Photovoltaic panel fault intelligent detection circuit and instrument

Abstract

The utility model discloses a photovoltaic panel fault intelligent detection circuit and instrument, comprising a photovoltaic cell string current detection circuit, a voltage detection circuit, a temperature monitoring circuit, an insulation resistance detection circuit, a data acquisition and processing unit and a power supply management circuit which are connected with each other. The photovoltaic cell string current detection circuit is used for monitoring current of each string of photovoltaic cells, each string of photovoltaic cells is correspondingly provided with a Hall effect sensor, a shunt resistor and an amplifier, and the voltage detection circuit is used for monitoring open-circuit voltage and working voltage of a photovoltaic panel and comprises a high-impedance voltage follower and a differential amplifier. The temperature monitoring circuit is used for monitoring the surface temperature and the environment temperature of the photovoltaic panel in real time and comprises a thermocouple and a signal conditioning circuit, and the insulation resistance detection circuit is used for detecting the insulation performance of the photovoltaic panel and a connecting line of the photovoltaic panel, measuring the leakage current or impedance change of the photovoltaic panel and judging the insulation condition by applying high-voltage pulse or alternating-current voltage to a photovoltaic array.

Description

Technical Field

[0001] The utility model relates to the field of photovoltaic panel circuits, in particular to an intelligent photovoltaic panel fault detection circuit and an instrument. Background Art

[0002] As the global demand for sustainable energy continues to grow and environmental awareness increases, the application of solar energy as a clean, renewable energy form has received increasing attention. Solar photovoltaic power generation technology, especially the application of photovoltaic panels, has become one of the mainstream ways to convert sunlight into electrical energy, and is widely used in residential, commercial facilities and even large photovoltaic power stations. However, photovoltaic panels are exposed to outdoor environments for a long time and are easily affected by factors such as climate, pollution, physical damage, and aging, resulting in reduced efficiency or failure, affecting power generation efficiency.

[0003] Traditionally, fault detection of photovoltaic panels relies on regular manual visual inspection and manual testing, which is time-consuming and labor-intensive, and difficult to detect in real time, and cannot detect hidden problems in time. With the development of electronic technology, especially the advancement of sensors, microprocessors and communication technology, intelligent monitoring systems are gradually introduced into photovoltaic panel maintenance to achieve real-time monitoring and early warning of faults.

[0004] In this context, how to design an integrated, high-precision, automated, low-energy, and easy-to-maintain intelligent photovoltaic panel fault detection system has become an urgent need in the industry. The system needs to be able to capture the key parameters of photovoltaic panels in real time, such as current, voltage changes, temperature, insulation conditions, etc., and quickly identify anomalies through data analysis algorithms to guide maintenance and ensure the stable and efficient operation of the photovoltaic system. Therefore, the development of an intelligent photovoltaic panel fault detection system that integrates comprehensive current, voltage, temperature, insulation detection, data processing, and power management, as well as its technical solutions, is crucial to promoting the intelligent transformation and efficiency improvement of the photovoltaic energy industry. Utility Model Content

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] A photovoltaic panel fault intelligent detection circuit includes a connected photovoltaic cell string current detection circuit, a voltage detection circuit, a temperature monitoring circuit, an insulation resistance detection circuit, a data acquisition and processing unit, and a power management circuit. The photovoltaic cell string current detection circuit is used to monitor the current of each string of photovoltaic cells. Each string of photovoltaic cells is correspondingly configured with a Hall effect sensor, a shunt resistor, and an amplifier. The voltage detection circuit is used to monitor the open circuit voltage and working voltage of the photovoltaic panel, including a high impedance voltage follower and a differential amplifier. The temperature monitoring circuit is used to monitor the surface and ambient temperature of the photovoltaic panel in real time, including a thermocouple and a signal conditioning circuit. The insulation resistance detection circuit is used to detect the insulation performance of the photovoltaic panel and its connecting wires, and measures its leakage current or impedance change by applying a high voltage pulse or an AC voltage to the photovoltaic array to judge the insulation condition. The data acquisition and processing unit is used to collect signals from each detection circuit, and after preliminary processing, the data is sent to a control center. The power management circuit includes a voltage stabilizer, a DC-DC converter, and a battery charging management circuit.

[0007] Furthermore, the Hall effect sensor is installed near the negative terminal of the battery string, the shunt resistor is connected in series to the forward current path of the battery string, and the Hall effect sensor and the shunt resistor are electrically connected to the amplifier respectively.

[0008] Furthermore, the output wires of the Hall sensor and the shunt resistor are twisted pairs and equipped with a shielding layer, the shielding layer is grounded at the amplifier end, and a transient voltage suppression diode or an RC filter circuit is electrically connected to the front end of the input amplifier.

[0009] Furthermore, the data acquisition and processing unit includes a microcontroller, an analog-to-digital converter, and a digital signal processor. The data acquisition and processing unit adopts a 32-bit microcontroller, the analog-to-digital converter is a multi-channel high-speed ADC, and the digital signal processor is integrated in the microcontroller.

[0010] Furthermore, the communication interface adopts the Ethernet protocol, a Wi-Fi module interface is reserved, and the microcontroller is connected to the Ethernet controller or the Wi-Fi module via the SPI bus.

[0011] A photovoltaic panel fault intelligent detection instrument comprises a photovoltaic panel fault intelligent detection circuit.

[0012] Compared with the prior art, the beneficial effects of the utility model are as follows: This application proposes a technical solution of a photovoltaic panel fault intelligent detection circuit and instrument, which integrates multiple key components and circuits to form a complete monitoring system, aiming to monitor the operating status of photovoltaic panels in real time and quickly locate faults to ensure efficient and stable operation of the photovoltaic system. The following is an analysis of the main technical effects of the technical solution:

[0013] High precision and real-time performance:

[0014] The Hall effect sensor and shunt resistor are combined with a precision amplifier design to measure current directly on the battery string, reducing measurement errors. The high resolution and wide dynamic range of the analog-to-digital converter (ADC) ensure accurate capture of tiny signals, and the advanced algorithm analysis of the DSP enables instant identification and early warning of faults, improving system response speed and accuracy.

[0015] Comprehensiveness: The solution covers multiple dimensions such as current, voltage, temperature, insulation resistance and data processing, forming a comprehensive monitoring system. The voltage detection circuit uses a high-impedance amplifier to ensure that it does not interfere with the circuit. The temperature monitoring uses thermocouples to achieve real-time tracking of temperature changes. The insulation resistance detection uses pulse testing to determine the insulation performance, ensuring a comprehensive health status assessment of the photovoltaic panel.

[0016] Intelligence and remote management: The data acquisition and processing unit uses a high-performance microcontroller and integrated DSP to achieve complex data analysis and decision-making. Through the Ethernet or Wi-Fi communication interface, data is seamlessly transmitted to the remote control center or cloud platform, which facilitates real-time monitoring and strategy adjustment by operation and maintenance personnel, optimizes energy management, and improves operation and maintenance efficiency.

[0017] Low power consumption and durability: The power management circuit is designed with low power consumption in mind. The DC-DC converter and intelligent battery management ensure stable power supply under different lighting conditions. The low power mode is automatically activated when the light is insufficient, extending the system life and improving economy and environmental adaptability.

[0018] Easy maintenance and scalability: Modular design, such as the socket and connector of the communication interface, is convenient for quick replacement or upgrade. 2 The C / CAN bus facilitates expansion or module replacement and upgrading, which enhances system flexibility and maintenance convenience and reduces future maintenance costs.

[0019] Electromagnetic compatibility and protection: The system design complies with EMC standards, layout and wiring rules, and anti-electromagnetic interference. The addition of protection components such as TVS tubes and filter circuits ensures that the system operates stably in complex electromagnetic environments, does not interfere with photovoltaic panel power generation, and improves the reliability and safety of the overall system.

[0020] In summary, the technical solution of this application provides an advanced solution for photovoltaic panel fault detection and management through a comprehensive, intelligent, efficient, low-power, remote monitoring and maintenance-friendly design, thereby improving the efficiency, reliability and convenience of operation and maintenance of the photovoltaic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the circuit diagram of this application. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] The present application provides an intelligent photovoltaic panel fault detection circuit, the main goal of which is to achieve real-time monitoring of the operating status of the photovoltaic panel, timely discover and locate faults, and ensure efficient and stable operation of the photovoltaic system.

[0024] The present application provides a photovoltaic panel fault intelligent detection circuit, such as Figure 1 , including a connected photovoltaic cell string current detection circuit, a voltage detection circuit, a temperature monitoring circuit, an insulation resistance detection circuit, a data acquisition and processing unit, and a power management circuit.

[0025] Photovoltaic cell string current detection circuit:

[0026] Function: Monitor the current of each string of photovoltaic cells, because the change of current can directly reflect the working status of the battery, such as shading, damage and other faults.

[0027] Composition: Hall effect sensor and shunt resistor are equipped with precision amplifier to measure current. Hall sensor is non-contact measurement, which reduces system interference, while shunt resistor is low cost but needs to consider heating problem.

[0028] The Hall effect sensor is directly mounted near the negative terminal of the battery string, and detects the change in the magnetic field generated by the current flowing through the battery string without contact. The weak voltage signal output by the Hall effect sensor is transmitted to the precision amplifier connected to it through a low-noise shielded line. The amplifier is set with appropriate gain to amplify the millivolt signal of the Hall sensor to a voltage level suitable for processing by the analog-to-digital converter (ADC) while maintaining the high quality and integrity of the signal.

[0029] The shunt resistor is connected in series in the forward current path of the battery string. Due to its low resistance, it has little effect on the overall voltage of the battery string, but it is enough to produce a voltage drop proportional to the current when the current passes through. This voltage drop is also sent to the pre-amplifier for amplification to ensure that the ADC can accurately read and convert it into a digital signal.

[0030] In the actual wiring connection, in order to reduce the impact of electromagnetic interference (EMI) on the measurement accuracy, all sensitive signal lines, including the output lines of the Hall sensor and the shunt resistor, should use twisted pairs and be equipped with a shielding layer. The shielding layer is grounded at the amplifier end to form an effective electromagnetic shielding. At the same time, in order to prevent external voltage spikes or transient currents from damaging the circuit, a transient voltage suppression diode (TVS) or RC filter circuit can be added to the front end of the input amplifier as a protective measure.

[0031] In terms of overall layout, the Hall effect sensor, shunt resistor, and amplifier are tightly and orderly arranged on a customized PCB board to ensure the stability of electrical connections and the efficiency of signal transmission, while taking into account the requirements of heat dissipation and mechanical strength to ensure long-term stable and reliable operation.

[0032] Voltage detection circuit:

[0033] Function: Monitor the open circuit voltage and working voltage of the photovoltaic panel. Abnormal voltage also indicates the existence of a fault.

[0034] Composition: High impedance voltage follower and differential amplifier are used to accurately measure voltage values ​​to avoid loading the circuit.

[0035] Temperature monitoring circuit:

[0036] Function: The temperature of photovoltaic panels directly affects their efficiency and lifespan. Overheating may cause performance degradation or damage. This circuit is used to monitor the surface and ambient temperature of photovoltaic panels in real time.

[0037] Composition: Use thermocouples or thermistors with appropriate signal conditioning circuits to convert temperature changes into electrical signals.

[0038] Insulation resistance detection circuit:

[0039] Function: Detect the insulation performance of photovoltaic panels and their connecting wires to prevent leakage and short circuit faults.

[0040] Composition: High voltage pulses or AC voltage are applied to the photovoltaic array to measure its leakage current or impedance change to determine the insulation condition.

[0041] Data acquisition and processing unit:

[0042] Function: Collect the signals from the above detection circuits, perform preliminary processing (such as filtering, amplification, A / D conversion), and then send the data to the control center.

[0043] Composition: microcontroller (such as ARM Cortex-M series), analog-to-digital converter (ADC), digital signal processor (DSP) or field programmable gate array (FPGA), etc., selected according to the accuracy and complexity requirements.

[0044] Communication interface:

[0045] Function: Transmit the processed data to the remote monitoring system or cloud platform for centralized management and fault alarm.

[0046] Power management circuit:

[0047] Function: Provide stable power supply for the entire detection system. If necessary, it must also have energy recovery function, using the photovoltaic panel's own output to power the system.

[0048] Composition: including voltage regulator, DC-DC converter, battery charging management circuit, etc.

[0049] In a specific embodiment, in the connection between these circuits, the current and voltage detection circuits should be as close to the measured point as possible to reduce the measurement error.

[0050] The data acquisition and processing unit acts as a center and communicates with each detection module through a bus or point-to-point connection.

[0051] The communication interface should be designed to be modular to facilitate system upgrades or maintenance.

[0052] The power management circuit should ensure stable power supply to all components, while considering low power consumption design to extend system battery life.

[0053] The core component of the data acquisition and processing unit adopts a high-performance 32-bit microcontroller with a multi-channel high-speed ADC (analog-to-digital converter), which can simultaneously and parallelly process analog signals from the photovoltaic cell string current detection circuit, voltage detection circuit, temperature monitoring circuit and insulation resistance detection circuit. The microcontroller has a built-in large-capacity Flash memory to save the collected historical data, and is equipped with sufficient RAM to support the operation of complex algorithms to ensure the efficiency and accuracy of data processing.

[0054] The analog-to-digital converter (ADC) has high resolution (such as 24 bits) and wide dynamic range, ensuring accurate capture of tiny current changes and voltage fluctuations, while adapting to the conversion requirements of weak electrical signals output by thermocouples at different ambient temperatures. The ADC uses multiplexing technology to sample the data of each detection point in turn, achieving comprehensive and detailed monitoring of the entire photovoltaic panel system.

[0055] The digital signal processor (DSP) is integrated into the microcontroller or exists as an independent chip, responsible for executing advanced data analysis and fault diagnosis algorithms. The DSP uses mathematical tools such as fast Fourier transform (FFT) to perform spectrum analysis on the collected time series data, promptly identify potential current harmonics, voltage fluctuations and other problems, and evaluate the impact of temperature changes on photovoltaic efficiency through statistical analysis methods. In addition, the DSP also performs in-depth analysis of the insulation resistance test results, and accurately determines whether the insulation state is degraded by comparing historical data and threshold settings.

[0056] In order to enhance the scalability and remote monitoring capabilities of the system, the communication interface adopts the industrial standard Ethernet protocol and supports TCP / IP communication to ensure the stability and high speed of data transmission. At the same time, in order to adapt to different application scenarios, a Wi-Fi module interface is reserved to facilitate rapid deployment and maintenance in a wireless network environment. The microcontroller is connected to the Ethernet controller or Wi-Fi module through the SPI bus to achieve seamless data interaction with the control center or cloud platform, so that operation and maintenance personnel can remotely monitor the working status of the photovoltaic panels in real time, respond to fault warnings in a timely manner, and optimize energy management strategies.

[0057] In the data acquisition and processing unit, the connection relationship between the various parts is as follows:

[0058] Connection between microcontroller and analog-to-digital converter (ADC): The microcontroller is connected to the corresponding channel of the analog-to-digital converter through its built-in multiplexer control port to realize the sequential sampling of analog signals from the photovoltaic cell string current detection circuit, voltage detection circuit, temperature monitoring circuit and insulation resistance detection circuit. The conversion end signal of the ADC is connected to the microcontroller through the interrupt pin. Once the ADC completes a conversion, it notifies the microcontroller to read the data, thereby ensuring the efficiency and real-time performance of data acquisition.

[0059] Connection between analog-to-digital converter (ADC) and amplifier: The output of the amplifier is directly connected to the input of the analog-to-digital converter. In the design, the gain and offset settings of the amplifier are carefully calculated according to the different signal characteristics of the Hall effect sensor and the shunt resistor output to ensure that the signal received by the ADC is neither overloaded nor lower than its minimum resolvable voltage, thereby optimizing the dynamic range and measurement accuracy.

[0060] Integration of digital signal processor (DSP) and microcontroller: In this solution, the functions of digital signal processor are integrated into 32-bit microcontroller, and complex algorithm processing such as filtering, trend analysis, fault diagnosis logic, etc. is realized through software programming. The program executed by the microcontroller contains DSP algorithm module, which processes the signal collected and digitized by ADC, and completes functions such as data analysis, feature extraction and abnormality identification.

[0061] Communication interface connection: The microcontroller is connected to the Ethernet controller or Wi-Fi module through its SPI interface. When Ethernet communication is selected, the SPI port of the microcontroller is connected to the corresponding pin of the Ethernet controller to control the sending and receiving of data packets; if the Wi-Fi module is used, the Wi-Fi module exchanges data with the microcontroller through the SPI interface to achieve wireless network communication. To ensure the reliability and security of data transmission, a standard network protocol stack is used during the communication process, and encryption mechanisms such as WPA2 or higher-level security protocols can be set.

[0062] This connection relationship ensures that the entire process from sensor signal acquisition, preprocessing, data conversion, complex analysis to remote transmission runs efficiently and stably, providing a solid technical foundation for intelligent detection of photovoltaic panel faults.

[0063] The design of the current and voltage detection circuits must be installed close to the photovoltaic cell string and bus connection point, and connected with milliohm-level low-resistance wires to reduce line voltage drop and signal attenuation to ensure the accuracy of the measurement results. To increase flexibility and maintainability, all detection circuits and data acquisition and processing units use industrial standard I 2 C or CAN bus communication protocol to achieve efficient data exchange between modules, while facilitating future system expansion or replacement and upgrade of individual modules.

[0064] The communication interface module is designed with plug-in sockets or connectors to support fast switching or upgrading of Ethernet and Wi-Fi modules, ensuring that the communication needs of the system in different application scenarios are flexibly met. The modular design not only simplifies on-site maintenance work, but also facilitates the future iteration of the system's communication technology.

[0065] In terms of power management circuits, high-efficiency DC-DC converters (such as synchronous step-down converters) are integrated to ensure stable output over a wide input voltage range. At the same time, combined with low-power design ideas, components with extremely low power consumption in sleep mode and intelligent power management algorithms are selected to enable the system to automatically enter low-power mode when there is insufficient light or no light, thereby maximizing the service life of the built-in battery or supercapacitor.

[0066] The present application also provides a photovoltaic panel fault intelligent detection instrument, including a photovoltaic panel fault intelligent detection circuit.

[0067] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A photovoltaic panel fault intelligent detection circuit, characterized in that: It includes a connected photovoltaic cell string current detection circuit, a voltage detection circuit, a temperature monitoring circuit, an insulation resistance detection circuit, a data acquisition and processing unit, and a power management circuit. The photovoltaic cell string current detection circuit is used to monitor the current of each string of photovoltaic cells. Each string of photovoltaic cells is correspondingly configured with a Hall effect sensor, a shunt resistor, and an amplifier. The voltage detection circuit is used to monitor the open circuit voltage and working voltage of the photovoltaic panel, including a high-impedance voltage follower and a differential amplifier. The temperature monitoring circuit is used to monitor the surface and ambient temperature of the photovoltaic panel in real time, including a thermocouple and a signal conditioning circuit. The insulation resistance detection circuit is used to detect the insulation performance of the photovoltaic panel and its connecting wires. By applying high-voltage pulses or AC voltage to the photovoltaic array, its leakage current or impedance change is measured to determine the insulation condition. The data acquisition and processing unit is used to collect signals from each detection circuit, and after preliminary processing, the data is sent to the control center. The power management circuit includes a voltage stabilizer, a DC-DC converter, and a battery charging management circuit.

2. A photovoltaic panel fault intelligent detection circuit according to claim 1, characterized in that: The Hall effect sensor is installed near the negative terminal of the battery string, the shunt resistor is connected in series to the forward current path of the battery string, and the Hall effect sensor and the shunt resistor are electrically connected to the amplifier respectively.

3. A photovoltaic panel fault intelligent detection circuit according to claim 1, characterized in that: The output wires of the Hall sensor and the shunt resistor are twisted pairs and equipped with a shielding layer, the shielding layer is grounded at the amplifier end, and a transient voltage suppression diode or an RC filtering circuit is electrically connected to the front end of the input amplifier.

4. A photovoltaic panel fault intelligent detection circuit according to claim 1, characterized in that: The data acquisition and processing unit comprises a microcontroller, an analog-to-digital converter, and a digital signal processor. The data acquisition and processing unit adopts a 32-bit microcontroller, the analog-to-digital converter is a multi-channel high-speed ADC, and the digital signal processor is integrated in the microcontroller.

5. A photovoltaic panel fault intelligent detection circuit according to claim 1, characterized in that: The communication interface adopts Ethernet protocol, and a Wi-Fi module interface is reserved. The microcontroller is connected to the Ethernet controller or Wi-Fi module through the SPI bus.

6. A photovoltaic panel fault intelligent detection instrument, characterized in that: It comprises a photovoltaic panel fault intelligent detection circuit as described in claim 1.

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