CN111585324A - Low-voltage protection circuit and charger - Google Patents
Low-voltage protection circuit and charger Download PDFInfo
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- CN111585324A CN111585324A CN202010436774.4A CN202010436774A CN111585324A CN 111585324 A CN111585324 A CN 111585324A CN 202010436774 A CN202010436774 A CN 202010436774A CN 111585324 A CN111585324 A CN 111585324A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
- H02J7/0031—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits using battery or load disconnect circuits
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/24—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to undervoltage or no-voltage
- H02H3/243—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to undervoltage or no-voltage for DC systems
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/34—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering
- H02J7/35—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering with light sensitive cells
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2207/00—Indexing scheme relating to details of circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J2207/10—Control circuit supply, e.g. means for supplying power to the control circuit
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
Abstract
The invention relates to the technical field of protection circuits, and discloses a low-voltage protection circuit and a charger, which are applied to a charging loop of a photovoltaic power generation energy storage system. Therefore, when the charging loop is in a low voltage state, the comparison circuit controls the switch circuit to be in a broken circuit working state, and then the power supply for the system controller is cut off, so that the system controller is prevented from working in an undervoltage state, and the system controller is reliably protected from low voltage.
Description
Technical Field
The invention relates to the technical field of protection circuits, in particular to a low-voltage protection circuit and a charger.
Background
In the use process of the off-grid photovoltaic power generation energy storage product, the intelligent requirement of a user on the energy storage product is higher and higher, and particularly the requirements on intelligent activation and intelligent charging of the energy storage product are increasingly remarkable. When a user uses the solar photovoltaic power generation panel, the user usually hopes that after the photovoltaic power generation panel is connected with the energy storage product, the product can be intelligently activated and intelligently charged, even if the change of day and night is passed, in the morning of the next day, when the photovoltaic power generation panel has energy output, the energy storage product can still be normally activated to be charged. Therefore, in the off-grid photovoltaic power generation energy storage product, most energy storage products adopt a power supply scheme of activating the MCU by double power supplies in the design of the MCU power supply loop, namely, the power supply loop design with mutually compatible batteries and photovoltaic power generation panels is adopted, the software control strategy is right, and the charging port of the energy storage product is detected in real time so as to control, so that the intelligent activation and charging of the energy storage product by the photovoltaic power generation panels can be realized.
However, in the practical use process, because the photovoltaic power generation board is influenced by the illumination intensity greatly, when external illumination intensity is weaker, the electric energy output by the photovoltaic power generation board is very low, though the MCU can be activated, the energy required by the normal work of the MCU cannot be maintained, so that the MCU is in an under-voltage working state for a long time, and further the MCU enters a dormant state, and the user experience is seriously influenced because the requirements of intelligent activation and intelligent charging of a user cannot be met. Therefore, in an off-grid photovoltaic power generation and energy storage product, the design of a low-voltage protection circuit for MCU power supply is very important.
Disclosure of Invention
In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a low voltage protection circuit and a charger, so as to implement low voltage protection.
The purpose of the invention is realized by the following technical scheme:
in order to solve the above technical problem, in a first aspect, an embodiment of the present invention provides a low voltage protection circuit applied to a charging loop of a photovoltaic power generation energy storage system, including:
the sampling circuit is used for sampling the input voltage of the charging loop;
the voltage stabilizing circuit is used for providing reference voltage;
the comparison circuit is respectively connected with the sampling circuit and the voltage stabilizing circuit and is used for outputting a control signal according to a sampling signal and the reference voltage; and
and the switching circuit is respectively connected with the comparison circuit and the charging loop and is used for controlling the working state of the charging loop according to the control signal, and the working state comprises a closed circuit state and an open circuit state.
Optionally, the switching circuit includes: the first switch circuit and the second switch circuit are connected in series, the first switch circuit is further connected with the comparison circuit, and the second switch circuit is further connected with the charging loop.
Optionally, the sampling circuit includes a first operational amplifier, a non-inverting input terminal of the first operational amplifier is connected to the input voltage negative electrode of the charging loop, an inverting input terminal of the first operational amplifier is connected to the input voltage positive electrode of the charging loop, and an output terminal of the first operational amplifier is connected to the comparison circuit.
Optionally, the comparison circuit includes a second operational amplifier, a non-inverting input terminal of the second operational amplifier is connected to the output terminal of the first operational amplifier, and an inverting input terminal of the second operational amplifier is connected to the voltage stabilizing circuit and the positive input voltage terminal of the charging loop, respectively.
Optionally, a power supply end of the second operational amplifier is connected to a positive electrode of the input voltage of the charging loop.
Optionally, the first switch circuit is a triode, a base of the triode is connected with an output end of the second remote computing amplifier, a collector of the triode is connected with the second switch circuit, and an emitter of the triode is grounded.
Optionally, the second switch circuit is an MOS switch tube, and a collector of the triode is connected to a gate of the MOS switch tube to control on or off of the MOS switch tube.
Optionally, the voltage stabilizing circuit includes a voltage regulator tube, a negative electrode of the voltage regulator tube is connected to the inverting input terminal of the second operational amplifier, and a positive electrode of the voltage regulator tube is grounded.
In a second aspect, an embodiment of the present invention provides a charger, including:
the photovoltaic power generation system is used for generating electric energy by adopting the photovoltaic system;
the low-voltage protection circuit is connected with the photovoltaic power generation system and used for low-voltage protection; and
and the charging loop is respectively connected with the low-voltage protection circuit and the system controller and is used for supplying power to the system controller by the electric energy generated by the photovoltaic power generation system.
Compared with the prior art, the invention has the beneficial effects that: different from the situation of the prior art, the embodiment of the invention provides a low-voltage protection circuit, which is applied to a charging loop of a photovoltaic power generation energy storage system, and comprises a sampling circuit, a voltage stabilizing circuit, a comparison circuit and a switch circuit, wherein the sampling circuit is used for sampling an input voltage of the charging loop, the voltage stabilizing circuit is used for providing a reference voltage, the comparison circuit is respectively connected with the sampling circuit and the voltage stabilizing circuit and is used for outputting a control signal according to the sampling signal and the reference voltage, and the switch circuit is respectively connected with the comparison circuit and the charging loop and is used for controlling the working state of the charging loop according to the control signal, and the working state comprises an on state and an off state. Therefore, when the charging loop is in a low voltage state, the comparison circuit controls the switch circuit to be in a broken circuit working state, and then the power supply for the system controller is cut off, so that the system controller is prevented from working in an undervoltage state, and the system controller is reliably protected from low voltage.
Drawings
One or more embodiments are illustrated by the accompanying figures in the drawings that correspond thereto and are not to be construed as limiting the embodiments, wherein elements/modules and steps having the same reference numerals are represented by like elements/modules and steps, unless otherwise specified, and the drawings are not to scale.
Fig. 1 is a schematic structural diagram of a charger according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of a low voltage protection circuit according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of a low voltage protection circuit according to another embodiment of the present invention;
fig. 4 is a schematic circuit diagram of a low voltage protection circuit according to yet another embodiment of the present invention.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
Referring to fig. 1, fig. 1 is a diagram illustrating a charger applied to a photovoltaic power generation energy storage system according to an embodiment of the present invention, where the photovoltaic power generation system is a power generation system that directly converts light energy into electric energy without a thermal process. Its main components are solar cell, accumulator, controller and inverter. The device has the characteristics of high reliability, long service life, no environmental pollution, independent power generation and grid-connected operation. The photovoltaic power generation system comprises a storage battery pack and a system controller, wherein the storage battery pack is used for storing electric energy generated by a solar cell matrix when the solar cell matrix is illuminated and supplying power to a load at any time, and the system controller is equipment for controlling charging and discharging of a storage battery. Meanwhile, the electric energy generated by the photovoltaic power generation system supplies power to the system controller, so that the system controller can normally work, and when the electric energy output by the photovoltaic power generation panel is low, the system controller can enter a dormant state when the system controller is in an under-voltage working state, the intelligent charging requirement cannot be met, and the use experience of a user is influenced. Therefore, low-voltage protection needs to be performed on the system controller, and when the charging input voltage is low, the low-voltage protection circuit cuts off the charging loop, so that the system controller is completely turned off, the system controller stops working, and the system controller is prevented from entering a sleep state.
As shown in fig. 1, the charger includes a photovoltaic power generation system 400, a low-voltage protection circuit 100, and a charging loop 200, wherein electric energy generated by the photovoltaic power generation system 400 supplies power to a system controller 300 through the charging loop 200, so that the system controller 300 can normally operate and normally control circuits of various parts in the photovoltaic power generation system 400, for example: and controlling the photovoltaic power generation system 400 to charge the storage battery pack so as to store energy. The low-voltage protection circuit 100 is disposed between the photovoltaic power generation system 400 and the charging circuit 200, the charging circuit 200 is connected to the low-voltage protection circuit 100 and the system controller 300, when power is supplied to the system controller 300, the low voltage protection circuit 100 is in an on state, so that the photovoltaic power generation system 400 can normally supply power to the system controller 300 through the charging loop 200, if the power generated by the photovoltaic power generation system 400 is low, so that the system controller 300 operates in an undervoltage state, the low-voltage protection circuit 100 detects that the charging input voltage reaches a low voltage value, the circuit between the photovoltaic power generation system 400 and the charging circuit 200 is broken, so that the charger operates in an open-circuit operating state, therefore, the charger can not supply power to the system controller 300 any more, and the system controller 300 is completely turned off, so as to achieve the purpose of low-voltage protection of the system controller 300.
Referring to fig. 2, fig. 2 is a schematic structural diagram of a low voltage protection circuit according to an embodiment of the present invention, as shown in fig. 2, the low voltage protection circuit 100 includes a sampling circuit 10, a voltage stabilizing circuit 20, a comparing circuit 30 and a switching circuit 40, the sampling circuit 10 is configured to sample an input voltage of a charging circuit 200, the voltage stabilizing circuit 20 is configured to provide a reference voltage, and the comparing circuit 30 is respectively connected to the sampling circuit 10 and the voltage stabilizing circuit 20 and configured to generate a control signal according to a sampling signal and the reference voltage output by the sampling circuit 10; and a switch circuit 40 connected to the comparison circuit 30 and the charging circuit 200 respectively for controlling the operating state of the charging circuit 200 according to the control signal, wherein the operating state includes a connection state and a disconnection state. Therefore, when the charging circuit 200 has a low voltage, the control signal output by the comparison circuit 30 controls the switch circuit 40 to be in the open-circuit working state, so that the charging circuit 200 is disconnected, the photovoltaic power generation system 400 can not supply power to the system controller 300 any more, and the system controller 300 is reliably protected from the low voltage.
Referring to fig. 3, fig. 3 is a diagram illustrating a low voltage protection circuit according to another embodiment of the present invention, as shown in fig. 3, the low voltage protection circuit 100 includes a sampling circuit 10, a voltage stabilizing circuit 20, a comparing circuit 30 and a switching circuit 40, the sampling circuit 10 is respectively connected to a charging circuit 200 and the comparing circuit 30, the comparing circuit 30 is respectively connected to the sampling circuit 10, the voltage stabilizing circuit 20 and the switching circuit 40, the switching circuit 40 is further connected to the charging circuit 200, and the operating state of the switching circuit 40 controls the on/off of the charging circuit 200.
The sampling circuit 30 is configured to output the control signal to control the operating state of the switch circuit 40 according to the sampling signal and the reference voltage, where the operating state includes an on state and an off state. The sampling signal is the input voltage of the charging circuit 200, the reference voltage is a preset defined voltage value, and is provided by the voltage stabilizing circuit 20, when the sampling voltage value is smaller than the reference voltage, it indicates that the power supply voltage of the system controller 300 reaches the low voltage protection value, the comparison circuit 21 outputs a control signal, and the control signal controls the switch circuit 40 to be switched off, so that the charging circuit 200 works in the open circuit working state, the charging circuit 200 cannot supply power to the system controller 300 any more, and the low voltage protection is reliably realized for the system controller behind. The reference voltage may be set as needed, and is not particularly limited.
In some embodiments, with reference to fig. 3, the switch circuit 40 includes a first switch circuit 41 and a second switch circuit 42 connected in series, the first switch circuit 41 is further connected to the comparison circuit 30, the second switch circuit 42 is further connected to the charging loop 200, and specifically, the second switch circuit 42 is disposed on a charging bus of the charging loop 200. When the charging input voltage is low, the output signal of the comparison circuit 30 controls the first switch circuit 41 to be turned off, and the turning off of the first switch circuit 41 causes the second switch circuit 42 to operate in the open-circuit operating state, so that the charging bus of the charging circuit 200 is in the open-circuit state, the charging circuit 200 is turned off, and power cannot be supplied to the system controller 300, so that the system controller 300 is completely turned off, and low-voltage protection is reliably realized.
In some embodiments, the entire charging system further includes an auxiliary power circuit 400, and the auxiliary power circuit 40 is connected to the charging circuit 200 and the system controller 300 respectively, and is configured to adjust the operating voltage provided by the charging circuit 200 and apply the adjusted operating voltage to the system controller 300. The auxiliary power circuit 400 is used for converting the power provided by the charging loop 200 into a voltage suitable for the system controller 300, so that the system controller 300 can be normally powered, and the system controller 300 can normally work. Generally, the voltage provided by the auxiliary power circuit 40 is a low voltage, and it should be noted that the operating voltage of the system controller 300 can be determined by a specific chip of the controller, and is not limited to a specific value.
Referring to fig. 4, fig. 4 is a schematic circuit diagram of a low voltage protection circuit according to yet another embodiment of the present invention. As shown in fig. 4, the sampling circuit 10 includes a first operational amplifier U1, an inverting Input terminal of the first operational amplifier U1 is connected to the positive Input + of the Input voltage of the charging loop 200, the non-inverting Input terminal of the operational amplifier U1 is connected to the negative Input-of the Input voltage of the charging circuit 200, the output end of the first operational amplifier U1 is connected with the comparison circuit 30, specifically, the output end of the first operational amplifier U1 is connected with the input end of the comparison circuit 30, meanwhile, in order to filter noise in the input signal of the charging circuit 200, the sampling circuit 10 further includes a first filter capacitor C1 and a second filter capacitor C2, the first filter capacitor C1 is respectively connected to the inverting input terminal of the first operational amplifier U1 and the output terminal of the first operational amplifier, and the second filter capacitor C2 is respectively connected to the non-inverting input terminal of the first operational amplifier U1 and ground.
In some embodiments, referring to fig. 4, the sampling circuit 10 further includes a first resistor R1, a second resistor R2, a third resistor R3 and a fourth resistor R4, the first resistor R1 is connected in series between the positive Input terminal of the charging loop 200 and the inverting Input terminal of the first operational amplifier U1, the second resistor R2 is connected in series between the negative Input terminal of the charging loop and the non-inverting Input terminal of the first operational amplifier U1, the third resistor R3 is connected in series between the inverting Input terminal of the first operational amplifier U1 and the output terminal of the first operational amplifier U1, which is a feedback resistor, and the fourth resistor is connected in series between the negative Input terminal and the non-inverting Input terminal of the first operational amplifier U1.
In some embodiments, with continued reference to fig. 4, the voltage regulator circuit 20 includes a voltage regulator ZD1, a negative electrode of the voltage regulator ZD1 is connected to the comparison circuit 30, and a positive electrode of the voltage regulator ZD1 is grounded. The zener ZD1 is used to provide a reference voltage V _ ref. The model of the voltage regulator tube ZD1 is selected according to the required reference voltage.
In some embodiments, with continued reference to fig. 4, the comparison circuit 30 includes a second operational amplifier U2, the non-inverting input of the second operational amplifier U2 is connected to the output of the first operational amplifier U1, and the inverting input of the second operational amplifier U2 is connected to the reference voltage.
In some embodiments, with continued reference to fig. 4, the comparison circuit 30 further includes a third capacitor C3, and the third capacitor C3 is connected in series between the non-inverting input terminal of the second operational amplifier U2 and ground. The comparison circuit 30 further includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8 and a ninth resistor R9, the sixth resistor R6 is connected in series to the non-inverting Input terminal of the second operational amplifier U2 and the output terminal of the first operational amplifier U1, the fifth resistor R5 is connected in series between the inverting Input terminal of the second operational amplifier U2 and the ground, one end of the seventh resistor R7 is connected to the inverting Input terminal of the second operational amplifier U2, the other ends of the seventh resistor R7 are connected to the eighth resistor R8 and the ninth resistor R9, and the eighth resistor R8 and the ninth resistor R9 are connected in series to the output terminal of the second operational amplifier U2 and the positive Input + of the charging Input. The power supply terminal of the second operational amplifier U2 is connected to a common connection point of the seventh resistor R7, the eighth resistor R8, and the ninth resistor R9.
The second operational amplifier U2 outputs a high level signal or a low level signal according to the output signal of the first operational amplifier U1 and the reference voltage, if the output signal of the first operational amplifier U1 is smaller than the reference voltage, it is proved that the voltage for supplying power to the system controller reaches the low voltage protection value, the second operational amplifier U2 outputs a low level signal to control the switching circuit 40 at the rear end to work in the open circuit working state, if the output signal of the first operational amplifier U1 is larger than the reference voltage, it is proved that the voltage for supplying power to the system controller does not reach the low voltage protection value, the second operational amplifier U2 outputs a high level signal to control the switching circuit 40 at the rear end to work in the open circuit working state, so that the charger loop 200 continues to supply power to the system controller.
In some embodiments, referring to fig. 4, the first switch circuit 41 is a transistor Q1, the second switch circuit 42 is a MOS switch Q2, a base of the transistor Q1 is connected to the output terminal of the comparison circuit 30, a collector of the transistor Q1 is connected to a gate of the MOS switch Q2 to control the on/off of the MOS switch Q2, and a source and a drain of the MOS switch Q2 are both connected to a bus of the charging loop.
Specifically, the switch circuit 40 further includes a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13 and a fourteenth resistor R14. The tenth resistor is connected in series between the base of the triode Q1 and the output end of the second operational amplifier U2, the eleventh resistor is connected in series between the output end of the second operational amplifier U2 and the ground, the twelfth resistor R12 and the fourteenth resistor R14 are connected in series between the collector of the triode Q1 and the gate of the MOS transistor Q2, the thirteenth resistor R13 is connected in series between the connection point of the twelfth resistor R12 and the fourteenth resistor R14 and the positive Input + of the charging circuit Input, the MOS switch Q2 is disposed on the bus of the charging circuit 200, the source of the MOS switch Q2 is connected to the positive Input + of the charging Input, and the MOS switch Q2 is a PMOS switch.
Therefore, when the transistor Q1 is turned off, the potential of the collector terminal of the transistor Q1 is equal to the positive Input + potential of the charging Input terminal, and the potential of the gate terminal of the MOS switch Q2 is equal to the positive Input + potential of the charging Input terminal, so that the MOS switch Q2 is turned off, and the charging loop is disconnected. If the triode Q1 is conducted, the potential of the collector terminal of the triode Q1 is pulled low, and the MOS switch tube is further conducted, so that the charging loop normally works and normally supplies power to the system controller.
With continuing reference to fig. 4, the operation of the low voltage protection circuit is described with reference to the devices of fig. 4, which is as follows:
the charging circuit 200 supplies power to the back-end system controller, the sampling circuit 10 samples the Input end voltage Input of the charging circuit, the first remote computing amplifier U1 outputs a sampling signal, the sampling signal is Input to the non-inverting Input end of the second operational amplifier U2, meanwhile, the voltage regulator tube is broken down by the positive electrode voltage Input + of the charging Input end, and then the voltage regulator value is kept, the voltage regulator value is the reference voltage, the reference voltage is Input to the inverting Input end of the second operational amplifier U2, if the output signal of the first operational amplifier U1 is greater than the reference voltage, it is proved that the system controller to be supplied with power does not reach the low voltage protection value, the second operational amplifier U2 outputs a high level signal, the high level signal acts on the base of the triode Q1 to conduct the triode Q1, and further to conduct the PMOS switch tube Q2, so that the charging circuit normally supplies power to the system controller, if the sampling signal is less than the reference voltage, the system controller which is supplied with power achieves a low-voltage protection value, the second operational amplifier U2 outputs a low-level signal, the low-level signal acts on the base electrode of the triode Q1, the triode Q1 is cut off, the PMOS switching tube Q2 is cut off, the charging loop is cut off, the system controller is completely turned off, the system controller is prevented from working in an undervoltage state, the purpose of low-voltage protection of the system controller is achieved, and the low-voltage protection circuit works stably and can reliably achieve low-voltage protection.
The embodiment of the invention provides a low-voltage protection circuit which is applied to a charging loop of a photovoltaic power generation energy storage system. The low-voltage protection circuit is completely realized by a hardware circuit, has a simple structure and lower cost, has stronger anti-interference capability and is more convenient to popularize and apply.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; within the idea of the invention, also technical features in the above embodiments or in different embodiments may be combined and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or technical features in areas thereof may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present invention.
Claims (9)
1. The utility model provides a low-voltage protection circuit, is applied to photovoltaic power generation energy storage system's charge circuit which characterized in that includes:
the sampling circuit is used for sampling the input voltage of the charging loop;
the voltage stabilizing circuit is used for providing reference voltage;
the comparison circuit is respectively connected with the sampling circuit and the voltage stabilizing circuit and is used for outputting a control signal according to a sampling signal and the reference voltage; and
and the switching circuit is respectively connected with the comparison circuit and the charging loop and is used for controlling the working state of the charging loop according to the control signal, and the working state comprises a closed circuit state and an open circuit state.
2. The low voltage protection circuit of claim 1, wherein the switching circuit comprises: the first switch circuit and the second switch circuit are connected in series, the first switch circuit is further connected with the comparison circuit, and the second switch circuit is further connected with the charging loop.
3. The low-voltage protection circuit according to claim 2, wherein the sampling circuit comprises a first operational amplifier, a non-inverting input terminal of the first operational amplifier is connected to a negative terminal of the input voltage of the charging loop, an inverting input terminal of the first operational amplifier is connected to a positive terminal of the input voltage of the charging loop, and an output terminal of the first operational amplifier is connected to the comparison circuit.
4. The low voltage protection circuit of claim 3, wherein the comparison circuit comprises a second operational amplifier, a non-inverting input terminal of the second operational amplifier is connected to the output terminal of the first operational amplifier, and an inverting input terminal of the second operational amplifier is connected to the voltage stabilizing circuit and the positive input voltage terminal of the charging loop, respectively.
5. The low voltage protection circuit of claim 4, wherein a power supply terminal of the second operational amplifier is connected to a positive terminal of the input voltage of the charging loop.
6. The low voltage protection circuit according to claim 4, wherein the first switching circuit is a transistor, a base of the transistor is connected to the output terminal of the second remote computing amplifier, a collector of the transistor is connected to the second switching circuit, and an emitter of the transistor is grounded.
7. The low voltage protection circuit according to claim 6, wherein the second switch circuit is an MOS switch transistor, and a collector of the transistor is connected to a gate of the MOS switch transistor to control on/off of the MOS switch transistor.
8. The low-voltage protection circuit according to any one of claims 4 to 7, wherein the voltage stabilizing circuit comprises a voltage regulator tube, the negative electrode of the voltage regulator tube is connected with the inverting input end of the second operational amplifier, and the positive electrode of the voltage regulator tube is grounded.
9. A charger, characterized in that the charger comprises:
the photovoltaic power generation system is used for generating electric energy by adopting the photovoltaic system;
the low voltage protection circuit of any one of claims 1-8, connected to the photovoltaic power generation system for low voltage protection; and
and the charging loop is respectively connected with the low-voltage protection circuit and the system controller and is used for supplying power to the system controller by the electric energy generated by the photovoltaic power generation system.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010436774.4A CN111585324A (en) | 2020-05-21 | 2020-05-21 | Low-voltage protection circuit and charger |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010436774.4A CN111585324A (en) | 2020-05-21 | 2020-05-21 | Low-voltage protection circuit and charger |
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| CN111585324A true CN111585324A (en) | 2020-08-25 |
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| CN202010436774.4A Pending CN111585324A (en) | 2020-05-21 | 2020-05-21 | Low-voltage protection circuit and charger |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112510641A (en) * | 2020-10-29 | 2021-03-16 | 北京有感科技有限责任公司 | Protective circuit |
| CN116846041A (en) * | 2023-09-01 | 2023-10-03 | 昆山硕通电子有限公司 | Under-voltage protection circuit |
-
2020
- 2020-05-21 CN CN202010436774.4A patent/CN111585324A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112510641A (en) * | 2020-10-29 | 2021-03-16 | 北京有感科技有限责任公司 | Protective circuit |
| CN116846041A (en) * | 2023-09-01 | 2023-10-03 | 昆山硕通电子有限公司 | Under-voltage protection circuit |
| CN116846041B (en) * | 2023-09-01 | 2023-11-21 | 昆山硕通电子有限公司 | Under-voltage protection circuit |
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