A power supply circuit

Abstract

This application provides a power supply circuit including a power supply control module, a boost module, and a controller. The control terminal of the boost module is connected to the controller, the input terminal of the power supply control module is connected to the output terminal of the photovoltaic module, the output terminal of the power supply control module is connected to the input terminal of the boost module, and the output terminal of the boost module is connected to the power supply terminal of the photovoltaic shutdown device. This application, through the power supply control module and the boost module, provides a stable voltage output to the subsequent photovoltaic shutdown device in the event of undervoltage in the photovoltaic module, ensuring the normal operation of the photovoltaic module.

Description

Technical Field

[0001] This application relates to the field of photovoltaic power generation technology, and in particular to a power supply circuit. Background Technology

[0002] Photovoltaic power generation technology refers to a renewable energy power generation technology that uses the photovoltaic effect to directly convert sunlight into electrical energy. Specifically, the direct current (DC) output from photovoltaic modules is converted into alternating current (AC) by an inverter before being transmitted to the power grid. In a photovoltaic power generation system, the output terminals of multiple photovoltaic modules are usually connected in series to form strings, so each string has a high voltage. To improve the safety of the photovoltaic system, current technology typically installs a shutdown device on each photovoltaic module.

[0003] The function of a shutdown device is to actively or passively cut off the output of photovoltaic modules, reduce the output voltage of the string, and thus improve the safety of the photovoltaic system. The shutdown device usually includes electronic components such as control chips and MOSFETs, which need to be powered by the photovoltaic modules to work properly.

[0004] Therefore, based on the above situation, once the photovoltaic module is undervoltage or without power, the control switch of the shutdown device will be disconnected. After that, because the control switch is disconnected, the photovoltaic module will immediately return to the open circuit voltage, and the control system will close the control switch again. At this time, it is equivalent to starting under load. At the moment of closing, the voltage of the photovoltaic module is pulled down instantly, causing it to shut down again due to undervoltage. This process repeats, which is the phenomenon of photovoltaic module hiccups. This will seriously affect the stability of the photovoltaic system. Utility Model Content

[0005] In view of this, the purpose of this application is to provide at least one power supply circuit that, through a power supply control module and a boost module, provides a stable voltage output to the subsequent photovoltaic shutdown device in the event of undervoltage of the photovoltaic module, thereby ensuring the normal operation of the photovoltaic module.

[0006] This application mainly includes the following aspects:

[0007] In a first aspect, embodiments of this application provide a power supply circuit, which includes a power supply control module, a boost module, and a controller. The control terminal of the boost module is connected to the controller, the input terminal of the power supply control module is connected to the output terminal of the photovoltaic module, the output terminal of the power supply control module is connected to the input terminal of the boost module, and the output terminal of the boost module is connected to the power supply terminal of the photovoltaic switch. The power supply control module is used to supply power to the boost module in the on state or to stop supplying power to the boost module in the off state.

[0008] In one possible implementation, the power supply circuit further includes a step-down module, the input of which is connected to the output of the photovoltaic module, the output of which is connected to the power supply of the photovoltaic switch, and the control of which is connected to the controller.

[0009] In one possible implementation, the power supply circuit further includes a first diode, a second diode, and a first capacitor, wherein the anode of the first diode is connected to the output terminal of the boost module, and the anode of the second diode is connected to the output terminal of the buck module; the cathode of the first diode is connected to the power supply terminal of the photovoltaic switch, the cathode of the second diode, and grounded through the first capacitor.

[0010] In one possible implementation, the power supply control module includes a voltage divider unit, a comparator unit, a first resistor, and a switching control unit. The first connection terminal of the voltage divider unit is connected to the positive terminal of the photovoltaic module, the second connection terminal of the voltage divider unit is connected to the negative terminal of the photovoltaic module, the sampling terminal of the voltage divider unit is connected to the sampling input terminal of the comparator unit, the anode input terminal of the comparator unit is connected to the negative terminal of the photovoltaic module, the cathode output terminal of the comparator unit is connected to the input terminal of the switching control unit and to the positive terminal of the photovoltaic module through the first resistor, and the output terminal of the switching control unit is connected to the boost module.

[0011] In one possible implementation, the comparison unit includes a comparator, a voltage reference chip, a transistor, and a third diode. The non-inverting input of the comparator is connected to the sampling terminal of the voltage divider unit, and the inverting input of the comparator is connected to the voltage reference chip. The negative power supply terminal of the comparator is connected to the negative terminal of the photovoltaic module, and the positive power supply terminal of the comparator is connected to the input terminal of the on / off control unit and to the positive terminal of the photovoltaic module through a first resistor. The output terminal of the comparator is connected to the base of the transistor, the emitter of the transistor is connected to the anode of the third diode and the negative power supply terminal of the comparator, and the collector of the transistor is connected to the positive power supply terminal of the comparator and the cathode of the third diode.

[0012] In one possible implementation, the on / off control unit includes a first on / off control component and a second on / off control component. The control input terminal of the first on / off control component is connected to the cathode output terminal of the comparator unit and the positive terminal of the photovoltaic module through a first resistor. The first connection terminal of the first on / off control component is connected to the negative terminal of the photovoltaic module, and the second connection terminal of the first on / off control component is connected to the control input terminal of the second on / off control component. The first connection terminal of the second on / off control component is connected to the positive terminal of the photovoltaic module, and the second connection terminal of the second on / off control component is connected to the boost module.

[0013] In one possible implementation, the first on / off control component includes a first driving resistor, a second driving resistor, a first Zener diode, and a first control switch. One end of the first driving resistor is connected to the cathode of the first Zener diode and the cathode output terminal of the comparator unit, respectively. The other end of the first driving resistor is connected to the control terminal of the first control switch and one end of the second driving resistor, respectively. The first connection terminal of the first control switch is connected to the other end of the second driving resistor, the anode of the first Zener diode, and the negative terminal of the photovoltaic module, respectively. The second connection terminal of the first control switch is connected to the control input terminal of the second on / off control component.

[0014] In one possible implementation, the second on / off control component includes a third driving resistor, a fourth driving resistor, a second Zener diode, and a second control switch. One end of the third driving resistor is connected to one end of the fourth driving resistor and the second connection terminal of the first on / off control component. The other end of the third driving resistor is connected to the anode of the second Zener diode and the control terminal of the second control switch. The first connection terminal of the second control switch is connected to the cathode of the second Zener diode, the other end of the fourth driving resistor, and the positive electrode of the photovoltaic module. The second connection terminal of the second control switch is connected to the boost module.

[0015] In one possible implementation, the boost module includes a first inductor, a third control switch, a fourth diode, and a second capacitor. The control terminal of the third control switch is connected to a controller, the first connection terminal of the third control switch is connected to the negative terminal of the photovoltaic module, and the second connection terminal of the third control switch is connected to the anode of the fourth diode and, through the first inductor, to the output terminal of the power supply control module. The cathode of the fourth diode serves as the output terminal of the boost module and is connected to the power supply terminal of the photovoltaic shutdown device and, through the second capacitor, to the negative terminal of the photovoltaic module.

[0016] In one possible implementation, the step-down module includes a fourth control switch, a second inductor, a fifth diode, and a third capacitor. The control terminal of the fourth control switch is connected to a controller, the first connection terminal of the fourth control switch is connected to the positive terminal of the photovoltaic module, the second connection terminal of the fourth control switch is connected to the cathode of the fifth diode and one end of the second inductor, and the other end of the second inductor serves as the output terminal of the step-down module, connected to one end of the third capacitor and the power supply terminal of the photovoltaic switch. The other end of the third capacitor is connected to the anode of the fifth diode and the negative terminal of the photovoltaic module.

[0017] The power supply circuit provided in this application includes a power supply control module, a boost module, and a controller. The control terminal of the boost module is connected to the controller, the input terminal of the power supply control module is connected to the output terminal of the photovoltaic module, the output terminal of the power supply control module is connected to the input terminal of the boost module, and the output terminal of the boost module is connected to the power supply terminal of the photovoltaic shutdown device. The power supply control module is used to supply power to the boost module when it is on, or to stop supplying power to the boost module when it is off. Through the power supply circuit provided in this application, a stable voltage output is provided to the subsequent photovoltaic shutdown device in the event of undervoltage in the photovoltaic module, ensuring the normal operation of the photovoltaic module.

[0018] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This illustration shows one of the structural schematic diagrams of a power supply circuit provided in an embodiment of this application;

[0021] Figure 2 This is a second schematic diagram of a power supply circuit provided in an embodiment of this application;

[0022] Figure 3 This paper shows a schematic diagram of the structure of a power supply control module provided in an embodiment of this application;

[0023] Figure 4 This paper shows a schematic diagram of the structure of a comparison unit provided in an embodiment of this application;

[0024] Figure 5 The third schematic diagram shows a power supply circuit provided in an embodiment of this application. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0026] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0027] Photovoltaic (PV) power generation technology refers to a renewable energy generation technology that directly converts sunlight into electrical energy using the photovoltaic effect. Specifically, the direct current (DC) output from PV modules is converted into alternating current (AC) by an inverter before being transmitted to the power grid. In a PV power generation system, the output terminals of multiple PV modules are typically connected in series to form strings. Each string then has a high voltage. To improve the safety of the PV system, current technology usually installs a shutdown device on each PV module. The shutdown device actively or passively cuts off the output of the PV module, reducing the output voltage of the string and thus improving the safety of the PV system. The shutdown device typically includes electronic components such as control chips and MOSFETs, which require power from the PV modules to function properly.

[0028] Therefore, based on the above situation, once the photovoltaic module is undervoltage or without power, the control switch of the shutdown device will be disconnected. After that, because the control switch is disconnected, the photovoltaic module will immediately return to the open circuit voltage, and the control system will close the control switch again. At this time, it is equivalent to starting under load. At the moment of closing, the voltage of the photovoltaic module is pulled down instantly, causing it to shut down again due to undervoltage. This process repeats, which is the phenomenon of photovoltaic module hiccups. This will seriously affect the stability of the photovoltaic system.

[0029] Based on this, this application provides a power supply circuit that, through a power supply control module and a boost module, provides a stable voltage output to the subsequent photovoltaic shutdown device when the photovoltaic module experiences undervoltage, ensuring the normal operation of the photovoltaic module, as detailed below:

[0030] Please see Figure 1 , Figure 1 This illustration shows one of the structural schematic diagrams of a power supply circuit provided in an embodiment of this application. For example... Figure 1 As shown, the power supply circuit provided in this application embodiment includes a power supply control module 1, a boost module 2, and a controller 3. The control terminal of the boost module 2 is connected to the controller 3, the input terminal of the power supply control module 1 is connected to the output terminal of the photovoltaic module PV, the output terminal of the power supply control module 1 is connected to the input terminal of the boost module 2, and the output terminal of the boost module 2 is connected to the power supply terminal of the photovoltaic shutdown device 4.

[0031] The power supply control module 1 is used to supply power to the boost module 2 when it is on, or to stop supplying power to the boost module 2 when it is off.

[0032] In an alternative embodiment, such as Figure 1 As shown, the power supply circuit also includes a step-down module 5. The input terminal of the step-down module 5 is connected to the output terminal of the photovoltaic module PV, the output terminal of the step-down module 5 is connected to the power supply terminal of the photovoltaic shut-off device 4, and the control terminal of the step-down module 5 is connected to the controller 3.

[0033] In a specific example, when the output voltage Vpv of the photovoltaic module PV is in the range of 2V~10V, the power supply control module 1 is turned on, the joint controller 3 drives the boost module 2 to work, and the output voltage Vpv of the photovoltaic module PV supplies power to the photovoltaic shutdown device 4 through the output voltage Vout of the boost module 2.

[0034] When the output voltage Vpv of the photovoltaic module PV is in the range of 10V~100V, the power supply control module 1 is disconnected, the controller 3 drives the step-down module 5 to work, and the output voltage Vpv of the photovoltaic module PV supplies power to the photovoltaic shutdown device 4 through the output voltage Vout of the step-down module 5.

[0035] Therefore, the power supply circuit provided in this application, when the output voltage Vpv of the photovoltaic module PV is in an abnormal operating range (2V~10V), the power supply control module 1 is turned on, and the output voltage Vpv of the photovoltaic module PV is boosted through the boost module 2, so that the photovoltaic shutdown device 4 can obtain a stable and continuous power supply. When the output voltage Vpv of the photovoltaic module PV is in the normal operating range (10V~100V), the power supply control module 1 is turned off, and the output voltage Vpv of the photovoltaic module PV is stepped down through the buck module 5 to supply power to the photovoltaic shutdown device 4.

[0036] Specifically, the voltage Vout is preset to 10V~11V, which is consistent with the operating voltage of the photovoltaic switch 4.

[0037] In a preferred embodiment, please refer to Figure 2 , Figure 2 This is a second schematic diagram of a power supply circuit provided in an embodiment of this application. For example... Figure 2 As shown, the power supply circuit also includes a first diode D1, a second diode D2, and a first capacitor C1. The anode of the first diode D1 is connected to the output terminal of the boost module 2, the anode of the second diode D2 is connected to the output terminal of the buck module 5, and the cathode of the first diode D1 is connected to the power supply terminal of the photovoltaic switch 5, the cathode of the second diode D2, and ground GND through the first capacitor C1.

[0038] Specifically, both the first diode D1 and the second diode D2 are anti-reverse current diodes.

[0039] In a preferred embodiment, please refer to Figure 3 , Figure 3 A schematic diagram of a power supply control module provided in an embodiment of this application is shown. Figure 3 As shown, the power supply control module 1 includes a voltage divider unit 11, a comparator unit 12, a first resistor R1, and an on / off control unit 13. The first connection terminal of the voltage divider unit 11 is connected to the positive electrode PV+ of the photovoltaic module, the second connection terminal of the voltage divider unit 11 is connected to the negative electrode PV- of the photovoltaic module, the sampling terminal of the voltage divider unit 11 is connected to the sampling input terminal of the comparator unit 12, the anode input terminal of the comparator unit 12 is connected to the negative electrode PV- of the photovoltaic module, the cathode output terminal of the comparator unit 12 is connected to the input terminal of the on / off control unit 13 and the positive electrode PV+ of the photovoltaic module through the first resistor R1, and the output terminal of the on / off control unit 13 is connected to the boost module 2.

[0040] like Figure 3 The voltage divider unit 11 includes a first voltage divider resistor Rs1 and a second voltage divider resistor Rs2. One end of the first voltage divider resistor Rs1 is connected to the positive terminal PV+ of the photovoltaic module. The other end of the first voltage divider resistor Rs1 is connected to one end of the second voltage divider resistor Rs2 and serves as the sampling terminal of the voltage divider unit 11, which is connected to the sampling input terminal of the comparator unit 12. The other end of the second voltage divider resistor Rs2 is connected to the negative terminal PV- of the photovoltaic module.

[0041] In one specific embodiment, please refer to Figure 4 , Figure 4 A schematic diagram of a comparison unit provided in an embodiment of this application is shown. Figure 4As shown, the comparison unit 12 includes a comparator U1, a voltage reference chip 121, a transistor Q1, and a third diode D3. The non-inverting input of the comparator U1 is connected to the sampling terminal of the voltage divider unit (i.e., the other end of the first voltage divider resistor Rs1), and the inverting input of the comparator U1 is connected to the voltage reference chip 121. The voltage reference chip 121 provides a reference voltage Vref for the comparator U1. The negative power supply terminal of the comparator U1 serves as the anode input terminal ANODE of the comparison unit 12 and is connected to the negative terminal PV- of the photovoltaic module. The positive power supply terminal of the comparator U1 serves as the cathode output terminal CATHODE of the comparison unit 12 and is connected to the input terminal of the on / off control unit 13 and the positive terminal PV+ of the photovoltaic module through the first resistor R1.

[0042] The output of comparator U1 is connected to the base of transistor Q1. The emitter of transistor Q1 is connected to the anode of the third diode D3 and the negative power supply terminal of comparator U1, respectively. The collector of transistor Q1 is connected to the positive power supply terminal of comparator U1 and the cathode of the third diode D3, respectively.

[0043] In this application, transistor Q1 can be an NPN transistor, and voltage reference chip 121 is also connected to the output voltage Vpv of the photovoltaic module.

[0044] Specifically, for the comparator unit provided in this application, the output voltage Vpv of the photovoltaic module is divided by the voltage divider component and input to the non-inverting input terminal of the comparator U1. When the output voltage Vpv is within the normal operating range (10V~100V), the voltage after voltage division by the voltage divider component is greater than the reference voltage Vref. The comparator U1 outputs a high level, the transistor Q1 is turned on, and the anode input terminal ANODE and the cathode output terminal CATHODE of the comparator unit 12 are connected. The cathode output terminal CATHODE of the comparator unit 12 is pulled low (low level). At this time, the on / off control unit 13 is turned off, the boost module 2 does not work, and the buck module 5 works.

[0045] When the output voltage Vpv is outside the normal operating range (2V~10V), the voltage after voltage division by the voltage divider component is less than the reference voltage Vref. The comparator U1 outputs a low level, the transistor Q1 is turned off, and there is no conduction between the anode input terminal ANODE and the cathode output terminal CATHODE of the comparator unit 12. The cathode output terminal CATHODE of the comparator unit 12 is at a high level. At this time, the on / off control unit 13 is turned on, the boost module 2 works, and the buck module 5 does not work.

[0046] In a preferred embodiment, return Figure 3The on / off control unit 13 includes a first on / off control component 131 and a second on / off control component 132. The control input terminal of the first on / off control component 131 is connected to the cathode output terminal CATHODE of the comparator unit 12 and the positive electrode PV+ of the photovoltaic module through the first resistor R1. The first connection terminal of the first on / off control component 131 is connected to the negative electrode PV- of the photovoltaic module. The second connection terminal of the first on / off control component 131 is connected to the control input terminal of the second on / off control component 132. The first connection terminal of the second on / off control component 132 is connected to the positive electrode PV+ of the photovoltaic module. The second connection terminal of the second on / off control component 132 is connected to the boost module 2.

[0047] In one specific implementation, such as Figure 3 The first on / off control component 131 includes a first driving resistor Rg1, a second driving resistor Rg2, a first Zener diode DM1, and a first control switch K1. The first control switch K1 can be an NMOS switch. The gate of the NMOS switch is used as the control terminal of the first control switch K1, the source of the gate of the NMOS switch is used as the first connection terminal of the first control switch K1, and the drain of the NMOS switch is used as the second connection terminal of the first control switch K1.

[0048] One end of the first driving resistor Rg1 is connected to the cathode of the first Zener diode DM1 and the cathode output terminal CATHODE of the comparator unit 12, respectively. The other end of the first driving resistor Rg1 is connected to the control terminal of the first control switch K1 and one end of the second driving resistor Rg2, respectively. The first connection terminal of the first control switch K1 is connected to the other end of the second driving resistor Rg2, the anode of the first Zener diode DM1 and the negative terminal PV- of the photovoltaic module, respectively. The second connection terminal of the first control switch K1 is connected to the control input terminal of the second on / off control component 132.

[0049] In another specific embodiment, the second on / off control component 132 includes a third driving resistor Rg3, a fourth driving resistor Rg4, a second Zener diode DM2, and a second control switch K2. The second control switch K1 can be a PMOS switch. The gate of the PMOS switch is used as the control terminal of the second control switch K2, the source of the gate of the PMOS switch is used as the first connection terminal of the second control switch K2, and the drain of the PMOS switch is used as the second connection terminal of the second control switch K2.

[0050] One end of the third driving resistor Rg3 is connected to one end of the fourth driving resistor Rg4 and the second connection terminal of the first control switch K1. The other end of the third driving resistor Rg3 is connected to the anode of the second Zener diode DM2 and the control terminal of the second control switch K2. The first connection terminal of the second control switch K2 is connected to the cathode of the second Zener diode DM2, the other end of the fourth driving resistor Rg4 and the positive electrode PV+ of the photovoltaic module. The second connection terminal of the second control switch K2 is connected to the boost module 2.

[0051] Please see Figure 5 , Figure 5 This is shown as a third schematic diagram of a power supply circuit according to an embodiment of this application. Figure 5 As shown, the boost module 2 includes a first inductor L1, a third control switch K3, a fourth diode D4, and a second capacitor C2. The third control switch K3 can be a PMOS switch. The gate of the PMOS switch is used as the control terminal of the third control switch K3, the source of the gate of the PMOS switch is used as the first connection terminal of the third control switch K3, and the drain of the PMOS switch is used as the second connection terminal of the second control switch K2.

[0052] The control terminal of the third control switch K3 is connected to the controller (not shown in the figure), the first connection terminal of the third control switch K3 is connected to the negative terminal PV- of the photovoltaic module, the second connection terminal of the third control switch K3 is connected to the anode of the fourth diode D4 and the second connection terminal of the second control switch K2 through the first inductor L1, and the cathode of the fourth diode D4 serves as the output terminal of the boost module 2 and is connected to the power supply terminal of the photovoltaic shut-off device 4 and the negative terminal PV- of the photovoltaic module through the second capacitor C2.

[0053] In a preferred embodiment, the step-down module 5 includes a fourth control switch K4, a second inductor L2, a fifth diode D5, and a third capacitor C3. The fourth control switch K4 can be a PMOS switch. The gate of the PMOS switch is used as the control terminal of the fourth control switch K4, the source of the gate of the PMOS switch is used as the first connection terminal of the fourth control switch K4, and the drain of the PMOS switch is used as the second connection terminal of the fourth control switch K4.

[0054] The control terminal of the fourth control switch K4 is connected to the controller (not shown in the figure). The first connection terminal of the fourth control switch K4 is connected to the positive terminal PV+ of the photovoltaic module. The second connection terminal of the fourth control switch K4 is connected to the cathode of the fifth diode D5 and one end of the second inductor L2. The other end of the second inductor L2 serves as the output terminal of the step-down module 5 and is connected to one end of the third capacitor C3 and the power supply terminal of the photovoltaic switch 5. The other end of the third capacitor C3 is connected to the anode of the fifth diode D5 and the negative terminal PV- of the photovoltaic module. The negative terminal PV- of the photovoltaic module is grounded to GND.

[0055] Specifically, the fourth control switch K4 is controlled by the controller and is used to adjust the output voltage of the buck module 5. Similarly, the third control switch K3 is controlled by the controller and is used to adjust the output voltage of the boost module 2.

[0056] Based on the power supply circuit provided in this application, when the output voltage Vpv of the photovoltaic module is 2V~10V, the first control switch K1 and the second control switch K2 are turned on, the control terminal of the third control switch K3 is connected to the PWM signal generated by the controller, so that the boost module 2 enters the boost working mode, the fourth control switch K4 is turned off, and the buck module 5 does not work. At this time, although the photovoltaic module is in a low voltage abnormal output, through the action of the boost module 2, a working voltage of 10V~11V is provided to the power supply terminal of the photovoltaic shutdown device.

[0057] When the output voltage Vpv of the photovoltaic module is 10V~100V, the first control switch K1 and the second control switch K2 are disconnected, the third control switch K3 is disconnected, the boost module 2 stops working, the control terminal of the fourth control switch K4 is connected to the PWM signal generated by the controller, and the buck module 5 enters the buck working mode. At this time, the output voltage Vpv of the photovoltaic module is supplied with a working voltage of 10V~11V to the power supply terminal of the photovoltaic shutdown device after passing through the buck module 5.

[0058] Furthermore, during sunrise, sunset, or when the photovoltaic module (PV) is shaded, its output voltage Vpv decreases. When Vpv is around 10V, the photovoltaic switch can receive a "heartbeat," and its control signal (a type of semiconductor switching device) is pulled high. However, at this time, the output voltage Vpv provided by the photovoltaic module is extremely unstable, and it may drop below 10V or even "hiccup" at 10V. In other words, this voltage state will increase the switching losses or conduction losses of the photovoltaic switch. Specifically, the following risks exist:

[0059] 1. The lower the conduction voltage of the photovoltaic switch, the higher the conduction resistance, and the photovoltaic switch will experience abnormal heating.

[0060] 2. When the conduction voltage of the photovoltaic switch exhibits a "hiccup" pattern, the photovoltaic switch will increase its conduction loss. This loss is directly proportional to the frequency of the "hiccup," meaning the higher the frequency, the greater the loss and the more severe the heat generation.

[0061] Based on the aforementioned risks, this application proposes a power supply circuit that activates the boost module and shuts down the buck module when the output voltage of the photovoltaic module is outside the normal operating range. This allows the output voltage of the photovoltaic module to be boosted to a larger voltage range, which can stably control the photovoltaic shutdown device, increase the output efficiency of the photovoltaic module, increase the stability of the power supply system, and effectively avoid the aforementioned risks.

[0062] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A power supply circuit, characterized by comprising: The power supply circuit includes a power supply control module, a boost module, and a controller. The control terminal of the boost module is connected to the controller, the input terminal of the power supply control module is connected to the output terminal of the photovoltaic module, the output terminal of the power supply control module is connected to the input terminal of the boost module, and the output terminal of the boost module is connected to the power supply terminal of the photovoltaic shutdown device. The power supply control module is used to supply power to the boost module when it is on, or to stop supplying power to the boost module when it is off.

2. The power supply circuit according to claim 1, characterized in that, The power supply circuit also includes a step-down module, the input of which is connected to the output of the photovoltaic module, the output of which is connected to the power supply of the photovoltaic switch, and the control of which is connected to the controller.

3. The power supply circuit of claim 2, wherein, The power supply circuit also includes a first diode, a second diode, and a first capacitor. The anode of the first diode is connected to the output terminal of the boost module, and the anode of the second diode is connected to the output terminal of the buck module. The cathode of the first diode is connected to the power supply terminal of the photovoltaic switch, the cathode of the second diode, and grounded through the first capacitor.

4. The power supply circuit of claim 1, wherein, The power supply control module includes a voltage divider unit, a comparator unit, a first resistor, and an on / off control unit. The voltage divider unit has a first connection terminal connected to the positive electrode of the photovoltaic module, a second connection terminal connected to the negative electrode of the photovoltaic module, a sampling terminal connected to the sampling input terminal of the comparator unit, an anode input terminal connected to the negative electrode of the photovoltaic module, a cathode output terminal connected to the input terminal of the on / off control unit and the positive electrode of the photovoltaic module via a first resistor, and an output terminal connected to the boost module.

5. The power supply circuit of claim 4, wherein, The comparison unit includes a comparator, a voltage reference chip, a transistor, and a third diode. The non-inverting input of the comparator is connected to the sampling terminal of the voltage divider unit, and the inverting input of the comparator is connected to the voltage reference chip. The negative power supply terminal of the comparator is connected to the negative terminal of the photovoltaic module, and the positive power supply terminal of the comparator is connected to the input terminal of the on / off control unit and to the positive terminal of the photovoltaic module through the first resistor; The output terminal of the comparator is connected to the base of the transistor, the emitter of the transistor is connected to the anode of the third diode and the negative power supply terminal of the comparator, and the collector of the transistor is connected to the positive power supply terminal of the comparator and the cathode of the third diode.

6. The power supply circuit of claim 4, wherein, The on / off control unit includes a first on / off control component and a second on / off control component. The control input terminal of the first on / off control component is connected to the cathode output terminal of the comparator unit and the positive terminal of the photovoltaic module through the first resistor, respectively. The first connection terminal of the first on / off control component is connected to the negative terminal of the photovoltaic module, and the second connection terminal of the first on / off control component is connected to the control input terminal of the second on / off control component. The first connection terminal of the second on / off control component is connected to the positive electrode of the photovoltaic module, and the second connection terminal of the second on / off control component is connected to the boost module.

7. The power supply circuit of claim 6, wherein, The first on / off control component includes a first driving resistor, a second driving resistor, a first Zener diode, and a first control switch. One end of the first driving resistor is connected to the cathode of the first Zener diode and the cathode output terminal of the comparator unit, respectively. The other end of the first driving resistor is connected to the control terminal of the first control switch and one end of the second driving resistor, respectively. The first connection terminal of the first control switch is connected to the other end of the second driving resistor, the anode of the first Zener diode and the cathode of the photovoltaic module, respectively. The second connection terminal of the first control switch is connected to the control input terminal of the second on / off control component.

8. The power supply circuit of claim 6, wherein, The second on / off control component includes a third driving resistor, a fourth driving resistor, a second Zener diode, and a second control switch. One end of the third driving resistor is connected to one end of the fourth driving resistor and the second connection terminal of the first on / off control component. The other end of the third driving resistor is connected to the anode of the second Zener diode and the control terminal of the second control switch. The first connection terminal of the second control switch is connected to the cathode of the second Zener diode, the other end of the fourth driving resistor, and the positive electrode of the photovoltaic module. The second connection terminal of the second control switch is connected to the boost module.

9. The power supply circuit of claim 1, wherein, The boost module includes a first inductor, a third control switch, a fourth diode, and a second capacitor. The control terminal of the third control switch is connected to the controller, the first connection terminal of the third control switch is connected to the negative electrode of the photovoltaic module, and the second connection terminal of the third control switch is connected to the anode of the fourth diode and the output terminal of the power supply control module through the first inductor. The cathode of the fourth diode serves as the output terminal of the boost module and is connected to the power supply terminal of the photovoltaic switch and the negative terminal of the photovoltaic module via the second capacitor.

10. The power supply circuit of claim 2, wherein, The step-down module includes a fourth control switch, a second inductor, a fifth diode, and a third capacitor. The control terminal of the fourth control switch is connected to the controller, the first connection terminal of the fourth control switch is connected to the positive electrode of the photovoltaic module, the second connection terminal of the fourth control switch is connected to the cathode of the fifth diode and one end of the second inductor, and the other end of the second inductor serves as the output terminal of the step-down module and is connected to one end of the third capacitor and the power supply terminal of the photovoltaic switch. The other end of the third capacitor is connected to the anode of the fifth diode and the cathode of the photovoltaic module, respectively.

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