Photovoltaic system undervoltage control circuit and photovoltaic system circuit

Abstract

The utility model provides a photovoltaic system undervoltage control circuit and a photovoltaic system circuit. The undervoltage control circuit of the photovoltaic system comprises an output voltage monitoring circuit, a control logic circuit and a compensation power supply circuit, the output voltage monitoring circuit is connected with the control logic circuit, the control logic circuit is connected with the compensation power supply circuit, the output voltage monitoring circuit is used for monitoring the output voltage of a photovoltaic (PV) system in real time and sending a voltage signal to the control logic circuit, and the control logic circuit triggers the compensation power supply circuit to work according to the voltage signal. And the output voltage of the system is controlled and adjusted through the filtering, voltage division or current limiting work of the compensation power supply circuit. According to the invention, the under-voltage state of the PV system can be simply and efficiently adjusted, and the working stability of the photovoltaic system is improved.

Description

Technical Field

[0001] This application relates to the field of photovoltaic power generation technology, and in particular to an undervoltage control circuit for a photovoltaic system and a photovoltaic system circuit. Background Technology

[0002] Photovoltaic (PV) power generation is a technology that directly converts light energy into electrical energy using the photovoltaic effect at semiconductor interfaces. It mainly consists of three parts: solar panels (modules), controllers, and inverters, with its main components being electronic devices. In a photovoltaic power generation system, factors such as weather conditions, shading effects, and solar panel aging can cause a drop in the output voltage of the photovoltaic panels. When the output voltage of the photovoltaic panels fluctuates around the driving voltage, it affects the performance of the entire power generation system.

[0003] Therefore, in order to solve the above problems, it is necessary to design a PV undervoltage control circuit to improve the output performance in the low voltage region; however, no very simple and efficient control circuit has been found in the related technology to adjust the undervoltage state of the PV system. Utility Model Content

[0004] This application addresses the aforementioned deficiencies in the prior art by providing a photovoltaic system undervoltage control circuit and a photovoltaic system circuit.

[0005] According to one aspect of this application, a photovoltaic system undervoltage control circuit is provided, comprising:

[0006] Output voltage monitoring circuit module, control logic circuit module, and compensation power supply circuit module;

[0007] The output voltage monitoring circuit is connected to the logic control circuit, and the logic control circuit is connected to the compensation power supply circuit. The output voltage monitoring circuit is used to monitor the output voltage of the photovoltaic (PV) system in real time and send a voltage signal to the control logic circuit. The control logic triggers the compensation power supply circuit to work according to the voltage signal, and controls and adjusts the system output voltage through the filtering, voltage division or current limiting work of the compensation power supply circuit.

[0008] In an optional embodiment of the first aspect of this application, the output voltage monitoring circuit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, and an eighth resistor, as well as a second fast diode, a third fast diode, and a first Zener diode; the control logic circuit includes a second Zener diode and a control chip, the sixth resistor is connected to a pin of the control chip; one end of the fourth resistor is connected to the PV voltage input terminal.

[0009] In an optional embodiment of the first aspect of this application, the above-mentioned compensation voltage circuit includes: an eighth resistor, a third fast diode, and a first fast diode.

[0010] Secondly, this application provides a photovoltaic system circuit, including a photovoltaic circuit module, wherein the PV input voltage terminal of the photovoltaic circuit module is connected to the photovoltaic system undervoltage control circuit described in any of the first aspects above.

[0011] This application provides an undervoltage control circuit and a photovoltaic system circuit for a photovoltaic system. The undervoltage control circuit includes an output voltage monitoring circuit module, a control logic circuit module, and a compensation power supply circuit module. The output voltage monitoring circuit is connected to the logic control circuit, and the control logic circuit is connected to the compensation power supply circuit. The output voltage monitoring circuit monitors the output voltage of the photovoltaic (PV) system in real time and sends a voltage signal to the control logic circuit. The control logic circuit triggers the compensation power supply circuit to operate based on the voltage signal, and controls and regulates the system output voltage through filtering, voltage division, or current limiting by the compensation power supply circuit. This photovoltaic system undervoltage control circuit improves the system's performance under low voltage conditions, increases the reliability and efficiency of the entire system, and has the advantages of simplicity, high efficiency, low cost, and wide applicability. Attached Figure Description

[0012] Other features, objects, and advantages of this invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0013] Figure 1 This is a schematic diagram of the structure of an undervoltage control circuit for a photovoltaic system according to an embodiment of the present invention;

[0014] Figure 2 This is a schematic diagram of the structure of an undervoltage control circuit for a photovoltaic system in a specific embodiment of this utility model;

[0015] Figure 3 This is a schematic diagram of the PV control principle of an undervoltage control circuit for a photovoltaic system in a specific embodiment of this utility model;

[0016] Figure 4 This is a schematic diagram of the hysteresis feedback principle of an undervoltage control circuit for a photovoltaic system in a specific embodiment of this utility model. Detailed Implementation

[0017] In photovoltaic (PV) power generation systems, factors such as weather conditions, shading effects, and solar panel aging can cause a drop in PV panel output voltage. When the PV panel output voltage fluctuates around the drive voltage, it affects the performance of the entire power generation system. To address this issue, a PV undervoltage control circuit needs to be designed to improve output performance in the low-voltage region.

[0018] The purpose of this invention is to provide a PV undervoltage control circuit. It addresses the shortcomings of existing PV undervoltage control systems through in-depth research, thereby improving system performance under low voltage conditions and increasing the overall system reliability and efficiency. The technical solution of this application will be described in detail below through specific embodiments.

[0019] Reference Figure 1 The embodiment shown provides an undervoltage control circuit for a photovoltaic system, including: an output voltage monitoring circuit, a control logic circuit, and a compensation power supply circuit.

[0020] The aforementioned output voltage monitoring circuit is connected to a logic control circuit, which in turn is connected to a compensation power supply circuit. The output voltage monitoring circuit monitors the output voltage of the photovoltaic (PV) system in real time and sends a voltage signal to the control logic circuit. The control logic circuit then triggers the compensation power supply circuit to operate based on this voltage signal. The compensation power supply circuit then controls and regulates the output voltage of the PV system through filtering, voltage division, or current limiting to achieve voltage stabilization.

[0021] Reference Figure 2 In one specific embodiment shown, the output voltage monitoring circuit of the photovoltaic system undervoltage control circuit includes: a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and an eighth resistor R8, as well as a second fast diode D2, a third fast diode D3, and a first Zener diode D1. The circuit composed of R1, R2, R3, R4, R5, R6, R8, and the fast diodes D2, D3, and Zener diode D1 monitors the output voltage of the photovoltaic (PV) system in real time. When the output voltage is lower than a set threshold, this part of the circuit sends a signal. Next, after receiving the signal from the voltage detection part, the control logic circuit determines whether a compensation mechanism needs to be activated. Once the control logic circuit activates the compensation mechanism, the compensation power supply circuit begins to operate.

[0022] Specifically, refer to Figure 3 In one specific embodiment shown, when the PV input is less than a set threshold, diode D1 is cut off, the first transistor Q1 is not conducting, and the second transistor Q2 is conducting, causing comp to be at a low level with no signal. However, when the PV input is greater than the set threshold, the first Zener diode D1 breaks down in reverse, causing the first transistor Q1 to conduct, thus causing the second transistor Q2 to be at a low level and not conducting. The chip's comp pin outputs a signal, enabling the chip to start working, and the auxiliary power supply starts working, outputting +12V and +5V voltages.

[0023] The aforementioned control logic circuit includes a first Zener diode and a control chip. The sixth resistor R6 is connected to a pin of the control chip. One end of the fourth resistor R4 is connected to the PV voltage input terminal.

[0024] In one embodiment of this application, the above-mentioned compensation voltage circuit includes: an eighth resistor R8, a third fast diode, and a first fast diode.

[0025] Specifically, refer to Figure 4 In one specific embodiment shown, the auxiliary power supply +12V output is connected to the negative terminal of the first Zener diode D1 via a third fast diode D3. When the PV output fluctuates near a set threshold, the first Zener diode D1 remains in reverse breakdown, achieving stable operation during voltage fluctuations. When the voltage remains below the set threshold, the voltage across the first Zener diode D1 drops, pausing reverse conduction and turning off the first transistor Q1. At this time, the second transistor Q2 receives an electrical signal that brings its comp pin low, thereby stopping the auxiliary power supply from operating.

[0026] In summary, this utility model discloses a PV undervoltage control circuit, including a Zener diode D1, fast recovery diodes D2 and D3, transistors Q1 and Q2, and capacitor C1. Q1 is controlled to conduct via resistors R1, R2, R3, C1, and D1, achieving a switching function; Q2 is controlled to conduct via resistors R4, R5, D2, and R6, achieving a switching function. Furthermore, D1 is controlled via an auxiliary power supply (+12V), resistors R8, and D3 to achieve undervoltage control. The circuit input is connected to the PV circuit, and the output sends a signal to the driver chip to activate the auxiliary power supply. The auxiliary power supply outputs 12V and 5V. The 12V circuit is connected to the negative terminal of the Zener diode D1 via diode D3, enabling the entire circuit to achieve PV undervoltage control and ensuring stable output of the entire system.

[0027] In a specific embodiment, a PV input threshold is set. When the PV input exceeds the threshold, the auxiliary power supply starts normally, outputting 12V and 5V. When the PV input voltage fluctuates around the set threshold, without a PV undervoltage control circuit, the overall system performance will be affected when the input voltage falls below the set threshold voltage, leading to reduced power generation efficiency, system instability, or even shutdown. With the addition of feedback compensation, the 12V output of the auxiliary power supply is connected to D3 to achieve feedback regulation, ensuring normal system output even when the PV input fluctuates around the set threshold. Therefore, this embodiment effectively ensures stable system operation and efficient power generation.

[0028] In another specific embodiment of this application, a photovoltaic system circuit is also provided, including a photovoltaic circuit module, wherein the PV input voltage terminal of the photovoltaic circuit module is connected to the photovoltaic system undervoltage control circuit described in any of the above embodiments. This photovoltaic system circuit possesses highly efficient and stable operation capabilities.

[0029] The specific embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the substantive content of this utility model.

Claims

1. An undervoltage control circuit for a photovoltaic system, characterized in that, include: Output voltage monitoring circuit, control logic circuit, and compensation power supply circuit; The output voltage monitoring circuit is connected to the control logic circuit, and the control logic circuit is connected to the compensation power supply circuit. The output voltage monitoring circuit is used to monitor the output voltage of the photovoltaic (PV) system in real time and send a voltage signal to the control logic circuit. The control logic circuit triggers the compensation power supply circuit to work according to the voltage signal, and controls and adjusts the system output voltage through the filtering, voltage division or current limiting work of the compensation power supply circuit.

2. The circuit according to claim 1, characterized in that, The output voltage monitoring circuit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, and an eighth resistor, as well as a second fast diode, a third fast diode, and a first Zener diode; the control logic circuit includes a second Zener diode and a control chip, the sixth resistor is connected to a pin of the control chip; one end of the fourth resistor is connected to the PV voltage input terminal.

3. The circuit according to claim 1 or 2, characterized in that, The compensation power supply circuit includes: an eighth resistor, a third fast diode, and a first fast diode.

4. A photovoltaic system circuit, comprising a photovoltaic circuit module, characterized in that, The PV input voltage terminal of the photovoltaic circuit module is connected to the circuit described in any one of claims 1-3.

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