CN115912926A - Auxiliary power supply control circuit, auxiliary power supply and photovoltaic grid-connected inverter - Google Patents
Auxiliary power supply control circuit, auxiliary power supply and photovoltaic grid-connected inverter Download PDFInfo
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Abstract
The invention provides an auxiliary power supply control circuit, an auxiliary power supply and a photovoltaic grid-connected inverter, wherein the auxiliary power supply control circuit comprises: the power supply comprises a power supply chip, a flyback transformer, an undervoltage turn-off circuit and a switch circuit; the first secondary side of the flyback transformer supplies power to the power supply chip through a power supply port of the power supply chip; the primary side of the flyback transformer responds to a control signal of an output port of the power supply chip to enable the auxiliary power supply to be started according to corresponding starting voltage; the undervoltage turn-off circuit is powered by a first secondary side of the flyback transformer; the under-voltage turn-off circuit is used for indicating the power chip to turn off the auxiliary power supply when the starting voltage of the primary side of the flyback transformer is less than the voltage of the under-voltage protection turn-off point; the switch circuit is used for controlling the start of the undervoltage turn-off circuit after a preset delay time when the auxiliary power supply is started. By adding the switch circuit, the start of the undervoltage turn-off circuit is delayed when the auxiliary power supply is started, so that the influence of the leakage current of the undervoltage turn-off circuit on the start of the auxiliary power supply according to the normal starting voltage is avoided.
Description
Technical Field
The invention belongs to the technical field of switching power supplies, and particularly relates to an auxiliary power supply control circuit, an auxiliary power supply and a photovoltaic grid-connected inverter.
Background
An auxiliary power supply (hereinafter referred to as an auxiliary source) of a household string photovoltaic grid-connected inverter generally requires a wider voltage and temperature working range, so that the auxiliary source generally adopts a single-tube flyback power supply, and the working voltage range is 80-600 Vdc.
In the prior art, the flyback power supply can generally set a power supply chip and an under-voltage turn-off circuit on the same secondary side for supplying power, but under a low-temperature environment, the auxiliary power supply can not be normally started frequently, in order to find out the reason of the unable normal start of the auxiliary power supply, the system environment temperature is increased, the starting voltage of the temperature-increased power supply is reduced, the fact that the temperature is the reason of the unable normal start of the auxiliary power supply is confirmed, but in order to solve the problem that the auxiliary power supply can not be started, when the system is under the low-temperature environment, it is unrealistic to go to heat the system, for this, the reason that the starting voltage is increased under the low-temperature is further analyzed. Under the low-temperature environment, the capacity of the capacitor is attenuated, the capacity value of the voltage-stabilizing capacitor is tried to be enlarged, the low-temperature starting voltage does not have obvious change after enlargement, a main power consumption device of the undervoltage turn-off circuit is cancelled, the starting voltage rises back to some extent at the same temperature, and the fact that the auxiliary power supply cannot be normally started is proved to be caused by leakage current of the device. The comparator in the undervoltage turn-off circuit generates a large leakage current, so that the power supply voltage of the power supply chip on the same secondary side is influenced, and the auxiliary power supply cannot be normally started under the conventional starting voltage.
Disclosure of Invention
In view of this, the invention provides an auxiliary power control circuit, an auxiliary power and a photovoltaic grid-connected inverter, and aims to solve the problem that the auxiliary power cannot be started normally in the prior art.
A first aspect of an embodiment of the present invention provides an auxiliary power supply control circuit, including: the power supply comprises a power supply chip, a flyback transformer, an under-voltage turn-off circuit and a switch circuit;
the first secondary side of the flyback transformer supplies power to the power supply chip through a power supply port of the power supply chip; the primary side of the flyback transformer responds to a control signal of an output port of the power supply chip to enable the auxiliary power supply to be started according to corresponding starting voltage;
the undervoltage turn-off circuit is powered by a first secondary side of the flyback transformer; the undervoltage turn-off circuit is used for indicating the power chip to turn off the auxiliary power supply when the starting voltage of the primary side of the flyback transformer is less than the voltage of the undervoltage protection turn-off point;
the switch circuit is used for controlling the undervoltage turn-off circuit to start after a preset delay time when the auxiliary power supply is started.
In some possible implementations, the switching circuit is an RC delay circuit; the RC time delay circuit comprises a transistor; the transistor is in a cut-off state when the auxiliary voltage is not started;
the RC time delay circuit is used for controlling the transistor to be switched from a cut-off state to a conducting state after preset delay time when the auxiliary power supply is started.
In some possible implementations, the under-voltage shutdown circuit includes a first power port and a second power port; the first power supply port is connected with the first secondary side; the second power supply port is connected with the drain electrode of the transistor; the source of the transistor is connected to ground.
In some possible implementations, the RC delay circuit includes a first resistor and a first capacitor;
the first end of the first resistor is connected with a reference value output port of the voltage chip; the second end of the first resistor is connected with the grid electrode of the transistor; the first capacitor is connected between the grid and the source of the transistor in parallel;
the source electrode of the transistor is grounded; the drain electrode of the transistor is connected with the undervoltage turn-off circuit.
In some possible implementations, the first capacitor is a temperature sensitive capacitor with a negative temperature coefficient.
In some possible implementations, the RC delay circuit further includes a second resistor; the second resistor is connected in parallel with the first capacitor.
In some possible implementations, the second resistance is a negative temperature coefficient thermistor.
In some possible implementations, the switching circuit is a time delay relay.
In some possible implementations, the voltage of the natural low voltage turn-off point of the auxiliary voltage is the same as the voltage of the undervoltage protection turn-off point of the undervoltage shutdown circuit.
A second aspect of an embodiment of the present invention provides an auxiliary power supply, including: the auxiliary power supply control circuit as described above in the first aspect.
A third aspect of an embodiment of the present invention provides a photovoltaic grid-connected inverter, including: an auxiliary power supply as in the second aspect above.
The auxiliary power supply control circuit, the auxiliary power supply and the photovoltaic grid-connected inverter provided by the embodiment of the invention are characterized in that the auxiliary power supply control circuit comprises: the power supply comprises a power supply chip, a flyback transformer, an undervoltage turn-off circuit and a switch circuit; the first secondary side of the flyback transformer supplies power to the power supply chip through a power supply port of the power supply chip; the primary side of the flyback transformer responds to a control signal of an output port of the power supply chip to enable the auxiliary power supply to be started according to corresponding starting voltage; the undervoltage turn-off circuit is powered by a first secondary side of the flyback transformer; the undervoltage turn-off circuit is used for indicating the power chip to turn off the auxiliary power supply when the starting voltage of the primary side of the flyback transformer is less than the voltage of the undervoltage protection turn-off point; the switch circuit is used for controlling the undervoltage turn-off circuit to start after a preset delay time when the auxiliary power supply is started. By adding the switch circuit, the start of the undervoltage turn-off circuit is delayed when the auxiliary power supply is started, so that the influence of the leakage current of the undervoltage turn-off circuit on the start of the auxiliary power supply according to the normal starting voltage is avoided.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required to be used in the embodiments or the prior art description will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings may be obtained according to these drawings without inventive labor.
Fig. 1 is a schematic structural diagram of an auxiliary power control circuit according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of an auxiliary power supply main circuit provided by an embodiment of the invention;
FIG. 3 is a schematic diagram of an under-voltage shutdown circuit provided in an embodiment of the present invention;
fig. 4 is a schematic structural diagram of a switching circuit provided in an embodiment of the present invention.
Detailed Description
In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.
Fig. 1 is a schematic structural diagram of an auxiliary power supply control circuit according to an embodiment of the present invention. As shown in fig. 1, in some embodiments, an auxiliary power control circuit includes: a power supply chip 11, a flyback transformer 12, an under-voltage shutdown circuit 13, and a switch circuit 14.
The first secondary side of the flyback transformer 12 supplies power to the power chip 11 through a power supply port of the power chip 11; the primary side of the flyback transformer 12 responds to a control signal of the output port of the power chip 11, so that the auxiliary power supply is started according to the corresponding starting voltage; the undervoltage turn-off circuit 13 is powered by the first secondary side of the flyback transformer 12; the undervoltage shutdown circuit 13 is configured to instruct the power chip 11 to shut off the auxiliary power supply when the starting voltage of the primary side of the flyback transformer 12 is less than the voltage of the undervoltage protection shutdown point; the switch circuit 14 is used for controlling the under-voltage shutdown circuit 13 to start after a preset delay time when the auxiliary power supply is started.
In the embodiment of the present invention, the power chip 11 has a plurality of ports, which may specifically include a power supply port, a compensation port, a feedback port, an output port, a reference value output port, a ground port, and the like. The flyback transformer 12 includes a primary side and a plurality of secondary sides; the power supply port of the power chip 11 and the power supply port of the undervoltage shutdown circuit 13 are connected to the same secondary side, i.e., the first secondary side.
The power supply chip 11 is arranged at one end of the primary side of the flyback transformer 12, and the other end of the primary side of the flyback transformer 12 is connected with the bus; when the auxiliary power supply needs to be started, the bus provides a starting voltage to the other end of the primary side of the flyback transformer 12, and then the first secondary side supplies power to the power supply port of the power supply chip 11, so that the output port of the power supply chip 11 outputs a control signal to adjust the voltage of the primary side of the flyback transformer 12, and the auxiliary power supply is started.
The undervoltage shutdown circuit 13 collects the starting voltage of the primary side of the flyback transformer 12, and compares the starting voltage with the voltage of the undervoltage protection shutdown point output by the reference value output port of the power chip 11 to realize undervoltage protection of the auxiliary power supply.
Under the low temperature environment, the undervoltage shutdown circuit 13 may generate a large leakage current, and since the undervoltage shutdown circuit is powered by the first secondary side, the equivalent load of the first secondary side may be increased, so that the power chip 11 connected to the first secondary side is powered off, and the auxiliary power supply may not be started at the normal starting voltage.
Because the auxiliary power supply is easily influenced by leakage current in the starting stage, but the influence of the leakage current on the power supply chip is small after the auxiliary power supply is started and stably operates, in the embodiment of the invention, the starting of the undervoltage shutdown circuit is delayed when the auxiliary power supply is started by adding the switch circuit, so that the influence of the leakage current of the undervoltage shutdown circuit on the starting of the auxiliary power supply according to the normal starting voltage is avoided.
In some embodiments, switching circuit 14 is an RC delay circuit; the RC time delay circuit comprises a transistor; the transistor is in a cut-off state when the auxiliary voltage is not started; the RC time delay circuit is used for controlling the transistor to be switched from a cut-off state to a conducting state after preset delay time when the auxiliary power supply is started.
In the embodiment of the invention, at least one resistor and at least one capacitor are arranged in the RC delay circuit, when the auxiliary power supply is started, the capacitor arranged in the RC delay circuit is slowly charged, and the RC delay circuit cannot reach the control voltage of the transistor until the RC delay circuit is fully charged, so that the state of the transistor is switched. The process of charging the capacitor is the above-mentioned delay process. The transistor may be a switching device such as a MOS transistor, and is not limited herein. Because the leakage current of the MOS tube is smaller and is connected in series with a power supply point of a comparator in the undervoltage turn-off circuit, the leakage current can be further limited. Therefore, the mode of combining the RC delay circuit and the MOS tube not only can delay the starting of the undervoltage turn-off circuit, but also can limit the influence of leakage current on the auxiliary power supply when the undervoltage turn-off circuit is started and after the undervoltage turn-off circuit is started, so that the auxiliary power supply has better low-temperature adaptability.
The switch circuit can be arranged at any power supply end of the undervoltage shutdown circuit. In some embodiments, the under-voltage shutdown circuit includes a first power supply port and a second power supply port; the first power supply port is connected with the first secondary side; the second power supply port is connected with the drain electrode of the transistor; the source of the transistor is connected to ground.
In some embodiments, the RC delay circuit includes a first resistor and a first capacitor; the first end of the first resistor is connected with the reference value output port of the voltage chip; the second end of the first resistor is connected with the grid electrode of the transistor; the first capacitor is connected between the grid and the source of the transistor in parallel; the source electrode of the transistor is grounded; the drain of the transistor is connected to the undervoltage shutdown circuit 13.
In the embodiment of the invention, the size of the first capacitor is increased along with the reduction of the temperature, so that the undervoltage turn-off circuit has short preset delay time which is equivalent to normal turn-on when the temperature is normal, and provides relatively long preset delay time when the temperature is low, thereby avoiding the influence of leakage current.
In some embodiments, the RC delay circuit further comprises a second resistor; the second resistor is connected in parallel with the first capacitor.
In some embodiments, the second resistance is a negative temperature coefficient thermistor.
In the embodiment of the invention, besides the capacity change of the first capacitor, a resistor, namely a second resistor, can be connected in parallel at two ends of the first capacitor, so that the adjustment of the charging time of the capacitor is realized. The larger the resistance of the second resistor is, the longer the charging time required by the capacitor is, i.e., the longer the predetermined delay time is.
In some embodiments, the switching circuit 14 is a time delay relay.
In the embodiment of the invention, when the time delay relay detects the starting of the auxiliary power supply, the time delay relay attracts and closes the electric shock switch of the auxiliary power supply after the time delay, so that the undervoltage turn-off circuit is electrified and starts to work. Compared with the undervoltage turn-off circuit and the transistor, the delay relay is more complex in structure, can only limit leakage current during starting (namely, no leakage current exists in delay time), and does not limit the leakage current after the auxiliary power supply is started.
In some embodiments, the voltage at the natural low voltage turn-off point of the auxiliary voltage is the same as the voltage at the undervoltage protection turn-off point of the undervoltage shutdown circuit 13.
In the embodiment of the present invention, if the voltage of the natural low-voltage turn-off point of the auxiliary voltage and the under-voltage protection turn-off point of the under-voltage turn-off circuit 13 are set to be the same voltage point, the feedback loop of the auxiliary voltage can automatically turn off the auxiliary voltage at a low voltage, so as to replace the low-voltage turn-off circuit to a certain extent, and ensure that the under-voltage turn-off circuit does not have a fault in the process of delayed start.
The present invention will be described below with reference to an embodiment, but the present invention is not limited thereto. Fig. 2 is a schematic structural diagram of an auxiliary power supply main circuit provided in an embodiment of the present invention. Fig. 3 is a schematic structural diagram of an under-voltage shutdown circuit provided by an embodiment of the present invention. As shown in fig. 2 and fig. 3, in this implementation example, the power supply chip 11 includes a power supply port VCC, a compensation port COM, a feedback port Vfb, a feedback port Is, an output port OUT, a reference value output port Vref, a ground port GND, and an operating frequency design port RC. The auxiliary winding comprises a plurality of coils, wherein the coils numbered 18 and 20 correspond to the primary winding, the other coils are auxiliary windings, and the coils numbered 23 and 24 are the first secondary side. R294, R295, and R264 in the dashed box a are output buffer resistors, and R331 and R319 in the dashed box B are current limiting resistors. The power supply port VCC is supplied from the node VCC +15V on the first secondary side, and the output port OUT is connected to the gate of the transistor on the primary side of the flyback transformer 12.
When the auxiliary power supply needs to be started, the BUS provides a starting voltage to the other end of the primary side of the flyback transformer 12, then the node VCC _ 15V on the first secondary side reaches a corresponding voltage, so that the power chip 11 is powered on and started, the output port OUT outputs a control signal, and the control transistor outputs a signal with a corresponding duty ratio to adjust the voltage of the primary side of the flyback transformer 12, thereby completing the starting of the auxiliary power supply.
The undervoltage shutdown circuit 13 collects the voltage of the primary side HV node and the BUS grounding point voltage (representing the BUS), compares the voltage with the voltage of the undervoltage protection shutdown point output by the reference value output port Vref of the power chip 11, and sends the comparison result to the compensation port COM to realize the undervoltage protection of the auxiliary power supply.
The undervoltage shutdown circuit in fig. 3 is an 8-port comparator, where reference numerals 2, 3, 5, and 6 are input ports, reference numerals 1 and 7 are output ports, and reference numerals 4 and 8 are power ports. Under a low-temperature environment, the undervoltage shutdown circuit 13 may generate a large leakage current, and since the undervoltage shutdown circuit is powered by the VCC _ +15v _snode on the first secondary side, an increase in the leakage current may cause a point location of the VCC _ +15v _snode to decrease, which is equivalent to an increase in the equivalent load of the first secondary side, and at this time, a potential of the VCC _ +15v _sis lower than a potential of the VCC _ +15V, which causes the diode D29 to be turned off, so that the VCC of the power supply port loses a point, and the auxiliary power supply cannot be started at a normal start voltage.
Fig. 4 is a schematic structural diagram of a switching circuit provided in an embodiment of the present invention. As shown in fig. 4, the switch circuit includes a first resistor R12, a second resistor R13, and a first capacitor C5; the first end of the first resistor R12 is connected with the reference value output port of the voltage chip; a second end of the first resistor R12 is connected with the grid electrode of the transistor Q1; the first capacitor C5 is connected between the grid and the source of the transistor Q1 in parallel; the source of the transistor Q1 is grounded; the drain electrode of the transistor Q1 is connected with the undervoltage turn-off circuit 13; the second resistor R13 is connected in parallel with the first capacitor C5.
The switch circuit is arranged between the power supply port of the undervoltage turn-off circuit and the grounding end of a bus, so that the undervoltage turn-off circuit is started in a delayed manner when the auxiliary power supply is started, the influence of leakage current on the potential of VCC _ +15V _Scan be effectively avoided, and after the auxiliary power supply operates stably, the influence of the leakage current on the operation of the auxiliary power supply is small, so that the undervoltage turn-off circuit can work normally after delay time, and an MOS (metal oxide semiconductor) tube in the switch circuit shown in figure 3 is a device with small leakage current and is connected with the undervoltage turn-off circuit in series, so that the switch circuit can still well limit the leakage current after the delayed start is completed.
The auxiliary power supply feedback loop Is provided with a protection signal introduced into a CS pin (corresponding to a feedback port Is of the power supply chip 11), when the input PV voltage Is low to a certain degree, the difference value between the feedback and the given value of the main output loop Is increased, so that the level of the CS pin Is changed into V _ ref, the driving Is closed, and therefore, the lower input PV voltage cannot meet the requirement of the re-working of the self-powered flyback transformer, and the auxiliary power supply Is reliably turned off. Therefore, if the voltage of the natural low-voltage turn-off point of the auxiliary voltage and the undervoltage protection turn-off point of the undervoltage turn-off circuit 13 are set to be the same voltage point, the feedback loop of the auxiliary voltage can automatically turn off the auxiliary voltage at low voltage, so as to replace the low-voltage turn-off circuit to a certain extent, and ensure that the undervoltage turn-off circuit cannot break down in the delayed start process.
In conclusion, the beneficial effects of the invention are as follows: by adding the switch circuit, the start of the undervoltage turn-off circuit is delayed when the auxiliary power supply is started, so that the influence of the leakage current of the undervoltage turn-off circuit on the start of the auxiliary power supply according to the normal starting voltage is avoided.
The invention provides an auxiliary power supply, which is a single-tube flyback power supply and comprises: an auxiliary power supply control circuit as in any preceding embodiment. In addition, the auxiliary power supply may include devices/circuits for rectification, voltage regulation, protection, heat dissipation, and the like.
The invention also provides a photovoltaic grid-connected inverter which comprises the auxiliary power supply in the embodiment, for example, a photovoltaic inverter which can be a household string photovoltaic grid-connected inverter SPI5-40k type photovoltaic inverter.
It should be understood that, the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.
It should be clear to those skilled in the art that, for convenience and simplicity of description, the foregoing division of the functional units and modules is only used for illustration, and in practical applications, the above function distribution may be performed by different functional units and modules as needed, that is, the internal structure of the device is divided into different functional units or modules, so as to perform all or part of the above described functions. Each functional unit and module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working processes of the units and modules in the system may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the technical solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
In the embodiments provided in the present invention, it should be understood that the disclosed apparatus/terminal and method may be implemented in other ways. For example, the above-described apparatus/terminal embodiments are merely illustrative, and for example, a module or a unit may be divided into only one type of logical function, and may be implemented in another manner, for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not implemented. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.
Units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit may be implemented in the form of hardware, or may also be implemented in the form of a software functional unit.
The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; 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 some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present invention, and are intended to be included within the scope of the present invention.
Claims (10)
1. An auxiliary power supply control circuit, comprising: the power supply comprises a power supply chip, a flyback transformer, an undervoltage turn-off circuit and a switch circuit;
the first secondary side of the flyback transformer supplies power to the power supply chip through a power supply port of the power supply chip; the primary side of the flyback transformer responds to a control signal of the output port of the power supply chip to enable the auxiliary power supply to be started according to corresponding starting voltage;
the undervoltage turn-off circuit is powered by a first secondary side of the flyback transformer; the under-voltage turn-off circuit is used for indicating the power chip to turn off the auxiliary power supply when the starting voltage of the primary side of the flyback transformer is less than the voltage of the under-voltage protection turn-off point;
and the switching circuit is used for controlling the under-voltage turn-off circuit to be started after a preset delay time when the auxiliary power supply is started.
2. The auxiliary power control circuit according to claim 1, wherein the switching circuit is an RC delay circuit; the RC delay circuit comprises a transistor; the transistor is in a cut-off state when the auxiliary voltage is not started;
the RC time delay circuit is used for controlling the transistor to be switched from a cut-off state to a conducting state after preset delay time when the auxiliary power supply is started.
3. The auxiliary power control circuit of claim 2, wherein the under-voltage shutdown circuit comprises a first power port and a second power port; the first power port is connected with the first secondary side; the second power supply port is connected with the drain electrode of the transistor; the source of the transistor is grounded.
4. The auxiliary power control circuit of claim 3, wherein the RC delay circuit comprises a first resistor and a first capacitor;
the first end of the first resistor is connected with the reference value output port of the voltage chip; the second end of the first resistor is connected with the grid electrode of the transistor; the first capacitor is connected between the grid electrode and the source electrode of the transistor in parallel;
the source electrode of the transistor is grounded; and the drain electrode of the transistor is connected with the undervoltage turn-off circuit.
5. The auxiliary power control circuit of claim 3, wherein the RC delay circuit further comprises a second resistor; the second resistor is connected in parallel with the first capacitor.
6. The auxiliary power control circuit of claim 5, wherein the second resistor is a negative temperature coefficient thermistor.
7. The auxiliary power supply control circuit according to claim 2, wherein the switching circuit is a time delay relay.
8. The auxiliary power supply control circuit according to claim 1, wherein a voltage of a natural low voltage turn-off point of the auxiliary voltage is the same as a voltage of an undervoltage protection turn-off point of the undervoltage shutdown circuit.
9. An auxiliary power supply, comprising: an auxiliary power control circuit as claimed in any one of claims 1 to 8 above.
10. A photovoltaic grid-connected inverter, comprising: an auxiliary power supply as claimed in claim 9 above.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211351130.0A CN115912926A (en) | 2022-10-31 | 2022-10-31 | Auxiliary power supply control circuit, auxiliary power supply and photovoltaic grid-connected inverter |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211351130.0A CN115912926A (en) | 2022-10-31 | 2022-10-31 | Auxiliary power supply control circuit, auxiliary power supply and photovoltaic grid-connected inverter |
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| CN115912926A true CN115912926A (en) | 2023-04-04 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116846041A (en) * | 2023-09-01 | 2023-10-03 | 昆山硕通电子有限公司 | Under-voltage protection circuit |
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2022
- 2022-10-31 CN CN202211351130.0A patent/CN115912926A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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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