CN216290694U - Power-down holding device - Google Patents
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- CN216290694U CN216290694U CN202122265987.8U CN202122265987U CN216290694U CN 216290694 U CN216290694 U CN 216290694U CN 202122265987 U CN202122265987 U CN 202122265987U CN 216290694 U CN216290694 U CN 216290694U
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Abstract
The utility model relates to the field of switching power supplies, and discloses a power failure holding device which comprises an isolation unit, a voltage boosting and reducing unit, a starting circuit unit, an auxiliary power supply unit, a control unit and an energy storage unit, wherein the input end of the isolation unit is connected with an input voltage, the output end of the isolation unit is connected to the input end of a voltage boosting mode of the voltage boosting and reducing unit, and the output end of the voltage boosting mode of the voltage boosting and reducing unit is connected with the energy storage unit. The boost-buck unit can work in a boost mode and a buck mode according to the condition of input voltage, and when the input voltage is normal, the boost-buck unit works in the boost mode to store energy for the energy storage unit; when the input voltage is in power failure, the voltage boosting and reducing unit works in a voltage reduction mode, the energy storage unit releases energy for the power supply module, and the power failure holding time is prolonged. The power failure holding device internally integrates the auxiliary power supply unit, can be applied to a power supply module with wider input voltage range and higher input voltage value, is independent of the power supply module, and has wider application range.
Description
Technical Field
The utility model relates to the field of switching power supplies, in particular to a power-down holding device of a switching power supply, which has a wider input voltage range and a higher input voltage value.
Background
At present, almost all electronic equipment needs a switching power supply to supply power for the electronic equipment, and in some fields with high reliability requirements, such as railway and aviation fields, for reliable operation of the electronic equipment, when the power supply is cut off, namely when the input voltage of the switching power supply suddenly fails, the power supply still can be maintained for a certain time to output energy, the electronic equipment needs to store power failure state data and orderly switch to a standby power supply, so that a switching power supply system is required to have a long power failure retention time. For example, in the field of railway power supplies, a power-down retention time of not less than 10ms is required.
Generally, a typical solution is to connect a large-capacity electrolytic capacitor in parallel at an input end of a power supply, but for an application occasion with a wide input voltage, a large number of electrolytic capacitors are often needed to be connected in parallel to meet a power-down retention time requirement during low-voltage power-down, so that a module power supply product has a large peripheral volume and high cost, and a problem of large startup surge current is caused.
In order to avoid such drawbacks, in the prior art, a Boost and buck circuit is usually used to implement a two-stage topology series connection mode, as shown in fig. 1, a Boost circuit is used at a front stage to Boost an input voltage to a certain value, and a normal buck topology is used at a rear stage to perform conversion, such as flyback, forward, full bridge, and the like. The external energy storage capacitor C0 is connected to the middle node of the two-stage topology, namely the output end of the Boost circuit, and when the input energy is cut off, the external energy storage capacitor C0 can continue to provide energy for the rear stage to realize the power-down retention time. Although the capacitor requirement is reduced when the capacitor energy storage is promoted by the boosting mode, the two stages are connected in series, and the voltage reduction circuit and the boosting circuit respectively need a power inductor, a switching tube and other power devices, so that the problems of size and cost are not solved well.
In addition, for the situation with a wide input voltage range and a high voltage value, such as a railway power supply, the input voltage of the railway power supply is usually 40 to 160VDC, and because the input voltage is high, the prior art usually needs to adopt an auxiliary power supply unit of a rear-stage power supply module to supply power to a front-stage power-down holding device, or directly get power from the input voltage and then design an auxiliary power supply unit for the power-down holding device, so that the system cost is further increased, and the application range is limited.
SUMMERY OF THE UTILITY MODEL
In view of this, the utility model provides a power-down maintaining device, which solves the problems that the two-stage structure in the prior art is large in size, high in cost and not suitable for high-voltage wide-input application occasions.
In order to solve the above problem, an aspect of the present invention is to provide a power down holding apparatus, including: the device comprises a voltage boosting and reducing unit, an energy storage unit, a control unit and an auxiliary power supply unit;
the buck-boost unit is provided with a capacitor C1, a transformer, a switch S1 and a switch S2; one end of a capacitor C1 is connected to the first end of the primary winding of the transformer, the other end of the capacitor C1 is connected with the ground, the second end of the primary winding of the transformer is connected with the first end of a switch S1, and the second end of a switch S1 is connected with the ground; the first end of the switch S2 is connected with the second end of the primary winding of the transformer, the second end of the switch S2 is connected to the energy storage unit, and the connection point of the switch tube S2 and the energy storage unit is used as the output end of the voltage boosting and reducing unit when working in the voltage boosting mode and is also used as the input end of the voltage boosting and reducing unit when working in the voltage reducing mode;
the auxiliary power supply unit is provided with the transformer, a rectifier switch SD and a capacitor C2; the first end of a secondary winding of the transformer is connected with one end of the rectifier switch, the other end of the rectifier switch is connected with one end of a capacitor C2, the other end of a capacitor C2 is connected with the second end of the secondary winding of the transformer, and the connection point of the rectifier switch and the capacitor C2 is used as the output end of the auxiliary power supply unit; the output end of the auxiliary power supply unit is connected with the control unit and used for supplying power to the control unit when the input voltage of the buck-boost unit is powered down.
Preferably, the energy storage unit is a capacitor, and stores energy when the boost-buck unit works in a boost mode; and releasing the stored energy when the voltage increasing and reducing unit works in a voltage reducing mode.
Preferably, the power-down holding device is further provided with an isolation unit, an input end of the isolation unit is connected with the input voltage of the voltage boosting and reducing unit, an output end of the isolation unit is connected to the voltage boosting and reducing unit, the isolation unit is switched on when the input voltage is normal, and the isolation unit is switched off when the input voltage is in power-down.
Preferably, the power-down holding device is further provided with a starting circuit, and the starting circuit unit is connected with the control unit and used for supplying power to the control unit in the starting process.
Preferably, when the voltage boosting and reducing unit operates in the voltage boosting mode and the voltage of the output end of the auxiliary power supply unit is smaller than the output voltage of the starting circuit, the starting circuit unit supplies power to the control unit.
Preferably, the control unit is connected to the control terminal of the switch S1 and the control terminal of the switch S2, and the control unit enables the buck-boost unit to operate in the boost mode or the buck mode by controlling the switch S1 and the switch S2; when the voltage boosting and reducing unit works in a voltage boosting mode, the output voltage of the output end of the auxiliary power supply unit changes along with the change of the input voltage; when the voltage increasing and reducing unit works in a voltage reducing mode, the output voltage of the output end of the auxiliary power supply unit is a stable value.
Preferably, when the input voltage is powered down, the buck-boost unit works in a buck mode.
Preferably, the rectifier switch is a diode; the isolation unit is a diode, an MOS tube or a triode; the switch S1 and the switch S2 are MOS transistors, respectively, the first terminal of the switch S1 is a drain, the second terminal of the switch S1 is a source, the first terminal of the switch S2 is a source, and the second terminal of the switch S2 is a drain.
Preferably, the first end of the primary winding of the transformer and the first end of the secondary winding of the transformer are homonymous ends.
The present invention also provides a power-down holding apparatus, comprising: the device comprises a voltage boosting and reducing unit, an energy storage unit, a control unit and an auxiliary power supply unit;
the buck-boost unit is provided with a capacitor C1, a transformer, a switch S1 and a switch S2; one end of a capacitor C1 is connected with the first end of the primary winding of the transformer, the other end of a capacitor C1 is connected with the ground, the second end of the primary winding of the transformer is connected with the first end of a switch S1, and the second end of a switch S1 is connected with the ground; the first end of the switch S2 is connected with the second end of the primary winding of the transformer, the second end of the switch S2 is connected to the energy storage unit, and the connection point of the switch tube S2 and the energy storage unit is used as the output end of the voltage boosting and reducing unit working in the voltage boosting mode and is also used as the input end of the voltage boosting and reducing unit working in the voltage reducing mode;
the auxiliary power supply unit is provided with the transformer, a rectifier switch SD, a capacitor C2 and a voltage reduction circuit; the first end of a secondary winding of the transformer is connected with one end of a rectifier switch, the other end of the rectifier switch is connected with one end of a capacitor C2, and the other end of a capacitor C2 is connected with the second end of the secondary winding of the transformer; the voltage reduction circuit is connected to two ends of the capacitor C2 and is used for converting the voltage of the two ends of the capacitor C2 into an operating voltage suitable for the control unit so as to supply power to the control unit.
The detailed working principle of the present invention will be described later with reference to specific embodiments, which are not described herein, and compared with the prior art, the present invention has the following beneficial effects:
(1) the power failure holding device adopts a bidirectional buck-boost circuit, and auxiliary power supply is generated by using a secondary winding of the transformer, so that the size is effectively reduced, and the cost is reduced.
(2) The auxiliary power supply unit is integrated in the power failure holding device, the power failure holding device can work in the occasions with high voltage and wide input voltage range and is independent of the power supply module, and the application range is wider.
Drawings
Fig. 1 is a structural block diagram of a two-stage scheme buck-boost for power-down delay in the prior art;
FIG. 2 is a block diagram of the power down hold apparatus of the present invention;
FIG. 3 is a circuit schematic of a power down hold means according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of a starting circuit unit of a power down hold apparatus according to an embodiment of the present invention;
fig. 5 is a schematic circuit diagram of a second power-down holding apparatus according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in 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 utility model and are not intended to limit the utility model.
First embodiment
Fig. 2 is a block diagram of a power-down maintaining apparatus according to the present invention, and fig. 3 is a schematic diagram of a power-down maintaining apparatus according to a first embodiment of the present invention, where the power-down maintaining apparatus includes an isolation unit, a voltage boosting and reducing unit, a starting circuit unit, an auxiliary power supply unit, an energy storage unit, and a control unit, where the energy storage unit is an energy storage capacitor C0, such as an electrolytic capacitor, a thin film capacitor, and other devices or devices having an energy storage function; the control unit includes a controller M1.
The input end of the isolation unit is connected with the input voltage Vin, the output end of the isolation unit is connected to the input end of the voltage boosting and reducing unit working in a voltage boosting mode, and the output end of the voltage boosting and reducing unit working in the voltage boosting mode is connected with the energy storage capacitor C0; the input end of the starting circuit unit is connected with the output end of the isolation unit, and the output end Vo3 of the starting circuit unit is connected with the output end Vo2 of the auxiliary power supply unit and the power supply end V0 of the controller M1. In this embodiment, the isolation unit is a switching device, which may be a diode, a MOS transistor, or other switching devices, and is used to reverse the energy of the energy storage capacitor C0 to the input when the voltage reduction mode is performed.
The buck-boost unit comprises a capacitor C1, a transformer T1, a switch S1 and a switch S2, wherein the switch S1 and the switch S2 are MOS transistors respectively; one end of a capacitor C1 is connected to the output end of the isolation unit, the other end of the capacitor C1 is connected to GND, the dotted end of the primary winding of a transformer T1 is connected to a capacitor C1, the synonym end of the primary winding of the transformer T1 is connected to the drain (first end) of a switch S1, the source (second end) of a switch S1 is connected to GND, the source (first end) of a switch S2 is connected to the synonym end of the primary winding of the transformer T1, and the drain (second end) of the switch S2 is connected to an energy storage capacitor C0. The connection point of the switching tube S2 and the energy storage capacitor C0 serves as the output Vo1 of the buck-boost unit when operating in the boost mode, and is also the input of the buck-boost unit in the buck mode.
The energy storage unit is used for storing energy in a high-voltage mode when the voltage boosting and reducing unit works in a voltage boosting mode, and releasing the stored energy when the voltage boosting and reducing unit works in a voltage reducing mode.
The auxiliary power supply unit comprises a transformer T1, a rectifier switch SD and a capacitor C2, wherein the rectifier switch SD is a diode; the dotted terminal of the secondary winding of the transformer T1 is connected with one end of a rectifier switch SD, the other end of the rectifier switch SD is connected with one end of a capacitor C2, and the other end of the capacitor C2 is connected with the dotted terminal of the secondary winding of the transformer T1 and then is connected to GND together; the connection point of the rectifying switch SD and the capacitor C2 serves as the output Vo2 of the auxiliary power supply unit.
A power supply end V0 of the controller M1 is connected with an output end Vo2 of the auxiliary power supply unit and an output end Vo3 of the starting circuit unit, a boost voltage sampling end V3 of the controller M1 is connected with an output end Vo1 of the boost-buck unit when the boost-buck unit works in a boost mode, a buck voltage sampling end V1 of the controller M1 is connected with an output end of the isolation unit, an input voltage sampling end V2 of the controller M1 is connected with an input end of the isolation unit, and a current sampling end V4 of the controller M1 detects a current of a primary winding of the transformer T1. The first output terminal G1 of the controller M1 is connected to the gate (control terminal) of the switch S1, and the second output terminal G2 of the controller M1 is connected to the gate (control terminal) of the switch S2. The ground GND of the controller M1 is connected to the input GND. The controller M1 can control the switch S1 and the switch S2 according to the input voltage Vin of the buck-boost unit, so that the buck-boost unit can operate in the boost mode and the buck mode. Specifically, the method comprises the following steps: when the input voltage Vin is normal, the voltage boosting and reducing unit works in a voltage boosting mode to store energy for the energy storage unit; when the input voltage is in power failure, the voltage boosting and reducing unit works in a voltage reduction mode, the energy storage unit releases energy for the power supply module, and the power failure holding time is prolonged.
The starting circuit unit comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4, a zener diode D1, a zener diode D2, a diode D3, a diode D4, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a switch S3 and a triode Q1. One end of a resistor R1 and one end of a switch S3 are connected to the output end of the isolation unit, the other end of the resistor R1 and the cathode of a zener diode D1 are connected to one end of a resistor R2, the other end of the resistor R2 is connected with the control end of a switch S3, one end of a capacitor C3 is connected to the cathode of a zener diode D1, the other end of the capacitor C3 and the anode of a zener diode D1 are connected to GND, one end of a resistor R3, one end of a resistor R4 and one end of a capacitor C4 are commonly connected to the other end of the switch S4, the other end of the capacitor C4 is connected to GND, the other end of the resistor R4 is connected to the collector of an S triode Q4, the other end of the resistor R4 is connected to the base of a triode Q4, the cathode of the zener diode D4 is connected to the GND, the anode of the triode Q4 is connected to the GND, the emitter of the diode Q4 is connected to the anode of the diode D, the diode D4, the cathode of the diode D is connected to the diode D, the cathode of the diode D4, one end of the diode D4 is connected to the output end of the auxiliary power supply unit, one end of the capacitor C5 is connected with an emitter of the triode Q1, the other end of the capacitor C5 is connected with GND, a connection point of the emitter of the triode Q1 and anodes of the capacitor C5 and the diode D3 serves as an output end Vo3 of the auxiliary power supply unit, and an output end of the isolation unit serves as an input end of the starting unit.
The Boost-buck unit of the power-down holding device in this embodiment is a bidirectional converter, and the operating principle of the Boost-buck unit is that if the operating voltage range of a power module applied by the Boost-buck unit is Vmin to Vmax, when the power module is within a normal input voltage range, the Boost-buck unit operates in a Boost mode, that is, a Boost circuit is formed by a primary winding of a transformer T1, a switch S1, a switch S2, and an energy storage capacitor C0, and a controller M1 generates a driving signal according to a feedback value (for voltage stabilization) of the voltage of the energy storage capacitor C0 (that is, the voltage of an output terminal Vo 1) received through a Boost voltage sampling terminal V3 and a current value (for current limiting) of the transformer T1 received through a current sampling terminal V4, so as to turn on and turn off the switches S1 and S2, thereby realizing control in the Boost mode to Boost the energy storage capacitor C0 after a lower input voltage is increased to a higher voltage.
When the input voltage is powered down, the controller M1 detects that the input voltage Vin is lower than a certain threshold voltage Vth according to the feedback value of the input voltage Vin received through the input voltage sampling terminal V2, Vth is greater than or equal to Vmin (the lowest input voltage of the power module), the Buck-boost unit works in the Buck mode, the controller M1 controls a Buck circuit formed by the switch S2, the switch S1 and the primary winding of the transformer T1, the controller M1 realizes the on-off of the switches S1 and S2 according to the feedback value of the voltage on the capacitor C1 received through the Buck voltage sampling terminal V1 (for realizing Buck voltage stabilization) and the current value of the transformer T1 received through the current sampling terminal V4 (for current limiting), therefore, the control in the voltage reduction mode is realized, the high voltage of the energy storage capacitor C0 is converted into the nominal input voltage of the power module, and the energy stored in the energy storage capacitor C0 is used for prolonging the power-down holding time of the power module.
In the working principle of the buck-boost unit, it should be noted that, in the boost mode, the primary winding of the transformer T1 transmits energy to the secondary side while being excited, and similarly, the boost mode works in a forward mode, and it is considered that, as a person skilled in the art can understand that the forward principle is not stated herein, at this time, the voltage of the output Vo2 of the auxiliary power supply unit is not stabilized, and the voltage of the output Vo2 of the auxiliary power supply unit is derived as Vin x D/n, D is the duty ratio of the boost mode switching tube S1 and n is the transformer turn ratio according to the change of the input voltage Vin, and the voltage of the output Vo2 can be within a certain voltage range Vo2min to Vo2max by reasonably designing the transformer turn ratio. In addition, in the boost mode, only the energy storage capacitor C0 is charged, and the controller M1 operates in the idle mode, so that the overall power consumption of the controller M1 is relatively small, and the power supply of the controller M1 can be completely realized by using the starting circuit, and therefore, the present embodiment uses this point, and in the boost mode, the controller M1 is supplied by using the voltage of the output terminal Vo2 of the auxiliary power supply unit and the starting circuit in a combined manner. Specifically, when the input voltage Vin is high, the voltage of the output terminal Vo2 of the auxiliary power supply unit is also high, when the voltage is higher than the voltage of the starting circuit, the auxiliary power supply unit supplies power to the controller M1, when the input voltage Vin is low, the voltage of the output terminal Vo2 of the auxiliary power supply unit is low, and when the voltage is lower than the voltage of the starting circuit, the starting circuit unit supplies power to the controller M1. In the step-down mode, the transformer T1 does not transfer energy to the secondary side when it is excited, and transfers energy to the secondary side when it is demagnetized, and its working mode is the same as flyback topology (flyback), and it can be understood by those skilled in the art that the flyback principle is not stated here, and at this time, the voltage of the output Vo2 of the auxiliary power supply unit is stabilized, and its magnitude is Vc1/n, Vc1 is the voltage on the capacitor C1, and n is the transformer turn ratio. Therefore, the auxiliary power supply unit may output a stable voltage to power the controller M1 in the buck mode. In addition, in the step-down mode, the energy storage capacitor C0 discharges for the power module, and works in the full-load mode, so the overall power consumption of the control unit is relatively large, and in consideration of this point, the auxiliary power supply unit is adopted in the embodiment to supply power for the control unit, so that insufficient power supply is prevented. It should be noted that the boost mode and the buck mode share a turn ratio n, and therefore need to be designed together. For example, in a power input of 40VDC to 160VDC and a nominal 110V application, a design turn ratio n of 9, Vo2 in the boost mode ranges from 4V to 10.7V, and Vo2 in the buck mode has a voltage of 12.3V, so the starting voltage can be designed to be about 10V. In the boosting mode, the auxiliary power supply unit supplies power when the power module is in high-voltage input, and the starting circuit unit supplies power when the power module is in low-voltage input. In the step-down mode, the auxiliary power supply unit is always used for supplying power.
In addition, the starting circuit unit of the power-down holding device of this embodiment is a linear regulator, and as shown in fig. 4, the specific working principle of the starting circuit unit of the circuit is that, when the starting circuit is powered on, the zener diode D1 stabilizes voltage, the switch S3 is turned on, the capacitor C4 charges to a value near the regulated voltage value of the zener diode D1, and the resistor R3, the resistor R4, the triode Q1, the zener diode D2, and the capacitor C5 constitute a regulator, so that the voltage at the output terminal Vo3 of the starting circuit is maintained near the regulated voltage value of the zener diode D2. It should be noted that, only one kind of start circuit unit is shown here, and not by way of limitation, and all that adopts such a circuit structure and is consistent with the power supply core concept of the present invention should be within the protection scope.
Second embodiment
Fig. 5 is a schematic circuit diagram of a power down holding apparatus according to a second embodiment of the present invention, and as shown in the drawing, the present embodiment is different from the first embodiment in that: the auxiliary power supply unit further comprises a voltage-reducing circuit 101 for converting the non-regulated output voltage Vc2 of the capacitor C2 into a regulated output when the buck-boost unit operates in the boost mode, and an output Vo2 of the voltage-reducing circuit 101 serves as an output terminal of the auxiliary power supply unit. When the voltage increasing and decreasing unit works in the voltage decreasing mode, the voltage is still output in a voltage stabilizing mode. Therefore, the problem that the voltage of the output end Vo2 of the auxiliary power supply unit is too high when the high voltage is input in the boost mode when the input voltage range of the power supply module is large is solved. In this way, the voltage stabilizing power supply is realized more easily than the direct voltage stabilizing power supply of the input Vin high voltage through the voltage reducing circuit 101 after the input voltage Vin with wide range and high voltage is converted into low voltage and wide input.
The present embodiment is also different from the first embodiment in that: the starting circuit unit is only used for converting the voltage of the output end of the isolation unit into the power supply voltage required by the control unit in the starting process.
Specifically, in this embodiment, the power supply logic of the control unit of the power down holding device is as follows: when the device is started, the starting circuit supplies power to the device, and when the voltage boosting and reducing unit works in a voltage boosting mode, the unstable voltage output in the first embodiment is converted into stable voltage output through the voltage reducing circuit; when the buck-boost unit works in the buck mode, the voltage-stabilizing output of the auxiliary power supply unit is still the voltage-stabilizing output through the buck circuit, so that the controller M1 is only powered by the auxiliary power supply unit no matter in the boost mode or the buck mode. For example, in an application that the input of the power module is 40 VDC-160 VDC and the nominal voltage is 110V, if the design turn ratio n is 3, the Vo2 range is 12V-32V in the boost mode, and the Vo2 voltage is 36V in the buck mode, the input voltage range of the buck circuit 101 is 12V-36V, and the input voltage range can be completely realized by a voltage regulator tube, a linear regulator or a low-power and low-cost switching power supply. The buck-boost unit, the isolation unit and the energy storage unit of this embodiment are the same as those of the first embodiment, and are not described herein again.
Preferably, the voltage reduction circuit 101 of the power down holding apparatus of this embodiment may be a voltage stabilizing circuit formed by a voltage regulator tube, or may also be a circuit or a device having a voltage stabilizing function, such as a linear voltage regulator or a switching power supply circuit.
Preferably, the starting circuit unit of the power-down holding device of the present embodiment is used for supplying power to the starting process of the power-down holding device, and may be the starting circuit unit in the first embodiment, or may be another circuit having a starting and supplying function.
The above is only a preferred embodiment of the present invention, and it should be noted that the above preferred embodiment should not be considered as limiting the present invention, and the protection scope of the present invention should be subject to the scope defined by the claims. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the utility model, and these modifications and variations should be considered as within the scope of the utility model as defined in the appended claims.
Claims (10)
1. A power loss holding apparatus, comprising: the device comprises a voltage boosting and reducing unit, an energy storage unit, a control unit and an auxiliary power supply unit;
the buck-boost unit is provided with a capacitor C1, a transformer, a switch S1 and a switch S2; one end of the capacitor C1 is connected to the first end of the primary winding of the transformer, the other end of the capacitor C1 is connected to ground, the second end of the primary winding of the transformer is connected to the first end of the switch S1, and the second end of the switch S1 is connected to ground; a first end of the switch S2 is connected to a second end of the primary winding of the transformer, a second end of the switch S2 is connected to the energy storage unit, and a connection point of the switch tube S2 and the energy storage unit serves as an output end of the buck-boost unit when the buck-boost unit works in the boost mode and also serves as an input end of the buck-boost unit when the buck-boost unit works in the buck mode;
the auxiliary power supply unit is provided with the transformer, a rectifier switch SD and a capacitor C2; a first end of a secondary winding of the transformer is connected with one end of the rectifier switch, the other end of the rectifier switch is connected with one end of the capacitor C2, the other end of the capacitor C2 is connected with a second end of the secondary winding of the transformer, and a connection point of the rectifier switch and the capacitor C2 is used as an output end of the auxiliary power supply unit; the output end of the auxiliary power supply unit is connected with the control unit and used for supplying power to the control unit when the input voltage of the buck-boost unit is in power failure.
2. The power-down retention device according to claim 1, wherein the energy storage unit is a capacitor,
the energy storage unit stores energy when the voltage boosting and reducing unit works in a voltage boosting mode; and releasing the stored energy when the voltage increasing and decreasing unit works in a voltage decreasing mode.
3. The power failure holding device according to claim 1, further comprising an isolation unit, wherein an input end of the isolation unit is connected to the input voltage of the voltage step-up and step-down unit, an output end of the isolation unit is connected to the voltage step-up and step-down unit, and the isolation unit is turned on when the input voltage is normal and turned off when the input voltage is power failure.
4. The power-down retention device according to claim 1, further comprising a start circuit unit, wherein the start circuit unit is connected with the control unit and used for supplying power to the control unit during start.
5. The power-down maintaining device of claim 4, wherein the starting circuit unit supplies power to the control unit when the voltage boosting and reducing unit operates in a voltage boosting mode and the voltage of the output end of the auxiliary power supply unit is smaller than the output voltage of the starting circuit.
6. The power-down retention device according to claim 1, wherein: the control unit is connected with a control end of the switch S1 and a control end of the switch S2, and the control unit enables the buck-boost unit to work in a boost mode or a buck mode by controlling the switch S1 and the switch S2; when the voltage boosting and reducing unit works in a voltage boosting mode, the output voltage of the output end of the auxiliary power supply unit changes along with the change of the input voltage; when the voltage increasing and reducing unit works in a voltage reducing mode, the output voltage of the output end of the auxiliary power supply unit is a stable value.
7. The power-down retention device according to claim 1, wherein: when the input voltage is powered down, the voltage boosting and reducing unit works in a voltage reduction mode.
8. The power-down retention device of claim 3, wherein the rectifying switch is a diode; the isolation unit is a diode, an MOS tube or a triode; the switch S1 and the switch S2 are MOS transistors, respectively, a first end of the switch S1 is a drain, a second end of the switch S1 is a source, a first end of the switch S2 is a source, and a second end of the switch S2 is a drain.
9. The power-down retention device according to claim 1, wherein the first end of the primary winding of the transformer and the first end of the secondary winding of the transformer are homonymous ends.
10. A power loss holding apparatus, comprising: the device comprises a voltage boosting and reducing unit, an energy storage unit, a control unit and an auxiliary power supply unit;
the buck-boost unit is provided with a capacitor C1, a transformer, a switch S1 and a switch S2; one end of the capacitor C1 is connected to the first end of the primary winding of the transformer, the other end of the capacitor C1 is connected to ground, the second end of the primary winding of the transformer is connected to the first end of the switch S1, and the second end of the switch S1 is connected to ground; a first end of the switch S2 is connected to a second end of the primary winding of the transformer, a second end of the switch S2 is connected to the energy storage unit, and a connection point of the switching tube S2 and the energy storage unit serves as an output end of the buck-boost unit working in a boost mode and also serves as an input end of the buck-boost unit working in a buck mode;
the auxiliary power supply unit is provided with the transformer, a rectifier switch SD, a capacitor C2 and a voltage reduction circuit; a first end of a secondary winding of the transformer is connected with one end of the rectifier switch, the other end of the rectifier switch is connected with one end of the capacitor C2, and the other end of the capacitor C2 is connected with a second end of the secondary winding of the transformer; the voltage reduction circuit is connected to two ends of the capacitor C2 and is used for converting the voltage of the two ends of the capacitor C2 into a working voltage suitable for the control unit so as to supply power to the control unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN202122265987.8U CN216290694U (en) | 2021-09-17 | 2021-09-17 | Power-down holding device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN202122265987.8U CN216290694U (en) | 2021-09-17 | 2021-09-17 | Power-down holding device |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2023216586A1 (en) * | 2022-05-13 | 2023-11-16 | 华为数字能源技术有限公司 | Solid state transformer |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023216586A1 (en) * | 2022-05-13 | 2023-11-16 | 华为数字能源技术有限公司 | Solid state transformer |
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