Photovoltaic panel access detection circuit and device

Abstract

This utility model discloses a photovoltaic panel access detection circuit and device. The photovoltaic panel access detection circuit, connected between the photovoltaic panel and the rechargeable battery, includes a low-side switch module, a first voltage divider resistor R1, a second voltage divider resistor R2, and a protection module. The first terminal of the low-side switch module is connected to the negative input terminal of the photovoltaic panel and the first terminal of the second voltage divider resistor R2. The second terminal of the low-side switch module is connected to the negative terminal of the rechargeable battery. The second terminal of the second voltage divider resistor R2 is connected to the first terminal of the first voltage divider resistor R1 and the protection module. The second terminal of the first voltage divider resistor R1 is connected to the positive input terminal of the photovoltaic panel and the positive terminal of the rechargeable battery. This utility model, using components such as a low-side switch, voltage divider resistors, and a protection module, provides a highly efficient and reliable photovoltaic panel access detection circuit. It can not only monitor the input voltage of the photovoltaic panel but also automatically protect the battery and circuit through a clamping protection mechanism when the voltage is too high, ensuring the safe and stable operation of the entire system.

Description

Technical Field

[0001] This utility model relates to the field of detection circuit technology, and in particular to a photovoltaic panel access detection circuit and device. Background Technology

[0002] Photovoltaic (PV) energy storage is becoming increasingly popular. Typically, a high-side switch is used to connect the battery's main circuit to the PV system. In this case, because the battery's main circuit and the PV share a common ground, a simple resistor divider can be used to detect the voltage at the PV port, regardless of whether the high-side switch is closed or open, thus determining whether the PV is connected. However, high-side switches are usually expensive. Some low-cost products require the use of a low-side switch, with the PV directly charging the battery. In this application, when the low-side switch is closed, the PV negative terminal is also disconnected from the main circuit ground. Therefore, it is necessary to consider how to use a low-cost circuit to detect the PV connection. Utility Model Content

[0003] The main purpose of this invention is to provide a photovoltaic panel access detection circuit.

[0004] To achieve the above objectives, this utility model provides a photovoltaic panel access detection circuit connected between a photovoltaic panel and a rechargeable battery. The circuit includes a low-side switch module, a first voltage divider resistor R1, a second voltage divider resistor R2, and a protection module. The first terminal of the low-side switch module is connected to the negative input terminal of the photovoltaic panel and the first terminal of the second voltage divider resistor R2. The second terminal of the low-side switch module is connected to the negative terminal of the rechargeable battery. The second terminal of the second voltage divider resistor R2 is connected to the first terminal of the first voltage divider resistor R1 and the protection module. The second terminal of the first voltage divider resistor R1 is connected to the positive input terminal of the photovoltaic panel and the positive terminal of the rechargeable battery.

[0005] In the photovoltaic panel access detection circuit provided by this utility model, the ratio of the resistance value of the first voltage divider resistor R1 to the resistance value of the second voltage divider resistor R2 is greater than 10:1.

[0006] In the photovoltaic panel access detection circuit provided by this utility model, the protection module includes a diode D1, the negative terminal of the diode D1 is connected to the second end of the second voltage divider resistor R2, and the positive terminal of the diode D1 is grounded.

[0007] In the photovoltaic panel access detection circuit provided by this utility model, the protection module further includes a current-limiting resistor R3. The first end of the current-limiting resistor R3 is connected to the second end of the second voltage divider resistor R2, and the second end of the current-limiting resistor R3 is connected to the negative terminal of the diode D1.

[0008] In the photovoltaic panel access detection circuit provided by this utility model, the low-side switch module is an N-channel MOSFET or an NPN transistor.

[0009] According to another aspect of the present invention, a photovoltaic panel access detection device is also provided, including the photovoltaic panel access detection circuit and control chip as described above, wherein the control chip is connected to the protection module.

[0010] The photovoltaic panel connection detection circuit provided by this utility model has the following beneficial effects: This utility model uses components such as a low-side switch, voltage divider resistors, current-limiting resistors, and diodes to provide a high-efficiency and reliable photovoltaic panel connection detection circuit. It can not only monitor the input voltage of the photovoltaic panel, but also automatically protect the battery and circuit through a clamping protection mechanism when the voltage is too high, ensuring the safe and stable operation of the entire system. Through the design of the protection mechanism of diode D1 and current-limiting resistor R3, the circuit can automatically protect the battery and other circuit components when the input voltage of the photovoltaic panel is too high, avoiding damage. Through the configuration of the voltage divider resistors and current-limiting resistors, the circuit can accurately measure the input voltage of the photovoltaic panel, which is crucial for monitoring the health status of the photovoltaic power generation system. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0012] Figure 1 The diagram shown is a circuit diagram of a photovoltaic panel access detection circuit provided in an embodiment of this utility model. Detailed Implementation

[0013] To facilitate understanding of this utility model, a more complete description will be given below with reference to the accompanying drawings. The drawings illustrate typical embodiments of this utility model. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of this utility model more thorough and complete.

[0014] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0015] Figure 1The diagram shown is a circuit diagram of a photovoltaic panel access detection circuit according to an embodiment of this utility model. Figure 1 As shown, the photovoltaic panel access detection circuit provided by this invention is connected between the photovoltaic panel 100 and the rechargeable battery 200. It includes a low-side switch module 300, a first voltage divider resistor R1, a second voltage divider resistor R2, and a protection module. The first terminal of the low-side switch module 300 is connected to the negative input terminal of the photovoltaic panel 100 and the first terminal of the second voltage divider resistor R2. The second terminal of the low-side switch module 300 is connected to the negative terminal of the rechargeable battery 200. The second terminal of the second voltage divider resistor R2 is connected to the first terminal of the first voltage divider resistor R1 and the protection module. The second terminal of the first voltage divider resistor R1 is connected to the positive input terminal of the photovoltaic panel 100 and the positive terminal of the rechargeable battery 200. The protection module includes a diode D1 and a current-limiting resistor R3. The first terminal of the current-limiting resistor R3 is connected to the second terminal of the second voltage divider resistor R2, and the second terminal of the current-limiting resistor R3 is connected to the negative terminal of the diode D1. The positive terminal of the diode D1 is grounded.

[0016] In this embodiment, the low-side switch module is the key switching component of the circuit, employing a low-cost N-channel MOSFET or NPN transistor, responsible for controlling the connection between the photovoltaic panel and the rechargeable battery. By controlling the opening and closing of this switch, the current paths of the photovoltaic panel and the rechargeable battery can be effectively separated. Voltage divider resistors R1 and R2 are used to divide the input voltage (the voltage from the photovoltaic panel) to allow voltage measurements at different circuit nodes. The ratio of these resistors determines the voltage distribution of the circuit, thus aiding in the calculation of the input voltage to the photovoltaic panel. The protection module consists of diode D1 and current-limiting resistor R3. The main function of diode D1 is to provide overvoltage protection. When the input voltage is too high, the diode conducts, thereby protecting other components in the circuit from damage. Current-limiting resistor R3 is used to limit the magnitude of the current, preventing excessive current from damaging the circuit.

[0017] like Figure 1 As shown, when the low-side switch module 300 is disconnected, the current paths of the photovoltaic panel and the rechargeable battery are separated, and the current will not flow directly into the battery. In this state, the voltage of the photovoltaic panel forms a voltage distribution loop through two voltage divider resistors (R1 and R2). Specifically, loop I is formed from the positive input terminal of the photovoltaic panel 100 through the first voltage divider resistor R1 and the second voltage divider resistor R2 to the negative input terminal of the photovoltaic input panel 100, and loop II is formed from the positive terminal of the rechargeable battery 200 through the first voltage divider resistor R1, the current limiting resistor R3, and the diode D1.

[0018] For loop I, the voltage drop across the first voltage divider resistor R1 is shown in the following formula (1), where Vpv is the input voltage of the photovoltaic panel 100 and Vr1 is the voltage drop across the first voltage divider resistor R1.

[0019] Vr1 = Vpv * R1 / ( R1 + R2 ) (1)

[0020] For loop II, when diode D1 is not conducting...

[0021] Vdet = Vdiv = Vbat – Vr1 (2)

[0022] Where Vdet is the voltage at one end of the current-limiting resistor R3, Vdiv is the voltage at the other end of the current-limiting resistor R3, and Vbat is the battery voltage.

[0023] From formulas (1) and (2), we can obtain:

[0024] Vdet = Vbat–Vpv*R1 / (R1 + R2 ) (3)

[0025] Since the voltage Vdet at one end of the current-limiting resistor R3 and the battery voltage Vbat can be obtained by the ADC, and the first voltage divider resistor R1 and the second voltage divider resistor R2 are also known, the input voltage Vpv of the photovoltaic panel 100 can be obtained as shown in the following formula (4):

[0026] Vpv=(Vbat–Vdet)*(1+R2 / R1) (4).

[0027] Furthermore, in this embodiment, as shown in formula (3), if the input voltage of the photovoltaic panel 100 is too high, the voltage Vdet at one end of the current limiting resistor R3 will be negative. At this time, the diode D1 will be turned on to provide clamping protection.

[0028] Furthermore, in this embodiment, the ratio of the resistance of the first voltage divider resistor R1 to the resistance of the second voltage divider resistor R2 is greater than 10:1. When the resistance of the first voltage divider resistor R1 is more than 10 times greater than the resistance of the second voltage divider resistor R2, then when a sufficiently high input voltage of the photovoltaic panel 100 is connected, the voltage Vdet at one end of the current limiting resistor R3 will jump from the battery voltage Vbat to a very low level, which can be regarded as a low-level pulse, thereby waking up the control chip for detection.

[0029] This invention employs components such as a low-side switch, voltage divider resistors, current-limiting resistors, and diodes to provide a highly efficient and reliable photovoltaic panel connection detection circuit. It not only monitors the input voltage of the photovoltaic panel in real time but also automatically protects the battery and circuitry through a clamping protection mechanism when the voltage is too high, ensuring the safe and stable operation of the entire system. By designing the protection mechanism of diode D1 and current-limiting resistor R3, the circuit can automatically protect the battery and other circuit components from damage when the input voltage of the photovoltaic panel is too high. Through the configuration of the voltage divider resistors and current-limiting resistors, the circuit can accurately measure the input voltage of the photovoltaic panel, which is crucial for monitoring the health status of the photovoltaic power generation system.

[0030] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the present invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0031] Similarly, it should be understood that, in order to simplify this disclosure and aid in understanding one or more of the various aspects of the invention, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof. However, this method of disclosure should not be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the following claims, the inventive aspect lies in fewer than all features of a single foregoing disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of the invention.

[0032] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this invention and form different embodiments. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0033] It should be noted that the above embodiments are illustrative of the present invention and not restrictive, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.

Claims

1. A photovoltaic panel access detection circuit, connected between a photovoltaic panel (100) and a rechargeable battery (200), characterized in that, The device includes a low-side switch module (300), a first voltage divider resistor R1, a second voltage divider resistor R2, and a protection module. The first end of the low-side switch module (300) is connected to the negative input terminal of the photovoltaic panel (100) and the first end of the second voltage divider resistor R2. The second end of the low-side switch module (300) is connected to the negative terminal of the rechargeable battery (200). The second end of the second voltage divider resistor R2 is connected to the first end of the first voltage divider resistor R1 and the protection module. The second end of the first voltage divider resistor R1 is connected to the positive input terminal of the photovoltaic panel (100) and the positive terminal of the rechargeable battery (200).

2. The photovoltaic panel access detection circuit of claim 1, wherein, The ratio of the resistance of the first voltage divider resistor R1 to the resistance of the second voltage divider resistor R2 is greater than 10:

1.

3. The photovoltaic panel access detection circuit of claim 1, wherein, The protection module includes a diode D1, the negative terminal of which is connected to the second terminal of the second voltage divider resistor R2, and the positive terminal of which is grounded.

4. The photovoltaic panel access detection circuit of claim 3, wherein, The protection module also includes a current-limiting resistor R3, the first end of which is connected to the second end of the second voltage divider resistor R2, and the second end of which is connected to the negative terminal of the diode D1.

5. The photovoltaic panel access detection circuit of claim 1, wherein, The low-side switching module (300) is an N-channel MOSFET or an NPN transistor.

6. A photovoltaic panel access detection device, characterized in that, It includes a photovoltaic panel access detection circuit and a control chip as described in any one of claims 1-5, wherein the control chip is connected to the protection module.

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