Photovoltaic power supply system

Abstract

The utility model discloses a photovoltaic power supply system, which comprises a photovoltaic power supply module, a first under-voltage protection circuit, a power supply conversion module, a controller and a first load, and is characterized in that the first under-voltage protection circuit sends a first trigger signal in an effective state to the controller when a first power supply voltage output by the photovoltaic power supply module is greater than or equal to a first preset voltage; when the first power supply voltage is smaller than a first preset voltage, a first output voltage is output to the first load and the power supply conversion module, when the first power supply voltage is smaller than the first preset voltage, a first trigger signal in an invalid state is sent to the controller, and the first output voltage is stopped from being output to the first load and the power supply conversion module. And stopping outputting the first output voltage to the first load and the power supply conversion module, thereby reducing the risk that the first load is damaged when the low voltage of the first power supply voltage is unstable, protecting the photovoltaic power supply module, preventing the photovoltaic power supply module from being damaged or burnt out due to over-discharge, and improving the reliability of the photovoltaic power supply system.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic power supply, in particular to a photovoltaic power supply system. Background Art

[0002] With the advancement of energy conservation and emission reduction, the application of photovoltaic power supply systems is becoming more and more extensive. Photovoltaic power supply systems need to be equipped with frequency conversion controllers. The power supply of the frequency conversion controller is provided by the battery power supply module, and the power supply of the water pump is provided by the photovoltaic power supply module. Since the photovoltaic power supply module has the phenomenon of low voltage instability, if the photovoltaic power supply module still supplies power to the water pump under the condition of low voltage instability, the water pump may be damaged. Utility Model Content

[0003] The utility model provides a photovoltaic power supply system, which is used to solve the problem that when the voltage output by the photovoltaic power supply module is in a low-voltage unstable state, the load may be damaged.

[0004] In a first aspect, the utility model provides a photovoltaic power supply, including: a photovoltaic power supply module, a first undervoltage protection circuit, a power conversion module, a controller and a first load, wherein:

[0005] The photovoltaic power supply module outputs a first power supply voltage;

[0006] The first undervoltage protection circuit is connected to the output end of the photovoltaic power supply module and receives the first power supply voltage;

[0007] The power conversion module is connected to the first undervoltage protection circuit and the controller;

[0008] The controller is connected to the first undervoltage protection circuit;

[0009] The first load is connected to the first undervoltage protection circuit and the controller;

[0010] The first undervoltage protection circuit sends a first trigger signal of a valid state to the controller and outputs a first output voltage to the first load and the power conversion module when the first power supply voltage is greater than or equal to a first preset voltage. The first undervoltage protection circuit sends a first trigger signal of an invalid state to the controller and stops outputting the first output voltage to the first load and the power conversion module when the first power supply voltage is less than the first preset voltage.

[0011] In a possible implementation, when the first power supply voltage is greater than or equal to the first preset voltage, after receiving the first output voltage, the power conversion module converts the first output voltage into a supply voltage, and the supply voltage powers the controller and the first undervoltage protection circuit.

[0012] In a possible implementation, the first trigger signal in a valid state controls the controller to drive the first load to work normally, and the first trigger signal in an invalid state controls the controller to turn off the drive to stop the first load from working.

[0013] In a possible implementation, it also includes a battery power supply module, a second undervoltage protection circuit, a voltage reduction module, and a second load;

[0014] The battery power supply module is connected between the power conversion module and the second undervoltage protection circuit, and the battery power supply module outputs a second power supply voltage;

[0015] The voltage reduction module is connected to the power conversion module and the second undervoltage protection circuit;

[0016] The controller is connected to the voltage reduction module and the second undervoltage protection circuit;

[0017] The first undervoltage protection circuit is also connected to the voltage reduction module;

[0018] The second load is connected to the second undervoltage protection circuit and the controller;

[0019] The second under-voltage protection circuit sends a second trigger signal of a valid state to the controller and outputs a second output voltage to the second load and the buck module when the second power supply voltage is greater than or equal to the second preset voltage, and sends a second trigger signal of an invalid state to the controller and stops outputting the second output voltage to the second load and the buck module when the second power supply voltage is less than the second preset voltage, wherein the second trigger signal of a valid state indicates that the second power supply voltage is greater than or equal to the second preset voltage, and the second trigger signal of an invalid state indicates that the second power supply voltage is less than the second preset voltage;

[0020] Wherein, the first preset voltage is greater than the second preset voltage.

[0021] In a possible implementation, when the first power supply voltage is greater than or equal to the first preset voltage, the power conversion module converts the first output voltage into an intermediate power supply voltage after receiving the first output voltage, and the step-down module converts the intermediate power supply voltage into a power supply voltage after receiving the intermediate power supply voltage, and the power supply voltage powers the controller, the first under-voltage protection circuit, and the second under-voltage protection circuit.

[0022] In a possible implementation, when the second power supply voltage is greater than or equal to the second preset voltage, after receiving the second output voltage, the step-down module converts the second output voltage into a supply voltage, and the supply voltage powers the controller, the first under-voltage protection circuit, and the second under-voltage protection circuit.

[0023] In a possible implementation, the second trigger signal in a valid state controls the controller to drive the second load to work normally, and the second trigger signal in an invalid state controls the controller to turn off the drive to stop the second load from working.

[0024] In a possible implementation, in the first undervoltage protection circuit, when the first power supply voltage is greater than or equal to the first preset voltage, the power conversion module charges the battery power supply module; when the first power supply voltage is less than the first preset voltage, the power conversion module does not charge the battery power supply module.

[0025] In a possible implementation, the controller includes a variable frequency controller.

[0026] In a possible implementation manner, the first load includes a water pump.

[0027] In a possible implementation manner, the second load includes a device powered by a battery.

[0028] In a possible implementation, the first undervoltage protection circuit includes:

[0029] a first voltage stabilizing unit connected between the first switch unit and the ground terminal, wherein when the voltage across the first voltage stabilizing unit is greater than or equal to the first preset voltage, the first voltage stabilizing unit is turned on and provides a first control signal and a second control signal, and when the voltage across the first voltage stabilizing unit is less than the first preset voltage, the first voltage stabilizing unit is turned off;

[0030] The first switch unit, the first end of the first switch unit receives the first power supply voltage, the control end of the first switch unit receives the first control signal, when the first voltage stabilizing unit is turned on, the first control signal controls the first switch unit to be turned on, and the second end of the first switch unit outputs the first output voltage, when the first voltage stabilizing unit is turned off, the first switch unit is turned off, and the second end of the first switch unit stops outputting the first output voltage;

[0031] The first signal detection unit is connected between the power supply terminal and the ground terminal, receives the power supply voltage, and receives the second control signal. When the first voltage stabilizing unit is turned on, the second control signal controls the first signal detection unit to turn on the path between the power supply terminal and the ground terminal, and the first signal detection unit outputs the first trigger signal in a valid state. When the first voltage stabilizing unit is turned off, the first signal detection unit disconnects the path between the power supply terminal and the ground terminal, and the first signal detection unit outputs the first trigger signal in an invalid state.

[0032] In a possible implementation, the first voltage stabilizing unit includes a first diode and a first resistor;

[0033] A cathode of the first diode is connected to the first switch unit, and an anode of the first diode is connected to a first end of the first resistor and the first signal detection unit;

[0034] The second end of the first resistor is connected to the ground end.

[0035] In a possible implementation, the first switch unit includes a first switch tube;

[0036] The first end of the first switch tube receives the first power supply voltage, the control end of the first switch tube is connected to the first voltage stabilizing unit, when the first switch tube is turned on, the second end of the first switch tube outputs the first output voltage, and when the first switch tube is turned off, the second end of the first switch tube stops outputting the first output voltage.

[0037] In a possible implementation, the first signal detection unit includes a second resistor, a third resistor, and a second switch tube;

[0038] A first end of the second resistor is connected to the first voltage stabilizing unit, and a second end of the second resistor is connected to the control end of the second switch tube;

[0039] The first end of the second switch tube is connected to the first end of the third resistor and outputs the first trigger signal, and the second end of the second switch tube is connected to the ground end;

[0040] The second end of the third resistor is connected to the power supply end.

[0041] In a possible implementation manner, the first undervoltage protection circuit further includes:

[0042] A fourth resistor, wherein a first end of the fourth resistor is connected to the first power supply voltage input end, a second end of the fourth resistor is connected to a common node of the first switch unit and the first voltage stabilizing unit, and the fourth resistor shunts the driving current flowing into the first switch unit.

[0043] In a possible implementation manner, the first undervoltage protection circuit further includes:

[0044] A first capacitor is connected between a first power supply voltage input terminal and the ground terminal, and the first capacitor stabilizes the first power supply voltage.

[0045] In a possible implementation manner, the first preset voltage is a rated voltage of the first diode.

[0046] In a possible implementation, the second undervoltage protection circuit:

[0047] a second voltage stabilizing unit connected between the second switch unit and the ground terminal, when the voltage across the second voltage stabilizing unit is greater than or equal to the second preset voltage, the second voltage stabilizing unit is turned on and provides a third control signal and a fourth control signal, and when the voltage across the second voltage stabilizing unit is less than the second preset voltage, the second voltage stabilizing unit is turned off;

[0048] The second switch unit, the first end of the second switch unit receives the second power supply voltage, the control end of the second switch unit receives the third control signal, when the second voltage stabilizing unit is turned on, the third control signal controls the second switch unit to be turned on, and the second end of the second switch unit outputs the second output voltage, when the second voltage stabilizing unit is turned off, the second switch unit is turned off, and the second end of the second switch unit stops outputting the second output voltage;

[0049] The second signal detection unit is connected between the power supply terminal and the ground terminal, receives the power supply voltage, and receives the fourth control signal. When the second voltage stabilizing unit is turned on, the fourth control signal controls the second signal detection unit to turn on the path between the power supply terminal and the ground terminal, and the second signal detection unit outputs the second trigger signal in a valid state. When the second voltage stabilizing unit is turned off, the second signal detection unit disconnects the path between the power supply terminal and the ground terminal, and the second signal detection unit outputs the second trigger signal in an invalid state.

[0050] In a possible implementation, the second voltage stabilizing unit includes a second diode and a fifth resistor;

[0051] A cathode of the second diode is connected to the second switch unit, and an anode of the second diode is connected to the first end of the fifth resistor and the second signal detection unit;

[0052] The second end of the fifth resistor is connected to the ground end.

[0053] In a possible implementation, the second switch unit includes a third switch tube;

[0054] The first end of the third switch tube receives the second power supply voltage, the control end of the third switch tube is connected to the second voltage stabilizing unit, when the third switch tube is turned on, the second end of the third switch tube outputs the second output voltage, and when the third switch tube is turned off, the second end of the third switch tube stops outputting the second output voltage.

[0055] In a possible implementation, the second signal detection unit includes a sixth resistor, a seventh resistor and a fourth switch tube;

[0056] The first end of the sixth resistor is connected to the second voltage stabilizing unit, and the second end of the sixth resistor is connected to the control end of the fourth switch tube;

[0057] The first end of the fourth switch tube is connected to the first end of the seventh resistor and outputs the second trigger signal, and the second end of the fourth switch tube is connected to the ground end;

[0058] The second end of the seventh resistor is connected to the power supply end.

[0059] In a possible implementation manner, the second undervoltage protection circuit further includes:

[0060] An eighth resistor, wherein a first end of the eighth resistor is connected to the second power supply voltage input end, a second end of the eighth resistor is connected to a common node of the second switch unit and the second voltage stabilizing unit, and the eighth resistor shunts the driving current flowing into the second switch unit.

[0061] In a possible implementation manner, the second undervoltage protection circuit further includes:

[0062] A second capacitor is connected between a second power supply voltage input terminal and the ground terminal, and the second capacitor stabilizes the second power supply voltage.

[0063] In a possible implementation manner, the second preset voltage is a rated voltage of the second diode.

[0064] The beneficial effects of the utility model are as follows:

[0065] The utility model provides a photovoltaic power supply system, comprising a photovoltaic power supply module, a first undervoltage protection circuit, a power conversion module, a controller and a first load. When a first power supply voltage output by the photovoltaic power supply module is greater than or equal to a first preset voltage, the first undervoltage protection circuit sends a first trigger signal of a valid state to the controller, and outputs a first output voltage to the first load and the power conversion module. When the first power supply voltage is less than the first preset voltage, the first undervoltage protection circuit sends a first trigger signal of an invalid state to the controller, and stops outputting the first output voltage to the first load and the power conversion module. Since the first output voltage is stopped from being output to the first load and the power conversion module when the first power supply voltage is less than the first preset voltage, the risk of the first load being damaged is reduced when the first power supply voltage is low and unstable, and the photovoltaic power supply module is protected to prevent the photovoltaic power supply module from being damaged or caught fire due to over-discharge, thereby improving the reliability of the photovoltaic power supply system. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0067] Figure 1 A schematic diagram of the structure of a photovoltaic power supply system provided by an embodiment of the utility model;

[0068] Figure 2 A schematic diagram of the structure of another photovoltaic power supply system provided by an embodiment of the utility model;

[0069] Figure 3 A circuit diagram of a first undervoltage protection circuit provided by an embodiment of the utility model;

[0070] Figure 4 A circuit diagram of another first undervoltage protection circuit provided by an embodiment of the utility model;

[0071] Figure 5 A circuit diagram of a second undervoltage protection circuit provided by an embodiment of the utility model;

[0072] Figure 6 A circuit diagram of another second undervoltage protection circuit provided by an embodiment of the utility model;

[0073] Figure 7 A connection diagram of a voltage protection circuit provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0074] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0075] A photovoltaic power supply system provided by an embodiment of the utility model includes a photovoltaic power supply module, a first undervoltage protection circuit, a power conversion module, a controller and a first load. When the first power supply voltage output by the photovoltaic power supply module is greater than or equal to a first preset voltage, the first undervoltage protection circuit sends a first trigger signal of a valid state to the controller, and outputs a first output voltage to the first load and the power conversion module. When the first power supply voltage is less than the first preset voltage, the first undervoltage protection circuit sends a first trigger signal of an invalid state to the controller, and stops outputting the first output voltage to the first load and the power conversion module. Since the first output voltage is stopped from being output to the first load and the power conversion module when the first power supply voltage is less than the first preset voltage, the risk of the first load being damaged is reduced when the first power supply voltage is low and unstable, and the photovoltaic power supply module is protected to prevent damage or fire caused by over-discharge of the photovoltaic power supply module, thereby improving the reliability of the photovoltaic power supply system.

[0076] The present application is described in detail below with reference to specific embodiments.

[0077] like Figure 1 , which is a schematic diagram of the structure of a photovoltaic power supply system provided by an embodiment of the utility model, the photovoltaic power supply system includes a photovoltaic power supply module 11, a first undervoltage protection circuit 12, a power conversion module 13, a controller 14 and a first load 15;

[0078] Photovoltaic power supply module 11, outputting a first power supply voltage Vin1;

[0079] A first undervoltage protection circuit 12 is connected to the output end of the photovoltaic power supply module 11 and receives a first power supply voltage Vin1;

[0080] A power conversion module 13 connected to the first undervoltage protection circuit 12 and the controller 14;

[0081] A controller 14 connected to the first undervoltage protection circuit 12;

[0082] A first load 15 connected to the first undervoltage protection circuit 12 and the controller 14;

[0083] The first undervoltage protection circuit 12, when the first power supply voltage Vin1 is greater than or equal to the first preset voltage, sends a first trigger signal Vtro1 in a valid state to the controller, and outputs the first output voltage Vout1 to the first load 15 and the power conversion module 13; when the first power supply voltage Vin1 is less than the first preset voltage, sends a first trigger signal Vtig1 in an invalid state to the controller 14, and stops outputting the first output voltage Vout1 to the first load 15 and the power conversion module 13.

[0084] The first trigger signal Vtig1 in the valid state indicates that the first power supply voltage Vin1 is greater than or equal to the first preset voltage, and the first trigger signal Vtig1 in the invalid state indicates that the first power supply voltage Vin1 is less than the first preset voltage.

[0085] In one embodiment, when the first power supply voltage Vin is greater than or equal to the first preset voltage, after receiving the first output voltage Vout1, the power conversion module 13 converts the first output voltage Vout1 into a power supply voltage Vmcu, and the power supply voltage Vmcu supplies power to the controller 14 and the first undervoltage protection circuit 12;

[0086] After the controller 14 receives the power supply voltage Vmcu, it starts to work. When the controller 14 receives the first trigger signal Vtig1 in a valid state, it sends a drive signal to the first load 15 to control the first load 15 to work normally. When the controller 14 receives the first trigger signal Vtig1 in an invalid state, it turns off the drive, that is, stops sending the drive signal to the first load 15 to control the first load 15 to stop working.

[0087] like Figure 2 As shown, the photovoltaic power supply system further includes a battery power supply module 16, a second undervoltage protection circuit 17, a voltage reduction module 18 and a second load 19;

[0088] The battery power supply module 16 is connected between the power conversion module 13 and the second undervoltage protection circuit 17, and the battery power supply module 16 outputs a second power supply voltage Vin2;

[0089] The voltage reduction module 18 is connected to the power conversion module 13 and the second undervoltage protection circuit 17;

[0090] The controller 14 is connected to the voltage reduction module 18 and the second undervoltage protection circuit 17;

[0091] The first undervoltage protection circuit 12 is also connected to the voltage reduction module 18;

[0092] A second load 19 connected to the second undervoltage protection circuit 17 and the controller 14;

[0093] The second undervoltage protection circuit 17 sends a second trigger signal Vtig2 in a valid state to the controller 14 when the second power supply voltage Vin2 is greater than or equal to the second preset voltage, and outputs the second output voltage Vout2 to the second load 19 and the buck module 18; and sends a second trigger signal Vtig2 in an invalid state to the controller 14 when the second power supply voltage Vin2 is less than the second preset voltage, and stops outputting the second output voltage Vout2 to the second load 19 and the buck module 18;

[0094] Wherein, the first preset voltage is greater than the second preset voltage.

[0095] The second trigger signal Vtig2 in the valid state indicates that the second power supply voltage Vin2 is greater than or equal to the second preset voltage, and the second trigger signal Vtig2 in the invalid state indicates that the second power supply voltage Vin2 is less than the second preset voltage.

[0096] In the embodiment of the utility model, when the second power supply voltage Vin2 is less than the second preset voltage, the second undervoltage protection circuit 17 sends an invalid second trigger signal Vtig2 to the controller 14, and stops outputting the second output voltage Vout2 to the second load 19 and the buck module 18, thereby preventing the battery power supply module from being over-discharged and causing damage to the battery power supply module, or catching fire and burning.

[0097] In one embodiment, when the first power supply voltage Vin is greater than or equal to the first preset voltage, the power conversion module 13 converts the first output voltage Vout1 into an intermediate power supply voltage after receiving the first output voltage Vout1, and the step-down module 18 converts the intermediate power supply voltage into a power supply voltage Vmcu after receiving the intermediate power supply voltage, and the power supply voltage Vmcu supplies power to the controller 14, the first undervoltage protection circuit 12 and the second undervoltage protection circuit 17.

[0098] When the second power supply voltage Vin2 is greater than or equal to the second preset voltage, the step-down module 18 receives the second output voltage Vout2 and converts the second output voltage Vout2 into a power supply voltage Vmcu, which supplies power to the controller 14, the first undervoltage protection circuit 12 and the second undervoltage protection circuit 17.

[0099] In the embodiment of the utility model, the second trigger signal Vtig2 in the effective state controls the controller 14 to drive the second load 19 to work normally, and the second trigger signal Vtig2 in the invalid state controls the controller 14 to turn off the drive, so that the second load 19 stops working, that is, after the controller 14 receives the second trigger signal Vtig2 in the effective state, it drives the second load 19 to work normally, and after the controller 14 receives the second trigger signal Vtig2 in the invalid state, it controls the second load 19 to stop working. Since the second trigger signal Vtig2 in the invalid state is output by the second under-voltage protection voltage when the second power supply voltage Vin2 is less than the second preset voltage, it can prevent the battery power supply module from being over-discharged and causing damage to the battery power supply module, or catching fire and burning.

[0100] In one embodiment, when the first power supply voltage Vin1 is greater than or equal to the first preset voltage, the power conversion module 13 charges the battery power supply module 16. When the first power supply voltage Vin1 is less than the first preset voltage, the power conversion module 13 does not charge the battery power supply module 16.

[0101] In the embodiment of the utility model, the power conversion module 13 converts the first output voltage Vout1, and provides the converted intermediate power supply voltage to the step-down module 18. The battery power supply module 16 can be charged with the voltage converted by the power conversion module 13. When the photovoltaic power supply module 11 is normal, the system can use the voltage provided by the photovoltaic power supply module 11 for power supply. When the photovoltaic power supply module 11 is abnormal, the system can use the voltage provided by the battery power supply module 16 for power supply.

[0102] The use of the photovoltaic power supply module 11 or the battery power supply module 16 for power supply can improve the flexibility of the system.

[0103] In a specific implementation, the controller 14 may be a variable frequency controller, the first load 15 may be a water pump, and the second load 19 may be a device powered by a battery.

[0104] Figure 2 In the photovoltaic power supply system shown, when the first power supply voltage Vin1 is greater than or equal to the first preset voltage, the first undervoltage protection circuit 12 outputs the first output voltage Vout1 to the power conversion module 13 and the first load 18, and outputs the first trigger signal Vtig1 of the valid state to the controller 14. After receiving the first trigger signal Vtig1 of the valid state, the controller 14 outputs normally to the first load 15. After receiving the first output voltage Vout1 output by the first undervoltage protection circuit 12 and the normal output of the controller 14, the first load 15 works normally.

[0105] After receiving the first output voltage Vout1 output by the first undervoltage protection circuit 12, the power conversion module 16 performs voltage conversion on the received first output voltage Vout1 to obtain an intermediate power supply voltage, and outputs the intermediate power supply voltage to the step-down module 18, and the power conversion module 16 performs voltage conversion on the first output voltage Vout1, and uses the converted voltage to charge the battery power supply module 16;

[0106] The battery power supply module 16 is charged by the voltage output by the power conversion module 13, and the battery power supply module 16 outputs the second power supply voltage Vin2 to the step-down module 18 and the second load 19;

[0107] After the voltage is reduced, the voltage reduction module 18 provides the power supply voltage Vmcu to the controller 14 and also provides the power supply voltage Vmcu to the first undervoltage protection circuit 12;

[0108] When the first power supply voltage Vin1 is less than the first preset voltage, the first undervoltage protection circuit 12 stops outputting the first output voltage Vout1 to the first load 15 and the power conversion module 13, and sends the first trigger signal Vtig1 of the invalid state to the controller 14;

[0109] After receiving the first trigger signal Vtig1 in the invalid state, the controller 14 stops outputting the driving signal to the first load 15, and controls the first load 15 to stop working, so as to reduce the risk of the first load 15 being damaged under low voltage conditions, thereby protecting the load;

[0110] The first undervoltage protection circuit 12 stops outputting the first output voltage Vout1 to the power conversion module 13 , and the power conversion module 13 stops working, thereby protecting the power conversion module 13 from the risk of being damaged in a low voltage situation.

[0111] In the embodiment of the utility model, when the first power supply voltage Vin1 is less than the first preset voltage, the load in the photovoltaic power supply system stops working, thereby reducing the risk of the load being damaged due to low-voltage power supply.

[0112] The specific structures of the first undervoltage protection circuit 12 and the second undervoltage protection circuit 17 provided in the embodiment of the utility model are described in detail below.

[0113] In the specific implementation, Figure 3 , which is a circuit diagram of a first undervoltage protection circuit provided by an embodiment of the utility model, the first undervoltage protection circuit includes a first switch unit 111, a first voltage stabilizing unit 112 and a first signal detection unit 113;

[0114] A first voltage stabilizing unit 112 is connected between the first switch unit 111 and the ground terminal. When the voltage across the first voltage stabilizing unit 112 is greater than or equal to the first preset voltage, the first voltage stabilizing unit 112 is turned on and provides a first control signal and a second control signal. When the voltage across the first voltage stabilizing unit 112 is less than the first preset voltage, the first voltage stabilizing unit 112 is turned off.

[0115] A first switch unit 111, wherein a first end of the first switch unit 111 receives a first power supply voltage Vin1, and a control end of the first switch unit 111 receives a first control signal. When the first voltage stabilizing unit 112 is turned on, the first control signal controls the first switch unit 111 to be turned on, and a second end of the first switch unit 111 outputs a first output voltage Vout1. When the first voltage stabilizing unit 112 is turned off, the first switch unit 111 is turned off, and a second end of the first switch unit 111 stops outputting the first output voltage Vout1.

[0116] The first signal detection unit 113 is connected between the power supply end and the ground end, receives the power supply voltage Vmcu, and receives the second control signal. When the first voltage stabilizing unit 112 is turned on, the second control signal controls the first signal detection unit 113 to turn on the path between the power supply end and the ground end, and the first signal detection unit 113 outputs the first trigger signal Vtig1 in a valid state. When the first voltage stabilizing unit 112 is turned off, the first signal detection unit 113 disconnects the path between the power supply end and the ground end, and the first signal detection unit 113 outputs the first trigger signal Vtig1 in an invalid state.

[0117] Specifically, Figure 3 As shown, the first voltage stabilizing unit 112 includes a first diode D1 and a first resistor R1;

[0118] The cathode of the first diode D1 is electrically connected to the control end of the first switch tube Q1, and the anode of the first diode D1 is electrically connected to the first end of the first resistor R1 and the first signal detection unit 113;

[0119] The second end of the first resistor R1 is electrically connected to the ground end GND.

[0120] like Figure 3 As shown, the first switch unit 111 includes a first switch tube Q1;

[0121] The first end of the first switch tube Q1 receives the first power supply voltage Vin1, and the control end of the first switch tube Q1 is connected to the first voltage stabilizing unit 112. When the first switch tube Q1 is turned on, the second end of the first switch tube Q1 outputs the first output voltage Vout1. When the first switch tube Q1 is turned off, the second end of the first switch tube Q1 stops outputting the first output voltage Vout1.

[0122] like Figure 3 As shown, the first signal detection unit 113 includes a second switch tube Q2, a second resistor R2 and a third resistor R3;

[0123] A first end of the second resistor R2 is connected to the first voltage stabilizing unit 112, and a second end of the second resistor R2 is connected to the control end of the second switch tube Q2;

[0124] A first end of the second switch tube Q2 is connected to a first end of the third resistor R3 and outputs a first trigger signal Vtig1 , and a second end of the second switch tube Q2 is connected to a ground end;

[0125] The second end of the third resistor R3 is connected to the power supply end.

[0126] In the embodiment of the utility model, the first diode D1 may be a voltage regulator tube, and the first preset voltage may be the rated voltage of the voltage regulator tube, that is, the first preset voltage may be the rated voltage of the first diode D1.

[0127] Refer to the following Figure 3 The working principle of the first undervoltage protection circuit provided in the embodiment of the utility model is described.

[0128] When the first power supply voltage Vin1 is less than the rated voltage of the Zener tube (first diode D1), the first switch tube Q1 is not turned on, and the rear-end load (the first load 15 and the power conversion module 13) is not powered, thereby protecting the rear-end load; since the Zener tube is not turned on, the second switch tube Q2 is not turned on, and the first signal detection unit 113 outputs the first trigger signal Vtig1 in an invalid state, that is, a high level. After receiving the first trigger signal Vtig1 in an invalid state, the controller 14 turns off the power supply of other loads to prevent the load from being damaged due to excessively low voltage.

[0129] When the first power supply voltage Vin1 is greater than or equal to the rated voltage of the Zener tube, the first switch tube Q1 is turned on to supply power to the back-end load. Since the Zener tube is turned on, the second switch tube Q2 is turned on, and the first signal detection unit 113 outputs the first trigger signal Vtig1 in a valid state, that is, a low level. After the controller 14 receives the first trigger signal Vtig1 in a valid state, the system works normally.

[0130] In one embodiment, if Figure 4 As shown, the first undervoltage protection circuit provided by the utility model further includes a fourth resistor R4;

[0131] A first end of the fourth resistor R4 is connected to the first power supply voltage input terminal, a second end of the fourth resistor R4 is connected to a common node of the first switch unit 111 and the first voltage stabilizing unit 112 , and the fourth resistor R4 shunts the driving current flowing into the first switch unit 111 .

[0132] The first power supply voltage input terminal inputs the first power supply voltage Vin1.

[0133] like Figure 4 As shown, the first undervoltage protection circuit provided by the embodiment of the utility model may further include a first capacitor C1;

[0134] The first capacitor C1 is connected between the first power voltage input terminal and the ground terminal, and the first capacitor C1 stabilizes the first power voltage Vin1.

[0135] In one embodiment, if Figure 5 As shown, the second undervoltage protection circuit 19 includes a second switch unit 191, a second voltage stabilizing unit 192 and a second signal detection unit 193;

[0136] The second voltage stabilizing unit 192 is connected between the second switch unit 191 and the ground terminal. When the voltage across the second voltage stabilizing unit 192 is greater than or equal to the second preset voltage, the second voltage stabilizing unit 192 is turned on and provides a third control signal and a fourth control signal. When the voltage across the second voltage stabilizing unit 192 is less than the second preset voltage, the second voltage stabilizing unit 192 is turned off.

[0137] A second switch unit 191, wherein a first end of the second switch unit 191 receives a second power supply voltage Vin2, and a control end of the second switch unit 191 receives a third control signal. When the second voltage stabilizing unit 192 is turned on, the third control signal controls the second switch unit 191 to be turned on, and a second end of the second switch unit 191 outputs a second output voltage Vout2. When the second voltage stabilizing unit 192 is turned off, the second switch unit 191 is turned off, and a second end of the second switch unit 191 stops outputting the second output voltage Vout2.

[0138] The second signal detection unit 193 is connected between the power supply terminal and the ground terminal, receives the power supply voltage Vmcu, and receives the fourth control signal. When the second voltage stabilizing unit 191 is turned on, the fourth control signal controls the second signal detection unit 193 to turn on the path between the power supply terminal and the ground terminal, and the second signal detection unit 193 outputs the second trigger signal Vtig2 in a valid state. When the second voltage stabilizing unit 191 is turned off, the second signal detection unit 193 disconnects the path between the power supply terminal and the ground terminal, and the second signal detection unit 193 outputs the second trigger signal Vtig2 in an invalid state.

[0139] Specifically, Figure 5 As shown, the second voltage stabilizing unit 192 includes a second diode D2 and a fifth resistor R5;

[0140] The cathode of the second diode D2 is connected to the second switch unit 191, and the anode of the second diode D2 is connected to the first end of the fifth resistor R5 and the second signal detection unit 193;

[0141] A second end of the fifth resistor R5 is connected to the ground.

[0142] like Figure 5 As shown, the second switch unit 191 includes a third switch tube Q3;

[0143] The first end of the third switch tube Q3 receives the second power supply voltage Vin2, and the control end of the third switch tube Q3 is connected to the second voltage stabilizing unit 192. When the third switch tube Q3 is turned on, the second end of the third switch tube Q3 outputs the second output voltage Vout2. When the third switch tube Q3 is turned off, the second end of the third switch tube Q3 stops outputting the second output voltage Vout2.

[0144] like Figure 5 As shown, the second signal detection unit 193 includes a sixth resistor R6, a seventh resistor R7 and a fourth switch tube Q4;

[0145] A first end of the sixth resistor R6 is connected to the second voltage stabilizing unit 192, and a second end of the sixth resistor R6 is connected to the control end of the fourth switch tube Q4;

[0146] A first end of the fourth switch tube Q4 is connected to a first end of the seventh resistor R7 and outputs a second trigger signal Vtig2, and a second end of the fourth switch tube Q4 is connected to the ground end;

[0147] A second end of the seventh resistor R7 is connected to the power supply end.

[0148] In one embodiment, if Figure 6 As shown, the second undervoltage protection circuit also includes:

[0149] The eighth resistor R8 has a first end connected to the second power supply voltage input end, a second end connected to a common node of the second switch unit 191 and the second voltage stabilizing unit 192 , and the eighth resistor R8 shunts the driving current flowing into the second switch unit 191 .

[0150] like Figure 6 As shown, the second undervoltage protection circuit also includes:

[0151] The second capacitor C2 is connected between the second power supply voltage input terminal and the ground terminal, and the second capacitor C2 stabilizes the second power supply voltage.

[0152] In the embodiment of the utility model, the second diode D2 may be a voltage regulator tube, and the second preset voltage may be the rated voltage of the voltage regulator tube, that is, the rated voltage of the second diode D2.

[0153] Combine the following Figure 2 and Figure 6The working principle of the second undervoltage protection circuit in the photovoltaic power supply system provided by the embodiment of the utility model is explained.

[0154] When the second power supply voltage Vin2 output by the battery power supply module 16 is less than the rated voltage of the second diode D2, the third switch tube Q3 is not turned on, and no power is supplied to the rear-end load (the second load 19 and the step-down module 18), thereby protecting the rear-end load and the battery power supply module 16. Since the second diode D2 is not turned on, the fourth switch tube Q4 is not turned on, and the second signal detection unit 193 outputs the second trigger signal Vtig2 in the valid state, that is, a high level. After receiving the second trigger signal Vtig2 in the valid state, the controller 14 turns off the drive signal of the second load 19 to prevent the load from being damaged due to too low voltage.

[0155] When the second power supply voltage Vin2 is greater than or equal to the rated voltage of the second diode D2, the third switch tube Q3 is turned on to supply power to the rear-end load. Since the second diode D2 is turned on, the fourth switch tube Q4 is turned on, and the second signal detection unit 193 outputs the second trigger signal Vtig2 in an invalid state, that is, a low level. After receiving the second trigger signal Vtig2 in an invalid state, the controller 14 provides a drive signal to the second load 19.

[0156] It should be noted that when the photovoltaic power supply system includes both the first undervoltage protection circuit and the second undervoltage protection circuit, when the controller 14 receives any one of the first trigger signal Vtig1 in the effective state and the second trigger signal Vtig2 in the effective state, or receives both, the controller 14 will control the load to stop working, thereby protecting the load.

[0157] In one embodiment, the photovoltaic power supply system provided by the utility model may further include a first voltage detection circuit;

[0158] The first voltage detection circuit is connected between the photovoltaic power supply module 11 and the controller 14, and is used to detect the first power supply voltage Vin1. When the first power supply voltage Vin1 is higher than the third preset voltage, an alarm signal is sent to the controller 14, and the system alarm is shut down to prevent damage to other equipment.

[0159] The photovoltaic power supply system provided by the embodiment of the utility model may further include a second voltage detection circuit;

[0160] The second voltage detection circuit is connected between the battery power module 16 and the controller 14, and is used to detect the second power supply voltage Vin2 output by the battery power module. When the second power supply voltage Vin2 is higher than the fourth preset voltage, an alarm signal is sent to the controller 14, and the system alarm is shut down to prevent damage to other equipment.

[0161] The photovoltaic power supply system provided in the embodiment of the utility model includes an undervoltage protection circuit (a first undervoltage protection circuit or a second undervoltage protection circuit), such as Figure 7 As shown, the DC power supply output passes through the undervoltage protection circuit as the power input of the device. The DC power supply output can be the power output of the photovoltaic power supply module or the power output of the battery power supply module. The undervoltage protection circuit detects whether the voltage of the DC power supply output meets the preset voltage (the first preset voltage or the second preset voltage). If it meets the preset voltage, the undervoltage protection circuit outputs the voltage of the DC power supply output to the load, and sends a trigger signal of a valid state (the first trigger signal or the second trigger signal) to the controller, triggering the controller to output a drive signal to the load connected thereto; if it does not meet the preset voltage, the undervoltage protection circuit does not input or output the DC power supply output to the load, and sends an invalid state trigger signal (the first trigger signal or the second trigger signal) to the controller. If the load does not receive the DC power supply output, it stops working. The controller receives the invalid state trigger signal and does not output the drive signal to the load connected thereto, and the load connected thereto does not work, thereby protecting the load and the power supply.

[0162] The undervoltage protection circuit in the embodiment of the utility model can be placed at the output end of any power supply in the circuit of the photovoltaic power supply system, and can also be placed at the front end of the auxiliary power supply (battery power supply module).

[0163] The embodiment of the utility model adopts transistors and voltage regulators to realize undervoltage protection, and the cost of both devices is reduced and the solution is simple. In addition, the embodiment of the utility model can prevent the input power supply from being effectively protected when the software fails, thereby causing damage to the input power supply or over-discharge, especially in battery applications, where over-discharge of the battery is easy to damage and cause fire.

[0164] Those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include these modifications and variations.

Claims

1. A photovoltaic power supply system, characterized in that: include: A photovoltaic power supply module, a first undervoltage protection circuit, a power conversion module, a controller and a first load, wherein: The photovoltaic power supply module outputs a first power supply voltage; The first undervoltage protection circuit is connected to the output end of the photovoltaic power supply module and receives the first power supply voltage; The power conversion module is connected to the first undervoltage protection circuit and the controller; The controller is connected to the first undervoltage protection circuit; The first load is connected to the first undervoltage protection circuit and the controller; The first undervoltage protection circuit sends a first trigger signal of a valid state to the controller and outputs a first output voltage to the first load and the power conversion module when the first power supply voltage is greater than or equal to a first preset voltage. The first undervoltage protection circuit sends a first trigger signal of an invalid state to the controller and stops outputting the first output voltage to the first load and the power conversion module when the first power supply voltage is less than the first preset voltage.

2. The photovoltaic power supply system according to claim 1, characterized in that: When the first power supply voltage is greater than or equal to the first preset voltage, the power conversion module converts the first output voltage into a supply voltage after receiving the first output voltage, and the supply voltage supplies power to the controller and the first undervoltage protection circuit.

3. The photovoltaic power supply system according to claim 1, characterized in that: The first trigger signal in a valid state controls the controller to drive the first load to work normally, and the first trigger signal in an invalid state controls the controller to turn off the drive, so that the first load stops working.

4. The photovoltaic power supply system according to claim 1, characterized in that: It also includes a battery power supply module, a second undervoltage protection circuit, a voltage reduction module and a second load; The battery power supply module is connected between the power conversion module and the second undervoltage protection circuit, and the battery power supply module outputs a second power supply voltage; The voltage reduction module is connected to the power conversion module and the second undervoltage protection circuit; The controller is connected to the voltage reduction module and the second undervoltage protection circuit; The first undervoltage protection circuit is also connected to the voltage reduction module; The second load is connected to the second undervoltage protection circuit and the controller; The second under-voltage protection circuit sends a second trigger signal of a valid state to the controller and outputs a second output voltage to the second load and the step-down module when the second power supply voltage is greater than or equal to a second preset voltage, and sends a second trigger signal of an invalid state to the controller and stops outputting the second output voltage to the second load and the step-down module when the second power supply voltage is less than the second preset voltage; Wherein, the first preset voltage is greater than the second preset voltage.

5. The photovoltaic power supply system according to claim 4, characterized in that: When the first power supply voltage is greater than or equal to the first preset voltage, the power conversion module converts the first output voltage into an intermediate power supply voltage after receiving the first output voltage, and the step-down module converts the intermediate power supply voltage into a power supply voltage after receiving the intermediate power supply voltage, and the power supply voltage supplies power to the controller, the first under-voltage protection circuit and the second under-voltage protection circuit.

6. The photovoltaic power supply system according to claim 4, characterized in that: When the second power supply voltage is greater than or equal to the second preset voltage, the step-down module converts the second output voltage into a supply voltage after receiving the second output voltage, and the supply voltage supplies power to the controller, the first undervoltage protection circuit and the second undervoltage protection circuit.

7. The photovoltaic power supply system according to claim 4, characterized in that: The second trigger signal in a valid state controls the controller to drive the second load to work normally, and the second trigger signal in an invalid state controls the controller to turn off the drive, so that the second load stops working.

8. The photovoltaic power supply system according to claim 4, characterized in that: The first undervoltage protection circuit is configured such that when the first power supply voltage is greater than or equal to the first preset voltage, the power conversion module charges the battery power supply module; when the first power supply voltage is less than the first preset voltage, the power conversion module does not charge the battery power supply module.

9. The photovoltaic power supply system according to any one of claims 1 to 6, characterized in that: The controller comprises a variable frequency controller.

10. The photovoltaic power supply system according to claim 1, characterized in that: The first load includes a water pump.

11. The photovoltaic power supply system according to claim 4, characterized in that: The second load includes a device powered by a battery.

12. The photovoltaic power supply system according to claim 1, characterized in that: The first undervoltage protection circuit comprises: a first voltage stabilizing unit connected between the first switch unit and the ground terminal, wherein when the voltage across the first voltage stabilizing unit is greater than or equal to the first preset voltage, the first voltage stabilizing unit is turned on and provides a first control signal and a second control signal, and when the voltage across the first voltage stabilizing unit is less than the first preset voltage, the first voltage stabilizing unit is turned off; The first switch unit, the first end of the first switch unit receives the first power supply voltage, the control end of the first switch unit receives the first control signal, when the first voltage stabilizing unit is turned on, the first control signal controls the first switch unit to be turned on, and the second end of the first switch unit outputs the first output voltage, when the first voltage stabilizing unit is turned off, the first switch unit is turned off, and the second end of the first switch unit stops outputting the first output voltage; The first signal detection unit is connected between the power supply terminal and the ground terminal, receives the power supply voltage, and receives the second control signal. When the first voltage stabilizing unit is turned on, the second control signal controls the first signal detection unit to turn on the path between the power supply terminal and the ground terminal, and the first signal detection unit outputs the first trigger signal in a valid state. When the first voltage stabilizing unit is turned off, the first signal detection unit disconnects the path between the power supply terminal and the ground terminal, and the first signal detection unit outputs the first trigger signal in an invalid state.

13. The photovoltaic power supply system according to claim 12, characterized in that: The first voltage stabilizing unit includes a first diode and a first resistor; A cathode of the first diode is connected to the first switch unit, and an anode of the first diode is connected to a first end of the first resistor and the first signal detection unit; The second end of the first resistor is connected to the ground end.

14. The photovoltaic power supply system according to claim 12, characterized in that: The first switch unit includes a first switch tube; The first end of the first switch tube receives the first power supply voltage, the control end of the first switch tube is connected to the first voltage stabilizing unit, when the first switch tube is turned on, the second end of the first switch tube outputs the first output voltage, and when the first switch tube is turned off, the second end of the first switch tube stops outputting the first output voltage.

15. The photovoltaic power supply system according to claim 12, characterized in that: The first signal detection unit includes a second resistor, a third resistor and a second switch tube; A first end of the second resistor is connected to the first voltage stabilizing unit, and a second end of the second resistor is connected to the control end of the second switch tube; The first end of the second switch tube is connected to the first end of the third resistor and outputs the first trigger signal, and the second end of the second switch tube is connected to the ground end; The second end of the third resistor is connected to the power supply end.

16. The photovoltaic power supply system according to claim 12, characterized in that: The first undervoltage protection circuit further includes: A fourth resistor, wherein a first end of the fourth resistor is connected to the first power supply voltage input end, a second end of the fourth resistor is connected to a common node of the first switch unit and the first voltage stabilizing unit, and the fourth resistor shunts the driving current flowing into the first switch unit.

17. The photovoltaic power supply system according to claim 12, characterized in that: The first undervoltage protection circuit further includes: A first capacitor is connected between a first power supply voltage input terminal and the ground terminal, and the first capacitor stabilizes the first power supply voltage.

18. The photovoltaic power supply system according to claim 13, characterized in that: The first preset voltage is a rated voltage of the first diode.

19. The photovoltaic power supply system according to claim 4, characterized in that: The second undervoltage protection circuit: a second voltage stabilizing unit connected between the second switch unit and the ground terminal, when the voltage across the second voltage stabilizing unit is greater than or equal to the second preset voltage, the second voltage stabilizing unit is turned on and provides a third control signal and a fourth control signal, and when the voltage across the second voltage stabilizing unit is less than the second preset voltage, the second voltage stabilizing unit is turned off; The second switch unit, the first end of the second switch unit receives the second power supply voltage, the control end of the second switch unit receives the third control signal, when the second voltage stabilizing unit is turned on, the third control signal controls the second switch unit to be turned on, and the second end of the second switch unit outputs the second output voltage, when the second voltage stabilizing unit is turned off, the second switch unit is turned off, and the second end of the second switch unit stops outputting the second output voltage; The second signal detection unit is connected between the power supply terminal and the ground terminal, receives the power supply voltage, and receives the fourth control signal. When the second voltage stabilizing unit is turned on, the fourth control signal controls the second signal detection unit to turn on the path between the power supply terminal and the ground terminal, and the second signal detection unit outputs the second trigger signal in a valid state. When the second voltage stabilizing unit is turned off, the second signal detection unit disconnects the path between the power supply terminal and the ground terminal, and the second signal detection unit outputs the second trigger signal in an invalid state.

20. The photovoltaic power supply system according to claim 19, characterized in that: The second voltage stabilizing unit includes a second diode and a fifth resistor; A cathode of the second diode is connected to the second switch unit, and an anode of the second diode is connected to the first end of the fifth resistor and the second signal detection unit; The second end of the fifth resistor is connected to the ground end.

21. The photovoltaic power supply system according to claim 19, characterized in that: The second switch unit includes a third switch tube; The first end of the third switch tube receives the second power supply voltage, the control end of the third switch tube is connected to the second voltage stabilizing unit, when the third switch tube is turned on, the second end of the third switch tube outputs the second output voltage, and when the third switch tube is turned off, the second end of the third switch tube stops outputting the second output voltage.

22. The photovoltaic power supply system according to claim 19, characterized in that: The second signal detection unit includes a sixth resistor, a seventh resistor and a fourth switch tube; The first end of the sixth resistor is connected to the second voltage stabilizing unit, and the second end of the sixth resistor is connected to the control end of the fourth switch tube; The first end of the fourth switch tube is connected to the first end of the seventh resistor and outputs the second trigger signal, and the second end of the fourth switch tube is connected to the ground end; The second end of the seventh resistor is connected to the power supply end.

23. The photovoltaic power supply system according to claim 19, characterized in that: The second undervoltage protection circuit further includes: An eighth resistor, wherein a first end of the eighth resistor is connected to the second power supply voltage input end, a second end of the eighth resistor is connected to a common node of the second switch unit and the second voltage stabilizing unit, and the eighth resistor shunts the driving current flowing into the second switch unit.

24. The photovoltaic power supply system according to claim 19, characterized in that: The second undervoltage protection circuit further includes: A second capacitor is connected between a second power supply voltage input terminal and the ground terminal, and the second capacitor stabilizes the second power supply voltage.

25. The photovoltaic power supply system according to claim 20, characterized in that: The second preset voltage is a rated voltage of the second diode.

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