Device for detecting direct current grounding and remotely notifying fault of photovoltaic module

Abstract

The utility model discloses a device for detecting DC grounding and remotely notifying a fault of a photovoltaic module. The device comprises a bias detection circuit, a plurality of DC loops, a DC-AC inverter, a single-chip microcomputer, a notification module and a double-color LED matrix. The bias detection circuit comprises a plurality of detection branches, each detection branch is correspondingly connected with each direct current loop, and each detection branch is formed by connecting three bias resistors in series; the notification module comprises a cloud platform, a Bluetooth unit, an encryption unit, an offline early warning control unit and a storage unit; each detection branch is connected with a comparator in parallel, and the comparator is connected with a single-chip microcomputer; the single-chip microcomputer is connected with the storage unit of the notification module. According to the utility model, the bias detection circuit is used for carrying out voltage detection and comparison on the photovoltaic module, a direct current loop with problems is rapidly determined, the efficiency is high, conventional devices are used, and the cost is low; and the notification module is used for carrying out remote notification and offline early warning on faults, so that the tedious process of continuous offline patrol of personnel is omitted, and potential safety hazards are reduced.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic device technology, specifically to a device for detecting DC grounding in photovoltaic modules and remotely notifying of faults. Background Technology

[0002] Photovoltaic power generation is a power generation method with broad application prospects and already in large-scale use. As the basic unit of photovoltaic power generation system, the stability and reliability of photovoltaic modules are directly related to the power generation efficiency and operational safety of the entire photovoltaic system.

[0003] In the process of photovoltaic power generation, the photovoltaic panels used in photovoltaic modules generate electricity, which can be considered as a constant current source within a certain period of time. That is, the current does not change or changes very little. Such a constant current source is difficult to detect for faults using electronic devices. Moreover, if a photovoltaic module fails, and there are two or more grounding problems, it is extremely easy to cause a short circuit, which can lead to serious problems such as equipment damage or even fire.

[0004] Traditional methods for detecting ground faults in photovoltaic (PV) modules using constant current sources rely heavily on manual inspections, which are costly, inefficient, and difficult to locate in a timely manner. Furthermore, given that PV module power generation is equivalent to a constant current source, it's difficult to directly use ground fault detection sensors for protection. Firstly, PV power generation often involves a large number of modules, and ground fault detection sensors are not inexpensive, making it prohibitively expensive to detect ground faults in a large number of modules. Secondly, ground fault detection sensors are significantly affected by the environment, while PV modules often operate outdoors, making them prone to errors. Thirdly, most ground fault detection sensors are likely to fail when detecting constant current sources because they primarily detect current changes, while the current in a constant current source remains constant or nearly constant.

[0005] Currently, there are at least three problems with fault detection for DC grounding of photovoltaic modules:

[0006] 1) It is inefficient, prone to errors, and difficult to accurately locate the fault.

[0007] 2) The cost is too high, especially when there are many photovoltaic power generation devices;

[0008] 3) Lack of secure and timely remote notification methods. Utility Model Content

[0009] To address the three issues mentioned above, the purpose of this invention is to propose a device for detecting DC grounding in photovoltaic modules and remotely notifying users of the fault. It utilizes a bias detection circuit to detect and compare the voltage of the DC loop formed by the photovoltaic module, quickly identifying the problematic DC loop. This method is efficient and uses conventional components such as resistors, power supplies, and comparators, resulting in low and controllable costs. Simultaneously, a notification module is used for remote fault notification and offline early warning, eliminating the tedious task of continuous on-site inspections by staff. This effectively alerts on-site personnel near the photovoltaic modules and informs on-site personnel of the fault, enabling manual intervention and reducing safety hazards.

[0010] The specific technical solution is as follows:

[0011] A device for detecting DC grounding in photovoltaic modules and remotely notifying users of the fault includes a bias detection circuit, multiple DC loops, a DC-AC inverter, a microcontroller, a comparator, a notification module, a dual-color LED matrix, and a buzzer. Each DC loop includes multiple photovoltaic modules connected in series. The bias detection circuit includes multiple parallel detection branches and a bias power supply for each detection branch. Each detection branch is connected to each DC loop and consists of three bias resistors connected in series. The notification module includes a parallel cloud platform, a Bluetooth unit, an encryption unit, an offline early warning control unit, and a storage unit. The DC-AC inverter is connected to each DC loop. Each detection branch is connected to a comparator in parallel, and then the comparator is connected to the microcontroller. The microcontroller is connected to the storage unit in the notification module. The dual-color LED matrix is ​​connected to the buzzer and the offline early warning control unit.

[0012] The bias detection circuit can detect the bias voltage of the DC circuit using inexpensive resistors and other conventional components. By comparing the results, it can effectively determine the location of the bias voltage problem, which is the DC circuit of the photovoltaic module that is faulty. At the same time, the fault is remotely transmitted via Bluetooth or cloud platform using the notification module. Combined with the warning from the offline early warning control unit, it forms a dual warning system, eliminating the tedious task of constant on-site inspections by offline staff. It can effectively remind offline staff and inform online personnel of the fault situation, enabling them to handle it manually.

[0013] Preferably, the storage unit is DDR3 or a three-layer BRAM; wherein, in the three-layer BRAM, the first layer is the primary storage layer, the second layer is the secondary storage layer, and the third layer is the backup storage layer. DDR3 can store data quickly, while BRAM can save costs compared to DDR3. At the same time, the three-layer structure of BRAM can effectively ensure storage efficiency, thereby ensuring the operating efficiency of this device.

[0014] Preferably, the microcontroller is an STM32 series microcontroller, and the Bluetooth unit uses Bluetooth 5.1 or later. Bluetooth 5.1 and later versions have a longer transmission distance and better power consumption. The STM32 series microcontroller is easy to develop and use and has a low-power design, which can ensure the device can operate for a long time.

[0015] Preferably, the dual-color LED matrix includes a first LED sub-matrix and a second LED sub-matrix connected in parallel. The first LED sub-matrix consists of multiple red LEDs connected in series, and the second LED sub-matrix consists of multiple blue LEDs connected in series. The dual-color LED matrix can provide offline early warnings, and when combined with remote early warnings from a notification module, it forms a dual early warning system. Furthermore, the two different colors can correspond to different severity levels, effectively reminding personnel offline accordingly.

[0016] Preferably, a corresponding grounding capacitor is connected in parallel between each detection branch and the comparator. The parallel grounding capacitors can both protect the circuit and filter out some of the possible interference noise, thereby improving the accuracy of the detection.

[0017] The advantages of this utility model compared with the prior art are:

[0018] This invention utilizes a bias detection circuit to detect and compare the voltage of the DC circuit formed by the photovoltaic module, quickly identifying the problematic DC circuit. It is efficient and uses conventional components such as resistors, power supplies, and comparators, making it low-cost and controllable. Simultaneously, it employs a notification module for remote fault notification and offline early warning, eliminating the tedious task of continuous on-site inspections by staff. This effectively alerts on-site personnel near the photovoltaic module and informs on-site personnel of the fault, enabling manual handling and reducing safety hazards. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a device for detecting DC grounding in photovoltaic modules and remotely notifying users of the fault. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model. Example

[0021] like Figure 1The diagram shows a device for detecting DC grounding in photovoltaic modules and remotely notifying users of the fault. The device mainly includes a bias detection circuit, multiple DC loops, a DC-AC inverter, a microcontroller, a comparator, a notification module, a dual-color LED matrix, and a buzzer. It is used to compare bias voltages to quickly identify the location of the abnormal bias voltage, which is the DC loop of the faulty photovoltaic module, and then notify the user so that staff can handle the situation promptly and reduce safety hazards.

[0022] Each DC loop includes multiple photovoltaic modules connected in series for photovoltaic power generation. Each DC loop is connected to a DC-AC inverter, which converts the DC power generated by the photovoltaic modules into AC power, which is then transmitted to the external power grid for storage or use.

[0023] The bias detection circuit includes multiple parallel detection branches and a bias power supply for each detection branch. Each detection branch is connected to a corresponding DC circuit, and each detection branch consists of three bias resistors connected in series. For example, bias resistors R1, R11, and R12 are connected in series to form a detection branch, with R1 and R11 connected in parallel to a corresponding DC circuit; bias resistors R2, R21, and R22 are connected in series to form a detection branch, with R2 and R21 connected in parallel to a corresponding DC circuit; and so on, with bias resistors Rn, Rn1, and Rn2 connected in series to form a detection branch, with Rn and Rn1 connected in parallel to a corresponding DC circuit; bias resistors R1, R2...Rn are all powered by a bias power supply of +5V to +100V, and bias resistors R12, R22...Rn2 are all grounded, where n is a positive integer not less than 3.

[0024] The comparator operates by internally setting a threshold value, comparing the input signal to this threshold for selection. The comparator's input is connected in parallel between bias resistors R11 and R12, R21 and R22, ..., Rn1 and Rn2, allowing it to detect and compare the voltage in the corresponding branch. When a photovoltaic module experiences a grounding fault, the voltage in the corresponding detection branch will change and meet the comparator's built-in threshold. This faulty voltage data is then transmitted, passed through a control switch, and finally sent to a microcontroller for processing. This process identifies the specific DC circuit that has malfunctioned, facilitating subsequent handling.

[0025] In addition, to protect the circuit and improve the accuracy of the detection, a corresponding grounding capacitor is connected in parallel between each detection branch and the comparator. For example, when the comparator wiring is connected between bias resistors R11 and R12, grounding capacitor C1 is connected in parallel between these two connections; when the comparator wiring is connected between bias resistors R21 and R22, grounding capacitor C2 is connected in parallel between these two connections; and so on, when the comparator wiring is connected between bias resistors Rn1 and Rn2, grounding capacitor Cn is connected in parallel between these two connections. The parallel grounding capacitors can both protect the circuit and filter out some possible interference noise, thereby improving the accuracy of the comparison results.

[0026] In this embodiment, the microcontroller can be an STM32 series microcontroller. The STM32 series microcontroller has a wide range of applications, is easy to develop and use, has a low power consumption design, a fast response speed, and can run for a long time, which also meets the requirement of timely fault detection.

[0027] In this embodiment, the notification module mainly includes a parallel cloud platform, a Bluetooth unit, an encryption unit, an offline early warning control unit, and a storage unit. The notification module is responsible for both online and offline early warning notifications. The Bluetooth unit uses Bluetooth 5.1 or later, which has a longer transmission distance and better power consumption. Theoretically, Bluetooth 5.1 has a transmission distance of about 300 meters. Using Bluetooth for remote notification is mainly due to its low cost and ease of use, making it suitable for situations where remote workers are not too far from the photovoltaic modules.

[0028] The encryption unit is used to encrypt data generated by other units during operation. There are many encryption methods that can be used here, and staff can choose according to their actual needs. For example, when high speed and a large amount of data need to be processed, AES-256 encryption can be used. This encryption method is widely used, efficient and secure. Or when the speed requirement is low and the amount of data processed is small, RSA encryption can be used.

[0029] In this embodiment, the cloud platform is used to support remote network transmission, that is, to transmit information about the faulty DC circuit to remote workers via a remote network. Here, the cloud platform can directly use an existing hybrid cloud platform, which is a technology used to support communication between local and cloud environments for enterprises.

[0030] In this embodiment, the storage unit can receive the processing results from the microcontroller and also store various data generated by other units in the notification module. The storage unit can use DDR3 or a three-layer BRAM structure. In the three-layer BRAM structure, the first layer is the primary storage layer, the highest layer of the BRAM, which can be used to store frequently accessed or currently needed data, and has the fastest data access speed. The second layer is the secondary storage layer, located below the primary storage layer, used to store data that is not frequently accessed but still needs to be retained, and has a slower data access speed. The third layer is the backup storage layer, the lowest layer of the BRAM, with the slowest access speed, but provides sufficient storage space. DDR3 can store data quickly and is a commonly used high-speed storage medium. BRAM is a block memory, which is generally cheaper. Using BRAM can save costs compared to using DDR3. At the same time, by improving the BRAM to adopt a three-layer structure, both cost and storage efficiency can be guaranteed, thereby ensuring the operating efficiency of this device.

[0031] In this embodiment, a dual-color LED matrix is ​​connected to both a buzzer and an offline early warning control unit. The dual-color LED matrix includes a first LED sub-matrix and a second LED sub-matrix connected in parallel. The first LED sub-matrix consists of multiple red LEDs connected in series, and the second LED sub-matrix consists of multiple blue LEDs connected in series. When only one faulty DC circuit is detected, the first LED sub-matrix illuminates; when at least two faulty DC circuits are detected, the second LED sub-matrix illuminates. The different lighting patterns provide clear visibility for personnel on-site and in the vicinity, allowing for timely clarification of the actual situation. The dual-color LED matrix can provide offline early warnings, and when combined with remote early warnings from the notification module, it forms a dual early warning system. Furthermore, the two different colors can correspond to different severity levels, effectively alerting personnel on-site.

[0032] In addition, when any sub-matrix in the dual-color LED matrix emits light, the buzzer will sound to provide an early warning, so that even if the staff nearby do not notice the light-up warning of the dual-color LED matrix immediately, they can still hear the buzzer's sound warning. The buzzer can be an SMD7525 buzzer.

[0033] In summary, this application utilizes a bias detection circuit to detect and compare the voltage of the DC circuit formed by the photovoltaic module, quickly identifying the problematic DC circuit. This method is efficient and uses conventional components such as resistors, power supplies, and comparators, resulting in low and controllable costs. Furthermore, it employs a notification module for remote fault notification and offline early warning, eliminating the tedious task of continuous on-site inspections by staff. This effectively alerts on-site personnel near the photovoltaic module and informs on-site personnel of the fault, enabling manual handling and reducing safety hazards, demonstrating significant advancements in technology.

[0034] The above embodiments are only for illustrating the technical concept of this utility model and should not be construed as limiting the scope of protection of this utility model. Any modifications made to the technical solution based on the technical concept proposed by this utility model shall fall within the scope of protection of this utility model.

Claims

1. A device for detecting DC grounding in photovoltaic modules and remotely notifying of faults, characterized in that, It includes a bias detection circuit, multiple DC loops, a DC-AC inverter, a microcontroller, a comparator, a notification module, a dual-color LED matrix, and a buzzer; each DC loop includes multiple photovoltaic modules connected in series; the bias detection circuit includes multiple parallel detection branches and a bias power supply for each detection branch, each detection branch is connected to each DC loop, and each detection branch consists of three bias resistors connected in series; the notification module includes a parallel cloud platform, a Bluetooth unit, an encryption unit, an offline early warning control unit, and a storage unit; In this circuit, the DC-AC inverter is connected to each DC circuit; each detection branch is connected to a comparator in parallel, and then the comparator is connected to the microcontroller. The microcontroller is connected to the storage unit in the notification module; the dual-color LED matrix is ​​connected to the buzzer and the offline early warning control unit respectively.

2. The device for detecting DC grounding in photovoltaic modules and remotely notifying faults according to claim 1, characterized in that... The storage unit is either DDR3 or a three-layer BRAM; in the three-layer BRAM, the first layer is the primary storage layer, the second layer is the secondary storage layer, and the third layer is the backup storage layer.

3. The device for detecting DC grounding in photovoltaic modules and remotely notifying of faults according to claim 1, characterized in that, The microcontroller is an STM32 series microcontroller, and the Bluetooth unit uses Bluetooth 5.1 or a later version.

4. The device for detecting DC grounding in photovoltaic modules and remotely notifying of faults according to claim 1, characterized in that, The dual-color LED matrix includes a first LED sub-matrix and a second LED sub-matrix connected in parallel. The first LED sub-matrix is ​​composed of multiple red LEDs connected in series, and the second LED sub-matrix is ​​composed of multiple blue LEDs connected in series.

5. The device for detecting DC grounding in photovoltaic modules and remotely notifying of faults according to claim 1, characterized in that, Each detection branch and comparator is also connected in parallel with a corresponding grounding capacitor.

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