Voltage regulation circuit and photovoltaic power generation system
By designing a voltage regulation circuit in the photovoltaic power generation system and adjusting the shutdown output voltage, the problem of unstable shutdown output voltage caused by the change in the number of photovoltaic components is solved, and the safety and detection accuracy of the system are improved.
Patent Information
- Application Number
- CN202421503127.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-27
- Publication Date
- 2025-05-23
- Estimated Expiration
- 2034-06-27
AI Technical Summary
In existing photovoltaic power generation systems, the shutdown voltage of the photovoltaic power optimizer is fixed, resulting in the shutdown output voltage between the positive electrode and the negative electrode at the output terminal when the number of photovoltaic modules is too high or too low, which poses safety hazards and low detection accuracy.
Design a voltage regulation circuit, including a shutdown voltage output circuit, a voltage sampling circuit and a control circuit, and control circuit, by adjusting the power supply voltage to control the shutdown output voltage, ensuring that it is within the preset range, avoiding the problem of excessive or low shutdown voltage.
It improves the safety and detection accuracy of the photovoltaic power generation system, ensures that the shutdown output voltage is within a controllable range under different number of photovoltaic components, reducing the risk during detection and improving the accuracy of detection.
Smart Images
Figure CN222897233U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of photovoltaic power generation technology, and in particular to a voltage regulation circuit and a photovoltaic power generation system. Background Art
[0002] For photovoltaic optimizers, photovoltaic shut-off devices and other related products, information such as output impedance and shut-off output voltage in the shutdown state is particularly important for construction, fault detection, etc. In the assembly process of the photovoltaic power generation system, after the photovoltaic components and photovoltaic optimizers in each photovoltaic array are connected, the positive output terminal and the negative output terminal of each photovoltaic array need to be connected to the inverter. Since the photovoltaic power generation system usually includes multiple photovoltaic arrays, it usually has multiple positive output terminals and negative output terminals. In the prior art, the shut-off output voltage between the positive output terminal of any photovoltaic array and the negative output terminal of any photovoltaic array is usually measured to determine whether the two are the output terminals of the same photovoltaic array. For example, if the shut-off output voltage of a photovoltaic power optimizer is 1V, and a photovoltaic array includes 30 photovoltaic power optimizers, that is, by detecting whether the shut-off output voltage between the positive output terminal of any photovoltaic array and the negative output terminal of any photovoltaic array is 30V, it can be determined whether the two are the output terminals of the same photovoltaic array.
[0003] However, in the prior art, the turn-off voltage of the photovoltaic power optimizer is a fixed value. When there are too many photovoltaic power optimizers in a photovoltaic module, the turn-off output voltage between the positive and negative output terminals is too high, resulting in a high risk during detection. When there are too few photovoltaic power optimizers in a photovoltaic module, the turn-off output voltage between the positive and negative output terminals is too low, making it difficult to accurately detect the turn-off output voltage. Utility Model Content
[0004] In order to solve the deficiencies of the prior art, the purpose of the present application is to provide a voltage regulation circuit and a photovoltaic power generation system with high safety and accuracy.
[0005] To achieve the above objectives, this application adopts the following technical solutions:
[0006] A voltage regulating circuit is applied to a photovoltaic power generation system. The photovoltaic power generation system includes a photovoltaic power optimizer and a power supply circuit for providing a power supply voltage. The voltage regulating circuit includes a shutoff voltage output circuit, a voltage sampling circuit and a control circuit. The shutoff voltage output circuit is respectively connected to the output ends of the power supply circuit and the photovoltaic power optimizer. The shutoff voltage output circuit is used to obtain the power supply voltage and adjust the power supply voltage to a shutoff output voltage before outputting it to the output end of the photovoltaic power optimizer. The voltage sampling circuit is connected to the output end of the photovoltaic power optimizer. The voltage sampling circuit is used to obtain the shutoff output voltage. The control circuit is respectively electrically connected to the shutoff voltage output circuit and the voltage sampling circuit. The control circuit is used to receive the shutoff output voltage and generate a control signal according to the shutoff output voltage. The shutoff voltage output circuit receives the control signal to adjust the power supply voltage.
[0007] Further, the shutdown voltage output circuit includes a first voltage-dividing resistor, a second voltage-dividing resistor, a third voltage-dividing resistor and a switch tube, the first end of the first voltage-dividing resistor is connected to the power supply circuit, and the second end of the first voltage-dividing resistor is connected to the output end of the photovoltaic power optimizer;
[0008] The control end of the switch tube is connected to the control circuit, one end of the switch tube is connected to the second end of the first voltage-dividing resistor, the other end of the switch tube is connected to one end of the second voltage-dividing resistor, one end of the third voltage-dividing resistor is connected to the other end of the second voltage-dividing resistor, the other end of the third voltage-dividing resistor is connected to the second end of the first voltage-dividing resistor, and the common end of the third voltage-dividing resistor and the second voltage-dividing resistor is grounded. The switch tube is used to receive a control signal to adjust its own conduction duty cycle to adjust the supply voltage.
[0009] Furthermore, the shutdown voltage output circuit also includes an isolation unit, through which the shutdown voltage output circuit is connected to the output end of the photovoltaic power optimizer and / or grounded, and the isolation unit is used to isolate the output current of the photovoltaic power optimizer to the shutdown voltage output circuit.
[0010] Furthermore, the isolation unit includes a first diode and a second diode, the first diode unidirectionally conducts and shuts off the output voltage, the anode of the second diode is connected to the common end of the third voltage-dividing resistor and the second voltage-dividing resistor, and the cathode of the second diode is grounded.
[0011] Furthermore, the shutdown voltage output circuit also includes a voltage drop resistor and a pull-down resistor, the two ends of the voltage drop resistor are respectively connected to the control circuit and the control end of the switch tube, and the two ends of the pull-down resistor are respectively connected to the control end of the switch tube and the reference ground; the voltage drop resistor is used to reduce the voltage value of the control signal output by the control circuit, and the pull-down resistor is used to keep the control end of the switch tube at a low level.
[0012] Furthermore, the shutdown voltage output circuit also includes a first filter capacitor, two ends of which are respectively connected to the second end of the first voltage divider resistor and the reference ground, and the first filter capacitor is used to reduce the ripple of the shutdown output voltage output by the shutdown voltage output circuit.
[0013] Furthermore, the first voltage-dividing resistor includes a first regulating resistor and a second regulating resistor, two ends of the first regulating resistor are respectively connected to the power supply circuit and the output end of the photovoltaic power optimizer, and the second regulating resistor is connected in parallel with the first regulating resistor.
[0014] Furthermore, the voltage sampling circuit includes a filtering unit and an operational amplifier, wherein two ends of the filtering unit are respectively connected to the output end of the photovoltaic power optimizer and the output end of the operational amplifier, and the input end of the operational amplifier is connected to the control circuit. The filtering unit is used to receive the shutdown output voltage and filter out the DC component and high-order harmonics of the shutdown output voltage. The operational amplifier is used to receive the filtered shutdown output voltage and amplify the filtered shutdown output voltage.
[0015] Furthermore, the filtering unit includes a first filter resistor, a second filter resistor and a second filter capacitor, the two ends of the first filter resistor are respectively connected to the output end of the photovoltaic power optimizer and one end of the second filter resistor, the other end of the second filter resistor is grounded, one end of the filter capacitor is connected to the common end of the first filter resistor and the second filter resistor, the other end of the filter capacitor is grounded, the first filter resistor is used to filter out the DC component of the shutdown output voltage, and the second filter resistor and the second filter capacitor are used to filter out the higher harmonics of the shutdown output voltage.
[0016] The present application also provides a photovoltaic power generation system, which includes the above-mentioned voltage regulation circuit.
[0017] The above-mentioned voltage regulation circuit is capable of controlling the shutdown output voltage of the photovoltaic power optimizer in the shutdown state by setting a shutdown voltage output circuit, a voltage sampling circuit and a control circuit, thereby avoiding the high danger caused by the shutdown voltage being too high and the low detection accuracy caused by the preset shutdown voltage being too low, thereby improving the safety and detection accuracy of the photovoltaic power generation system. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 is a circuit structure diagram of a voltage regulating circuit in an embodiment of the present application;
[0019] Figure 2 is a circuit structure diagram of a control circuit in an embodiment of the present application;
[0020] Figure 3 A circuit structure diagram of a shutdown voltage output circuit in an embodiment of the present application;
[0021] Figure 4is a circuit structure diagram of a voltage sampling circuit in an embodiment of the present application. DETAILED DESCRIPTION
[0022] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the specific implementation manner of the present application will be clearly and completely described below in conjunction with the drawings in the implementation manner of the present application.
[0023] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.
[0024] Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantitative limitation and may represent the singular or plural. The terms "include", "comprise", "have" and any of their variations involved in this application are intended to cover non-exclusive inclusions. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in this application refers to greater than or equal to two. "And / or" describes the association relationship of associated objects, indicating that there may be three relationships, for example, "A and / or B" may represent: A exists alone, A and B exist at the same time, and B exists alone. The terms "first", "second", "third" and the like involved in this application are merely to distinguish similar objects and do not represent a specific ordering of objects.
[0025] like Figure 1 As shown, the present application provides a voltage regulation circuit 100 and a photovoltaic power generation system 200, wherein the voltage regulation circuit 100 is applied to the photovoltaic power generation system 200, and the photovoltaic power generation system 200 includes a photovoltaic power optimizer 21, and the voltage regulation circuit 100 is electrically connected to the output terminal PVOUT+ of the photovoltaic power optimizer 21. When the photovoltaic power optimizer 21 is in a shutdown state, the voltage regulation circuit 100 is used to output a shutdown output voltage.
[0026] Specifically, the photovoltaic power generation system 200 further includes a power supply circuit 22, and the voltage regulation circuit 100 includes a shutdown voltage output circuit 11, a voltage sampling circuit 12, and a control circuit 13. The input end of the shutdown voltage output circuit 11 is connected to the power supply circuit 22, the output end of the shutdown voltage output circuit 11 is connected to the output end PVOUT+ of the photovoltaic power optimizer 21, the input end of the voltage sampling circuit 12 is connected to the output end PVOUT+ of the photovoltaic power optimizer 21, and the control circuit 13 is electrically connected to the control end of the shutdown voltage output circuit 11 and the output end of the voltage sampling circuit 12.
[0027] The power supply circuit 22 is used to provide a power supply voltage VCC. In the embodiment of the present application, the power supply circuit 22 is a voltage-regulated power supply with an output power supply voltage of 5V. The shutdown voltage output circuit 11 is used to obtain the power supply voltage VCC, and adjust the power supply voltage VCC to the shutdown output voltage and output it to the output terminal PVOUT+ of the photovoltaic power optimizer 21. The voltage sampling circuit 12 is used to obtain the shutdown output voltage and output the shutdown output voltage to the control circuit 13. The control circuit 13 is used to receive the shutdown output voltage and generate a control signal according to the shutdown output voltage. The control circuit 13 transmits the control signal to the shutdown voltage output circuit 11. The shutdown voltage output circuit 11 receives the control signal and adjusts the power supply voltage VCC to adjust the shutdown output voltage.
[0028] Exemplarily, a user can communicate with the control circuit 13 through a portable device. When the current shutdown output voltage Vout output by the shutdown voltage output circuit 11 is 1V, if the user sets the preset shutdown voltage Vset to 0.8V through the portable device, the control circuit 13 determines that the current shutdown output voltage Vout is higher than the preset shutdown output voltage Vout, and the control circuit 13 generates a control signal. The shutdown voltage output circuit 11 receives the control signal to reduce the current shutdown voltage Vout.
[0029] like Figure 2As shown, in the embodiment of the present application, the control circuit 13 is an MCU including a PWM pin and an ADC pin, such as STM32G0B1CCU7TR, the PWM pin is connected to the shutdown voltage output circuit 11, and the ADC pin is connected to the output end of the voltage sampling circuit 12. The control signal is a PWM signal with a fixed duty cycle, and the control circuit 13 controls the shutdown voltage output circuit 11 to adjust the shutdown output voltage by changing the duty cycle in the control signal. After the shutdown voltage output circuit 11 receives the control signal to reduce the current shutdown voltage Vout, the control circuit 13 obtains the reduced current shutdown voltage Vout through the voltage sampling circuit 12. When the control circuit 13 determines that the difference between the reduced current shutdown output voltage Vout and the preset shutdown output voltage Vset is less than or equal to 5%, that is, |(Vout-Vset)| / Vset≤5%, the control circuit 13 stops changing the duty cycle in the control signal, that is, the shutdown voltage output circuit 11 stops reducing the current shutdown voltage Vout. It can be understood that when the preset shutdown voltage Vset set by the user is higher than the current shutdown voltage Vout, the control circuit 13 can control the shutdown voltage output circuit 11 to increase the current working voltage Vout. Through the above settings, the control circuit 13 can adjust the current shutdown output voltage to the preset shutdown voltage through the shutdown voltage output circuit 11, thereby avoiding the shutdown voltage being too high, resulting in a higher risk during user detection, or the preset shutdown voltage being too low, resulting in a lower detection accuracy, thereby improving the safety and detection accuracy of the photovoltaic power generation system 200.
[0030] like Figure 3 As shown, specifically, the shutdown voltage output circuit 11 includes a first voltage-dividing resistor R1, a second voltage-dividing resistor R2, a third voltage-dividing resistor R3 and a switch tube Q1, the first end of the first voltage-dividing resistor R1 is connected to the power supply circuit 22, the second end of the first voltage-dividing resistor R1 is connected to the output end PVOUT+ of the photovoltaic power optimizer 21; the control end of the switch tube Q1 is connected to the PWM pin of the control circuit 13, one end of the switch tube Q1 is connected to the second end of the first voltage-dividing resistor R1, the other end of the switch tube Q1 is connected to one end of the second voltage-dividing resistor R2, one end of the third voltage-dividing resistor R3 is connected to the other end of the second voltage-dividing resistor R2, the other end of the third voltage-dividing resistor R3 is connected to the second end of the first voltage-dividing resistor R1, and the common end of the third voltage-dividing resistor R3 and the second voltage-dividing resistor R2 is grounded.
[0031] It should be noted that the shutdown output voltage is the divided voltage of the branch formed by the second voltage-dividing resistor R2 and the third voltage-dividing resistor R3. Since the switch tube Q1 is connected in series with the second voltage-dividing resistor R2, and the switch tube Q1 can adjust its own conduction duty cycle after receiving the control signal output by the control circuit 13, the resistance value of the branch where the second voltage-dividing resistor R2 is located can be controlled by the switch tube Q1, thereby adjusting the supply voltage to the shutdown output voltage.
[0032] When the user designs the voltage regulating circuit 100, the photovoltaic power optimizer 21 configured in the voltage regulating circuit 100 is different, so it is necessary to use the first voltage dividing resistor R1 with different resistance values. Since the resistors are set to fixed resistance values such as 10Ω, 5Ω and 1Ω when leaving the factory, if one voltage dividing resistor is used, it is impossible to accurately meet the design requirements in different scenarios.
[0033] like Figure 3 As shown, in order to meet the design requirements in different scenarios, as an optional implementation, the first voltage-dividing resistor R1 includes a first regulating resistor R11 and a second regulating resistor R12, one end of the first regulating resistor R11 is connected to the power supply circuit 11, and the other end of the first regulating resistor R11 is connected to the output terminal PVOUT+ of the photovoltaic power optimizer 21, one end of the second regulating resistor R12 is connected to the power supply circuit 11, and the other end of the second regulating resistor R12 is connected to the output terminal PVOUT+ of the photovoltaic power optimizer 21. It can be understood that by connecting the first regulating resistor R11 and the second regulating resistor R12 in parallel, and by selecting the first regulating resistor R11 and the second regulating resistor R12 with different resistance values, an equivalent resistor of any resistance value can be obtained.
[0034] For example, if an equivalent resistance of 2.5Ω is required, the equivalent resistance of 2.5Ω can be achieved by setting both the first adjustment resistor R11 and the second adjustment resistor R12 to 5Ω. Compared with setting only one voltage divider resistor, the embodiment of the present application can obtain an equivalent resistance of any resistance value by setting the first adjustment resistor R11 and the second adjustment resistor R12 in parallel, thereby meeting the design requirements of the voltage regulation circuit 100 in different usage scenarios.
[0035] In the implementation manner of the present application, the on-duty ratio and off-output voltage of the first regulating resistor R11, the second regulating resistor R12, the second voltage-dividing resistor R2, the third voltage-dividing resistor R3, and the switch tube Q1 satisfy the following relationship:
[0036]
[0037] Wherein V is the shutdown output voltage, R11 is the resistance value of the first regulating resistor, R12 is the resistance value of the second regulating resistor, R2 is the resistance value of the second voltage-dividing resistor, R3 is the resistance value of the third voltage-dividing resistor, and D is the on-duty cycle of the switch tube Q1.
[0038] like Figure 3As shown, further, the shutdown voltage output circuit 11 also includes an isolation unit 111, and the shutdown voltage output circuit 11 is connected to the output terminal PVOUT+ of the photovoltaic power optimizer 21 or grounded through the isolation unit 111, and the isolation unit 111 is used to isolate the output current output by the photovoltaic power optimizer 21 to the shutdown voltage output circuit 11. The isolation unit 111 includes a first diode D1 and a second diode D2, the anode of the first diode D1 is connected to the second end of the first voltage-dividing resistor R1, the cathode of the first diode D1 is connected to the output terminal PVOUT+ of the photovoltaic power optimizer 21, and the first diode D1 is used to unidirectionally conduct the shutdown output voltage; the anode of the second diode D2 is connected to the common end of the third voltage-dividing resistor R3 and the second voltage-dividing resistor R2, and the cathode of the second diode D2 is grounded.
[0039] It should be noted that, when the photovoltaic power optimizer 21 is in working state, the output terminal PVOUT+ of the photovoltaic power optimizer 21 will output voltage. By setting the first diode D1, the photovoltaic power optimizer 21 can be isolated from the shutdown voltage output circuit 11, thereby preventing the photovoltaic power optimizer 21 and the shutdown voltage output circuit 11 from forming a loop and generating a loop current, thereby preventing the photovoltaic power optimizer 21 from affecting the shutdown voltage output circuit 11. In addition, in the case of damage to the photovoltaic power optimizer 21, if the output voltage of the photovoltaic power optimizer 21 is reversed, that is, when the output voltage of the photovoltaic power optimizer 21 is less than 0, the photovoltaic power optimizer 21 can be isolated from the shutdown voltage output circuit 11 by setting the second diode D2, thereby preventing the photovoltaic power optimizer 21 and the shutdown voltage output circuit 11 from forming a loop and generating a loop current, thereby preventing the photovoltaic power optimizer 21 from affecting the shutdown voltage output circuit 11. Through the above-mentioned settings, the safety of the shutdown voltage output circuit 11 is improved.
[0040] like Figure 3 As shown, as an implementation method, the shutdown voltage output circuit 11 also includes a voltage drop resistor R4 and a pull-down resistor R5, one end of the voltage drop resistor R4 is connected to the control circuit 13, the other end of the voltage drop resistor R4 is connected to the control end of the switch tube Q1, one end of the pull-down resistor R5 is connected to the control end of the switch tube Q1, and the other end of the pull-down resistor R5 is grounded; the voltage drop resistor R4 is used to limit the current value of the control signal, and the pull-down resistor R5 is used to keep the control end of the switch tube Q1 at a low level.
[0041] In the embodiment of the present application, since the voltage value of the control signal output by the control circuit 13 is 3.3V, and the on-voltage of the switch tube Q1 is 0.6-0.7V, if the control signal is directly connected to the control end of the switch tube Q1, the switch tube Q1 will be damaged. Therefore, by setting the voltage drop resistor R4, the voltage value of the control signal received by the switch tube Q1 can be reduced, thereby avoiding damage to the switch tube Q1. In addition, since the signal output by the control circuit 13 includes a control signal for controlling the switch tube Q1 and useless clutter signals, if the clutter signal is directly passed to the switch tube Q1, it will cause the switch tube Q1 to be mis-turned on, thereby causing abnormal regulation of the shutdown voltage output circuit 11. By setting the pull-down resistor R5, the control end of the switch tube Q1 can be kept at a low level, thereby avoiding the mis-turning of the switch tube Q1 due to clutter signals, thereby improving the stability of the shutdown voltage output circuit 11.
[0042] like Figure 3 As shown, optionally, the shutdown voltage output circuit 11 also includes a first filter capacitor C1, one end of the first filter capacitor C1 is connected to the second end of the first voltage-dividing resistor R1, and the other end of the first filter capacitor C1 is grounded. The first filter capacitor C1 is used to reduce the ripple of the shutdown output voltage, thereby improving the stability of the shutdown output voltage.
[0043] like Figure 4 As shown, as an implementation, the voltage sampling circuit 12 includes a filter unit 121 and an operational amplifier U1, wherein the operational amplifier U1 is LMV321B-TR. One end of the filter unit 121 is connected to the output end PVOUT+ of the photovoltaic power optimizer 21, and the other end of the filter unit 121 is connected to the non-inverting input end IN+ of the operational amplifier U1. The output end OUT of the operational amplifier U1 is connected to the ADC pin of the control circuit 13. The output end OUT of the operational amplifier U1 is also connected to the inverting input end IN- of the amplifier U1 through a feedback resistor. The filter unit 121 is used to receive the shutdown output voltage and filter out the DC component and high-order harmonics of the shutdown output voltage. The operational amplifier U1 is used to receive the filtered shutdown output voltage and amplify the filtered shutdown output voltage, so that the control circuit 13 can accurately obtain the voltage value of the shutdown output voltage.
[0044] Specifically, the filtering unit 121 includes a first filter resistor R6, a second filter resistor R7 and a second filter capacitor C2, one end of the first filter resistor R6 is connected to the output terminal PVOUT+ of the photovoltaic power optimizer 21, the other end of the first filter resistor R6 is connected to one end of the second filter resistor R7, the other end of the second filter resistor R7 is grounded, one end of the second filter capacitor C2 is connected to the common end of the first filter resistor R6 and the second filter resistor R7, the other end of the second filter capacitor C2 is grounded, the first filter resistor R6 is used to filter out the DC component of the shut-off output voltage, and the second filter resistor R7 and the second filter capacitor C2 are used to filter out the high-order harmonics of the shut-off output voltage. Through the above settings, the sampling accuracy of the voltage sampling circuit is improved.
[0045] In summary, by setting the shutdown voltage output circuit 11, the voltage sampling circuit 12 and the control circuit 13, the shutdown output voltage of the photovoltaic power optimizer 21 in the shutdown state can be controlled, thereby avoiding the shutdown voltage being too high to cause higher danger and the preset shutdown voltage being too low to cause lower detection accuracy, thereby improving the safety and detection accuracy of the photovoltaic power generation system 200.
[0046] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the claims attached to this application.
Claims
1. A voltage regulating circuit, applied to a photovoltaic power generation system, wherein the photovoltaic power generation system comprises a photovoltaic power optimizer and a power supply circuit for providing a power supply voltage, characterized in that: The voltage regulating circuit comprises: A shutdown voltage output circuit, the shutdown voltage output circuit is connected to the power supply circuit and the output end of the photovoltaic power optimizer respectively, the shutdown voltage output circuit is used to obtain the power supply voltage, and adjust the power supply voltage to a shutdown output voltage and then output it to the output end of the photovoltaic power optimizer; A voltage sampling circuit, the voltage sampling circuit is connected to the output end of the photovoltaic power optimizer, and the voltage sampling circuit is used to obtain the shutdown output voltage; A control circuit, wherein the control circuit is electrically connected to the shutdown voltage output circuit and the voltage sampling circuit respectively, the control circuit is used to receive the shutdown output voltage and generate a control signal according to the shutdown output voltage, and the shutdown voltage output circuit receives the control signal to adjust the supply voltage.
2. The voltage regulating circuit according to claim 1, characterized in that: The shutdown voltage output circuit comprises a first voltage-dividing resistor, a second voltage-dividing resistor, a third voltage-dividing resistor and a switch tube, wherein the first end of the first voltage-dividing resistor is connected to the power supply circuit, and the second end of the first voltage-dividing resistor is connected to the output end of the photovoltaic power optimizer; The control end of the switch tube is connected to the control circuit, one end of the switch tube is connected to the second end of the first voltage-dividing resistor, the other end of the switch tube is connected to one end of the second voltage-dividing resistor, one end of the third voltage-dividing resistor is connected to the other end of the second voltage-dividing resistor, the other end of the third voltage-dividing resistor is connected to the second end of the first voltage-dividing resistor, the common end of the third voltage-dividing resistor and the second voltage-dividing resistor is grounded, and the switch tube is used to receive the control signal to adjust its own conduction duty cycle to adjust the supply voltage.
3. The voltage regulating circuit according to claim 2, characterized in that: The shutdown voltage output circuit also includes an isolation unit, through which the shutdown voltage output circuit is connected to the output end of the photovoltaic power optimizer and / or grounded, and the isolation unit is used to isolate the output current of the photovoltaic power optimizer to the shutdown voltage output circuit.
4. The voltage regulating circuit according to claim 3, characterized in that: The isolation unit includes a first diode and a second diode, the first diode unidirectionally conducts the shutdown output voltage, the anode of the second diode is connected to the common end of the third voltage-dividing resistor and the second voltage-dividing resistor, and the cathode of the second diode is grounded.
5. The voltage regulating circuit according to claim 2, characterized in that: The shutdown voltage output circuit also includes a voltage-dropping resistor and a pull-down resistor, wherein the two ends of the voltage-dropping resistor are respectively connected to the control circuit and the control end of the switch tube, and the two ends of the pull-down resistor are respectively connected to the control end of the switch tube and a reference ground; the voltage-dropping resistor is used to reduce the voltage value of the control signal output by the control circuit, and the pull-down resistor is used to keep the control end of the switch tube at a low level.
6. The voltage regulating circuit according to claim 2, characterized in that: The shutdown voltage output circuit also includes a first filter capacitor, the two ends of which are respectively connected to the second end of the first voltage-dividing resistor and the reference ground, and the first filter capacitor is used to reduce the ripple of the shutdown output voltage output by the shutdown voltage output circuit.
7. The voltage regulating circuit according to claim 2, characterized in that: The first voltage-dividing resistor includes a first regulating resistor and a second regulating resistor, the two ends of the first regulating resistor are respectively connected to the power supply circuit and the output end of the photovoltaic power optimizer, and the second regulating resistor is connected in parallel with the first regulating resistor.
8. The voltage regulating circuit according to claim 1, characterized in that: The voltage sampling circuit includes a filtering unit and an operational amplifier, wherein two ends of the filtering unit are respectively connected to the output end of the photovoltaic power optimizer and the output end of the operational amplifier, and the input end of the operational amplifier is connected to the control circuit. The filtering unit is used to receive the shutdown output voltage and filter out the DC component and high-order harmonics of the shutdown output voltage. The operational amplifier is used to receive the shutdown output voltage after filtering and amplify the shutdown output voltage after filtering.
9. The voltage regulating circuit according to claim 8, characterized in that: The filtering unit includes a first filtering resistor, a second filtering resistor and a second filtering capacitor, wherein two ends of the first filtering resistor are respectively connected to the output end of the photovoltaic power optimizer and one end of the second filtering resistor, the other end of the second filtering resistor is grounded, one end of the filtering capacitor is connected to the common end of the first filtering resistor and the second filtering resistor, the other end of the filtering capacitor is grounded, the first filtering resistor is used to filter out the DC component of the shutdown output voltage, and the second filtering resistor and the second filtering capacitor are used to filter out the higher harmonics of the shutdown output voltage.
10. A photovoltaic power generation system, characterized in that: The photovoltaic power generation system comprises the voltage regulating circuit described in any one of claims 1-9.