A kind of AC-DC converter based on PFC+LLC topologyTechnical field
The present invention relates to technical field of automotive electronics, convert more particularly to a kind of AC-DC based on PFC+LLC topologyDevice.
Background technique
For automobile AC-DC charger as the important car-mounted device to charge to new energy car battery, the quality of performance is straightConnect the service life for influencing new energy car battery and vehicle security.With the development of science and technology with various countries for new since 21 centuryThe quick promotion of energy automobile, the demand of Vehicular charger also increasingly increase, simultaneously for the charging time of Vehicular chargerShorter and shorter, the power requirement hence for Vehicular charger is also increasing, because while charger power improves, meetingThe loss of charger power device is caused to greatly increase, traditional large power supply uses forward topology, half-bridge and full-bridge substantiallyTopology since its magnetic characteristic works in first quartile, and is hard switching operating mode come what is realized, determines that the circuit existsSome intrinsic defects.And loss of efficiency is relatively serious.
The problem of forward topology, half-bridge and full-bridge topology realize large power supply using hard switching has:
1. within the general 100K of switching frequency that forward topology, half-bridge and full-bridge topology use, for high-power,The volume of transformer is very big, leads to the loss of power, so that the reduction of effective power, so for the design power of transformerIt is required that improving, the volume of entire charger is also increased；
2. forward topology, half-bridge and full-bridge topology are realized using hard switching, so the switching moments of its power deviceVoltage and current stress is very high, causes device temperature relatively high, and switching loss is very big, and the service life also shortens；
3. dv/dt and di/dt compare, larger, EMI and EMI problem is relatively difficult to resolve certainly；
4. the whole cost of product is relatively much higher.
Summary of the invention
In view of the foregoing deficiencies of prior art, the purpose of the present invention is to provide a kind of based on PFC+LLC topologyAC-DC converter for solving in the prior art since its magnetic characteristic works in first quartile, and is hard switching Working mouldIt is some intrinsic to determine that the circuit haves the defects that for formula.And the problem that loss of efficiency is relatively serious.
The present invention provides a kind of AC-DC converter based on PFC+LLC topology, including conversion circuit, the conversion circuitIncluding current rectifying and wave filtering circuit, soft start switch, booster circuit, reduction voltage circuit, constant voltage and current limiting circuit, feedback regulating circuit, protectionCircuit and auxiliary power circuit；The current rectifying and wave filtering circuit, the soft start switch, the booster circuit, the reduction voltage circuitIt is sequentially connected electrically with the constant voltage and current limiting circuit；The protection circuit respectively with the booster circuit, the reduction voltage circuit and instituteState the electrical connection of constant voltage and current limiting circuit；The auxiliary power circuit respectively with the soft start switch, the booster circuit and describedReduction voltage circuit electrical connection；The feedback regulating circuit is connected between the reduction voltage circuit and the constant voltage and current limiting circuit.
In one embodiment of the invention, the booster circuit is PFC boost electricity of the prime using BOOST topology formationRoad.
In one embodiment of the invention, the reduction voltage circuit is LLC resonance reduction voltage circuit.
In one embodiment of the invention, the AC-DC converter further includes bottom plate, control panel, power amplifier board and upper cover；InstituteLid is stated equipped with heat sink；An accommodation space is formed after the bottom plate and upper cover engaging, the conversion circuit setting existsOn the control panel, the control panel is vertically fixed on the power amplifier board；The control panel and the power amplifier board are arranged in instituteIt states in accommodation space.
In one embodiment of the invention, mounting hole is offered on the upper lid, radiation air is installed on the mounting holeFan.
In one embodiment of the invention, the heat sink is cell structure.
It further include controller and temperature collecting device in one embodiment of the invention, the controller and the temperatureAcquisition device is fixed on the power amplifier board；The controller is connected with the conversion circuit with the radiator fan；The controlDevice processed controls the conversion circuit according to the temperature that the temperature collecting device acquires and the radiator fan works.
In one embodiment of the invention, it is all connected on the input terminal, the output end and the temperature collecting deviceThere is waterproof connector.
In one embodiment of the invention, the control panel and bottom plate interval setting, and spacing distance is greater than0.254mm。
As described above, a kind of AC-DC converter based on PFC+LLC topology of the invention, has the advantages that
Using LLC Sofe Switch, working frequency is increased substantially, while realizing that the no-voltage of switching device is opened, and is dropped significantlyLow switching loss, improves whole power.
Ensure the promotion of power simultaneously, temperature control changes in a certain range, reduces the power damage of each power deviceConsumption, while structure uses maximized heat dissipation design, the heat dissipation of large area adds fan cooling to ensure that converter is stable and reliable in work.
It ensures safety, multi-protective function is devised in circuit design, protect self-security.It is set using PFCMeter, considerably reduces the interference to power grid, improves whole safety.
Detailed description of the invention
Fig. 1 is shown as the frame structure signal of conversion circuit in the AC-DC converter based on PFC+LLC topology in the present inventionFigure.
Fig. 2 is shown as the configuration schematic diagram of the AC-DC converter based on PFC+LLC topology in the present invention.
Fig. 3 is shown as the bottom view of Fig. 2.
Component label instructions:
1 conversion circuit
2 bottom plates
3 control panels
4 power amplifier boards
5 upper covers
51 radiator fans
52 heat sinks
Specific embodiment
Illustrate embodiments of the present invention below by way of specific specific example, those skilled in the art can be by this specificationOther advantages and efficacy of the present invention can be easily understood for disclosed content.The present invention can also pass through in addition different specific realitiesThe mode of applying is embodied or practiced, the various details in this specification can also based on different viewpoints and application, without departing fromVarious modifications or alterations are carried out under spirit of the invention.It should be noted that in the absence of conflict, following embodiment and implementationFeature in example can be combined with each other.
It should be noted that illustrating the basic structure that only the invention is illustrated in a schematic way provided in following embodimentThink, only shown in schema then with related component in the present invention rather than component count, shape and size when according to actual implementationDraw, when actual implementation kenel, quantity and the ratio of each component can arbitrarily change for one kind, and its assembly layout kenelIt is likely more complexity.
Referring to Fig. 1 to Fig. 3, it should however be clear that this specification structure depicted in this specification institute accompanying drawings, ratio, size etc., only to matchThe revealed content of specification is closed, so that those skilled in the art understands and reads, is not intended to limit the invention implementableQualifications, therefore do not have technical essential meaning, the modification of any structure, the change of proportionate relationship or the adjustment of size,In the case where not influencing the effect of present invention can be generated and the purpose that can reach, should all still fall in disclosed technologyIn the range of Rong get Neng is covered.Meanwhile it is cited such as "upper", "lower", "left", "right", " centre " and " one " in this specificationDeng term, be merely convenient to being illustrated for narration, rather than to limit the scope of the invention, the change of relativenessOr adjustment, under the content of no substantial changes in technology, when being also considered as the enforceable scope of the present invention.
As shown in Figure 1 to Figure 3, Fig. 1 is shown as converting electricity in the AC-DC converter based on PFC+LLC topology in the present inventionThe frame structure schematic diagram on road (1).Fig. 2 is shown as the detonation configuration of the AC-DC converter based on PFC+LLC topology in the present inventionSchematic diagram.Fig. 3 is shown as the bottom view of Fig. 2.The present invention provides a kind of AC-DC converters based on PFC+LLC topology, includingConversion circuit 1, the conversion circuit 1 include current rectifying and wave filtering circuit, soft start switch, booster circuit, reduction voltage circuit, constant voltage and current limitingCircuit, feedback regulating circuit, protection circuit and auxiliary power circuit；It is the current rectifying and wave filtering circuit, the soft start switch, describedBooster circuit, the reduction voltage circuit and the constant voltage and current limiting circuit are sequentially connected electrically；The protection circuit respectively with the boostingCircuit, the reduction voltage circuit and constant voltage and current limiting circuit electrical connection；The auxiliary power circuit is opened with the soft start respectivelyIt closes, the booster circuit and the reduction voltage circuit are electrically connected；The feedback regulating circuit be connected to the reduction voltage circuit with it is describedBetween constant voltage and current limiting circuit.
In an embodiment of the present invention, the booster circuit is the PFC boost circuit that prime uses BOOST topology formation.The reduction voltage circuit is LLC resonance reduction voltage circuit.Meanwhile soft start switch uses LLC Sofe Switch, realizes zero electricity of switching devicePressure is opened, and the power loss of each power device is reduced.Meanwhile booster circuit is designed using PFC, is considerably reduced to power gridInterference, improve whole safety.Prime uses the PFC boost circuit of BOOST topology formation, behind input commercial power rectificationDc voltage boost adjusts power factor (PF) to DC400V, can almost ignore to the interference of power grid.Major loop mainly usesLLC Sofe Switch and LLC reduction voltage circuit, which are constituted, carries out reduction regulation, and the resonant frequency point of LLC is chosen to be 100K.In order to guarantee zero electricitySofe Switch operating mode is pressed, is realized using the combination of transformer leakage inductance and resonant inductance to Zero-voltage soft in feedback regulating circuitThe adjusting of switch.12V low-voltage needed for each circuit is entirely to be provided by independent isolated auxiliary power circuit, shouldThe rated power of auxiliary power circuit design is 15W, and very big limit meets auxiliary power required for whole system.
In an embodiment of the present invention, the AC-DC converter further includes bottom plate 2, control panel 3, power amplifier board 4 and upper cover 5；The upper cover 5 is equipped with heat sink 52；The bottom plate 2 and the upper cover 5 form an accommodation space, the conversion circuit after engaging1 is arranged on the control panel 3, and the control panel 3 is vertically fixed on the power amplifier board 4；The control panel 3 and the powerPlate 4 is arranged in the accommodation space.Further, mounting hole is offered in the upper cover 5, is equipped on the mounting hole scatteredHot-air fan 51.Meanwhile the heat sink 52 is cell structure.Structure uses maximized heat dissipation design, and the heat dissipation of large area addsFan cooling ensures that converter is stable and reliable in work.
It in a preferred embodiment, further include controller and temperature collecting device, the controller and the temperature acquisitionDevice is fixed on the power amplifier board 4；The controller is connected with the conversion circuit 1 with the radiator fan 51；The controlDevice processed controls the conversion circuit 1 according to the temperature that the temperature collecting device acquires and the radiator fan 51 works.Into oneStep, waterproof connector is respectively connected on the input terminal, the output end and the temperature collecting device.Preferably, describedControl panel 3 and the setting of the interval of the bottom plate 2, and spacing distance is greater than 0.254mm.To guarantee heat dissipation effect.
AC-DC converter design rated output power be Shang kilowatt, be for the partial switch device electric current to be passed throughIt is bigger, so also having stringenter design for fan heat problem, it is contemplated that the problem of heat dissipation and volume, power device designOn the aluminum substrate with preferable heat-sinking capability, aluminum substrate touch shell, control device PCB on aluminum substrate, it is high-power walkFor line by carrying out upper and lower level grafting with a thickness of 1.5mm, the copper post that diameter is 12, the additional fan Hot-air fan of shell takes into account consideration heat dissipationProblem, and improve whole stability.
In conclusion the AC-DC converter of the invention based on PFC+LLC topology, using LLC Sofe Switch, working frequencyIt increases substantially, while realizing that the no-voltage of switching device is opened, greatly reduce switching loss, improve whole power.Ensure the promotion of power simultaneously, temperature control changes in a certain range, reduces the power loss of each power device, ties simultaneouslyStructure uses maximized heat dissipation design, and the heat dissipation of large area adds fan cooling to ensure that converter is stable and reliable in work.Ensure peaceQuan Xing devises multi-protective function in circuit design, protects self-security.It is designed, is considerably reduced pair using PFCThe interference of power grid improves whole safety.So the present invention effectively overcomes various shortcoming in the prior art and has heightValue of industrial utilization.
The above-described embodiments merely illustrate the principles and effects of the present invention, and is not intended to limit the present invention.It is any ripeThe personage for knowing this technology all without departing from the spirit and scope of the present invention, carries out modifications and changes to above-described embodiment.CauseThis, institute is complete without departing from the spirit and technical ideas disclosed in the present invention by those of ordinary skill in the art such asAt all equivalent modifications or change, should be covered by the claims of the present invention.