Utility model content
In order to solve shortcoming and defect existing in the prior art, the utility model provides a kind of to the defeated of AC powerGo out voltage successively after rectified filtering, flyback isolation and soft of current limited boost can soft bus capacitor CBUS to high pressureAC-DC isolated variable circuits, and then solve common inverse-excitation converting circuit outlet side diode and bear high voltage stressProblem.
In order to reach above-mentioned technical purpose, it is isolated the utility model proposes a kind of AC-DC for soft of bus capacitor and becomesCircuit is changed, is powered to dc-link capacitance CBUS for alternating current, the AC-DC isolated variables circuit, including：
The output end of current rectifying and wave filtering circuit for being connect with AC power, current rectifying and wave filtering circuit is connected with first order flybackThe output end of translation circuit, first order inverse-excitation converting circuit is connected with second level THE BOOST SWITCHING CIRCUIT, second level boosted switch electricityThe output end on road connects current limit circuit, and the output end of current-limiting circuit connects bus capacitor CBUS, first order inverse-excitation converting circuitIt is also associated with the first order power supply control chip for being controlled first order inverse-excitation converting circuit, second level boosted switch electricityRoad is also associated with the second level power supply control chip for being controlled second level THE BOOST SWITCHING CIRCUIT.
Optionally, the current-limiting circuit includes current-limiting resistance.
Optionally, the current rectifying and wave filtering circuit includes rectifier bridge and filter capacitor C1, and the input terminal connection of rectifier bridge is handed overGalvanic electricity source, the output end connection filter capacitor C1 of rectifier bridge.
Optionally, the first order inverse-excitation converting circuit includes transformer T1, switching tube Q1, diode D6, capacitance C3, is becomeOne end of one end connection filter capacitor C1 of depressor T1 primary coils, the other end connecting valve pipe Q1 of transformer T1 primary coilsDrain electrode, the grid of switching tube Q1 connects the first order power supply control chip for controlling switching tube Q1, the source electrode of switching tube Q1The other end of filter capacitor C1 is connected, the other end ground connection of filter capacitor C1, one end of transformer T1 secondary coils is through diodeThe other end of D6, capacitance C3 connection transformer T1 secondary coils, the other end ground connection of transformer T1 secondary coils.
Optionally, the second level THE BOOST SWITCHING CIRCUIT includes energy storage inductor L1, switching tube Q2, diode D7, Yi Ji electricityHold C4, the cathode of one end connection diode D6 of energy storage inductor L1, the drain electrode of one end connecting valve pipe Q2 of energy storage inductor L1 is openedSecond level power supply control chip of the grid connection of pipe Q2 for controlling switching tube Q2 is closed, the source electrode of switching tube Q2 connects transformerThe other end of T1 secondary coils, the other end of inductance L1 through diode D7, capacitance C4 connection transformer T1 secondary coils it is anotherEnd.
Optionally, the first order inverse-excitation converting circuit further includes the leakage inductance energy for absorbing transformer T1 storagesRCD clamp circuits.
Optionally, the RCD clamp circuits include resistance R1, capacitance C2, diode D5, and one end of resistance R1 connects transformationOne end of device T1 primary coils, the cathode of the other end connection diode D5 of resistance R1, the both ends connection capacitance C2 of resistance R1, twoThe other end of the anode connection transformer T1 primary coils of pole pipe D5.
The advantageous effect that technical solution provided by the utility model is brought is：
1, the design based on first order inverse-excitation converting circuit, realizes electrical isolation；
2, it based on the design for increasing second level THE BOOST SWITCHING CIRCUIT in the design of first order inverse-excitation converting circuit, reducesThe output voltage of first order inverse-excitation converting circuit, is conducive to the design of first order circuit transformer；
3, the design based on first order inverse-excitation converting circuit and second level THE BOOST SWITCHING CIRCUIT, reduces first order circuit deviceThe voltage stress of part such as reduces the requirement of circuit of reversed excitation outlet side diode voltage stress, and strong with large capacitive load ability.
Embodiment one
The utility model proposes a kind of AC-DC isolated variable circuits for soft of bus capacitor, for bus capacitorSoft of voltage CBUS, as shown in Figure 1, the AC-DC isolated variables circuit, including：
The output end of current rectifying and wave filtering circuit for being connect with AC power, current rectifying and wave filtering circuit is connected with first order flybackThe output end of translation circuit, first order inverse-excitation converting circuit is connected with second level THE BOOST SWITCHING CIRCUIT, second level boosted switch electricityThe output end on road connects current limit circuit, and the output end of current-limiting circuit connects bus capacitor CBUS, the both ends of bus capacitor CBUSIt is connected in parallel on load RL, first order inverse-excitation converting circuit is also associated with for being controlled first order inverse-excitation converting circuitPrimary power source controls chip, and second level THE BOOST SWITCHING CIRCUIT is also associated with for being controlled second level THE BOOST SWITCHING CIRCUITSecond level power supply control chip.
In force, general as described above, if powered to bus capacitor CBUS using common inverse-excitation converting circuitThe output voltage of logical inverse-excitation converting circuit must be very high, but the output voltage of common inverse-excitation converting circuit higher can make inverse-excitation convertingCircuit output side diode bears high voltage stress.Output voltage in order to solve common inverse-excitation converting circuit is higher to be madeThe problem of inverse-excitation converting circuit outlet side diode bears high voltage stress, the present embodiment propose a kind of for bus capacitorSoft AC-DC isolated variable circuit carries out soft, AC-DC isolated variables for electric main to dc-link capacitance CBUSCircuit includes current rectifying and wave filtering circuit, first order inverse-excitation converting circuit, second level THE BOOST SWITCHING CIRCUIT, the first level power supply control corePiece, second level power supply control chip, current-limiting circuit.
AC-DC isolated variable circuit operation principles：In the case of input AC alternating current (230V), electric main is rectifiedSmoother direct current, DC supply input first order inverse-excitation converting circuit are obtained after filtering, first order inverse-excitation converting circuit existsThe control of first order power supply control chip is lower to enter working condition, and direct current exports after first order inverse-excitation converting circuit electrical isolation280V direct currents, the direct current are pre-charged bus capacitor CBUS.
The supply voltage for just having started second level power supply control chip is less than the startup voltage of second level power supply control chip, greatlySupply voltage reaches the startup voltage of second level power supply control chip after about 4 seconds, and second level THE BOOST SWITCHING CIRCUIT is in second level electricitySource, which controls, enters working condition under chip controls, stablize output 900V direct currents after about 14 seconds soft process of current limited boostPressure, 900V DC voltages are exported after current-limiting circuit current limliting to bus capacitor CBUS again so that voltage foot on bus capacitor CBUSEnough height.
It is successively worked based on above-mentioned first order inverse-excitation converting circuit and second level THE BOOST SWITCHING CIRCUIT, reduces the first orderThe requirement of the voltage stress of inverse-excitation converting circuit outlet side diode, and it is strong with large capacitive load ability.
In addition, based on second level THE BOOST SWITCHING CIRCUIT is increased on the basis of first order inverse-excitation converting circuit, reduceThe output voltage of first order inverse-excitation converting circuit, to be conducive to the design of first order inverse-excitation converting circuit.
In addition, in the present embodiment first order power supply control chip model ICE3BR0680JZ, wherein the second level power supplyThe type for controlling chip is the power supply control chip with soft function of current limliting, the model of the second level power supply control chipIt is all made of peak-current mode controlling party inside UC2842D8, first order power supply control chip and second level power supply control chipFormula.
Optionally, the current-limiting circuit includes current-limiting resistance.
In force, current-limiting circuit, current limliting electricity are additionally provided between second level THE BOOST SWITCHING CIRCUIT and bus capacitor CBUSRoad includes current-limiting resistance, only with a current-limiting resistance Rrestrict in the present embodiment, as shown in Fig. 2, current-limiting resistanceOne end of Rrestrict connects second level THE BOOST SWITCHING CIRCUIT, and the other end of current-limiting resistance Rrestrict connects bus capacitorThe effect of CBUS, current-limiting resistance Rrestrict are limitation bus capacitor CBUS charging currents, to reach the entire circuit of reductionPeak power purpose so that entire circuit can normally start, can not to will not be forever all in the state started repeatedlyNormal work.
Optionally, as shown in Fig. 2, the current rectifying and wave filtering circuit includes rectifier bridge and filter capacitor C1, rectifier bridge it is defeatedEnter end connection AC power, the output end connection filter capacitor C1 of rectifier bridge.
In force, input first order inverse-excitation converting is electric after current rectifying and wave filtering circuit is used to electric main being converted into direct currentRoad, current rectifying and wave filtering circuit include rectifier bridge and filter capacitor C1, the alternating current direct current that first rectified bridge is pulsed, direct currentFiltered capacitance C1 filtering clutters, obtain smoother direct current, and by DC supply input first order inverse-excitation converting circuit.
Optionally, as shown in Fig. 2, the first order inverse-excitation converting circuit includes transformer T1, switching tube Q1, diodeD6, capacitance C3, one end of one end connection filter capacitor C1 of transformer T1 primary coils, the other end of transformer T1 primary coilsThe drain electrode of connecting valve pipe Q1, the grid of switching tube Q1 connect the first order power supply control chip for controlling switching tube Q1, openThe other end of the source electrode connection filter capacitor C1 of pipe Q1 is closed, the other end of filter capacitor C1 is grounded, transformer T1 secondary coilsThe other end of the one end through diode D6, capacitance C3 connection transformer T1 secondary coils, another termination of transformer T1 secondary coilsGround.
In force, as described above, first order inverse-excitation converting circuit carries out electrical isolation to the DC voltage of inputAfter export to second level THE BOOST SWITCHING CIRCUIT, second level power supply power supply chip, bus capacitor CBUS.At this point, first order flyback becomesThe output voltage for changing circuit is used to power to second level THE BOOST SWITCHING CIRCUIT and second level power supply control chip, is additionally operable to busbarCapacitance CBUS precharge.
In addition, first order inverse-excitation converting circuit, which has also risen, reduces switch tube Q1 when second level THE BOOST SWITCHING CIRCUIT startsThe effect of current stress.Since first order inverse-excitation converting circuit is pre-charged to bus capacitor, lead to second level THE BOOST SWITCHING CIRCUITThe current stress of switching tube Q1 is reduced when startup.
Optionally, the first order inverse-excitation converting circuit further includes the leakage inductance energy for absorbing transformer T1 storagesRCD clamp circuits.
Optionally, as shown in Fig. 2, the RCD clamp circuits include resistance R1, capacitance C2, diode D5, the one of resistance R1One end of end connection transformer T1 primary coils, the cathode of the other end connection diode D5 of resistance R1, the both ends of resistance R1 connectConnect capacitance C2, the other end of the anode connection transformer T1 primary coils of diode D5.
In force, all there is leakage inductance in any transformer, and because transformer T1 is there are leakage inductance, first order inverse-excitation converting circuit existsSwitching tube Q1 shutdown moments will produce prodigious peak voltage so that switching tube Q1 bears higher voltage stress, in some instances it may even be possible toSwitching tube Q1 is damaged, therefore increases RCD clamp circuits in first order inverse-excitation converting circuit, for absorbing transformer T1 storagesLeakage inductance energy ensure that first order inverse-excitation converting circuit can work normally to achieve the purpose that eliminate peak voltage.
Optionally, as shown in Fig. 2, the second level THE BOOST SWITCHING CIRCUIT includes energy storage inductor L1, switching tube Q2, diodeThe cathode of one end connection diode D6 of D7 and capacitance C4, energy storage inductor L1, one end connecting valve pipe Q2 of energy storage inductor L1Drain electrode, the grid of switching tube Q2 connects the second level power supply control chip for controlling switching tube Q2, the source electrode of switching tube Q2The other end of transformer T1 secondary coils is connected, the other end of inductance L1 is through diode D7, capacitance C4 connection T1 grade of transformerThe other end of coil.
In force, when the supply voltage of second level power supply control chip reaches the initiation value of second level power supply control chipWhen, second level THE BOOST SWITCHING CIRCUIT enters working condition under the control of second level power supply control chip, is risen through current limited boost is softCheng Hou gives bus capacitor CBUS current-limiting charges, until voltage is sufficiently high on bus capacitor CBUS.
It is used for the product of bus capacitor CBUS power supplies relative to other, one kind that the present embodiment proposes is used for bus capacitorSoft AC-DC isolated variable circuit, because of the switching tube inside first order inverse-excitation converting circuit and second level THE BOOST SWITCHING CIRCUITQuantity is few and pure simulation control, to reach lower-cost purpose.
The utility model provides a kind of AC-DC isolated variable circuits for soft of bus capacitor, for busbar electricityHold voltage CBUS soft, including：Current rectifying and wave filtering circuit, first order inverse-excitation converting circuit, second level THE BOOST SWITCHING CIRCUIT, firstLevel power supply controls chip and second level power supply control chip.Based on above-mentioned boosting AC-DC isolated variable circuits, the first level power supplyThe work of chip controls first order inverse-excitation converting circuit is controlled, the DC voltage of input is isolated in first order inverse-excitation converting circuitAfter export to second level THE BOOST SWITCHING CIRCUIT, second level power supply control chip, bus capacitor CBUS.When the second level power supply controls coreWhen the supply voltage of piece reaches the initiation value of second level power supply control chip, second level power supply control chip starts to control the second levelTHE BOOST SWITCHING CIRCUIT works, and after soft process of current limited boost, gives bus capacitor current-limiting charge, may finally make bus capacitorCBUS reaches the high pressure of soft needs of inverter.
Each serial number in above-described embodiment is for illustration only, the assembling for not representing each component or the elder generation during useSequence afterwards.
The above description is only the embodiments of the present invention, is not intended to limit the utility model, all in the utility modelSpirit and principle within, any modification, equivalent replacement, improvement and so on should be included in the protection model of the utility modelWithin enclosing.