CN110277769A - LLC power input excess voltage protection and over-voltage protection method - Google Patents
LLC power input excess voltage protection and over-voltage protection method Download PDFInfo
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- 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
- H02H7/125—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 rectifiers
- H02H7/1252—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 rectifiers responsive to overvoltage in input or output, e.g. by load dump
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Abstract
The present invention provides a kind of LLC power input excess voltage protection and over-voltage protection methods, and wherein circuit includes over-voltage detection circuit, switching tube off-state equalizer circuit, control circuit.Using simple components composition and precisely reliably can protect circuit by preset threshold, it is ensured that be within the scope of the limiting voltage that can bear of twice of switching tube in input supply voltage, switching tube will not aircraft bombing due to over-voltage, therefore the application occasion in super-pressure can be used.Using most basic circuit theory, by ingenious reasonable design and experimental verification repeatedly, not only reliability is high, and is instantly the simplest, minimum one of the circuit arrangement of cost.
Description
Technical field
The present invention relates to electronic circuit technology fields, and in particular, to a kind of LLC power input excess voltage protection and
Over-voltage protection method.
Background technique
The one kind of mode of resonance switch converters as Sofe Switch has working frequency height, loss small, high-efficient, small in size
The advantages that.And LLC mode of resonance switch converters are had both with it to realize that the ZVS of primary side switch pipe is opened in full-load range
It is logical, the characteristics of the ZCS shutdown of rectifier diode and the advantages such as integrated, wide input voltage range convenient for magnetic, in HF switch field
Obtain extensive concern and application.
The L6599 chip of STMicw Electronics is good, defeated with its regulated efficiency height, saving radiator, saving space, output intermodulation
Rectifying tube is resistance to out forces down and the advantages that primary side Sofe Switch bring EMI is small, accounts in the control chip field of half-bridge resonance power supply
According to half of the country.LLC topology belongs to soft switch circuit, and surge voltage caused by switching tube turns off is smaller, this makes switching tube
It is not easy to damage due to over-voltage in normal work.But in industrial application, often because switching overvoltage causes to convert
The input voltage of device is more than the breakdown voltage of switching device, so as to cause aircraft bombing.In face of this situation, most direct method is exactly
The breakdown voltage of switching tube is improved, or perhaps using the switching tube of more high voltage, but this aspect will increase cost and volume,
On the other hand, the working efficiency of Switching Power Supply can also be reduced.Therefore, just being had very much using the protection against excessive pressure of Switching Power Supply must
It wants.
In the overvoltage protection patent of existing Switching Power Supply, after detecting input over-voltage, general use makes Switching Power Supply
The method that chip stops working, such as:
CN201310466813 drags down switching power source chip supply voltage when detecting input direct-current electric voltage over press,
To make switching power source chip stop working lower than its minimum operating voltage；CN201611154552, detection auxiliary winding are defeated
Out voltage come determine direct current input whether over-voltage, CN201711120437, detect current slope come determine direct current input whether mistake
Pressure detects that protection signal is generated when direct current inputs over-voltage makes switching power source chip stop working.These measures can not be defeated
It remains to play a protective role when entering voltage more than switching tube breakdown voltage, because in this case, as long as switching tube is also subject to whole
A input voltage, even if it, which does not work, can also damage.
Other patents are after detecting input over-voltage, using the method that circuit is detached to input power, such as:
CN201110451970 is detected and is made circuit be detached from electricity by controlling relay after exchanging input side overvoltage
Pressure, this scheme increases volume and cost, and relay actuation time is too long, is unable to satisfy the needs of switching overvoltage protection.
CN201310121503 and CN201310134796, after detecting input direct-current electric voltage over press, control access switch
It disconnects, so that input direct-current voltage be made not continue to increase, the program is needed using can rapidly switch off, have compared with high voltage and electricity
The power switch component of stream increases the cost of circuit.
As it can be seen that existing switching voltage input power overvoltage protection has two: one is cannot be in input electricity
Pressure plays the role of being effectively protected when being more than switching tube breakdown voltage；The second is needing additional power switch component, increase electricity
Road cost.
Therefore it provides a kind of LLC power input excess voltage protection and over-voltage protection method value with higher
And meaning.
Summary of the invention
For the defects in the prior art, the object of the present invention is to provide a kind of LLC power input excess voltage protections
And over-voltage protection method.
A kind of LLC power input excess voltage protection provided according to the present invention, including half-bridge, filter capacitor, over-voltage
Detection circuit, switching tube off-state equalizer circuit and control circuit；
The half-bridge includes two field effect transistors, the two field effect transistors are denoted as the first field-effect crystalline substance respectively
Body pipe, the second field effect transistor；In drain electrode the two of the source electrode of first field effect transistor and the second field effect transistor,
One is connected with DC bus anode, and another one is connected with DC bus cathode；The drain electrode of first field effect transistor and
The source electrode of second field effect transistor is connected with half-bridge bridge arm midpoint；
The filter capacitor is connected with DC bus anode, DC bus cathode respectively；
The over-voltage detection circuit includes at least three signal ends, these three signal ends are positive, straight with DC bus respectively
Stream bus cathode, control circuit are connected；
The switching tube off-state equalizer circuit include at least four signal ends, this four signal ends respectively with DC bus just
Pole, DC bus cathode, filter capacitor, half-bridge bridge arm midpoint are connected；
The control circuit include at least three lead terminals, these three lead terminals respectively with the first field effect transistor
Grid, the second field effect transistor grid, over-voltage detection circuit be connected.
Preferably, the LLC power input excess voltage protection further includes main transformer；
The main transformer side is connected with load circuit, and the other side includes first port and second port；Described first
Port is connected with half-bridge bridge arm midpoint；The second port is connected with DC bus anode or DC bus cathode.
Preferably, the LLC power input excess voltage protection further includes accessory power supply；The accessory power supply includes defeated
Enter filter capacitor, output filter capacitor and voltage stabilizing chip；
The voltage stabilizing chip includes three signal ends, is denoted as input, output end, common end respectively；It is the input terminal, defeated
Outlet is connected with input filter capacitor anode, output filter capacitor anode respectively；The common end grounding；The input filter
Capacitor cathode and output filter capacitor cathode are grounded.
Preferably, the over-voltage lc circuit detection circuit includes that resistor voltage divider circuit, reference voltage circuit, stagnant ring are more electric
Multiple combinations are appointed on any one of road and anti-clutter circuit；
The resistor voltage divider circuit, reference voltage circuit are connected with the input terminal of stagnant ring comparison circuit each independently；
The output end of the stagnant ring comparison circuit is connected with anti-clutter circuit.
Preferably, the control circuit includes master chip, high pressure floating driving transformer and periphery configuration parameter；
In first field effect transistor, second field effect transistor the two, one, which floats to drive by high pressure, to be become
Depressor is connected with master chip, and another one is directly connected with master chip；
The voltage range that the high pressure floating driving transformer allows is 500V to 1000V；
The periphery configuration parameter refers to circuit element necessary to control circuit work, including oscillating circuit, soft start
Any one of circuit, current foldback circuit, driving circuit and controlling circuit of voltage regulation appoint multiple combinations.
Preferably, the switching tube off-state equalizer circuit includes resistor voltage divider circuit.
Preferably, the reference voltage circuit includes pull-up resistor R301, output filter capacitor C303 and source of stable pressure
U301；
The reference pole of the source of stable pressure, cathode are electrically connected with the both ends of output filter capacitor C303 respectively；The source of stable pressure
Anode be electrically connected with output node；One end of the pull-up resistor R301 is electrically connected with output node.
Preferably, the over-voltage detection circuit includes first resistor R401, second resistance R402,3rd resistor R403,
Four resistance R404, the 5th resistance R405, the 6th resistance R406, the 7th resistance R407, first capacitor C401, first diode D401
And comparator U401；
Input terminal VIN is successively grounded through first resistor R401, second resistance R402, by first resistor R401, second resistance
First node is denoted as between R402；One end of first capacitor C401 is electrically connected with first node, other end ground connection；By the 4th resistance
The both ends of R404 are denoted as second node, third node respectively；The one end the 3rd resistor R403 is electrically connected with second node, another
End is electrically connected with reference end VREF；Described 5th one end resistance R405 is electrically connected with third node, the other end and power end VCC electricity
Connection；The power end VCC is successively grounded through the 6th resistance R406, the 7th resistance R407, by the 6th resistance R406, the 7th resistance
Fourth node is denoted as between R407；The fourth node is electrically connected with voltage detection terminal LINE；The first diode D401 two
End is electrically connected with third node, fourth node respectively；Three ports of the comparator U401 respectively with first node, the second section
Point, the electrical connection of third node.
A kind of LLC power input over-voltage protection method provided according to the present invention, comprising:
Over-voltage detecting step: it receives electric resistance partial pressure and obtains the predeterminated voltage that voltage input signal and reference circuit voltage generate
Then two signals are compared, if voltage input signal is greater than by the two signals of threshold signal by stagnant ring comparison circuit
Predetermined voltage threshold signal, then comparator exports a low level, if voltage input signal is not more than predetermined voltage threshold signal,
Then comparator exports a high level, and the level signal of comparator output flows into control circuit by anti-clutter circuit；
Rate-determining steps: receiving the level signal of comparator output, if the signal received is low level, turns off driving letter
Number output, disconnect switching tube, separate the input of power supply；If the signal received is high level, driving signal is opened
Output, power supply work normally.
Preferably, the LLC power input over-voltage protection method further include:
Switching tube off-state presses step: when switching tube is closed, dividing equally the supply voltage inputted by resistor voltage divider circuit, keeps away
Exempt from switching tube and receives voltge surge before unstable.Compared with prior art, the present invention have it is following the utility model has the advantages that
1, LLC power input excess voltage protection provided by the invention, simple, high reliablity, wide usage with structure
Strong advantage；
2, LLC power input excess voltage protection and over-voltage protection method provided by the invention, by detection electricity
The ingehious design on road avoids interference of the high-voltage signal to chip, when avoiding the common problem, i.e. over-voltage of the prior art, control
Circuit processed driving signal shutdown it is not rapid enough, so as to cause various complexity operating condition (under overpressure situation, any interference
It may cause driving signal exception, so as to cause power supply damage, directly detect input voltage according to chip, then it may be by it
It interferes and driving signal cannot be turned off in time)；
3, LLC power input excess voltage protection and over-voltage protection method provided by the invention, circuit of the present invention it
Between mating reaction, using the concatenated two switching tubes shared input direct-current voltage of major loop half-bridge, there is no need to additional again
Increase switching tube, reduce using element, not only saves space, but also reduce product cost；
4, LLC power input excess voltage protection and over-voltage protection method provided by the invention, can be in input electricity
Pressure plays the role of being effectively protected when being more than switching tube breakdown voltage, and does not need additional power switch component.Enhancing electricity
The reliability of source overvoltage protection expands the voltage scope of application, can significantly improve the reliability of designed product；
5, LLC power input excess voltage protection and over-voltage protection method provided by the invention, be related to circuit be through
It is simultaneously stringent authenticated to cross ingehious design, uses most basic circuit theory, therefore circuit is reliably high, and precision
Height can enhance the ability that half-bridge circuit bears over-voltage, can make switching tube when idle, bear itself twice pressure resistance
The voltage of value efficiently solves the problems, such as power supply over-voltage aircraft bombing with simplest circuit.Circuit is few using element, can effectively drop
Low production cost saves design space, improves the reliability of complete machine.
Detailed description of the invention
Upon reading the detailed description of non-limiting embodiments with reference to the following drawings, other feature of the invention,
Objects and advantages will become more apparent upon:
Fig. 1 is overvoltage protection scheme schematic diagram in one embodiment of the invention；
Fig. 2 is auxiliary power circuit schematic diagram in one embodiment of the invention；
Fig. 3 is reference voltage circuit schematic diagram in one embodiment of the invention；
Fig. 4 is over-voltage detection circuit scheme schematic diagram in one embodiment of the invention；
Fig. 5 is switching tube off-state equalizer circuit and control circuit schematic diagram in one embodiment of the invention；
Fig. 6 is overall circuit schematic diagram when using in one embodiment of the invention.
Specific embodiment
The present invention is described in detail combined with specific embodiments below.Following embodiment will be helpful to the technology of this field
Personnel further understand the present invention, but the invention is not limited in any way.It should be pointed out that the ordinary skill of this field
For personnel, without departing from the inventive concept of the premise, several changes and improvements can also be made.These belong to the present invention
Protection scope.
A kind of LLC power input excess voltage protection provided according to the present invention, including half-bridge, filter capacitor, over-voltage
Detection circuit, switching tube off-state equalizer circuit and control circuit；
The half-bridge includes two field effect transistors, the two field effect transistors are denoted as the first field-effect crystalline substance respectively
Body pipe, the second field effect transistor；In drain electrode the two of the source electrode of first field effect transistor and the second field effect transistor,
One is connected with DC bus anode, and another one is connected with DC bus cathode；The drain electrode of first field effect transistor and
The source electrode of second field effect transistor is connected with half-bridge bridge arm midpoint；
The filter capacitor is connected with DC bus anode, DC bus cathode respectively；
The over-voltage detection circuit includes at least three signal ends, these three signal ends are positive, straight with DC bus respectively
Stream bus cathode, control circuit are connected；
The switching tube off-state equalizer circuit include at least four signal ends, this four signal ends respectively with DC bus just
Pole, DC bus cathode, filter capacitor, half-bridge bridge arm midpoint are connected；
The control circuit include at least three lead terminals, these three lead terminals respectively with the first field effect transistor
Grid, the second field effect transistor grid, over-voltage detection circuit be connected.
The LLC power input excess voltage protection further includes main transformer；
The main transformer side is connected with load circuit, and the other side includes first port and second port；Described first
Port is connected with half-bridge bridge arm midpoint；The second port is connected with DC bus anode or DC bus cathode.
The LLC power input excess voltage protection further includes accessory power supply；The accessory power supply includes input filter
Capacitor, output filter capacitor and voltage stabilizing chip；
The voltage stabilizing chip includes three signal ends, is denoted as input, output end, common end respectively；It is the input terminal, defeated
Outlet is connected with input filter capacitor anode, output filter capacitor anode respectively；The common end grounding；The input filter
Capacitor cathode and output filter capacitor cathode are grounded.
The over-voltage lc circuit detection circuit include resistor voltage divider circuit, reference voltage circuit, stagnant ring comparison circuit and
Any one of anti-clutter circuit appoints multiple combinations；
The resistor voltage divider circuit, reference voltage circuit are connected with the input terminal of stagnant ring comparison circuit each independently；
The output end of the stagnant ring comparison circuit is connected with anti-clutter circuit.
The control circuit includes master chip, high pressure floating driving transformer and periphery configuration parameter；
In first field effect transistor, second field effect transistor the two, one, which floats to drive by high pressure, to be become
Depressor is connected with master chip, and another one is directly connected with master chip；
The voltage range that the high pressure floating driving transformer allows is 500V to 1000V；
The periphery configuration parameter refers to circuit element necessary to control circuit work, including oscillating circuit, soft start
Any one of circuit, current foldback circuit, driving circuit and controlling circuit of voltage regulation appoint multiple combinations.
The switching tube off-state equalizer circuit includes resistor voltage divider circuit.
The reference voltage circuit includes pull-up resistor R301, output filter capacitor C303 and source of stable pressure U301；
The reference pole of the source of stable pressure, cathode are electrically connected with the both ends of output filter capacitor C303 respectively；The source of stable pressure
Anode be electrically connected with output node；One end of the pull-up resistor R301 is electrically connected with output node.
The over-voltage detection circuit includes first resistor R401, second resistance R402,3rd resistor R403, the 4th resistance
R404, the 5th resistance R405, the 6th resistance R406, the 7th resistance R407, first capacitor C401, first diode D401 and ratio
Compared with device U401；
Input terminal VIN is successively grounded through first resistor R401, second resistance R402, by first resistor R401, second resistance
First node is denoted as between R402；One end of first capacitor C401 is electrically connected with first node, other end ground connection；By the 4th resistance
The both ends of R404 are denoted as second node, third node respectively；The one end the 3rd resistor R403 is electrically connected with second node, another
End is electrically connected with reference end VREF；Described 5th one end resistance R405 is electrically connected with third node, the other end and power end VCC electricity
Connection；The power end VCC is successively grounded through the 6th resistance R406, the 7th resistance R407, by the 6th resistance R406, the 7th resistance
Fourth node is denoted as between R407；The fourth node is electrically connected with voltage detection terminal LINE；The first diode D401 two
End is electrically connected with third node, fourth node respectively；Three ports of the comparator U401 respectively with first node, the second section
Point, the electrical connection of third node.
A kind of LLC power input over-voltage protection method provided according to the present invention, comprising:
Over-voltage detecting step: it receives electric resistance partial pressure and obtains the predeterminated voltage that voltage input signal and reference circuit voltage generate
Then two signals are compared, if voltage input signal is greater than by the two signals of threshold signal by stagnant ring comparison circuit
Predetermined voltage threshold signal, then comparator exports a low level, if voltage input signal is not more than predetermined voltage threshold signal,
Then comparator exports a high level, and the level signal of comparator output flows into control circuit by anti-clutter circuit；
Rate-determining steps: receiving the level signal of comparator output, if the signal received is low level, turns off driving letter
Number output, disconnect switching tube, separate the input of power supply；If the signal received is high level, driving signal is opened
Output, power supply work normally.
The LLC power input over-voltage protection method further include:
Switching tube off-state presses step: when switching tube is closed, dividing equally the supply voltage inputted by resistor voltage divider circuit, keeps away
Exempt from switching tube and receives voltge surge before unstable.Compared with prior art, the present invention have it is following the utility model has the advantages that
Further, preference of the invention is related to a kind of LLC electrical source input overvoltage protection method and circuit, includes over-voltage
Detection circuit, switching tube off-state equalizer circuit, control circuit.Preset threshold can precisely be pressed using simple components composition and reliably
Protect circuit, it is ensured that within the scope of the limiting voltage that input supply voltage can bear for twice of switching tube, switching tube is not
Meeting aircraft bombing due to over-voltage, therefore the application occasion in super-pressure can be used.Using most basic circuit theory, by ingenious reasonable
Design and experimental verification repeatedly, not only reliability is high, and be it is instantly the simplest, the minimum circuit arrangement of cost it
One.
Preference of the present invention is related to term and is explained as follows:
LLC: the one-port network containing inductance, capacitor and resistive element, in certain working frequencies, occur port voltage and
When the identical situation of current waveform phase, claim circuit that resonance occurs.The circuit of resonance, referred to as resonance circuit can occur.
Overvoltage protection: when overvoltage protection refers to that protected circuit voltage is more than scheduled maximum value, power supply is made to disconnect or make
A kind of protected mode that controlled device voltage reduces.
Preference of the invention provides a kind of overvoltage crowbar it is characterized by: comprising over-voltage detection circuit, switching tube
Off-state equalizer circuit, control circuit.
Over-voltage detection circuit contains resistor voltage divider circuit, reference voltage circuit, stagnant ring comparison circuit, anti-clutter circuit.
The working method of over-voltage detection circuit are as follows: electric resistance partial pressure obtains voltage signal first, and reference circuit voltage generation one is preset
Then two signals are compared by voltage threshold by stagnant ring comparison circuit, if over-voltage, comparator exports a low electricity
Flat, if non-over-voltage, comparator exports a high level, and then comparator output flows into control circuit by anti-clutter circuit.
The effect of anti-clutter circuit is: only when comparator output voltage is low level, can just pass the signal to control electricity
Road avoids interference of the high level to control circuit.
Control circuit includes main control chip and necessary periphery configuration parameter and high pressure floating driving transformer, using transformation
The purpose of device is the high-voltage driven signal for making to be in control a floating on bridge arm.
Mating reaction between the circuit of preference of the present invention turns off input power using the switching tube of major loop, therefore
It no longer needs to additionally increase switching tube, reduce using element, not only save space, but also reduce product cost.
Switching tube off-state equalizer circuit is made of resistor voltage divider circuit, working method are as follows: is closed suddenly when switching tube
When, input supply voltage is divided equally by resistance R1, R3, and so that bridge arm mid-point voltage is equal to 1/2 supply voltage by R2, can had
Effect avoids switching tube from obtaining safe voltage before unstable, can effectively enhance the over-voltage grade that power supply can be born.
The function of over-voltage detection circuit is detection input voltage and judges whether to be more than preset overvoltage threshold, and circuit can
Judge whether that over-voltage also can judge whether over-voltage fault solves, circuit can be effectively prevented in this way and produced in pressure point continuous action excessively
Life is compared with high peak voltage, so that circuit be avoided to damage.Using two poles can be effectively prevented comparator output be high level when
Interference is generated to main circuit.As shown in Figure 1, over-voltage detection circuit mainly by three signal ends, connect respectively DC bus just
Between cathode and control circuit.
Switching tube off-state equalizer circuit divides equally DC bus-bar voltage after turning off switching tube by electric resistance partial pressure principle.Such as
Shown in Fig. 1, mainly there are four terminals for switching tube off-state voltage regulator circuit, connect positive and negative anodes, the capacitor midpoint, half of DC bus respectively
Bridge bridge arm midpoint.
Control circuit is mainly made of LLC power supply main control chip, and there are many control chip of model, but bases on the market at present
Present principles and function are almost the same.When the signal that chip detects that detection circuit is issued is over-voltage, chip can turn off driving letter
Number output, disconnect switching tube, separate the input of power supply.When detect signal that detection circuit provides be when over-voltage restores or
When non-over-voltage, chip is again turned on the output of driving signal, and power supply continues to work normally.Control circuit is relevant to overvoltage protection
There are three lead terminal is total, they connect over-voltage detection circuit, upper down tube gate-drive respectively, such as shown in Figure 1.
Technological difficulties of the invention are: when over-voltage, the driving signal shutdown of control circuit must be very clean benefit
Otherwise rope is likely to occur the operating condition of various complexity, under overpressure situation, any interference may cause driving signal exception,
So as to cause power supply damage.Input voltage is directly detected according to chip, then cannot may be turned off in time driving by its interference
Signal.
A kind of over-voltage protection method provided by the invention includes following process:
By over-voltage detection circuit obtain LLC power circuit input voltage amplitude, and with preset overpressure threshold value comparison,
Decision circuitry input voltage whether over-voltage.
After judgement, processed signal is inputed into control circuit, if the signal is over-voltage signal, inputs control
The signal of circuit processed is a low level signal, this signal can force control circuit to close power supply；If the signal determining is non-mistake
Pressure, then the signal of input control circuit is a high level signal, because of the presence of a diode, so that this signal will not influence
Control circuit operates normally.
After power supply is closed, the movement of switching tube off-state equalizer circuit keeps down tube on switching tube respectively defeated according to the ratio of 1:1
Enter supply voltage, enhancing half-bridge circuit bears the ability of voltage
Further, the present embodiment is the overvoltage crowbar of the resonant power based on L6599, including over-voltage detection electricity
Road, switching tube off-state equalizer circuit, control circuit.
1) in order to provide a power supply to circuit, this example design accessory power supply is mainly used to this system
Chip provides power supply, and this part is mainly made of simple DCDC lowering and stabilizing blood pressure chip, mainly uses in the present invention
78L15.Under being used cooperatively of external circuit, input voltage can be exported stable 15V power supply by 78L15 after internal conversion,
Its circuit is as shown in Figure 2:
Wherein.C201, C202 are respectively the filter capacitor output and input, if input voltage allows, VIN, which can be, is
System input voltage, is also possible to the supply voltage of other equipment offer.VCC herein be positive 15V output.
2) over-voltage detection circuit includes reference voltage circuit, stagnant ring comparison circuit
Reference voltage circuit can generate the accurate and stable voltage of comparison and overvoltage protection threshold is arranged make for us
With.Our department's parallel circuit has mainly used the TL431 that can export accurate voltage, under the cooperation of peripheral circuit, can export various
Accurately voltage.Circuit is as shown in Figure 3.Wherein, R301 is pull-up resistor, and C303 is output filter capacitor, and VREF is output base
Quasi- voltage, the signal are mainly used to detection circuit.
Over-voltage detection circuit, the function of this partial circuit are detection input voltages and judge whether to be more than preset over-voltage threshold
Value, overvoltage threshold can be set by R401, R402, and C401 is high-frequency filter capacitor, and can be suitable by selecting
R403, R404, R405 restore the voltage value worked normally overpressure value and circuit is arranged, and circuit can be effectively prevented in this way in mistake
Pressure point continuous action and generate compared with high peak voltage, so that circuit be avoided to damage.Circuit is as shown in Figure 4.Wherein, LM393 is electricity
Comparator is pressed, VREF is the generation of benchmark potential circuit, is that comparator exports as high electricity in order to prevent used here as diode D401
Interference is generated to main circuit when flat.The present invention is L6599 using control chip, and voltage sense pin is the 7th foot (LINE
Pin), its pin signal is named as LINE signal.R406 and R407 provides the LINE signal of a normal work.Only
In a certain range, our control chip could work normally the voltage magnitude of LINE signal, be below or above this model
It encloses, our control chip will stop working.When detecting does not have over-voltage, comparator output is high level, when over-voltage,
Comparator output is low level, that is, " 0 " current potential described in us, and diode forward is connected at this time, and LINE signal is pulled low,
Force LINE signal amplitude lower than normal range (NR), to turn off chip output.Overvoltage protection threshold and recovery value can by with
Lower formula is arranged:
3) control circuit is mainly made of control chip L6599 peripheral circuit, and circuit diagram is as shown in Figure 5.Wherein,
L6599 is the control chip of circuit system of the present invention, and two switching tubes of half-bridge major loop are driven by HVG and LVG, and
According to LINE signal to determine whether to turn off the output of HVG and LVG two-way driving signal.Because the present invention relates to schemes to pertain only to
L6599 to overvoltage protection, therefore in figure practical is to simplify pin.
Switching tube off-state equalizer circuit is made of R501, R502, R503 in Fig. 5, R501 and the resistance value of R503 should it is consistent and
Much larger than load, R502 selects desired value, can also be consistent with remaining two resistance value, when switching tube does not work, R501 and
R502 partial pressure, wherein the resistance value of R501 should be consistent with R503, after switching tube shutdown, under the bridge joint of R502,If R501=R503,Wherein VbusFor direct current
The voltage value of bus.
In the description of the present application, it is to be understood that term " on ", "front", "rear", "left", "right", " is erected at "lower"
Directly ", the orientation or positional relationship of the instructions such as "horizontal", "top", "bottom", "inner", "outside" is orientation based on the figure or position
Relationship is set, description the application is merely for convenience of and simplifies description, rather than the device or element of indication or suggestion meaning are necessary
It with specific orientation, is constructed and operated in a specific orientation, therefore should not be understood as the limitation to the application.
Specific embodiments of the present invention are described above.It is to be appreciated that the invention is not limited to above-mentioned
Particular implementation, those skilled in the art can make a variety of changes or modify within the scope of the claims, this not shadow
Ring substantive content of the invention.In the absence of conflict, the feature in embodiments herein and embodiment can any phase
Mutually combination.
Claims (10)
1. a kind of LLC power input excess voltage protection, which is characterized in that including half-bridge, filter capacitor, over-voltage detection electricity
Road, switching tube off-state equalizer circuit and control circuit；
The half-bridge includes two field effect transistors, the two field effect transistors are denoted as the first field effect transistor respectively
Pipe, the second field effect transistor；In drain electrode the two of the source electrode of first field effect transistor and the second field effect transistor, one
Person is connected with DC bus anode, and another one is connected with DC bus cathode；The drain electrode of first field effect transistor and
The source electrode of two field effect transistors is connected with half-bridge bridge arm midpoint；
The filter capacitor is connected with DC bus anode, DC bus cathode respectively；
The over-voltage detection circuit includes at least three signal ends, these three signal ends are female with DC bus anode, direct current respectively
Line cathode, control circuit are connected；
The switching tube off-state equalizer circuit include at least four signal ends, this four signal ends respectively with DC bus anode,
DC bus cathode, filter capacitor, half-bridge bridge arm midpoint are connected；
The control circuit includes at least three lead terminals, these three lead terminals grid with the first field effect transistor respectively
Pole, the grid of the second field effect transistor, over-voltage detection circuit are connected.
2. LLC power input excess voltage protection according to claim 1, which is characterized in that the LLC power input
Excess voltage protection further includes main transformer；
The main transformer side is connected with load circuit, and the other side includes first port and second port；The first port
It is connected with half-bridge bridge arm midpoint；The second port is connected with DC bus anode or DC bus cathode.
3. LLC power input excess voltage protection according to claim 1, which is characterized in that the LLC power input
Excess voltage protection further includes accessory power supply；The accessory power supply includes input filter capacitor, output filter capacitor and steady
Press chip；
The voltage stabilizing chip includes three signal ends, is denoted as input, output end, common end respectively；The input, output end
It is connected respectively with input filter capacitor anode, output filter capacitor anode；The common end grounding；The input filter capacitor
Cathode and output filter capacitor cathode are grounded.
4. LLC power input excess voltage protection according to claim 1, which is characterized in that the over-voltage lc circuit
Detection circuit include any one of resistor voltage divider circuit, reference voltage circuit, stagnant ring comparison circuit and anti-clutter circuit or
Appoint multiple combinations；
The resistor voltage divider circuit, reference voltage circuit are connected with the input terminal of stagnant ring comparison circuit each independently；It is described
The output end of stagnant ring comparison circuit is connected with anti-clutter circuit.
5. LLC power input excess voltage protection according to claim 1, which is characterized in that the control circuit packet
Include master chip, high pressure floating driving transformer and periphery configuration parameter；
In first field effect transistor, second field effect transistor the two, one is floated driving transformer by high pressure
It is connected with master chip, another one is directly connected with master chip；
The voltage range that the high pressure floating driving transformer allows is 500V to 1000V；
The periphery configuration parameter refer to control circuit work necessary to circuit element, including oscillating circuit, soft starting circuit,
Any one of current foldback circuit, driving circuit and controlling circuit of voltage regulation appoint multiple combinations.
6. LLC power input excess voltage protection according to claim 1, which is characterized in that the switching tube off-state
Equalizer circuit includes resistor voltage divider circuit.
7. LLC power input excess voltage protection according to claim 4, which is characterized in that the reference voltage electricity
Road includes pull-up resistor R301, output filter capacitor C303 and source of stable pressure U301；
The reference pole of the source of stable pressure, cathode are electrically connected with the both ends of output filter capacitor C303 respectively；The sun of the source of stable pressure
Pole is electrically connected with output node；One end of the pull-up resistor R301 is electrically connected with output node.
8. LLC power input excess voltage protection according to claim 1, which is characterized in that the over-voltage detection electricity
Road includes first resistor R401, second resistance R402,3rd resistor R403, the 4th resistance R404, the 5th resistance R405, the 6th electricity
Hinder R406, the 7th resistance R407, first capacitor C401, first diode D401 and comparator U401；
Input terminal VIN is successively grounded through first resistor R401, second resistance R402, by first resistor R401, second resistance R402
Between be denoted as first node；One end of first capacitor C401 is electrically connected with first node, other end ground connection；By the 4th resistance R404
Both ends be denoted as second node, third node respectively；The one end the 3rd resistor R403 is electrically connected with second node, the other end with
Reference end VREF electrical connection；Described 5th one end resistance R405 is electrically connected with third node, and the other end is electrically connected with power end VCC
It connects；The power end VCC is successively grounded through the 6th resistance R406, the 7th resistance R407, by the 6th resistance R406, the 7th resistance
Fourth node is denoted as between R407；The fourth node is electrically connected with voltage detection terminal LINE；The first diode D401 two
End is electrically connected with third node, fourth node respectively；Three ports of the comparator U401 respectively with first node, the second section
Point, the electrical connection of third node.
9. a kind of LLC power input over-voltage protection method characterized by comprising
Over-voltage detecting step: it receives electric resistance partial pressure and obtains the predetermined voltage threshold that voltage input signal and reference circuit voltage generate
Then two signals are compared by the two signals of signal by stagnant ring comparison circuit, preset if voltage input signal is greater than
Voltage threshold signals, then comparator exports a low level, if voltage input signal is not more than predetermined voltage threshold signal, compares
A high level is exported compared with device, the level signal of comparator output flows into control circuit by anti-clutter circuit；
Rate-determining steps: receiving the level signal of comparator output, if the signal received is low level, turns off driving signal
Output, disconnects switching tube, separates the input of power supply；If the signal received is high level, the output of driving signal is opened,
Power supply works normally.
10. LLC power input over-voltage protection method according to claim 9, which is characterized in that the LLC power supply is defeated
Enter over-voltage protection method further include:
Switching tube off-state presses step: when switching tube is closed, dividing equally the supply voltage inputted by resistor voltage divider circuit, avoids out
It closes before Guan Wei stablizes and receives voltge surge.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201910647436.2A CN110277769A (en) | 2019-07-17 | 2019-07-17 | LLC power input excess voltage protection and over-voltage protection method |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910647436.2A CN110277769A (en) | 2019-07-17 | 2019-07-17 | LLC power input excess voltage protection and over-voltage protection method |
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| CN110277769A true CN110277769A (en) | 2019-09-24 |
Family
ID=67964651
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111864886A (en) * | 2020-07-14 | 2020-10-30 | 北京诺信泰伺服科技有限公司 | Power supply and floodgate machine equipment |
| CN114567029A (en) * | 2021-09-30 | 2022-05-31 | 惠州市乐亿通科技有限公司 | Overvoltage protection circuit and charging device |
| CN115296327A (en) * | 2022-10-09 | 2022-11-04 | 北京金冠智能电气科技有限公司 | AC/DC microgrid operation protection circuit |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102223064A (en) * | 2010-04-14 | 2011-10-19 | 天网电子股份有限公司 | Serial resonant converter having overload delay mechanism and short-circuit protection mechanism |
| CN202135059U (en) * | 2011-06-30 | 2012-02-01 | 深圳市核达中远通电源技术有限公司 | Half-bridge LLC resonant converter |
| CN102355147A (en) * | 2011-10-28 | 2012-02-15 | 上海大学 | Digital control device and method for LLC (logical link control) synchronously-rectified resonant converter |
| CN103945613A (en) * | 2014-04-24 | 2014-07-23 | 常州戚墅堰机车车辆配件工业有限公司 | Locomotive headlamp illumination and flickering control device |
| CN203872267U (en) * | 2014-05-16 | 2014-10-08 | 江苏利通电子有限公司 | LED TV power supply backlight driving circuit |
| CN106059336A (en) * | 2016-08-01 | 2016-10-26 | 成都芯源***有限公司 | Integrated circuit for a switching converter circuit and method for providing a supply voltage for an integrated circuit |
| CN210092868U (en) * | 2019-07-17 | 2020-02-18 | 上海希形科技有限公司 | LLC power input overvoltage protection circuit |
-
2019
- 2019-07-17 CN CN201910647436.2A patent/CN110277769A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102223064A (en) * | 2010-04-14 | 2011-10-19 | 天网电子股份有限公司 | Serial resonant converter having overload delay mechanism and short-circuit protection mechanism |
| CN202135059U (en) * | 2011-06-30 | 2012-02-01 | 深圳市核达中远通电源技术有限公司 | Half-bridge LLC resonant converter |
| CN102355147A (en) * | 2011-10-28 | 2012-02-15 | 上海大学 | Digital control device and method for LLC (logical link control) synchronously-rectified resonant converter |
| CN103945613A (en) * | 2014-04-24 | 2014-07-23 | 常州戚墅堰机车车辆配件工业有限公司 | Locomotive headlamp illumination and flickering control device |
| CN203872267U (en) * | 2014-05-16 | 2014-10-08 | 江苏利通电子有限公司 | LED TV power supply backlight driving circuit |
| CN106059336A (en) * | 2016-08-01 | 2016-10-26 | 成都芯源***有限公司 | Integrated circuit for a switching converter circuit and method for providing a supply voltage for an integrated circuit |
| CN210092868U (en) * | 2019-07-17 | 2020-02-18 | 上海希形科技有限公司 | LLC power input overvoltage protection circuit |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111864886A (en) * | 2020-07-14 | 2020-10-30 | 北京诺信泰伺服科技有限公司 | Power supply and floodgate machine equipment |
| CN111864886B (en) * | 2020-07-14 | 2024-05-24 | 北京诺信泰伺服科技有限公司 | Power supply and floodgate machine equipment |
| CN114567029A (en) * | 2021-09-30 | 2022-05-31 | 惠州市乐亿通科技有限公司 | Overvoltage protection circuit and charging device |
| CN114567029B (en) * | 2021-09-30 | 2023-07-18 | 惠州市乐亿通科技有限公司 | Overvoltage protection circuit and charging device |
| CN115296327A (en) * | 2022-10-09 | 2022-11-04 | 北京金冠智能电气科技有限公司 | AC/DC microgrid operation protection circuit |
| CN115296327B (en) * | 2022-10-09 | 2023-01-24 | 北京金冠智能电气科技有限公司 | AC/DC microgrid operation protection circuit |
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