CN210958160U - Soft switching circuit - Google Patents
Soft switching circuit Download PDFInfo
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- CN210958160U CN210958160U CN201921442541.4U CN201921442541U CN210958160U CN 210958160 U CN210958160 U CN 210958160U CN 201921442541 U CN201921442541 U CN 201921442541U CN 210958160 U CN210958160 U CN 210958160U
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Abstract
The utility model discloses a soft switch circuit, soft switch circuit's input can insert high voltage direct current input power, soft switch circuit includes isolation transformer and partial pressure electric capacity more than two, isolation transformer more than two establishes ties on high voltage direct current input power holds, wherein: each of the more than two isolation transformers comprises an input voltage division capacitor, a half-bridge soft switching unit and a rectifying unit; all the rectifying units in the more than two isolation transformers share the output filter capacitor and form a power output end of the soft switching circuit. Implement the embodiment of the utility model provides a, can be according to input voltage, nimble isolation vary voltage module quantity of increasing and decreasing series connection when can bear high voltage input, still have input bleeder circuit from the voltage-sharing, control is simple, circuit high efficiency, output ripple current advantage such as little.
Description
Technical Field
The utility model relates to an electronic circuit technical field especially involves a soft switch circuit.
Background
When facing high-voltage direct current input, a three-level converter is generally adopted, and the method can reduce half voltage stress of a switching tube, or improve the withstand voltage of a device by using an IGBT (insulated gate bipolar transistor) and a SIC MOS (silicon-on-insulator MOS) to meet the stress requirement of the switching device. The disadvantages of these solutions are: the three-level converter is complex to control, can only reduce half of the voltage stress of a switching power device, can only work at a lower working frequency by the IGBT, can greatly increase the volume and the weight of a circuit, and is expensive and difficult to work at an input voltage of more than 1500V by the SIC MOS tube. Therefore, a soft switching circuit applicable to high voltage dc input is needed.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to overcome the not enough of prior art, the utility model provides a soft switch circuit can increase and decrease the isolation vary voltage module quantity of series connection in a flexible way according to input voltage to the realization satisfies high input voltage's demand.
Correspondingly, the embodiment of the utility model provides a soft switch circuit, high voltage direct current input power can be inserted to soft switch circuit's input, soft switch circuit includes more than two isolation transformer and input voltage-dividing capacitance, the isolation transformer that is more than two establishes ties on high voltage direct current input power holds, wherein: each of the two or more isolation transformers comprises an input voltage dividing capacitor, a half-bridge soft switching unit and a rectifying unit, all the input voltage dividing capacitors of the two or more isolation transformers are connected in series and connected to the high-voltage direct-current input power supply end, the input end of the half-bridge soft switching unit of each isolation transformer is connected to the voltage dividing capacitor of each isolation transformer, and the output end of the half-bridge soft switching unit of each isolation transformer is connected to the rectifying unit of each isolation transformer; all the rectifying units in the more than two isolation transformers share the output filter capacitor and form a power output end of the soft switching circuit.
The half-bridge soft switching unit includes: first resonance electric capacity, second resonance electric capacity, first switch tube, second switch tube, resonance inductance and transformer, wherein: the first resonant capacitor and the second resonant capacitor are connected in series to form a capacitor series circuit, the first switching tube and the second switching tube are connected in series to form a switching tube series circuit, and the capacitor series circuit and the switching tube series circuit are connected in parallel to an input voltage division capacitor of a corresponding isolation transformer; one end of the resonance inductor is connected to a circuit between the first harmonic capacitor and the second harmonic capacitor, and the other end of the resonance inductor is connected with the transformer; one end of the transformer is connected to a line between the first switch tube and the second switch tube, and the other end of the transformer is connected to the resonance inductor.
Each isolation transformer among the isolation transformer more than two works in frequency conversion voltage regulation mode, pulse width modulation PWM drive between the isolation transformer among the isolation transformer more than two works with same frequency fs, there is the wrong phase between the isolation transformer among the isolation transformer more than two, the angle of wrong phase is 180/N, and N is the isolation vary voltage module number of series connection.
The resonance inductor is an external independent inductor or leakage inductance of a transformer is utilized.
The rectifying unit is a full-bridge rectifying circuit.
The full-bridge rectification circuit comprises a first diode, a second diode, a third diode and a fourth diode, wherein: the first diode and the second diode are connected in series to form a first series circuit, the third diode and the fourth diode are connected in series to form a second series circuit, and the first series circuit and the second series circuit are connected in parallel to form a power supply output end.
The rectifying unit is a full-wave rectifying circuit.
The full-wave rectifying circuit comprises a first diode and a second diode which are connected in parallel to form a power supply output end.
The embodiment of the utility model provides a soft switch circuit can increase and decrease the isolation vary voltage module quantity of establishing ties in a flexible way according to input voltage, when can bear high voltage input, still has input bleeder circuit from the voltage-sharing, and control is simple, circuit high efficiency, output ripple current advantage such as little.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic circuit diagram of a soft switching circuit according to a first embodiment of the present invention;
fig. 2 is a schematic circuit diagram of a soft switching circuit according to a second embodiment of the present invention;
fig. 3 is a schematic circuit diagram of a soft switching circuit according to a third embodiment of the present invention;
fig. 4 is a schematic circuit diagram of a first embodiment of a soft switching circuit according to an embodiment of the present invention;
fig. 5 is a schematic circuit diagram of a first embodiment of a soft switching circuit according to the embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.
The embodiment of the utility model provides a soft switch circuit, this soft switch circuit's input can insert high voltage direct current input power, soft switch circuit includes isolation transformer and input voltage-dividing capacitance more than two, isolation transformer more than two establishes ties on high voltage direct current input power holds, wherein: each of the two or more isolation transformers comprises an input voltage dividing capacitor, a half-bridge soft switching unit and a rectifying unit, all the input voltage dividing capacitors of the two or more isolation transformers are connected in series and connected to the high-voltage direct-current input power supply end, the input end of the half-bridge soft switching unit of each isolation transformer is connected to the voltage dividing capacitor of each isolation transformer, and the output end of the half-bridge soft switching unit of each isolation transformer is connected to the rectifying unit of each isolation transformer; all the rectifying units in the more than two isolation transformers share the output filter capacitor and form a power output end of the soft switching circuit.
Specifically, fig. 1 shows a schematic circuit structure diagram of a first embodiment of the soft switching circuit in the embodiment of the present invention, and here, a series structure of two isolated voltage transformation modules is illustrated. The soft switching circuit comprises two isolation transformers (the isolation transformer structure is a component structure defined by a dotted line frame 4) and an output filter capacitor Co, wherein the two isolation transformers are connected in series on a high-voltage direct-current input power supply end, and the basic component structure of each isolation transformer is a part defined by a dotted line 4.
Each isolation transformer (4) comprises an input voltage division capacitor (1), a half-bridge soft switching unit (2) and a rectifying unit (3), the input voltage division capacitors of the two isolation transformers are connected in series (namely C1 and C2 are connected in series) and are connected to the high-voltage direct current input power supply end (namely VIN + and VIN-), the input end of the half-bridge soft switching unit (2) of each isolation transformer is connected to the voltage division capacitor of each isolation transformer, and the output end of the half-bridge soft switching unit (2) of each isolation transformer is connected to the rectifying unit (3) of each isolation transformer; all the rectifying units (3) in the more than two isolation transformers share the output filter capacitor Co and form the power output end (namely VO + and VO-) of the soft switching circuit.
It should be noted that, the half-bridge soft switching unit on the first isolation transformer includes: resonant capacitor C11, resonant capacitor C12, switching tube Q11, switching tube Q12, resonant inductor L1 and transformer T1, wherein: the resonant capacitor C11 and the resonant capacitor C12 are connected in series to form a capacitor series circuit, the switching tube Q11 and the switching tube Q12 are connected in series to form a switching tube series circuit, and the capacitor series circuit and the switching tube series circuit are connected in parallel to the input voltage-dividing capacitor C1 of the first isolation transformer; one end of a resonant inductor L1 is connected to a line between the harmonic capacitor C11 and the harmonic capacitor C12, and the other end of the resonant inductor L1 is connected to a transformer T1; one end of the transformer T1 is connected to a line between the switching tube Q11 and the switching tube Q12, and the other end of the transformer T1 is connected to the resonant inductor L1.
It should be noted that, the half-bridge soft switching unit on the second isolation transformer includes: resonant capacitor C21, resonant capacitor C22, switching tube Q21, switching tube Q22, resonant inductor L2 and transformer T2, wherein: the resonant capacitor C21 and the resonant capacitor C22 are connected in series to form a capacitor series circuit, the switching tube Q21 and the switching tube Q22 are connected in series to form a switching tube series circuit, and the capacitor series circuit and the switching tube series circuit are connected in parallel to the input voltage-dividing capacitor C2 of the second isolation transformer; one end of a resonant inductor L2 is connected to a line between the harmonic capacitor C21 and the harmonic capacitor C22, and the other end of the resonant inductor L2 is connected to a transformer T2; one end of the transformer T2 is connected to a line between the switching tube Q21 and the switching tube Q22, and the other end of the transformer T2 is connected to the resonant inductor L2.
Each isolation transformer can work in frequency conversion voltage regulation mode, and the pulse width modulation PWM drive between the isolation transformers works with same frequency fs, there is the wrong phase between the isolation transformers in the isolation transformers more than two, the angle of wrong phase is 180/N, and N is the isolation vary voltage module number of establishing ties, and N here is 2, and its angle of wrong phase is 90 to can reduce the current ripple of output side. The soft switching circuit does not need to sample the voltage on each voltage-dividing capacitor for voltage-sharing control, the voltage on each voltage-dividing capacitor is natural voltage sharing, namely the voltage on each input capacitor is VIN/N, wherein N is the number of the isolation voltage-transforming modules connected in series, and N in FIG. 2 is 2.
It should be noted that the resonant inductor is an external independent inductor, or a leakage inductor of a transformer is used.
It should be noted that the rectifying unit here is a full-bridge rectifying circuit, the input end of the rectifying unit on each isolation transformation module is connected to the corresponding transformer, and the output end is connected in parallel to the power output end of the soft switching circuit formed on the output filter capacitor Co.
Specifically, the first full-bridge rectification circuit comprises a diode D11, a diode D12, a diode D13 and a diode D14, and the four diodes form the full-bridge rectification circuit.
Specifically, the second full-bridge rectification circuit comprises a diode D21, a diode D22, a diode D23 and a diode D24, the four diodes form the full-bridge rectification circuit, and the output end of the second full-bridge rectification circuit is connected with the output end of the first full-bridge rectification circuit in parallel.
Fig. 2 shows a circuit structure schematic diagram of a second embodiment of the soft switching circuit in the embodiment of the present invention, which is a structure schematic diagram of the soft switching circuit connected in series through 3 isolation voltage transformation modules, and the circuit principle is the same as that shown in fig. 1, and is not repeated here. In specific operation, when the input voltage is 1500V, the voltage that can be divided on the capacitors C1, C2 and C3 is 500V. For the first isolated voltage division module, when the voltage on the capacitor C1 is 500V, the MOS transistors of 500V can be used for Q11 and Q12. When the circuit works, because the circuit has a self-voltage-sharing function, the voltages on the capacitors C1, C2 and C3 do not need to be sampled respectively and then subjected to voltage-sharing control, the voltage on each capacitor can still be ensured to be 500V, the control difficulty and the cost of the circuit can be greatly reduced, and the working stability of the circuit is also ensured. Similarly, when the input voltage is 2000V, a circuit formed by 4 voltage division modules can be adopted, the voltage on the capacitor of each voltage division module is also 500V, and a 500V voltage-resistant MOS transistor can be selected. If the scheme is not adopted, a common circuit is selected, when the input voltage is 1500V, only 2000V IGBT can be selected, the circuit cannot work in a high-frequency state (the working frequency is more than 100KHz) and only can work in the working frequency of 10-20KHz, and an inductor and a transformer are heavy. Because need not sample the voltage on the partial pressure electric capacity, this circuit of extension that can be very convenient, when input voltage is 2000V, can adopt 4 bleeder module circuits to build, the switching tube still can choose for use the withstand voltage MOS pipe of 500V, analogizes in the same way, when input voltage is 3000V, can choose for use 6 bleeder modules.
Fig. 3 shows a schematic circuit structure diagram of a third embodiment of the soft switching circuit in the embodiment of the present invention, in which the resonant inductor is implemented by using the leakage inductance of the transformer itself, and the principle is the same as that shown in fig. 1, and is not repeated here.
Fig. 4 shows a circuit schematic diagram of a fourth embodiment of the soft switching circuit in the embodiment of the present invention, which is a schematic diagram of a soft switching circuit structure under the series connection of N isolation voltage transformation modules, and the principle thereof is the same as that shown in fig. 1, and is not repeated here.
Fig. 5 shows a schematic circuit structure diagram of a fifth embodiment of the soft switching circuit in the embodiment of the present invention, where the rectifying unit adopts a full-wave rectification mode, the full-wave rectification circuit includes two diodes, and two full-bridge rectification circuits are connected in parallel at the output end. Fig. 3 is a full-bridge rectifier circuit composed of 4 diodes for rectifying the ac power from the transformer into dc power, and fig. 5 is a full-wave rectifier circuit composed of two diodes for achieving the same function as the full-bridge rectifier circuit except that the two diodes are different in application, and the voltage borne by the diodes of the full-bridge rectifier circuit is half of that of the full-wave rectifier circuit.
The embodiment of the utility model provides an in soft switch circuit, can be according to input voltage, the isolation vary voltage module quantity of nimble increase and decrease series connection when can bear high voltage input, still has input bleeder circuit from the voltage-sharing, control is simple, circuit high efficiency, output ripple current advantage such as little.
In addition, the above detailed description is made on the soft switching circuit provided by the embodiment of the present invention, and a specific example should be adopted herein to explain the principle and the implementation manner of the present invention, and the description of the above embodiment is only used to help understand the method and the core idea of the present invention; meanwhile, for the general technical personnel in the field, according to the idea of the present invention, there are changes in the specific implementation and application scope, to sum up, the content of the present specification should not be understood as the limitation of the present invention.
Claims (8)
1. A soft switch circuit is characterized in that an input end of the soft switch circuit can be connected to a high-voltage direct-current input power supply, the soft switch circuit comprises more than two isolation transformers and a voltage division capacitor, the more than two isolation transformers are connected to the high-voltage direct-current input power supply end in series, and the soft switch circuit comprises: each of the two or more isolation transformers comprises an input voltage dividing capacitor, a half-bridge soft switching unit and a rectifying unit, all the input voltage dividing capacitors of the two or more isolation transformers are connected in series and connected to the high-voltage direct-current input power supply end, the input end of the half-bridge soft switching unit of each isolation transformer is connected to the voltage dividing capacitor of each isolation transformer, and the output end of the half-bridge soft switching unit of each isolation transformer is connected to the rectifying unit of each isolation transformer; all the rectifying units in the more than two isolation transformers share the output filter capacitor and form the power output end of the soft switching circuit.
2. The soft-switching circuit of claim 1, wherein the half-bridge soft-switching cell comprises: first resonance electric capacity, second resonance electric capacity, first switch tube, second switch tube, resonance inductance and transformer, wherein: the first resonant capacitor and the second resonant capacitor are connected in series to form a capacitor series circuit, the first switching tube and the second switching tube are connected in series to form a switching tube series circuit, and the capacitor series circuit and the switching tube series circuit are connected in parallel to an input voltage division capacitor of a corresponding isolation transformer; one end of the resonance inductor is connected to a circuit between the first harmonic capacitor and the second harmonic capacitor, and the other end of the resonance inductor is connected with the transformer; one end of the transformer is connected to a line between the first switch tube and the second switch tube, and the other end of the transformer is connected to the resonance inductor.
3. The soft-switching circuit of claim 1, wherein each of the two or more isolation transformers operates in a variable frequency and voltage regulation mode, the PWM drive between the two or more isolation transformers operates at a same frequency fs, the isolation transformers of the two or more isolation transformers have a phase error therebetween, the phase error has an angle of 180 °/N, and N is the number of isolation transformer modules connected in series.
4. The soft switching circuit of claim 2, wherein the resonant inductor is an external independent inductor or a leakage inductor of a transformer is used.
5. The soft-switching circuit of any one of claims 1 to 4, wherein the rectifying unit is a full-bridge rectifying circuit.
6. The soft-switching circuit of claim 5, wherein the full-bridge rectification circuit is comprised of four diodes.
7. The soft switching circuit according to any one of claims 1 to 4, wherein the rectifying unit is a full-wave rectifying circuit.
8. The soft-switching circuit of claim 7, wherein the full-wave rectification circuit comprises a first diode and a second diode connected in parallel to form a power supply output.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921442541.4U CN210958160U (en) | 2019-08-29 | 2019-08-29 | Soft switching circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921442541.4U CN210958160U (en) | 2019-08-29 | 2019-08-29 | Soft switching circuit |
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| CN210958160U true CN210958160U (en) | 2020-07-07 |
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| CN201921442541.4U Active CN210958160U (en) | 2019-08-29 | 2019-08-29 | Soft switching circuit |
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| CN (1) | CN210958160U (en) |
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- 2019-08-29 CN CN201921442541.4U patent/CN210958160U/en active Active
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