CN107785873A - Voltage protection circuit and method of switching power supply and switching power supply - Google Patents

Voltage protection circuit and method of switching power supply and switching power supply Download PDF

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Publication number
CN107785873A
CN107785873A CN201711276334.1A CN201711276334A CN107785873A CN 107785873 A CN107785873 A CN 107785873A CN 201711276334 A CN201711276334 A CN 201711276334A CN 107785873 A CN107785873 A CN 107785873A
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CN
China
Prior art keywords
voltage
partial pressure
power supply
transformer
relay
Prior art date
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Granted
Application number
CN201711276334.1A
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Chinese (zh)
Other versions
CN107785873B (en
Inventor
朱晓蒙
宋爱
程海松
戴彪
杨坚
孙磊
胡宇辰
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Gree Electric Appliances Inc of Zhuhai
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Gree Electric Appliances Inc of Zhuhai
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Priority to CN201711276334.1A priority Critical patent/CN107785873B/en
Publication of CN107785873A publication Critical patent/CN107785873A/en
Application granted granted Critical
Publication of CN107785873B publication Critical patent/CN107785873B/en
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Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
    • H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
    • H02H7/1213—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for DC-DC converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
    • H02M3/33523—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters with galvanic isolation between input and output of both the power stage and the feedback loop
    • 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
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)

Abstract

The invention discloses a voltage protection circuit and method of a switching power supply and the switching power supply, and relates to the technical field of electric power, wherein the protection circuit comprises: a relay; a normally closed contact of the relay is arranged in a secondary side circuit of the switching power supply, and an excitation coil of the relay is electrically connected with the secondary side circuit; when the primary side winding of the transformer and the secondary side winding of the transformer are isolated and failed and the secondary side voltage on a secondary side circuit is the input voltage of the primary side winding of the transformer, the secondary side voltage is used for providing excitation voltage for the excitation coil, and the normally closed contact is opened to cut off the secondary side circuit. According to the voltage protection circuit, the method and the switching power supply, when the primary side winding and the secondary side winding of the transformer are in short circuit and other isolation failures, the secondary side circuit and the connection with the rear-end load are cut off through the relay of the protection circuit, and the functions of protecting the safety of experimenters and the rear-end load can be achieved; the product intellectualization is improved, and the use experience of the user is improved.

Description

Voltage protection circuit, method and the Switching Power Supply of Switching Power Supply
Technical field
The present invention relates to technical field of electric power, more particularly to a kind of voltage protection circuit of Switching Power Supply, method and open Powered-down source.
Background technology
Switching Power Supply is to utilize modern power electronics technology, the time ratio that controlling switch pipe turns on and off, and remains steady Determine a kind of power supply of output voltage.Switching Power Supply has polytype, such as single-ended Switching Power Supply of normal shock, inverse-excitation type etc..Switch The bus current potential of the primary side winding connection category forceful electric power scope of transformer in power supply, the direct current that primary side winding typically exports Pressure category light current category.Primary side winding is isolated with primary side winding by magnetic coupling, when occur transformer primary winding with become When the abnormal cases such as short circuit occur for depressor primary side winding, then the situation of the secondary-side circuitry of forceful electric power access Switching Power Supply occurs, There can be the risk of damage experiment personnel's personal safety.For example, often contact-making switch power supply is secondary when the upper electricity of experimenter is tested The component of level side, if with transformer secondary winding short circuit, the high direct current of bus occur for transformer primary winding Pressure is likely to result in security incident.The abnormal feelings such as short circuit occur with transformer secondary winding when there is transformer primary winding During shape, can also there is the possibility for the load that breakdown is connected with transformer secondary winding.For example, load is signal isolation chip, When short circuit occurs for transformer primary winding and transformer secondary winding, the High Level DC Voltage of bus can be with secondary-side circuitry Be connected on signal isolation chip, if the power supply of signal isolation chip opposite side be bus reference point, the signal isolation core Piece has breakdown possibility.
The content of the invention
In view of this, the invention solves a technical problem be to provide a kind of voltage protection circuit of Switching Power Supply, Method and Switching Power Supply, it can pass through when the isolated failures such as short circuit occur for transformer primary winding and primary side winding Relay cut-out secondary-side circuitry plays a protective role.
According to an aspect of the present invention, there is provided a kind of voltage protection circuit of Switching Power Supply, including：Relay；It is described The normally-closed contact of relay is arranged in the secondary-side circuitry of Switching Power Supply, the magnet exciting coil of the relay and the primary side Circuit electrically connects；Isolated failure occurs in transformer primary winding and transformer secondary winding and makes the secondary-side circuitry On secondary-side voltage be the transformer primary winding input voltage when, the secondary-side voltage be used for the excitation Coil provides excitation voltage, the normally-closed contact is disconnected, to cut off the secondary-side circuitry.
Alternatively, including：Mu balanced circuit unit；The magnet exciting coil passes through the mu balanced circuit unit and the primary side Circuit electrically connects；Wherein, the secondary-side voltage is the input voltage of the mu balanced circuit unit, the mu balanced circuit unit Output voltage is used to provide the excitation voltage to the magnet exciting coil.
Alternatively, including：Current-limiting resistance；The mu balanced circuit unit passes through the current-limiting resistance and the secondary-side circuitry Electrical connection.
Alternatively, the mu balanced circuit unit includes：Controllable accurate source of stable pressure；Wherein, the controllable accurate source of stable pressure is defeated Reference voltage of the reference voltage gone out as the output voltage.
Alternatively, the mu balanced circuit unit includes：First partial pressure matches somebody with somebody ratio resistance with ratio resistance and the second partial pressure；Described First end respectively first end with the magnet exciting coil, the negative electrode of the controllable accurate source of stable pressure and institute of one partial pressure with ratio resistance State current-limiting resistance connection；Second end of first partial pressure with ratio resistance respectively with the reference pole of the controllable accurate source of stable pressure and First end of second partial pressure with ratio resistance connects；Second partial pressure with ratio resistance the second end respectively with the controllable essence The anode of close source of stable pressure connects with the second end of the magnet exciting coil.
Alternatively, the output voltage Vo=Ur*(1+R2/R3)；Wherein, Ur is controllable accurate source of stable pressure output Reference voltage, R2Match somebody with somebody the resistance value of ratio resistance, R for first partial pressure3Match somebody with somebody the resistance value of ratio resistance for second partial pressure.
Alternatively, the electric capacity with the transformer secondary winding parallel is provided with the secondary-side circuitry, it is described Normally-closed contact is arranged between the electric capacity and the transformer secondary winding.
Alternatively, the quantity of the normally-closed contact of the relay is two, and two normally-closed contacts are separately positioned on institute State in the first line and the second circuit in secondary-side circuitry, wherein, the first line and second circuit respectively with institute State the both ends connection of transformer secondary winding.
According to another aspect of the present invention, there is provided a kind of Switching Power Supply, including：The voltage of Switching Power Supply as described above is protected Protection circuit.
According to another aspect of the invention, there is provided a kind of voltage protection method of Switching Power Supply, including：Relay is set, The normally-closed contact of the relay is arranged in the secondary-side circuitry of Switching Power Supply, the magnet exciting coil of the relay with it is described time Level lateral circuit electrical connection；When isolated failure occurs for transformer primary winding and transformer secondary winding and makes the primary side When secondary-side voltage on circuit is the input voltage of the transformer primary winding, the secondary-side voltage is used for described Magnet exciting coil provides excitation voltage, the normally-closed contact is disconnected, to cut off the secondary-side circuitry.
Alternatively, mu balanced circuit unit is set, and the magnet exciting coil passes through the mu balanced circuit unit and the primary side Circuit electrically connects；Wherein, the secondary-side voltage is the input voltage of the mu balanced circuit unit, the mu balanced circuit unit Output voltage is used to provide the excitation voltage to the magnet exciting coil.
Alternatively, current-limiting resistance is set, and the mu balanced circuit unit passes through the current-limiting resistance and the secondary-side circuitry Electrical connection.
Alternatively, the mu balanced circuit unit includes：Controllable accurate source of stable pressure；Wherein, the controllable accurate source of stable pressure is defeated Reference voltage of the reference voltage gone out as the output voltage.
Alternatively, the first partial pressure is set to match somebody with somebody ratio resistance with ratio resistance and the second partial pressure；First partial pressure matches somebody with somebody ratio resistance The first end with the magnet exciting coil, the negative electrode of the controllable accurate source of stable pressure and the current-limiting resistance are connected first end respectively； Match somebody with somebody respectively with the reference pole of the controllable accurate source of stable pressure and second partial pressure at the second end of first partial pressure with ratio resistance The first end connection of ratio resistance；Second end respectively anode with the controllable accurate source of stable pressure of second partial pressure with ratio resistance Connected with the second end of the magnet exciting coil.
Alternatively, the output voltage Vo=Ur*(1+R2/R3)；Wherein, Ur is controllable accurate source of stable pressure output Reference voltage, R2Match somebody with somebody the resistance value of ratio resistance, R for first partial pressure3Match somebody with somebody the resistance value of ratio resistance for second partial pressure.
Alternatively, the electric capacity with the transformer secondary winding parallel is provided with the secondary-side circuitry, by institute Normally-closed contact is stated to be arranged between the electric capacity and the transformer secondary winding.
Alternatively, the quantity of the normally-closed contact of the relay is two, and two normally-closed contacts are separately positioned on In first line and the second circuit in the secondary-side circuitry, wherein, the first line and second circuit respectively with The both ends connection of the transformer secondary winding.
Voltage protection circuit, method and the Switching Power Supply of the Switching Power Supply of the present invention, the normally-closed contact of relay are set In secondary-side circuitry, magnet exciting coil electrically connects with secondary-side circuitry；Isolated failure occurs in Transformer Winding and makes primary side When voltage is the input voltage of transformer primary winding, secondary-side voltage is used to provide excitation voltage to magnet exciting coil, disconnects Normally-closed contact, to cut off secondary-side circuitry；Short circuit etc. can occur with primary side winding in transformer primary winding to isolate During failure, by the relay cut-out secondary-side circuitry of protection circuit and the connection with backend load, protection staff can be played The effect of safety, backend load；Intelligent product is improved, improves the use feeling of user.
Brief description of the drawings
In order to illustrate more clearly about the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing There is the required accompanying drawing used in technology description to be briefly described, it should be apparent that, drawings in the following description are only Some embodiments of the present invention, for those of ordinary skill in the art, without having to pay creative labor, also Other accompanying drawings can be obtained according to these accompanying drawings.
Fig. 1 is the schematic diagram according to one embodiment of the voltage protection circuit of the Switching Power Supply of the present invention；
Fig. 2 is the schematic diagram according to another embodiment of the voltage protection circuit of the Switching Power Supply of the present invention；
Fig. 3 is the signal that the access in one embodiment according to the voltage protection circuit of the Switching Power Supply of the present invention loads Figure；
Fig. 4 is the method schematic diagram according to one embodiment of the voltage protection method of the Switching Power Supply of the present invention.
Embodiment
The present invention is described more fully with reference to the accompanying drawings, wherein illustrating the exemplary embodiment of the present invention.Under The accompanying drawing that face will be combined in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is clearly and completely described, and shows So, described embodiment is only part of the embodiment of the present invention, rather than whole embodiments.Based on the reality in the present invention Example is applied, the every other embodiment that those of ordinary skill in the art are obtained under the premise of creative work is not made, is all belonged to In the scope of protection of the invention.Many descriptions are carried out to technical scheme with reference to each figure and embodiment.
" first " hereinafter, " second " etc. are only used for distinguishing in description, not other special implications.
As shown in figure 1, the present invention provides a kind of voltage protection circuit of Switching Power Supply, Switching Power Supply can be opened for monofocal Powered-down source etc..Voltage protection circuit includes relay KM.Relay is a kind of electric control device, is to work as input quantity (energizing quantity) When change reaches regulation requirement, make controlled volume that a kind of electrical equipment of predetermined Spline smoothing occur in electric output circuit.It is secondary Lateral circuit be Switching Power Supply light current end, relay KM normally-closed contact S1With normally-closed contact S2It is arranged on the secondary of Switching Power Supply In lateral circuit, relay KM magnet exciting coil electrically connects with secondary-side circuitry, and secondary-side voltage can be to relay KM excitation Coil power supply.Relay KM magnet exciting coil and normally-closed contact can have a variety of settings, connected mode with secondary-side circuitry.
Normally-closed contact S1With normally-closed contact S2For two normally-closed contacts in relay KM, magnet exciting coil and normally-closed contact S1 With normally-closed contact S2It is all disposed within inside relay KM.Normally-closed contact S1With normally-closed contact S2Break-make be encouraging by relay KM Magnetic coil control, if being loaded with excitation voltage on magnet exciting coil, normally-closed contact S1With normally-closed contact S2Disconnect.
Isolated failure occurs in transformer primary winding 12 and transformer secondary winding 13 and makes in secondary-side circuitry Secondary-side voltage be transformer primary winding 12 input voltage when, secondary-side voltage carries to relay KM magnet exciting coil For excitation voltage, normally-closed contact S is disconnected1With normally-closed contact S2, secondary-side circuitry is cut off, to cut off secondary-side circuitry, plays guarantor Protect effect.
Mu balanced circuit unit 11 can be set, and relay KM magnet exciting coil passes through mu balanced circuit unit 11 and primary side electricity Road electrically connects, and secondary-side voltage is the input voltage of mu balanced circuit unit 11, and the output voltage of mu balanced circuit unit 11 is used for pair Magnet exciting coil provides excitation voltage.
In one embodiment, as shown in Fig. 2 transformer can be high frequency transformer.Secondary-side circuitry includes transformation Device primary side winding 13 and other circuits.The electric capacity in parallel with transformer secondary winding 13 is provided with secondary-side circuitry 17, electric capacity 17 is the Support Capacitor of secondary-side circuitry.Normally-closed contact S1With normally-closed contact S2Electric capacity 17 and transformation can be arranged on Between device primary side winding 13, i.e., in relay KM of the front end of electric capacity 17 connection with double normally-closed contacts.
Normally-closed contact S1With normally-closed contact S2The circuit 16 of first line 15 and second being separately positioned in secondary-side circuitry On, both ends of the circuit 16 of first line 15 and second respectively with transformer secondary winding 13 are connected.
Mu balanced circuit unit can be electrically connected by current-limiting resistance R1 with secondary-side circuitry, and mu balanced circuit unit 11 can have A variety of implementations.Mu balanced circuit unit 11 includes controllable accurate source of stable pressure K, and controllable accurate source of stable pressure is referred to as accurate steady Potential source.Controllable accurate source of stable pressure K output reference voltage can be as the reference voltage of the output voltage of mu balanced circuit unit.Can Control precision voltage regulator can have a variety of, for example, TL431 etc..Relay KM magnet exciting coil can be used as with controllable accurate voltage stabilizing Source (such as TL431) is the load of the mu balanced circuit unit of core.When the transformer primary winding 12 and primary side of Switching Power Supply When short circuit occurs for winding 13, the input voltage of transformer primary winding 12 is busbar voltage, and busbar voltage is mu balanced circuit list Member input voltage, now output voltage Vo can to relay KM magnet exciting coil be powered, pull open normally-closed contact S1Touched with normally closed Point S2, play the effect of protection.
As shown in Fig. 2 mu balanced circuit unit matches somebody with somebody ratio resistance R including the first partial pressure2Match somebody with somebody ratio resistance R with the second partial pressure3.First Partial pressure matches somebody with somebody ratio resistance R2First end respectively the first end with relay KM magnet exciting coil, controllable accurate source of stable pressure K negative electrode, Current-limiting resistance R1Connection, i.e. the first partial pressure match somebody with somebody ratio resistance R2First end and be connected to relay KM magnet exciting coil first end, can Control precision voltage regulator K negative electrode, current-limiting resistance R1.First partial pressure matches somebody with somebody ratio resistance R2The second end respectively with controllable accurate source of stable pressure K Reference pole and the second partial pressure match somebody with somebody ratio resistance R3First end connection, i.e. the first partial pressure matches somebody with somebody ratio resistance R2The second end and be connected to can Control precision voltage regulator K reference pole and the second partial pressure match somebody with somebody ratio resistance R3First end.
Second partial pressure matches somebody with somebody ratio resistance R3The second end respectively with controllable accurate source of stable pressure K anode and relay KM excitation The second end connection of coil, i.e. the second partial pressure match somebody with somebody ratio resistance R3The second end and be connected to controllable accurate source of stable pressure K anode and after Second end of electrical equipment KM magnet exciting coil.The reference point of mu balanced circuit unit output is the negative pole of Switching Power Supply bus bulky capacitor Point, it is the GND in Fig. 2.
S is the power switch pipe of Switching Power Supply, and T is isolating transformer, and diode 14 is that Switching Power Supply exports the pole of rectification two Pipe.The terminal voltage U of the transformer primary input bulky capacitor of Switching Power SupplyIAs busbar voltage, if P points are transformer primary The dynamic point of winding 12.If Switching Power Supply inputs 220V/50Hz civil power, after single-phase bridge uncontrollable rectifier circuit, transformer Primary side inputs the terminal voltage U of bulky capacitorIFor 311V (220*1.414).
If circuit abnormal, short circuit occurs for primary side winding 12 and the primary side winding 13 of transformer, i.e. isolation is lost Effect, Up1For P1Relative GND voltage is put, now P points and P1Point is identical relative to GND current potentials, is busbar voltage UI, the high voltage UIThe personal safety of experimenter may be caused a hidden trouble.As shown in figure 3, the secondary-side circuitry rear end connection of Switching Power Supply Signal isolation chip has breakdown possibility.
The output voltage of mu balanced circuit unit is Vo, and Vo provides electric current for relay KM magnet exciting coil, and Vo value can lead to Cross the first partial pressure and match somebody with somebody ratio resistance R2Match somebody with somebody ratio resistance R with the second partial pressure3Resistance value be configured with controllable accurate source of stable pressure K, can will Vo is configured such that the optimum operating voltage of relay KM actions.
Vo=Ur*(1+R2/R3) (1-1)；
Ur is the reference voltage of controllable accurate source of stable pressure K outputs.Vo matches somebody with somebody ratio resistance R in the second partial pressure3On partial pressure with can Control precision voltage regulator K accurate voltage is compared, and according to voltage error, flowing through controllable accurate source of stable pressure K electric current can occur Change, it is final to adjust Vo values, play voltage regulation result.Vo, R1, R2, R3 value determine according to relay KM electrical equipment grade.
The input voltage Up of mu balanced circuit unit1Fluctuate, such as Up1Increase, output voltage Vo can also increase therewith, After controllable accurate source of stable pressure K is by adjustment, electric current is changed, make to flow through current-limiting resistance R1Electric current increase, then R1Pressure drop Increase, therefore output voltage Vo can reduce, and realize that voltage stabilizing exports.Work as Up1During reduction, the principle of voltage stabilizing regulation is identical.
When volume voltage is bus high pressure in transformer secondary output lateral circuit, bus current potential Up can have certain fluctuation, pass through The Vo exported after mu balanced circuit unit can be basically stable at the optimum operating voltage that can make the actuating of relay, the reliability of KM work It is high.When transformer primary winding 12 is isolated with transformer secondary winding 13, bus current potential Up is mu balanced circuit unit Input voltage, now the output voltage Vo of mu balanced circuit unit can to relay KM magnet exciting coil provide excitation voltage, pull open Relay KM two normally-closed contacts S1 and S2, eliminate safe hidden trouble.
In one embodiment, the present invention provides a kind of Switching Power Supply, including the as above Switching Power Supply in any embodiment Voltage protection circuit.
Fig. 4 is according to the method schematic diagram of one embodiment of the voltage protection method of the Switching Power Supply of the present invention, such as Fig. 4 It is shown：
Step 401, relay is set, and the normally-closed contact of relay is arranged in the secondary-side circuitry of Switching Power Supply, relay The magnet exciting coil of device electrically connects with secondary-side circuitry.
Step 402, when isolated failure occurs for transformer primary winding and transformer secondary winding and makes primary side electric When secondary-side voltage on road is the input voltage of transformer primary winding, secondary-side voltage, which is used to provide magnet exciting coil, encourages Magnetoelectricity pressure, normally-closed contact is disconnected, to cut off secondary-side circuitry.
The electric capacity with transformer secondary winding parallel is provided with secondary-side circuitry, normally-closed contact is arranged on electric capacity Between transformer secondary winding.The quantity of the normally-closed contact of relay is two, and two normally-closed contacts are separately positioned on In first line and the second circuit in secondary-side circuitry, wherein, first line and the second circuit respectively with transformer secondary The both ends connection of winding.
In one embodiment, mu balanced circuit unit is set, and magnet exciting coil passes through mu balanced circuit unit and secondary-side circuitry Electrical connection, wherein, secondary-side voltage is the input voltage of mu balanced circuit unit, and the output voltage of mu balanced circuit unit is used for encouraging Magnetic coil provides excitation voltage.Current-limiting resistance is set, and mu balanced circuit unit is electrically connected by current-limiting resistance with secondary-side circuitry.Surely Volt circuit unit includes controllable accurate source of stable pressure etc., the reference of the output reference voltage of controllable accurate source of stable pressure as output voltage Voltage.
Set the first partial pressure match somebody with somebody ratio resistance with ratio resistance and the second partial pressure, the first partial pressure match somebody with somebody the first end of ratio resistance respectively with The first end of magnet exciting coil, the negative electrode of controllable accurate source of stable pressure connect with current-limiting resistance.First partial pressure matches somebody with somebody the second end of ratio resistance It is connected respectively with the first end of the reference pole of controllable accurate source of stable pressure and the second partial pressure with ratio resistance.Second partial pressure matches somebody with somebody ratio resistance Second end is connected with the anode of controllable accurate source of stable pressure and the second end of magnet exciting coil respectively.Output voltage Vo=Ur*(1+R2/ R3), wherein, Ur is the reference voltage of controllable accurate source of stable pressure output.
Voltage protection circuit, method and the Switching Power Supply of Switching Power Supply in above-described embodiment, the normally closed of relay are touched Point is arranged in secondary-side circuitry, and magnet exciting coil electrically connects with secondary-side circuitry；Isolated failure occurs in Transformer Winding and makes When secondary-side voltage is the input voltage of transformer primary winding, secondary-side voltage is used to provide magnet exciting coil excitation electricity Pressure, normally-closed contact is disconnected, to cut off secondary-side circuitry；Short circuit can occur in transformer primary winding and primary side winding Etc. isolated failure when, secondary-side circuitry and connection with backend load are cut off by the relay of protection circuit, guarantor can be played Protect the effect of personal security, backend load；Intelligent product is improved, improves the use feeling of user.
The method and system of the present invention may be achieved in many ways.For example, can by software, hardware, firmware or Software, hardware, firmware any combinations come realize the present invention method and system.The said sequence of the step of for method is only Order described in detail above is not limited in order to illustrate, the step of method of the invention, is especially said unless otherwise It is bright.In addition, in certain embodiments, the present invention can be also embodied as recording program in the recording medium, these programs include For realizing the machine readable instructions of the method according to the invention.Thus, the present invention also covering storage is used to perform according to this hair The recording medium of the program of bright method.
Description of the invention provides for the sake of example and description, and is not exhaustively or by the present invention It is limited to disclosed form.Many modifications and variations are obvious for the ordinary skill in the art.Select and retouch State embodiment and be to more preferably illustrate the principle and practical application of the present invention, and one of ordinary skill in the art is managed The present invention is solved so as to design the various embodiments with various modifications suitable for special-purpose.

Claims (17)

  1. A kind of 1. voltage protection circuit of Switching Power Supply, it is characterised in that including：
    Relay；The normally-closed contact of the relay is arranged in the secondary-side circuitry of Switching Power Supply, the excitation of the relay Coil electrically connects with the secondary-side circuitry；Isolated failure occurs simultaneously in transformer primary winding and transformer secondary winding When making the input voltage that secondary-side voltage in the secondary-side circuitry is the transformer primary winding, the primary side electricity Press for providing excitation voltage to the magnet exciting coil, the normally-closed contact is disconnected, to cut off the secondary-side circuitry.
  2. 2. voltage protection circuit as claimed in claim 1, it is characterised in that including：
    Mu balanced circuit unit；The magnet exciting coil is electrically connected by the mu balanced circuit unit with the secondary-side circuitry；Wherein, The secondary-side voltage is the input voltage of the mu balanced circuit unit, and the output voltage of the mu balanced circuit unit is used for institute State magnet exciting coil and the excitation voltage is provided.
  3. 3. voltage protection circuit as claimed in claim 2, it is characterised in that including：
    Current-limiting resistance；The mu balanced circuit unit is electrically connected by the current-limiting resistance with the secondary-side circuitry.
  4. 4. voltage protection circuit as claimed in claim 3, it is characterised in that
    The mu balanced circuit unit includes：Controllable accurate source of stable pressure；Wherein, the reference voltage of the controllable accurate source of stable pressure output Reference voltage as the output voltage.
  5. 5. voltage protection circuit as claimed in claim 4, it is characterised in that
    The mu balanced circuit unit includes：First partial pressure matches somebody with somebody ratio resistance with ratio resistance and the second partial pressure；The first partial pressure proportioning The first end of the resistance first end with the magnet exciting coil, the negative electrode of the controllable accurate source of stable pressure and the current-limiting resistance respectively Connection；Second end of first partial pressure with ratio resistance respectively with the reference pole of the controllable accurate source of stable pressure and described second point It is press-fitted the first end connection of ratio resistance；Second partial pressure with ratio resistance the second end respectively with the controllable accurate source of stable pressure Anode connects with the second end of the magnet exciting coil.
  6. 6. voltage protection circuit as claimed in claim 5, it is characterised in that
    The output voltage Vo=Ur*(1+R2/R3)；Wherein, the reference voltage that Ur exports for the controllable accurate source of stable pressure, R2For First partial pressure matches somebody with somebody the resistance value of ratio resistance, R3Match somebody with somebody the resistance value of ratio resistance for second partial pressure.
  7. 7. voltage protection circuit as claimed in claim 1, it is characterised in that
    The electric capacity with the transformer secondary winding parallel is provided with the secondary-side circuitry, the normally-closed contact is set Between the electric capacity and the transformer secondary winding.
  8. 8. voltage protection circuit as claimed in claim 1, it is characterised in that
    The quantity of the normally-closed contact of the relay is two, and two normally-closed contacts are separately positioned on the secondary-side circuitry In first line and the second circuit on, wherein, the first line and second circuit respectively with the transformer secondary output The both ends connection of side winding.
  9. A kind of 9. Switching Power Supply, it is characterised in that including：
    The voltage protection circuit of Switching Power Supply as described in any one of claim 1 to 8.
  10. A kind of 10. voltage protection method of Switching Power Supply, it is characterised in that including：
    Relay is set, and the normally-closed contact of the relay is arranged in the secondary-side circuitry of Switching Power Supply, the relay Magnet exciting coil electrically connects with the secondary-side circuitry；
    When isolated failure occurs for transformer primary winding and transformer secondary winding and makes time in the secondary-side circuitry When level side voltage is the input voltage of the transformer primary winding, the secondary-side voltage is used to carry the magnet exciting coil For excitation voltage, the normally-closed contact is disconnected, to cut off the secondary-side circuitry.
  11. 11. method as claimed in claim 10, it is characterised in that including：
    Mu balanced circuit unit is set, and the magnet exciting coil is electrically connected by the mu balanced circuit unit with the secondary-side circuitry； Wherein, the secondary-side voltage is the input voltage of the mu balanced circuit unit, and the output voltage of the mu balanced circuit unit is used In to the magnet exciting coil offer excitation voltage.
  12. 12. method as claimed in claim 11, it is characterised in that including：
    Current-limiting resistance is set, and the mu balanced circuit unit is electrically connected by the current-limiting resistance with the secondary-side circuitry.
  13. 13. method as claimed in claim 12, it is characterised in that
    The mu balanced circuit unit includes：Controllable accurate source of stable pressure；Wherein, the reference voltage of the controllable accurate source of stable pressure output Reference voltage as the output voltage.
  14. 14. method as claimed in claim 13, it is characterised in that
    The first partial pressure is set to match somebody with somebody ratio resistance with ratio resistance and the second partial pressure；First partial pressure with ratio resistance first end respectively with The first end of the magnet exciting coil, the negative electrode of the controllable accurate source of stable pressure connect with the current-limiting resistance；First partial pressure Match somebody with somebody the first of ratio resistance with the reference pole of the controllable accurate source of stable pressure and second partial pressure respectively in the second end with ratio resistance End connection；Second end respectively anode with the controllable accurate source of stable pressure and the excitation wire of second partial pressure with ratio resistance The second end connection of circle.
  15. 15. method as claimed in claim 14, it is characterised in that
    The output voltage Vo=Ur*(1+R2/R3)；
    Wherein, the reference voltage that Ur exports for the controllable accurate source of stable pressure, R2Match somebody with somebody the resistance of ratio resistance for first partial pressure Value, R3Match somebody with somebody the resistance value of ratio resistance for second partial pressure.
  16. 16. the method as described in claim 1, it is characterised in that
    The electric capacity with the transformer secondary winding parallel is provided with the secondary-side circuitry, the normally-closed contact is set Put between the electric capacity and the transformer secondary winding.
  17. 17. method as claimed in claim 16, it is characterised in that
    The quantity of the normally-closed contact of the relay is two, and two normally-closed contacts are separately positioned on into the primary side electricity In first line and the second circuit in road, wherein, the first line and second circuit are secondary with the transformer respectively The both ends connection of level side winding.
CN201711276334.1A 2017-12-06 2017-12-06 Voltage protection circuit and method of switching power supply and switching power supply Active CN107785873B (en)

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09205721A (en) * 1996-01-24 1997-08-05 Fujitsu Ltd Circuit breaker for emergency power source disconnection
CN201298441Y (en) * 2008-10-27 2009-08-26 魏明 Voltage stabilizing transformer
JP2014023300A (en) * 2012-07-19 2014-02-03 Murata Mach Ltd Overvoltage protection device
CN103722275A (en) * 2013-12-04 2014-04-16 山东金阳矿业集团有限公司 Energy-saving electric welding machine
CN105811370A (en) * 2016-06-03 2016-07-27 国网黑龙江省电力有限公司齐齐哈尔供电公司 Double limiting automatic protector for stable output of transformer
JP2017028818A (en) * 2015-07-21 2017-02-02 Idec株式会社 Switching power source
CN206517042U (en) * 2017-03-16 2017-09-22 国网黑龙江省电力有限公司 The shock controller of power transformer

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09205721A (en) * 1996-01-24 1997-08-05 Fujitsu Ltd Circuit breaker for emergency power source disconnection
CN201298441Y (en) * 2008-10-27 2009-08-26 魏明 Voltage stabilizing transformer
JP2014023300A (en) * 2012-07-19 2014-02-03 Murata Mach Ltd Overvoltage protection device
CN103722275A (en) * 2013-12-04 2014-04-16 山东金阳矿业集团有限公司 Energy-saving electric welding machine
JP2017028818A (en) * 2015-07-21 2017-02-02 Idec株式会社 Switching power source
CN105811370A (en) * 2016-06-03 2016-07-27 国网黑龙江省电力有限公司齐齐哈尔供电公司 Double limiting automatic protector for stable output of transformer
CN206517042U (en) * 2017-03-16 2017-09-22 国网黑龙江省电力有限公司 The shock controller of power transformer

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