest temperature of the five temperature measurement points of each component; the open circuit voltage temperature coefficient of the component is -0.26% / ℃.

[0022] Furthermore, the alarm information also includes a DCDC side alarm, and the DCDC side alarm includes:

[0023] DCDC photovoltaic side overvoltage: If the DCDC photovoltaic side voltage is higher than 350V and lasts for more than 1 hour, a high voltage alarm will be issued;

[0024] DCDC over-temperature alarm: When DCDC exceeds 80℃, an over-temperature alarm is issued to the bus;

[0025] DCDC overcooling alarm: When DCDC is lower than -15℃, a low temperature alarm is issued to the bus;

[0026] DCDC battery side overvoltage alarm: When the voltage exceeds 750V (different models have different voltages, depending on the model design), a battery side overvoltage alarm is sent to the bus;

[0027] DCDC battery side overcurrent: greater than 15A, maintained for 30s (different models, different currents, specifically designed according to the model), the battery side overcurrent alarm is sent to the bus;

[0028] DCDC photovoltaic side pre-charge failure alarm: There is a DC relay inside the DCDC connected to the photovoltaic side. If this pre-charge module fails or fails, this fault will be reported;

[0029] DCDC IGBT protection alarm: IGBT protection fails, DCDC cannot work normally, and needs to be immediately disabled.

[0030] Furthermore, the fault information is classified into the following levels according to severity:

[0031] Level 1 fault: any PV module overheats, DCDC IGBT protection; reporting cycle: immediate;

[0032] Secondary fault: DCDC overcurrent, DCDC photovoltaic side pre-charging failure; reporting cycle: shutdown for more than 10 minutes due to some reason and cannot be self-recovered;

[0033] Level 3 fault: any PV communication fault or low power generation alarm, DCDC overheating, DCDC PV side overvoltage, DCDC overcooling, DCDC battery side overvoltage, DCDC battery side undervoltage; reporting cycle: shutdown for more than 10 minutes due to reasons and cannot be self-recovered;

[0034] Among them, the first-level fault will be immediately reported to the bus driving dashboard. Once the first-level fault is reported, the bus will be disconnected and cannot be driven; the second and third-level faults are reported to the background, and the maintenance personnel will check regularly. Long-term reporting of second and third-level faults will be repaired.

[0035] The beneficial effects of the present invention are:

[0036] In view of the characteristics of mobile application terminals, an intelligent photovoltaic component monitoring and alarm system and monitoring and alarm method suitable for mobile application terminals are invented, which provides a solution for the safe and effective use of photovoltaic components in various mobile application terminals, such as buses, and broadens the application field of solar energy.

[0037] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the intelligent junction box system in the present invention;

[0039] Figure 2 It is a structural block diagram of the data acquisition and analysis device in the present invention;

[0040] Figure 3 A schematic diagram of the positions of temperature measurement points on the back of a photovoltaic module of a certain size in an embodiment of the present invention;

[0041] Figure 4 A schematic diagram of the positions of temperature measurement points on the back of a photovoltaic module of another size in an embodiment of the present invention;

[0042] Figure 5 This is a distribution diagram of photovoltaic modules on the roof of a bus in an embodiment of the present invention;

[0043] Figure 6 The present invention provides a specific test roadmap for the embodiments of the present invention. DETAILED DESCRIPTION

[0044] The present invention will be further described below in conjunction with the accompanying drawings.

[0045] Embodiment 1:

[0046] The mobile application terminal intelligent photovoltaic component monitoring and alarm system of the present invention is described by taking a bus as an example. This embodiment provides an intelligent photovoltaic component monitoring and alarm system applied to the illuminated part of the bus. In this embodiment, the photovoltaic component is installed on the top of the bus, such as Figure 5 As shown, 8 photovoltaic modules are installed on the roof of the bus, among which the modules numbered 1-6 have the same size and are in basically the same operating environment, so they are grouped together; the modules numbered 7-8 are half the size of the modules numbered 1-6 and are located on both sides of the air-conditioning outlets on the roof of the bus, so they are grouped together.

[0047] The monitoring system includes an intelligent junction box and a data acquisition analyzer. The intelligent junction box collects the current, voltage, power, temperature, power generation and cumulative power generation information of each component in real time and transmits it to the data acquisition analyzer. The data acquisition analyzer determines whether each photovoltaic component has a fault through a preset judgment condition and sends the fault information to the mobile application terminal. The intelligent junction box and the data acquisition analyzer can adopt the intelligent junction box and the data acquisition analyzer in the prior art.

[0048] like Figure 1 As shown, the core control module of the intelligent junction box is mainly composed of a bypass diode, a power conversion circuit, an A / D sampling circuit, a MOS tube driver, and a ZigBee transceiver. Its built-in bypass diode can provide a DC path when the components are mismatched. During normal operation, the onboard power conversion circuit steps down the output of the component to provide a suitable working voltage. The MCU converts the power generation parameters of the component during operation into digital quantities through its own multi-channel analog-to-digital conversion circuit, and sends them to the data collector through the ZigBee communication module.

[0049] The hardware design uses a balanced differential amplifier circuit to collect component voltage and current, which has extremely high calculation accuracy and common-mode rejection ratio. The switch part uses an ultra-low on-resistance N-channel metal oxide power MOS tube to reduce conduction loss and heat generation.

[0050] The software design uses the Z-stack OSAL polling operating system to manage task events and simplify the application layer system design. The data sampling uses mean filtering and bubble sorting algorithms to improve conversion accuracy. The 32-bit cyclic redundancy check algorithm is used during communication to improve the data transmission accuracy of the system.

[0051] In terms of communication, it adopts ZigBee wireless communication self-organizing network technology, which has low standby and transmission power consumption. Combined with its own network routing and multi-hop networking functions, it is not only suitable for small distributed and household photovoltaic power stations, but also can be applied to large distributed and ground power stations, eliminating complicated communication lines and making the operation and maintenance of power stations simpler and more efficient.

[0052] like Figure 2 As shown, the data acquisition analyzer includes: MCU minimum system, GPRS communication module, SPI flash card, SIM card interface, BEBUG port, LDO step-down circuit, lithium battery charging and discharging circuit, RS232 / RS485 circuit, input and output interface, antenna interface, etc.

[0053] In the present invention, the key technologies of the data acquisition and analysis device mainly include:

[0054] Remote communication uses a high-performance industrial-grade quad-band GSM / GPRS module with built-in TCP / IP protocol, which simplifies communication design and improves system stability and reliability;

[0055] The power circuit adopts surge prevention design and has high-frequency interference filter to enhance the stability of the system;

[0056] The RF antenna routing is strictly designed according to the 50Ω impedance control method, away from strong interference sources, and has stable wireless signal communication capabilities;

[0057] When downloading firmware packages remotely, the technology of breakpoint continuation and block transmission is adopted. By accurately operating the file stream, the success rate of remote update programs is greatly improved.

[0058] Adopt FTP and HTTP file transfer technology, file storage technology, IAP in-application programming technology to realize the function of online remote firmware update.

[0059] The smart junction box transmits the photovoltaic module data every second to the data acquisition and analysis device via wired or wireless means.

[0060] Embodiment 2:

[0061] A mobile application terminal intelligent photovoltaic component monitoring and alarm method, wherein the current, voltage, power, temperature, power generation and cumulative power generation information of each component are collected in real time through the intelligent junction box and transmitted to a data acquisition analyzer. The data acquisition analyzer determines whether each photovoltaic component has a fault through preset judgment conditions, and sends the fault information to the mobile application terminal in the form of an alarm.

[0062] Similarly, a bus is used as an example for explanation.

[0063] like Figure 5 As shown, 8 photovoltaic modules are installed on the roof of the bus, among which the modules numbered 1-6 have the same size and are in basically the same operating environment, so they are grouped together; the modules numbered 7-8 are half the size of the modules numbered 1-6 and are located at the air outlet position on the top of the bus, so they are grouped together.

[0064] The preset judgment conditions, i.e. the monitoring contents, include:

[0065] The output voltage of each photovoltaic module and the photovoltaic module as a whole, the output current of each photovoltaic module and the photovoltaic module as a whole, the temperature of each photovoltaic module, the output electric power of each photovoltaic module and the photovoltaic module as a whole, the power generation of each photovoltaic module and the photovoltaic module as a whole, and the faults of each module, including: undervoltage, overvoltage, overheating, and communication failure.

[0066] in:

[0067] 1. Temperature detection and judgment: First, select multiple points on the back of each component as detection points. Specifically, select 5 temperature measurement points on the back of the component, one of which is the center of the component. For components numbered 1-6, Figure 3 As shown; components numbered 7-8, such as Figure 4 As shown. Install temperature sensors at the above 5 temperature measurement points to measure and judge the temperature. Specifically, measure the temperature of 5 points and calculate the average value. If the temperature of a certain point exceeds the average value by 20%, it is judged as component overtemperature A.

[0068] If the temperature of a certain point of the No. 1-6 components exceeds 75 degrees Celsius, it is judged as overtemperature B; if the temperature of a certain point of No. 7 and 8 exceeds 100 degrees Celsius, it is judged as overtemperature B. Since components 7 and 8 are installed on both sides of the air outlet of the air conditioner, the temperature of components 7 and 8 is relatively high during operation (the temperature of the external unit outlet is about 43 degrees or more, plus the components themselves generate electricity and heat, overtemperature is defined as exceeding 100 degrees)

[0069] If a point is judged as over-temperature A and over-temperature B at the same time and lasts for 3 days, an over-temperature alarm will be issued.

[0070] 2. Detection and judgment of power generation:

[0071] Power generation detection: Since the photovoltaic system is installed on the roof, shadows are generated by buildings, traffic signs, tree shades, etc. Therefore, in the past, component abnormality cannot be judged solely by low voltage or current, but must be judged by power generation over a period of time.

[0072] Components numbered 1-6 are of the same size and are grouped together. The cumulative power generation of the first seven days is calculated, and the two components with the lowest power generation are removed to calculate the average value of the other components. The cumulative power generation of these six components in the first seven days is compared with the calculated average value. Components that are less than 20% below the average value are defined as having too low power generation;

[0073] Among them, the cumulative power generation is accumulated on the 1st to 7th day, the 2nd to 8th day, and the 3rd to 9th day, and is tested once a day.

[0074] The power of components No. 7 and 8 is half of that of other components, so the power generation of components No. 7 and 8 is doubled for 7 days respectively, and then compared with the average value of components No. 1-6. If it is lower than 25% of the average value, it is defined as too low power generation.

[0075] If the detection is 20% (modules numbered 1-6) or 25% (modules numbered 7-8) below the average value for three consecutive days, a low power generation alarm will be issued.

[0076] 3. Voltage detection and judgment:

[0077] Due to the shadowing problem, it is difficult to judge the voltage anomaly. It is not easy to determine whether the voltage drop is caused by the component itself or by the shadowing. Here, it is necessary to combine the temperature parameters to judge.

[0078] Component overvoltage fault: The voltage of any component from 1 to 6 is greater than 40.8×[1+(T pv_min -25)×-0.26%]V and lasts for more than 30 minutes, the component sends an overvoltage fault signal; if the voltage of any component of No. 7 or 8 is greater than 20.4×[1+(T pv_min -25)×-0.26%]V and lasts for more than 30 minutes, the component sends an overvoltage fault signal.

[0079] Where T pv_min It is the lowest temperature of the five temperature measurement points of each component; the open circuit voltage temperature coefficient of the component is -0.26% / ℃.

[0080] Module undervoltage fault: When any module from 1 to 6 is working in the photovoltaic system, the voltage is less than 11×[1+(T pv_max -25)×-0.26%]V or 33.85×[1+(T pv_max-25)×-0.26%]×85%V, and it continues for 7 consecutive days, the module sends an undervoltage abnormal fault signal; any module of No. 7 and 8 modules is working in the photovoltaic system, and the voltage is less than 5×[1+(T pv_max -25)×-0.26%]V or less than 16.92×[1+(T pv_max -25)×-0.26%]×85%V and it continues for 7 consecutive days, the component will send out an undervoltage abnormal fault signal.

[0081] Where T pv_max It is the highest temperature of the five temperature measurement points of each component; the open circuit voltage temperature coefficient of the component is -0.26% / ℃. Note that the 7 consecutive days here means that when the undervoltage occurs on the same day, the undervoltage situation must occur for 7 consecutive days before the undervoltage can be reported. It is a process that needs to be tested and traced every day. The reason for the 7 consecutive days of undervoltage is that a single undervoltage situation may be a temporary undervoltage caused by shadow blocking.

[0082] The undervoltage alarm is mainly caused by the components on the roof, and it is inconvenient for maintenance personnel to check the status of the components on the roof. Prevent the roof components from being partially blocked (wet newspapers, magazines, leaves or long-term dust accumulation on the roof components), which may cause hot spots to form and cause fires. Once there is a component undervoltage alarm, maintenance personnel need to go to the roof to check.

[0083] 4. DCDC side alarm setting:

[0084] DCDC photovoltaic side overvoltage: If the DCDC photovoltaic side voltage is higher than 350V and lasts for more than 1 hour, a high voltage alarm will be issued.

[0085] DCDC over-temperature alarm: When DCDC exceeds 80℃, an over-temperature alarm is issued to the bus;

[0086] DCDC overcooling alarm: When DCDC is lower than -15℃, a low temperature alarm is issued to the bus;

[0087] DCDC battery side overvoltage alarm: When the voltage exceeds 750V (different models have different voltages, depending on the model design), a battery side overvoltage alarm is sent to the bus;

[0088] DCDC battery side overcurrent: greater than 15A, maintained for 30s (different models, different voltages, specifically designed according to the model), the battery side overcurrent alarm is sent to the bus;

[0089] DCDC photovoltaic side pre-charge failure alarm: There is a DC relay inside the DCDC connected to the photovoltaic side. If this pre-charge module fails or fails, this fault will be reported;

[0090] DCDC IGBT protection alarm: IGBT protection fails, DCDC cannot work normally, and needs to be immediately disabled.

[0091] 5. Fault level:

[0092] Bus alarms are divided into three levels according to severity: Level 1 fault, Level 2 fault and Level 3 fault, with severity decreasing in turn. The fault contents reported are as follows:

[0093] Level 1 fault:

[0094] Report content: PV1--PV8 overtemperature, DCDC IGBT protection;

[0095] Reporting cycle: immediate;

[0096] Secondary fault:

[0097] Report content: DCDC overcurrent, DCDC photovoltaic side pre-charge failure;

[0098] Reporting cycle: If the system is down for more than 10 minutes and cannot be restored by itself, reporting will begin;

[0099] Level 3 fault:

[0100] Report content: PV1-PV8 communication failure, DCDC overheating, DCDC photovoltaic side overvoltage, DCDC overcooling, DCDC battery side overvoltage, DCDC battery side undervoltage, PV1-PV8 low power generation alarm;

[0101] Reporting cycle: If the system is down for more than 10 minutes and cannot be restored by itself, reporting will begin;

[0102] Among them, the first level fault will be immediately reported to the bus driving dashboard. Once the first level alarm is reported, the bus will be disconnected and cannot be driven. The second and third level faults will not affect the normal operation of the bus and will be reported to the background. Long-term reporting of second and third level faults will be repaired.

[0103] 6. Protection enable: Faults are reported only when DCDC is enabled.

[0104] The following is a further detailed description using a specific road measurement as an example. Figure 6 As shown, a cycle test was conducted, and the route environment included different road conditions such as tree shade (irregular shading on one side), wire shading (linear shading), overhead shadow shading (full shading or most shading) and no shading.

[0105] Testing time: 20 days;

[0106] Daily test distance: 53km, such as Figure 6 , one lap is 5.3km, and the subject runs 10 laps per day;

[0107] Test method: Every hour of the day, from 8 am to 5 pm, a total of 10 hours, a total of 10 laps (each lap is about 10 minutes), the rest of the time the car is parked in an open parking lot.

[0108] First of all, all roof components are qualified components;

[0109] Temperature test: This test is conducted in the summer (July-September) for 20 days, such as from July 19 to August 7. The temperature range of the components during normal operation is between 24 and 79 degrees, as shown in Table 1 below:

[0110] Table 1: Temperature test values ​​of each component within the first 20 days

[0111]

[0112]

[0113] During this period, the temperature was below the over-temperature alarm, so no alarm was issued by the monitoring system.

[0114] When the module No. 5 is replaced with an unqualified module (one of the modules has several cracks and broken wires), the temperature test is continued for 20 days, such as from August 13 to September 1. The test results of each module are as shown in Table 2:

[0115] Table 2: Temperature test values ​​of each component within the second 20 days

[0116] Component Number Maximum temperature Minimum temperature Average temperature 1 64.7 24.8 49.6 2 66.0 25.4 51.3 3 67.2 25.2 50.7 4 66.6 26.3 50.2 5 80.1 25.1 55.4 6 66.3 25.0 49.2 7 73.4 26.4 57.5 8 74.5 25.6 58.1

[0117] When the temperature of the No. 5 module of the bus exceeds 75 degrees, the bus will be cut off and the PV system will be disconnected at the DCDC output.

[0118] Power generation judgment:

[0119] Test of power generation of qualified components: The test time is 20 days, such as from July 19 to August 7. The test results are as follows in Table 3-9: Test values ​​of power generation of each component in the first 20 days:

[0120] Table 3:

[0121]

[0122]

[0123] Table 4:

[0124]

[0125] Table 5:

[0126]

[0127]

[0128] Table 6:

[0129]

[0130] Table 7:

[0131]

[0132]

[0133] Table 8:

[0134]

[0135] Table 9:

[0136]

[0137] During the driving process, the photovoltaic module on the right side of the bus, that is, the module No. 8, dropped significantly. However, the difference ratio is still within 20%, which is a low power generation within the normal range, not caused by the quality problem of the module itself (judgment condition: not less than -25%), so no low power generation alarm will be issued.

[0138] Similarly, after the No. 5 component is replaced, the test time is still 20 days, such as from July 19 to August 7. The test results are as follows Table 10-16: The power generation test values ​​of each component in the second 20 days:

[0139] Table 10:

[0140]

[0141] Table 11:

[0142]

[0143]

[0144] Table 12:

[0145]

[0146] Table 13:

[0147]

[0148] Table 14:

[0149]

[0150]

[0151] Table 15:

[0152]

[0153] Table 16:

[0154]

[0155]

[0156] It can be seen that the replaced module No. 5 has a significant drop in power generation compared to other modules. According to the calculation method of the 7-day cumulative power generation average, the two modules with the lowest power generation are not included in the average, making the average more accurate as a benchmark power generation.

[0157] Take the last week as an example.

[0158]

[0159] When the 7-day cumulative power generation of component No. 5 is less than 25% for 3 consecutive days, the system will send a level 3 fault of low power generation to the bus.

[0160] Voltage judgment:

[0161] The voltage data is measured every 1 second for 7 consecutive days. Take the data at a certain moment as an example to illustrate:

[0162] For example, the data at 12:03:10 on August 2, 2019 (qualified components), the voltage values ​​of each component are as shown in Table 17:

[0163] Table 17: Voltage values ​​of each component at a certain moment

[0164]

[0165]

[0166] Data at 12:03:10 on August 3, 2019, among which No. 5 failed, the surface of the component was blocked by foreign matter. At this time, the voltage values ​​of each component are as shown in Table 18:

[0167] Table 18: Voltage values ​​of each component at another time

[0168]

[0169] In addition, the measured voltage was undervoltage for 7 days, so the undervoltage alarm sounded. Unlike other components, other components of the bus sometimes undervoltage during driving because of shade from trees or other shadows. When the bus drove to the parking lot, there was no shadow and the voltage returned to normal. It did not reach the situation of continuous undervoltage for 7 days, so the undervoltage alarm was not reported to the bus.

[0170] The calculation method for the voltage upper limit of components numbered 1-6 is as follows:

[0171] 40.8×[1+(minimum component temperature - 25)×-0.26%]V;

[0172] Calculation method for voltage upper limit of No. 7 and 8:

[0173] 20.4×[1+(minimum component temperature - 25)×-0.26%]V;

[0174] Calculation method for voltage lower limit of No. 1-6:

[0175] 11×[1+(maximum component temperature - 25)×-0.26%]V or 33.85×[1+(maximum component temperature - 25)×-0.26%]*85%V;

[0176] Calculation method for voltage lower limit of No. 7 and 8:

[0177] 5×[1+(maximum component temperature - 25)×-0.26%]V or 16.92×[1+(maximum component temperature - 25)×-0.26%]*85%V;

[0178] All the above data are obtained after background detection.

[0179] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways without departing from the spirit of the present invention.

Claims

1. A mobile application terminal intelligent photovoltaic component monitoring and alarm method, characterized in that: The intelligent junction box collects the current, voltage, power, temperature, power generation and cumulative power generation information of each module in real time and transmits it to the data acquisition analyzer. The data acquisition analyzer determines whether there is a fault in each photovoltaic module based on the preset judgment conditions and sends the fault information to the mobile application terminal in the form of an alarm; The preset judgment conditions include: Component temperature: Set several temperature monitoring points on each component and calculate the average value of each point. If the temperature of a certain point exceeds the first set ratio of the average value, it is judged as overtemperature A; if the temperature of any point exceeds the set temperature threshold, it is judged as overtemperature B. If any temperature monitoring point on the component is judged as overtemperature A and overtemperature B at the same time and lasts for 3 days, the component will issue an overtemperature alarm; Module power generation: divide the PV modules of equal size into a group, calculate the cumulative power generation of each PV module in the same group for N consecutive days and calculate the average value, compare the power generation of each module in the previous N days with the average value, if it is lower than the second set ratio of the average value, it is judged that the module power generation is too low; Module voltage: PV modules of equal size are divided into a group. If the voltage of any PV module is higher than the set high voltage threshold and lasts for the first set time, the module is judged as an overvoltage fault; if the voltage of any PV module is higher than the set low voltage threshold and lasts for the second set time, the module is judged as an undervoltage fault; The high voltage threshold is calculated by the following formula: Vmax=40.8×[1+(T pv_min -25)×-0.26%]V, The first set time T1≥30min, where: T pv_min It is the lowest temperature of the five temperature measurement points of each component; The open circuit voltage temperature coefficient of the component is -0.26% / ℃; The low voltage threshold is calculated by the following formula: Vmin=11×[1+(T pv_max -25)×-0.26%]V , The second set time T2 is ≥ 3 days, where: T pv_max It is the highest temperature of the five temperature measurement points of each component; the open circuit voltage temperature coefficient of the component is -0.26% / ℃.

2. The mobile application terminal intelligent photovoltaic component monitoring and alarm method according to claim 1 is characterized in that: The first setting ratio is 10-40%, and the second setting ratio is 10-40%.

3. The mobile application terminal intelligent photovoltaic component monitoring and alarm method according to claim 1 is characterized in that: The alarm information also includes a DCDC side alarm, and the DCDC side alarm includes: DCDC photovoltaic side overvoltage: If the DCDC photovoltaic side voltage is higher than 350V and lasts for more than 1 hour, a high voltage alarm will be issued; DCDC over-temperature alarm: When DCDC exceeds 80℃, an over-temperature alarm is issued to the bus; DCDC overcooling alarm: When DCDC is lower than -15℃, a low temperature alarm is issued to the bus; DCDC battery side overvoltage alarm: If the voltage exceeds 750V, a battery side overvoltage alarm will be sent to the bus; DCDC battery side overcurrent: greater than 15A, maintained for 30s, the battery side overcurrent alarm is sent to the bus; DCDC photovoltaic side pre-charge failure alarm: There is a DC relay inside the DCDC connected to the photovoltaic side. If this pre-charge module fails or fails, this fault will be reported; DCDC IGBT protection alarm: IGBT protection fails, DCDC cannot work normally, and needs to be immediately disabled.

4. The mobile application terminal intelligent photovoltaic component monitoring and alarm method according to claim 1 is characterized in that: The fault information is divided into the following levels according to the severity: Level 1 fault: any PV module overheats, DCDC IGBT protection; reporting cycle: immediate; Secondary fault: DCDC overcurrent, DCDC photovoltaic side pre-charging failure; reporting cycle: shutdown for more than 10 minutes due to some reason and cannot be self-recovered; Level 3 fault: any PV communication fault or low power generation alarm, DCDC overheating, DCDC PV side overvoltage, DCDC overcooling, DCDC battery side overvoltage, DCDC battery side undervoltage; reporting cycle: shutdown for more than 10 minutes due to reasons and cannot be self-recovered; Among them, the first-level fault will be immediately sent to the bus driving dashboard. Once the first-level fault is reported, the bus will be disconnected and cannot be driven; the second and third-level faults are reported to the background, and long-term reporting of second and third-level faults will be carried out for maintenance.

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