A photovoltaic panel fault detection circuit

Abstract

The application discloses a photovoltaic panel fault detection circuit, and relates to the technical field of photovoltaic panel fault detection.The photovoltaic panel fault detection circuit comprises a diode, a photoelectric isolation module and a double NOT gate RC oscillator, the diode is connected in parallel across the photovoltaic panel, the first input end of the photoelectric isolation module is connected with the negative electrode of the diode, the second input end of the photoelectric isolation module is connected with the positive electrode of the diode, and the output end of the photoelectric isolation module is connected with the input end of the double NOT gate RC oscillator.Because the frequency signal can be transmitted at a long distance, maintenance personnel can detect the fault photovoltaic panel by measuring the frequency signal output by the double NOT gate RC oscillator.The circuit of the application can ensure that other photovoltaic panels connected in series with the fault photovoltaic panel are normally used during detection of the photovoltaic panel and during manual maintenance or replacement of the fault photovoltaic panel, and the manual detection speed and work efficiency are improved.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic panel fault detection technology, and in particular to a photovoltaic panel fault detection circuit. Background Technology

[0002] Desertified land is widely distributed, with long hours of sunshine and high solar radiation intensity, making it suitable for photovoltaic power generation. However, the complex environment of desert regions may cause various malfunctions in photovoltaic panels during operation, thereby affecting the power generation efficiency of photovoltaic power plants.

[0003] A photovoltaic power station consists of numerous photovoltaic modules, and its power generation efficiency is related to the working status of each module. Due to the complex environment in which photovoltaic arrays operate, various faults can occur during operation.

[0004] Solar cell modules are arranged in a specific way to better collect solar energy and improve its utilization rate. A common arrangement is a series-parallel structure of photovoltaic panels. When photovoltaic panels malfunction, it affects the output power of the photovoltaic power generation system and can also cause safety and reliability issues.

[0005] In addition, desert areas are geographically remote and have harsh environments, making it difficult for maintenance personnel to stay on-site for extended periods to inspect photovoltaic panel faults. Other scenarios prone to failure also need to be inspected to ensure efficient operation.

[0006] Therefore, it is essential to design a photovoltaic panel fault detection circuit that can determine faults by measuring circuit frequency, transmit data over long distances without being easily interfered with, and whose fault detection process does not affect the normal operation of other photovoltaic panels. Summary of the Invention

[0007] The purpose of this invention is to provide a photovoltaic panel fault detection circuit to solve the problems in the prior art that photovoltaic panels cannot be detected remotely and that non-faulty photovoltaic panels cannot work properly during the detection process.

[0008] To achieve the above objectives, the present invention provides the following solution:

[0009] A photovoltaic panel fault detection circuit includes: a diode, an opto-isolation module, and a double NOT gate RC oscillator; the diode is connected in parallel across the two ends of the photovoltaic panel, the first input terminal of the opto-isolation module is connected to the negative terminal of the diode, the second input terminal of the opto-isolation module is connected to the positive terminal of the diode, and the output terminal of the opto-isolation module is connected to the input terminal of the double NOT gate RC oscillator.

[0010] Optionally, the opto-isolation module includes a first optical coupler and a second optical coupler; the first input terminal of the first optical coupler is the first input terminal of the opto-isolation module, and the second input terminal of the second optical coupler is the second input terminal of the opto-isolation module.

[0011] The first input terminal of the first optocoupler is connected to the negative terminal of the diode, and the second input terminal of the first optocoupler is connected to the first input terminal of the second optocoupler; the second input terminal of the second optocoupler is connected to the positive terminal of the diode; the first output terminal of the first optocoupler, the second output terminal of the first optocoupler, the first output terminal of the second optocoupler, and the second output terminal of the second optocoupler are all connected to a double NOT gate RC oscillator.

[0012] Optionally, the double NOT gate RC oscillator includes: a first NOT gate, a second NOT gate, a first resistor, a second resistor, a third resistor, and a capacitor;

[0013] One end of the second resistor is connected to the first output terminal of the first optocoupler, the second output terminal of the second optocoupler, the output terminal of the first NOT gate, and the input terminal of the second NOT gate, respectively. The other end of the second resistor is connected to the second output terminal of the first optocoupler, the first output terminal of the second optocoupler, and one end of the third resistor, respectively.

[0014] One end of the first resistor is connected to the input of the first NOT gate, and the other end of the first resistor is connected to the other end of the third resistor and one end of the capacitor, respectively; the output of the second NOT gate is connected to the other end of the capacitor.

[0015] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0016] The photovoltaic panel fault detection circuit provided by this invention includes a diode, an opto-isolation module, and a double-NOT gate RC oscillator. The diode ensures that most of the fault current flows into the diode, protecting the opto-isolation module. The opto-isolation module converts the current signal into a light signal and then into a resistance signal. The double-NOT gate RC oscillator then converts the resistance signal into a frequency signal. Since the frequency signal can be transmitted over long distances, maintenance personnel can detect faulty photovoltaic panels by measuring the frequency. This circuit ensures the normal operation of other photovoltaic panels connected in series with the faulty photovoltaic panel during both the detection of the faulty panel and the manual repair or replacement of the faulty panel, improving the speed and efficiency of manual inspection. Attached Figure Description

[0017] Figure 1 A circuit diagram of the photovoltaic panel fault detection circuit provided by the present invention;

[0018] Figure 2 This is a schematic diagram showing the connection between the photovoltaic panel fault detection circuit and the photovoltaic panel provided by the present invention.

[0019] Symbol explanation: 1- Opto-isolation module, 2- Double NOT gate RC oscillator. Detailed Implementation

[0020] The purpose of this invention is to provide a photovoltaic panel fault detection circuit that converts current signals into light signals, then into resistance signals, and finally into frequency signals, and determines whether the photovoltaic panel is faulty by measuring the frequency of the circuit over a long distance.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] like Figure 1 As shown, the photovoltaic panel fault detection circuit provided by the present invention includes: diode D1, opto-isolation module 1, and double NOT gate RC oscillator 2.

[0023] Diode D1 is connected in parallel across the photovoltaic panel, enabling unidirectional conduction of the fault detection circuit. The first input terminal of opto-isolation module 1 is connected to the negative terminal of diode D1, the second input terminal is connected to the positive terminal of diode D1, and the output terminal is connected to the input terminal of the double NOT gate RC oscillator 2. Opto-isolation module 1 converts the current signal into an optical signal, and then converts the optical signal into a resistance signal; the double NOT gate RC oscillator 2 converts the resistance signal into a frequency signal fout. Unlike voltage, which suffers from attenuation, the frequency signal fout is less susceptible to interference and has the advantage of long-distance transmission.

[0024] Furthermore, the opto-isolation module 1 includes a first optical coupler Rx1 and a second optical coupler Rx2. The first input terminal of the first optical coupler Rx1 is the first input terminal of the opto-isolation module 1, and the second input terminal of the second optical coupler Rx2 is the second input terminal of the opto-isolation module 1.

[0025] The first input terminal of the first optocoupler Rx1 is connected to the negative terminal of diode D1, and the second input terminal of the first optocoupler Rx1 is connected to the first input terminal of the second optocoupler Rx2. The second input terminal of the second optocoupler Rx2 is connected to the positive terminal of diode D1. The first output terminal of the first optocoupler Rx1, the second output terminal of the first optocoupler Rx1, the first output terminal of the second optocoupler Rx2, and the second output terminal of the second optocoupler Rx2 are all connected to the double NOT gate RC oscillator 2. The symmetrical arrangement of the two optocouplers results in better waveform quality from the double NOT gate RC oscillator 2, with a duty cycle of approximately 50%. The output frequency signal fout is stable and has a wide adjustment range, improving the reliability and overall performance of subsequent detection of the frequency signal fout.

[0026] An optocoupler, composed of a light-emitting diode (LED) and a phototransistor, effectively blocks interference sources and reliably isolates signals to ensure detection stability. It is widely used in signal isolation within data transmission and acquisition systems. In this embodiment, both the first optocoupler Rx1 and the second optocoupler Rx2 are PC817 models, which offer good anti-interference performance and cost-effectiveness. The LED converts the current signal into an optical signal, and the phototransistor, upon receiving the optical signal, conducts and outputs current.

[0027] The anode of the LED in the first optocoupler Rx1 is its first input terminal, and the cathode is its second input terminal. The collector of the phototransistor in the first optocoupler Rx1 is its first output terminal, and the emitter is its second output terminal. Similarly, the anode of the LED in the second optocoupler Rx2 is its first input terminal, and the cathode is its second input terminal. The collector of the phototransistor in the second optocoupler Rx2 is its first output terminal, and the emitter is its second output terminal.

[0028] Furthermore, the dual-NOT gate RC oscillator 2 includes: a first NOT gate N1, a second NOT gate N2, a first resistor R1, a second resistor R2, a third resistor R3, and a capacitor C.

[0029] One end of the second resistor R2 is connected to the first output terminal of the first optocoupler Rx1, the second output terminal of the second optocoupler Rx2, the output terminal of the first NOT gate N1, and the input terminal of the second NOT gate N2. The other end of the second resistor R2 is connected to the second output terminal of the first optocoupler Rx1, the first output terminal of the second optocoupler Rx2, and one end of the third resistor R3. The input terminal of the second NOT gate N2 is the input terminal of the double NOT gate RC oscillator.

[0030] One end of the first resistor R1 is connected to the input terminal of the first NOT gate N1, and the other end of the first resistor R1 is connected to the other end of the third resistor R3 and one end of the capacitor C respectively; the output terminal of the second NOT gate N2 is connected to the other end of the capacitor C.

[0031] The function of the first resistor R1 is to stabilize the oscillation, and the function of the third resistor R3 is to eliminate waveform glitches. The frequency signal fout output from the output terminal of the second NOT gate N2 is related to the second resistor R2, the third resistor R3, and the capacitor C. Appropriately reducing the value of capacitor C increases the output frequency signal fout, which helps to improve the detection sensitivity and reduce errors.

[0032] like Figure 1 As shown, the photovoltaic panel fault detection circuit also includes a fourth resistor R4. One end of the fourth resistor R4 is connected to the positive terminal of the photovoltaic panel, and the other end is connected to the negative terminal of the diode D1. The fourth resistor R4 limits the current flowing into the photovoltaic panel fault detection circuit, preventing excessive current from damaging the light-emitting diode in the optocoupler. The fourth resistor R4 is a variable resistor.

[0033] like Figure 2 As shown, the photovoltaic panel fault detection circuit provided by this invention is installed in a series-connected photovoltaic array. Without affecting the operation of the photovoltaic array, the frequency of the fault detection circuit output can be detected sequentially, and the corresponding relative deviation of the photovoltaic panels can be calculated. This allows for rapid determination of whether a fault exists in the operating state of the photovoltaic panels, ultimately identifying the faulty photovoltaic panel. To prevent the fault current from impacting the photovoltaic panels when a fault occurs, each photovoltaic panel is connected in parallel with a bypass diode to receive most of the fault current.

[0034] The photovoltaic panel fault detection circuit provided by this invention has advantages such as simple design, low cost, and strong anti-interference ability. It has a wide range of applications and can be used for fault detection of indoor and outdoor photovoltaic arrays, providing valuable reference for photovoltaic panel fault detection. This invention can detect faulty photovoltaic panels while ensuring that photovoltaic panels connected in series with the faulty panel can function normally. During manual inspection or replacement of photovoltaic panels, the series circuit of the photovoltaic panels operates normally, improving the speed and efficiency of manual inspection.

[0035] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the circuit and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A photovoltaic panel fault detection circuit, characterized in that, include: Diodes, opto-isolation modules, and dual NOT gate RC oscillators; The diodes are connected in parallel across the photovoltaic panel. The first input terminal of the opto-isolation module is connected to the negative terminal of the diode, the second input terminal of the opto-isolation module is connected to the positive terminal of the diode, and the output terminal of the opto-isolation module is connected to the input terminal of the double NOT gate RC oscillator. The opto-isolation module includes a first optical coupler and a second optical coupler; the first input terminal of the first optical coupler is the first input terminal of the opto-isolation module, and the second input terminal of the second optical coupler is the second input terminal of the opto-isolation module. The first input terminal of the first optocoupler is connected to the negative terminal of the diode, and the second input terminal of the first optocoupler is connected to the first input terminal of the second optocoupler. The second input terminal of the second optocoupler is connected to the positive terminal of the diode; A double NOT gate RC oscillator includes: a first NOT gate, a second NOT gate, a first resistor, a second resistor, a third resistor, and a capacitor; One end of the second resistor is connected to the first output terminal of the first optocoupler, the second output terminal of the second optocoupler, the output terminal of the first NOT gate, and the input terminal of the second NOT gate, respectively. The other end of the second resistor is connected to the second output terminal of the first optocoupler, the first output terminal of the second optocoupler, and one end of the third resistor, respectively. One end of the first resistor is connected to the input of the first NOT gate, and the other end of the first resistor is connected to the other end of the third resistor and one end of the capacitor, respectively; the output of the second NOT gate is connected to the other end of the capacitor.

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