One kind recommending soft switch circuit method for adjusting resonance frequency and system
阅读说明：本技术 一种推挽软开关电路谐振频率调整方法和系统 (One kind recommending soft switch circuit method for adjusting resonance frequency and system ) 是由 赵鹏 贾正胜 于 2019-08-09 设计创作，主要内容包括：本发明涉及电子电路技术领域,具体涉及一种推挽软开关电路谐振频率调整方法和系统,该推挽电路包括第一开关管和第二开关管,其中调整方法包括：实时检测所述电路中第一开关管或第二开关管的通断状态切换时的关断电流；根据关断电流和预设的开关频率调整方法实时调节第一开关管和第二开关管的开关频率,这样通过不断获取关断电流实现闭环调节,使得关断电流稳定在电路的最小关断电流,或者使得关断电流在电路的最小关断电流附近浮动,减小第一开关管和第二开关管上的电能损耗,节约了电能。(The present invention relates to electronic circuit technology fields, soft switch circuit method for adjusting resonance frequency and system are recommended more particularly to one kind, the push-pull circuit includes first switch tube and second switch, and wherein method of adjustment includes: the cut-off current when on off operating mode of first switch tube or second switch switches in circuit described in real-time detection；Adjust the switching frequency of first switch tube and second switch in real time according to cut-off current and preset switching frequency method of adjustment, realize that closed loop is adjusted by constantly obtaining cut-off current in this way, so that cut-off current stablizes the minimum turn-off electric current in circuit, or cut-off current is floated near the minimum turn-off electric current of circuit, reduce the electric energy loss in first switch tube and second switch, saves electric energy.)
1. a kind of push-pull circuit method for adjusting resonance frequency, the push-pull circuit includes first switch tube and second switch, It is characterized in that, which comprises
The cut-off current when on off operating mode of first switch tube or second switch switches in circuit described in real-time detection；
The first switch tube and second switch are adjusted in real time according to the cut-off current and preset switching frequency method of adjustment The switching frequency of pipe, so that the cut-off current stablizes the minimum turn-off electric current in the circuit.
2. method of adjustment as described in claim 1, which is characterized in that described according to the cut-off current and preset switch frequency Rate method of adjustment adjusts the first switch tube in real time and the switching frequency of second switch includes:
Step 101: obtaining and record the cut-off current at current time, increase the switching frequency；
Step 102: obtaining corresponding cut-off current after switching frequency increases, and judge corresponding shutdown electricity after switching frequency increase Whether stream is less than corresponding cut-off current before switching frequency increases, if then return step 101, then follow the steps 103 if not；
Step 103: reducing the switching frequency；
Step 104: obtaining corresponding cut-off current after switching frequency reduces, and judge corresponding shutdown electricity after switching frequency reduction Whether stream is less than corresponding cut-off current before switching frequency reduces, if then return step 103, otherwise return step 101.
3. method of adjustment as described in claim 1, which is characterized in that described according to the cut-off current and preset switch frequency Rate method of adjustment adjusts the first switch tube in real time and the switching frequency of second switch includes:
Step 201: obtaining and record the cut-off current at current time, reduce the switching frequency；
Step 202: obtaining after switching frequency reduces corresponding cut-off current and judge after the reduction whether is corresponding cut-off current Less than corresponding cut-off current before reducing, if then return step 201, no to then follow the steps 203；
Step 203: increasing the switching frequency；
Step 204: obtaining after switching frequency increases corresponding cut-off current and judge after the increase whether is corresponding cut-off current Less than corresponding cut-off current before increasing, if then return step 203, otherwise return step 201.
4. method of adjustment as claimed in claim 2 or claim 3, which is characterized in that further include:
Every time increase perhaps reduce the switching frequency after judge increase or reduce after switching frequency whether be in it is preset In switching frequency range, if otherwise determining the circuit malfunctions.
5. method of adjustment as claimed in claim 4, which is characterized in that the preset adjustment amount is the switching frequency range 3%-6%.
6. method of adjustment as claimed in claim 5, which is characterized in that the upper and lower bound of the switching frequency range by with Lower method obtains:
The maximum value and minimum value for obtaining LC in the circuit respectively bring the maximum value of LC into following formula and switch are calculated The lower limit of frequency；Bring the minimum value of LC into switching frequency is calculated in following formula the upper limit；
In above formula, frFor switching frequency.
7. a kind of push-pull circuit resonance frequency adjusts system, the push-pull circuit includes first switch tube and second switch, It is characterized in that, the system comprises: acquisition module and processor；
When the acquisition module for acquiring the on off operating mode of first switch tube or second switch switching in the circuit in real time Cut-off current, and collected cut-off current is sent to the processor；
The processor is opened for adjusting described first in real time according to the cut-off current and preset switching frequency method of adjustment The switching frequency of pipe and second switch is closed, so that the cut-off current stablizes the minimum turn-off electric current in the circuit.
8. adjustment system as claimed in claim 7, which is characterized in that the processor is for according to the cut-off current and in advance If switching frequency method of adjustment adjust the first switch tube in real time and the switching frequency of second switch includes:
The processor is used to adjust the switching frequency of the first switch tube and second switch, obtains the switching frequency tune The cut-off current of the whole front and back circuit, obtains the variation tendency of the cut-off current, continues to adjust according to the variation tendency The switching frequency of the first switch tube and second switch, to reduce the cut-off current of the circuit.
9. adjustment system as claimed in claim 8, which is characterized in that described to obtain the switching frequency adjustment front and back electricity The cut-off current on road obtains the variation tendency of the cut-off current, is continued to adjust the first switch according to the variation tendency Pipe and the switching frequency of second switch include:
The cut-off current of the switching frequency adjustment front and back circuit is obtained, if before cut-off current adjusted is less than adjustment Cut-off current then continues the switching frequency for adjusting the first switch tube and second switch according to the adjustment mode of last time, no Then continue to adjust the switching frequency of the first switch tube and second switch using the adjustment mode opposite with last time；
The adjustment mode includes increasing the switching frequency of the first switch tube and second switch and reducing described first to open Close the switching frequency of pipe and second switch.
10. adjustment system as claimed in claim 8, which is characterized in that the preset adjustment amount is the switching frequency model The 3%-6% enclosed.
Technical field
The present invention relates to electronic circuit technology fields, and in particular to one kind recommends soft switch circuit method for adjusting resonance frequency And system.
Background technique
With being widely used for battery, in UPS or emergency power supply field, the high high-power pressure build-up technique of no-load voltage ratio is ground extensively Study carefully, wherein high-frequency push-pull Boost topology due to its structure it is simple, boosting efficiency is high, output power, in entire switch periods Energy is all transmitted outward, is used widely in battery booster link.
In booster circuit especially compared with large velocity ratio, its low-pressure side electric current as shown in Figure 1 can be bigger, makes Become the dominant loss of circuit work at low side power device loss, and its loss mostlys come from the switch of boosting MOSFET It is lost, the copper loss and iron loss of conduction loss and step-up transformer, is generally reduced in practical applications by hardware switch technology Switching loss, but simple hardware controls booster circuit technology, due to resonant inductance transformer leakage inductance and capacitance error and The influence to resonance point and circuit Q factor is loaded, the deviation of practical resonance point is caused, so that switching loss is larger.
Summary of the invention
Switching loss larger technical problem when in order to solve to simply use hardware control circuit in the prior art, this Shen One kind please be provided and recommend soft switch circuit method for adjusting resonance frequency and system, specifically included:
A kind of push-pull circuit method for adjusting resonance frequency, the push-pull circuit include first switch tube and second switch, The described method includes:
The cut-off current when on off operating mode of first switch tube or second switch switches in circuit described in real-time detection；
The first switch tube and second are adjusted in real time according to the cut-off current and preset switching frequency method of adjustment The switching frequency of switching tube, so that the cut-off current stablizes the minimum turn-off electric current in the circuit.
Wherein, described that the first switch is adjusted according to the cut-off current and preset switching frequency method of adjustment in real time Pipe and the switching frequency of second switch include:
Step 101: obtaining and record the cut-off current at current time, increase the switching frequency；
Step 102: obtaining corresponding cut-off current after switching frequency increases, and judge corresponding pass after switching frequency increase Whether power-off stream is less than corresponding cut-off current before switching frequency increases, if then return step 101, then follow the steps if not 103；
Step 103: reducing the switching frequency；
Step 104: obtaining corresponding cut-off current after switching frequency reduces, and judge corresponding pass after switching frequency reduction Whether power-off stream is less than corresponding cut-off current before switching frequency reduces, if then return step 103, otherwise return step 101.
Wherein, described that the first switch is adjusted according to the cut-off current and preset switching frequency method of adjustment in real time Pipe and the switching frequency of second switch include:
Step 201: obtaining and record the cut-off current at current time, reduce the switching frequency；
Step 202: obtaining corresponding cut-off current after switching frequency reduces and judge corresponding cut-off current after the reduction Whether reduce before corresponding cut-off current is less than, if then return step 201, no to then follow the steps 203；
Step 203: increasing the switching frequency；
Step 204: obtaining corresponding cut-off current after switching frequency increases and judge corresponding cut-off current after the increase Whether increase before corresponding cut-off current, if then return step 203, otherwise return step 201 are less than.
Further, further includes:
Every time increase perhaps reduce the switching frequency after judge increase or reduce after switching frequency whether be in it is pre- If switching frequency range in, if otherwise determining the circuit malfunctions.
Wherein, the preset adjustment amount is the 3%-6% of the switching frequency range.
Wherein, the upper and lower bound of the switching frequency range obtains by the following method:
The maximum value and minimum value for obtaining LC in the circuit respectively are brought the maximum value of LC into following formula and are calculated The lower limit of switching frequency；Bring the minimum value of LC into switching frequency is calculated in following formula the upper limit；
In above formula, frFor switching frequency.
A kind of push-pull circuit resonance frequency adjusts system, and the push-pull circuit includes first switch tube and second switch, The system comprises: acquisition module and processor；
The acquisition module is cut for acquiring the on off operating mode of first switch tube or second switch in the circuit in real time Cut-off current when changing, and collected cut-off current is sent to the processor；
The processor is used to adjust described the in real time according to the cut-off current and preset switching frequency method of adjustment The switching frequency of one switching tube and second switch, so that the cut-off current stablizes the minimum turn-off electric current in the circuit.
The processor is used to adjust described the in real time according to the cut-off current and preset switching frequency method of adjustment One switching tube and the switching frequency of second switch include:
The processor is used to adjust the switching frequency of the first switch tube and second switch, obtains the switch frequency The cut-off current of the rate adjustment front and back circuit, obtains the variation tendency of the cut-off current, is continued according to the variation tendency The switching frequency of the first switch tube and second switch is adjusted, to reduce the cut-off current of the circuit.
Wherein, the cut-off current for obtaining the switching frequency adjustment front and back circuit, obtains the cut-off current Variation tendency, include: according to the switching frequency that the variation tendency continues to adjust the first switch tube and second switch
The cut-off current of the switching frequency adjustment front and back circuit is obtained, if cut-off current adjusted is less than adjustment Preceding cut-off current then continues the switch frequency for adjusting the first switch tube and second switch according to the adjustment mode of last time Otherwise rate continues to adjust the switching frequency of the first switch tube and second switch using the adjustment mode opposite with last time；
The adjustment mode includes increasing the switching frequency of the first switch tube and second switch and reducing described the The switching frequency of one switching tube and second switch.
Preferably, the preset adjustment amount is the 3%-6% of the switching frequency range.
Soft switch circuit method for adjusting resonance frequency, first switch in real-time Acquisition Circuit are recommended according to above-described embodiment Cut-off current when pipe or the switching of the on off operating mode of second switch, and adjusted in real time according to preset switching frequency method of adjustment The switching frequency of first switch tube and second switch, so that minimum turn-off current value of the cut-off current at current time in circuit It nearby floats, reduces switching loss in this way, so that entire circuit is more energy saving.
Detailed description of the invention
Fig. 1 is the push-pull circuit figure of the embodiment of the present application；
Fig. 2 is the operational mode state figure of the push-pull circuit of the embodiment of the present application；
Fig. 3 is voltage and current state diagram of the push-pull circuit of the embodiment of the present application in the part of devices under mode 1-4；
Fig. 4 is the method for adjustment flow chart of the embodiment of the present application；
Fig. 5 is a kind of switching frequency method of adjustment flow chart of the embodiment of the present application；
Fig. 6 is another switching frequency method of adjustment flow chart of the embodiment of the present application.
Specific embodiment
Below by specific embodiment combination attached drawing, invention is further described in detail.Wherein different embodiments Middle similar component uses associated similar element numbers.In the following embodiments, many datail descriptions be in order to The application is better understood.However, those skilled in the art can recognize without lifting an eyebrow, part of feature It is dispensed, or can be substituted by other elements, material, method in varied situations.In some cases, this Shen Please it is relevant it is some operation there is no in the description show or describe, this is the core in order to avoid the application by mistake More descriptions are flooded, and to those skilled in the art, these relevant operations, which are described in detail, not to be necessary, they Relevant operation can be completely understood according to the general technology knowledge of description and this field in specification.
It is formed respectively in addition, feature described in this description, operation or feature can combine in any suitable way Kind embodiment.Meanwhile each step in method description or movement can also can be aobvious and easy according to those skilled in the art institute The mode carry out sequence exchange or adjustment seen.Therefore, the various sequences in the description and the appended drawings are intended merely to clearly describe a certain A embodiment is not meant to be necessary sequence, and wherein some sequentially must comply with unless otherwise indicated.
Push-pull circuit (push-pull) is exactly the output circuit connected between two opposed polarity transistors.Push-pull circuit is adopted With the identical power BJT pipe of two parameters or MOSFET pipe, it is present in circuit with push pull mode, the wave of each responsible positive-negative half-cycle Shape amplifies task, when circuit works, two symmetrical power switch tubes only one conducting every time, so the small efficiency of conduction loss It is high.Push-pull output both can also extract electric current from load to load sink current.Such as Fig. 1, the present embodiment recommends electricity with one kind The application method is illustrated for road, which includes first switch tube S1With second switch S2, further include power supply Vin, include load capacitance C in load circuitBWith load resistance RL.The push-pull circuit outputs and inputs side according to its transformer It divides, including lower-voltage circuit and high pressure lateral circuit, wherein lower-voltage circuit includes first switch tube S1, inductance L1, second open Close pipe S2, power supply VinWith load R1.Power supply VinAnode be electrically connected with the midpoint of inductance L1, power supply VinCathode series resistance First switch tube S is separately connected after R11The first pole and second switch S2The first pole, first switch tube S1The second pole with One end of inductance L1 connects, second switch S2The second pole connect with the other end of inductance L1.First switch tube S1Control electrode With second switch S2Control electrode connect with processor.High pressure lateral circuit includes inductance L2 (transformer secondary winding), electricity Feel Lr(leakage inductance that the present embodiment is transformer), capacitor Cr, first diode D1, the second diode D2, third diode D3, the 4th Diode D4, capacitor CBWith load RL.One end of inductance L2 passes through inductance LrConnect capacitor CrOne end, capacitor CrThe other end connect Meet first diode D1Anode and the 4th diode D4Cathode.First diode D1Cathode connect the second diode D2's Cathode, capacitor CBOne end and load RLOne end；Second diode D2Anode connection inductance L2 the other end and the three or two pole Pipe D3Cathode, third diode D3Anode connection the 4th diode D4Anode, capacitor CBThe other end and load RLIt is another One end.Capacitor CBBoth ends be respectively the first output terminals A and second output terminal B.First output terminals A and second output terminal B are used for Voltage V after output amplificationB.The push-pull circuit will appear four kinds of operating modes as shown in Figure 2 during the work time, and In each of these modes of operation in circuit electric current circuit diagram, Fig. 3 is circuit when working under four kinds of modes in Fig. 2 in circuit Voltage and voltage change conditions, Vg1 and Vg2 is respectively diode D in Fig. 1 in Fig. 31And D2On voltage, i1And i2Table respectively Show the electric current in first switch tube and second switch, wherein CS1 and CS2 are respectively indicated in first switch tube and second switch Cut-off current, VS1And VS2Respectively indicate the voltage in first switch tube and second switch, irIndicate capacitor C in Fig. 1rIt is upper The electric current crossed, VdIndicate diode D in Fig. 14On electric current, VBFor R in Fig. 1LThe voltage at both ends.Wherein, first switch tube and Two switching tubes work under fixed switching frequency, and in S1And S2Between there are certain dead zone, LC resonance frequency is rationally set and is opened It closes pipe switching frequency and quality factor q guarantees that resonance current is in discrete state.Fig. 2 show four kinds of moulds of circuit work Formula state, in mode 1, S1Open-minded, after resonance half period, battery current turns off S close to zero point at this time1；In mode 2, S1And S2It is turned off, due to the afterflow of transformer magnetizing current, S at this time1Junction capacity on switching tube will be charged to 2 times of batteries Voltage (cell voltage+transformer voltage), while S2On junction capacity be discharged into 0, S at this time2There are no-voltages to open condition； In mode 3, S2It is open-minded in zero-voltage state, the S when current resonance is to zero2Shutdown；Mode 4 is similar to mode 2, at this time S2Switch Junction capacity on pipe will be charged to 2 times of cell voltages, while S1On junction capacity be discharged into 0.To realize S1And S2In mould Realize that the no-voltage of switching tube is opened and zero-current switching in formula 2 and mode 4.Wherein, switching frequency be first switch tube and The frequency of second switch turn-on and turn-off, when switching frequency is equal to the resonance frequency of circuit, circuit is i.e. according to above-mentioned four kinds Mode work.Sampling hold circuit is also connected in the present embodiment in circuit, for the electric current in real-time detection push-pull circuit, Particularly for detecting the cut-off current when on off operating mode of first switch tube or second switch switching in the circuit, and export One current feedback signal.
In push-pull circuit especially compared with large velocity ratio, circuit as shown in Figure 1, low-pressure side electric current can compare It is larger, cause low side power device loss to become the dominant loss of circuit work, and its loss mostlys come from boosting Switching loss, the copper loss and iron loss of conduction loss and step-up transformer of MOSFET, by obtaining electricity in real time in the present embodiment The cut-off current when on off operating mode of first switch tube or second switch switches in road, and according to cut-off current and preset open The switching frequency that frequency adjusting method adjusts first switch tube and second switch in real time is closed, so that cut-off current is stablized in circuit Minimum turn-off electric current, in this way by constantly obtain cut-off current realize closed loop adjust, guarantee to open in first switch tube or second The cut-off current all-the-time stable flowed through when closing pipe on-off, in circuit or makes cut-off current in the minimum turn-off circuit of circuit It floats near the minimum turn-off electric current of circuit, can thus reduce the electric energy loss in first switch tube and second switch, Electric energy is saved.
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