CN216721182U - Isolated bidirectional DC/DC conversion circuit - Google Patents
Isolated bidirectional DC/DC conversion circuit Download PDFInfo
- Publication number
- CN216721182U CN216721182U CN202123370256.6U CN202123370256U CN216721182U CN 216721182 U CN216721182 U CN 216721182U CN 202123370256 U CN202123370256 U CN 202123370256U CN 216721182 U CN216721182 U CN 216721182U
- Authority
- CN
- China
- Prior art keywords
- switch tube
- tube
- switching tube
- voltage side
- electrically connected
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Dc-Dc Converters (AREA)
Abstract
The utility model discloses an isolated bidirectional DC/DC conversion circuit, which comprises a first full-Bridge circuit, a transformer, a second full-Bridge circuit and a controller, wherein the high-voltage side and the low-voltage side are isolated through the transformer; adopt the full-bridge structure, compare in half-bridge structure, when carrying out high-power transmission under the mode of operation that steps up, the electric stress of switch tube can reduce half, and at energy transmission's in-process, the inductive inductance of resonance inductance and output inductance and switch tube parasitic capacitance carry out the resonance and realize zero voltage switch, realize the bidirectional transfer of energy through the on-state of control switch tube and inside body diode.
Description
Technical Field
The utility model relates to the technical field of DC/DC conversion, in particular to an isolated bidirectional DC/DC conversion circuit.
Background
The energy storage device is connected with the direct current bus through the bidirectional DC/DC converter, and bidirectional flow between the energy storage device and the bus is realized. Some energy storage devices have a wide voltage fluctuation range, but the voltage level is far lower than that of the direct current bus, so that a wide-range bidirectional DC/DC converter needs to be provided to boost the energy storage output voltage. For a high-power isolated DC/DC converter, there are a resonant type and a non-resonant type. In the non-resonant isolated DC/DC converter, there are phase-shifted full-bridge and DAB (Dual-active bridge) circuits, but these circuit structures all have certain limitations. For example, the traditional phase-shifted full bridge can only transmit electric energy in one direction, the traditional DAB circuit structure can be suitable for high-power occasions, but the soft switch in the full-power range cannot be realized, and the voltage stress borne by the switch tube is direct-current bus voltage.
SUMMERY OF THE UTILITY MODEL
In view of the above analysis, the present invention provides an isolated bidirectional DC/DC conversion circuit to solve the deficiencies of the prior art.
The utility model is mainly realized by the following technical scheme:
the utility model also provides an isolated bidirectional DC/DC conversion circuit, which comprises a first full-bridge circuit, a transformer, a second full-bridge circuit and a controller, wherein the first full-bridge circuit comprises a first switch tube, a second switch tube, a third switch tube and a fourth switch tube, and the second full-bridge circuit comprises a fifth switch tube, a sixth switch tube, a seventh switch tube, an eighth switch tube and a first filtering unit; each switch tube is respectively connected with a body diode in parallel.
The first switch tube is connected with the second switch tube in series, the third switch tube is connected with the fourth switch tube in series, the first end of the third switch tube and the first end of the first switch tube are respectively electrically connected with the anode of the high-voltage side power supply, the second end of the second switch tube and the second end of the fourth switch tube are respectively electrically connected with the cathode of the high-voltage side power supply, one end of the first winding of the transformer is electrically connected with the serial connection part of the first switch tube and the second switch tube through the resonant inductor, the other end of the first winding of the transformer is electrically connected with the serial connection part of the third switch tube and the fourth switch tube, and the control ends of the first switch tube, the second switch tube, the third switch tube and the fourth switch tube are electrically connected with the controller.
The transformer is characterized in that the fifth switching tube is connected with the sixth switching tube in series, the seventh switching tube is connected with the eighth switching tube in series, the first end of the fifth switching tube and the first end of the seventh switching tube are connected and are electrically connected with the anode of the low-voltage side power supply through the output inductor, the second end of the sixth switching tube and the second end of the eighth switching tube are respectively electrically connected with the cathode of the low-voltage side power supply, one end of the second winding of the transformer is electrically connected with the serial connection positions of the fifth switching tube and the sixth switching tube, the other end of the second winding of the transformer is electrically connected with the serial connection positions of the seventh switching tube and the eighth switching tube, the control ends of the fifth switching tube, the sixth switching tube, the seventh switching tube and the eighth switching tube are electrically connected with the controller, and the first filtering units are arranged at two ends of the low-voltage side power supply.
Furthermore, the filter further comprises a second filtering unit, wherein the second filtering unit comprises a first capacitor, and two ends of the first capacitor are respectively and electrically connected with the positive electrode and the negative electrode of the high-voltage side power supply.
Furthermore, the first filtering unit comprises a second capacitor, and two ends of the second capacitor are respectively electrically connected with the positive electrode and the negative electrode of the low-voltage side power supply.
Further, the first switch tube, the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube are insulated gate bipolar transistors or metal-oxide semiconductor field effect transistors.
Further, the high-voltage side power supply is a photovoltaic module, and the low-voltage side power supply is a storage battery.
Compared with the prior art, the technical scheme of the utility model has the beneficial effects that:
compared with the traditional Dual-active Bridge circuit, the isolated bidirectional DC/DC conversion circuit has the advantages that the high-voltage side and the low-voltage side are isolated through the transformer, and the circuit needs relatively less capacitors because the first filtering unit and the output inductor filter together and the effective value of the current flowing through the first filtering unit is smaller under the condition that the current ripple rate of the low-voltage side is the same; adopt the full-bridge structure, compare in half-bridge structure, when carrying out high-power transmission under the mode of operation that steps up, the electric stress of switch tube can be reduced by half, and at energy transmission's in-process, the inductive inductance of resonance inductance and output inductance and switch tube parasitic capacitance carry out the resonance and realize zero voltage switch, realize the bidirectional transfer of energy through the on-state of control switch tube and inside body diode, can be applied to fields such as energy storage, electric automobile, new forms of energy.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic block diagram of a structure of an isolated bidirectional DC/DC conversion circuit according to an embodiment of the present invention;
fig. 2 is a schematic circuit diagram of an isolated bidirectional DC/DC conversion circuit according to an embodiment of the present invention;
fig. 3 is a schematic waveform diagram of each device of an isolated bidirectional DC/DC conversion circuit in a zero current mode according to an embodiment of the present invention;
fig. 4 is a schematic waveform diagram of each device of an isolated bidirectional DC/DC conversion circuit in a step-down mode according to an embodiment of the present invention;
fig. 5 is a schematic waveform diagram of each device of an isolated bidirectional DC/DC conversion circuit in a boost mode according to an embodiment of the present invention;
fig. 6 is an equivalent circuit of a switching mode 1 of an isolated bidirectional DC/DC conversion circuit in a zero current mode according to an embodiment of the present invention;
fig. 7 is an equivalent circuit of a switch mode 2 of an isolated bidirectional DC/DC conversion circuit in a zero current mode according to an embodiment of the present invention;
fig. 8 is an equivalent circuit of a switch mode 3 of an isolated bidirectional DC/DC conversion circuit in a zero current mode according to an embodiment of the present invention;
fig. 9 is an equivalent circuit of the isolated bidirectional DC/DC conversion circuit in the switching mode 4 in the zero current mode according to the embodiment of the present invention.
The reference numerals are as follows:
1. photovoltaic module, 2, first full-bridge circuit, 3, transformer, 4, second full-bridge circuit, 5, battery, 6, controller, 7, first filtering unit, 8, resonance inductance, 9, output inductance, 10, second filtering unit.
Detailed Description
In order that those skilled in the art will better understand the utility model and thus more clearly define the scope of the utility model as claimed, it is described in detail below with respect to certain specific embodiments thereof. It should be noted that the following is only a few embodiments of the present invention, and the specific direct description of the related structures is only for the convenience of understanding the present invention, and the specific features do not of course directly limit the scope of the present invention. Such alterations and modifications as are made obvious by those skilled in the art and guided by the teachings herein are intended to be within the scope of the utility model as claimed.
The utility model is further described with reference to the following figures and specific examples.
Example 1
As shown in fig. 1 and 2, the present invention provides an isolated bidirectional DC/DC conversion circuit, which includes a first full bridge circuit 2, a transformer 3, a second full bridge circuit 4 and a controller 6, wherein the first full bridge circuit 2 includes a first switch tube S1, a second switch tube S2, a third switch tube S3 and a fourth switch tube S4, the second full bridge circuit 4 includes a fifth switch tube S5, a sixth switch tube S6, a seventh switch tube S7, an eighth switch tube S8 and a first filtering unit 7; each switch tube is respectively connected with a body diode in parallel.
The first switching tube S1 is connected in series with the second switching tube S2, the third switching tube S3 is connected in series with the fourth switching tube S4, the first end of the third switching tube S3 and the first end of the first switching tube S1 are respectively electrically connected to the positive electrode of the high-voltage side power supply, the second end of the second switching tube S2 and the second end of the fourth switching tube S4 are respectively electrically connected to the negative electrode of the high-voltage side power supply, one end of the first winding of the transformer 3 is electrically connected to the connection between the first switching tube S1 and the second switching tube S2 through the resonant inductor 8, that is, the point a is electrically connected, the other end of the first winding of the transformer 3 is electrically connected to the connection between the third switching tube S3 and the fourth switching tube S4, that is, the point B is electrically connected, and the control terminals of the first switching tube S1, the second switching tube S2, the third switching tube S3 and the fourth switching tube S4 are electrically connected to the controller 6.
The fifth switch tube S5 is connected in series with the sixth switch tube S6, the seventh switch tube S7 is connected in series with the eighth switch tube S8, the first end of the fifth switch tube S5 and the first end of the seventh switch tube S7 are connected and electrically connected with the positive pole of the low-voltage side power supply through the output inductor 9, the second end of the sixth switch tube S6 and the second end of the eighth switch tube S8 are respectively electrically connected with the negative pole of the low-voltage side power supply, one end of the second winding of the transformer 3 is electrically connected with the series connection of the fifth switch tube S5 and the sixth switch tube S6, namely, the point C is electrically connected, the other end of the second winding of the transformer 3 is electrically connected with the serial connection part of the seventh switch tube S7 and the eighth switch tube S8, namely, the point D is electrically connected, the control terminals of the fifth switching tube S5, the sixth switching tube S6, the seventh switching tube S7 and the eighth switching tube S8 are electrically connected to the controller 6, and the first filter unit 7 is disposed at both ends of the low-voltage side power supply.
The switch tube of the high-voltage side only needs to control the geminate transistors to be opened or closed simultaneously, the switch tube of the low-voltage side only needs to control the opening time of the four transistors simultaneously, the control mode is simple, and phase shift control is not needed. The transformer 3 and the resonant inductor 8 can be replaced by a transformer with a large leakage inductance.
In this embodiment, the resonant inductor 8 is an inductor Lc, the output inductor 9 is an inductor Lo, the number of turns of the first winding of the transformer 3 is N1, the number of turns of the second winding of the transformer 3 is N2, N1> N2, and the specific number of turns needs to be designed according to the actual input and output voltage requirement.
Specifically, the first switch tube S1, the second switch tube S2, the third switch tube S3, the fourth switch tube S4, the fifth switch tube S5, the sixth switch tube S6, the seventh switch tube S7, and the eighth switch tube S8 are insulated gate bipolar transistors or metal-oxide semiconductor field effect transistors. Preferably an NMOS transistor.
Specifically, the first filtering unit 7 includes a second capacitor C2, and two ends of the second capacitor C2 are electrically connected to the positive electrode and the negative electrode of the low-voltage power supply, respectively.
Preferably, the filter further comprises a second filtering unit 10, the second filtering unit 10 comprises a first capacitor C1, and two ends of the first capacitor C1 are electrically connected to the positive electrode and the negative electrode of the high-voltage side power supply respectively. The first capacitor C1, the second capacitor C2, the inductor Lc, the inductor Lo and the parameter selection of each switching tube need to be determined according to the current ripple requirement of the output side.
Specifically, the high-voltage side power supply is a photovoltaic module 1, and the low-voltage side power supply is a storage battery 5. Wherein, the voltage at two ends of the photovoltaic component 1 is VHThe voltage across the accumulator 5 is VL。
The isolated bidirectional DC/DC conversion circuit provided by the utility model is part of a DC/DC converter between a photovoltaic component 1 and a storage battery 5 in an energy storage inverter system, and can realize the effect of isolated voltage boosting and reducing.
As shown in fig. 3 to 5, the isolated bidirectional DC/DC conversion circuit provided by the present invention includes three modes, i.e., a zero current mode, a buck mode and a boost mode, and controls the length of the simultaneous conduction time of the four low-voltage side transistors, i.e., t0 and t1, but t2-t0 remain unchanged, under the condition that the voltage requirements of the high-voltage side and the low-voltage side are not changed. In the step-down mode, if a high-voltage side bus is needed to charge a low-voltage side battery, the conduction time of the four low-voltage side tubes is shorter than that in the zero-current mode; in the boost mode, if the high-side bus needs to be powered by the low-side battery, the low-side four-tube conduction time is longer than that in the zero-current mode.
Where t0 denotes a time when the low-side switching tube is fully turned on, t1 denotes a time when the low-side switching tube is fully turned on, and t2 denotes a time when the high-side current multiplied by the transformer transformation ratio is equal to the low-side current.
Since the high-voltage side switching tube and the diagonal switching tube of the low-voltage side switching tube are simultaneously turned on and off, that is, the first switching tube S1 and the fourth switching tube S4 are simultaneously turned on and off, the second switching tube S2 and the third switching tube S3 are simultaneously turned on and off, the fifth switching tube S5 and the eighth switching tube S8 are simultaneously turned on and off, and the sixth switching tube S6 and the seventh switching tube S7 are simultaneously turned on and off. Therefore, the switching states of only one switching tube at each diagonal are indicated in fig. 3-5, and the shaded part of the low voltage in the figure indicates that four switching tubes at the low voltage side are simultaneously opened.
Four modes are provided in each mode, and the four-mode analysis in the zero-current mode is taken as an example:
As shown in fig. 6, before time t0, the high-voltage side third switch tube S3 and the second switch tube S2 are turned on, and the low-voltage side sixth switch tube S6 and the seventh switch tube S7 are turned on at the same time, so V is turned onAB＝-VH，
Current I on the resonant inductorLcWith a slope of-VLoReverse increase of/Lo, current I on output inductorLoWith a slope of VLothe/Lo increases in the positive direction, Lo being the inductance of the output inductor 9. Wherein, VLoAt the voltage of the low-side inductor Lo, i.e.
VABIs the voltage across point A and point B in FIG. 2, VCDThe voltages at points C and D in fig. 2.
As shown in fig. 7, at t0, t1]Fifth opening of the low pressure side at time t0 during the time periodThe off tube S5 and the eighth switching tube S8 are open. At this time, the four switching tubes on the low-voltage side are fully opened, the transformer 3 on the low-voltage side is short-circuited, and VCDWhen the output inductance Lo changes its voltage polarity, ILoWith a slope of VLothe/Lo begins to decrease; while the high-side transformer 3 voltage is clamped at 0V due to the short-circuiting of the low-side partial transformer 3, ILcWith a slope of-VHthe/Lc continues to increase in reverse, where Lc is the inductance value of the resonant inductor 8.
As shown in fig. 8, at t1, t2]In the time period, at time t1, the high-side second switching tube S2 and the third switching tube S3 are closed, and after a small dead time, the first switching tube S1 and the fourth switching tube S4 are opened, and the low-side part of the sixth switching tube S6 and the seventh switching tube S7 are closed. At this time, the high-voltage side portion VAB＝VH，ILcSame current as the high-voltage side of the transformer 3, ILoThe same as the low-voltage side current of the transformer 3. Since the high-voltage side current and the low-voltage side part do not reach the balance relation, the body diodes of all the switching tubes of the low-voltage side part are still in a conducting state in the period, so VCDStill equal to 0V, then ILcA current loop is formed by body diodes D1 and D4 of high-side first switching tube S1 and fourth switching tube S4, and after first switching tube S1 and fourth switching tube S4 are turned on, I is obtained due to the change of voltage polarity on inductor LcLcIn the time interval with the slope VHthe/Lc starts to decrease. I isLoThe direction increases reversely at time t1 with a slope VLo/Lo。
Mode 4
As shown in fig. 9, at t2, t3]During the time period, the high-voltage side current and the low-voltage side current are balanced at the time t2, namely ILc＝(N2/N1)*ILoThe body diode of the low-voltage side partial switching tube does not flow aftercurrent any more, so that the transformer 3 is not short-circuited any more, VCD＝(N2/N1)*VHThe high-pressure side portion and the low-pressure side portion start energy transmission. At the same time, ILoWith a slope of VLoPositive increase after negative decrease of/Lo, ILcIs also reversed with the same slopeDecreasing then increasing positively.
Under the conversion of the buck-boost mode, the working state of the circuit does not change suddenly, namely when the three modes are switched, the change mode of the current is switched among the 4 modes.
The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the utility model may occur to those skilled in the art without departing from the principle of the utility model, and are considered to be within the scope of the utility model.
Claims (5)
1. An isolated bidirectional DC/DC conversion circuit, characterized in that: the high-voltage power supply comprises a first full-bridge circuit (2), a transformer (3), a second full-bridge circuit (4) and a controller (6), wherein the first full-bridge circuit (2) comprises a first switch tube, a second switch tube, a third switch tube and a fourth switch tube, and the second full-bridge circuit (4) comprises a fifth switch tube, a sixth switch tube, a seventh switch tube, an eighth switch tube and a first filtering unit (7); each switching tube is respectively connected with a body diode in parallel;
the first switch tube is connected with the second switch tube in series, the third switch tube is connected with the fourth switch tube in series, the first end of the third switch tube and the first end of the first switch tube are respectively and electrically connected with the anode of the high-voltage side power supply, the second end of the second switch tube and the second end of the fourth switch tube are respectively and electrically connected with the cathode of the high-voltage side power supply, one end of a first winding of the transformer (3) is electrically connected with the serial connection part of the first switch tube and the second switch tube through a resonant inductor (8), the other end of the first winding of the transformer (3) is electrically connected with the serial connection part of the third switch tube and the fourth switch tube, and the control ends of the first switch tube, the second switch tube, the third switch tube and the fourth switch tube are electrically connected with the controller (6);
the transformer is characterized in that the fifth switching tube is connected with the sixth switching tube in series, the seventh switching tube is connected with the eighth switching tube in series, the first end part of the fifth switching tube and the first end part of the seventh switching tube are connected and are electrically connected with the anode of the low-voltage side power supply through an output inductor (9), the second end part of the sixth switching tube and the second end part of the eighth switching tube are respectively electrically connected with the cathode of the low-voltage side power supply, one end of the second winding of the transformer (3) is electrically connected with the series connection positions of the fifth switching tube and the sixth switching tube, the other end of the second winding of the transformer (3) is electrically connected with the series connection positions of the seventh switching tube and the eighth switching tube, the control ends of the fifth switching tube, the sixth switching tube, the seventh switching tube and the eighth switching tube are electrically connected with the controller (6), and the first filtering units (7) are arranged at two ends of the low-voltage side power supply.
2. The isolated bidirectional DC/DC converter circuit of claim 1, wherein: the high-voltage side power supply is characterized by further comprising a second filtering unit (10), wherein the second filtering unit (10) comprises a first capacitor, and two ends of the first capacitor are respectively and electrically connected with the positive electrode and the negative electrode of the high-voltage side power supply.
3. An isolated bidirectional DC/DC converter circuit as claimed in claim 1 or 2, wherein: the first filtering unit (7) comprises a second capacitor, and two ends of the second capacitor are respectively electrically connected with the positive electrode and the negative electrode of the low-voltage side power supply.
4. The isolated bidirectional DC/DC converter circuit of claim 1, wherein: the first switch tube, the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube are insulated gate bipolar transistors or metal-oxide semiconductor field effect transistors.
5. The isolated bidirectional DC/DC converter circuit of claim 1, wherein: the high-voltage side power supply is a photovoltaic module (1), and the low-voltage side power supply is a storage battery (5).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123370256.6U CN216721182U (en) | 2021-12-28 | 2021-12-28 | Isolated bidirectional DC/DC conversion circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123370256.6U CN216721182U (en) | 2021-12-28 | 2021-12-28 | Isolated bidirectional DC/DC conversion circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216721182U true CN216721182U (en) | 2022-06-10 |
Family
ID=81886678
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202123370256.6U Active CN216721182U (en) | 2021-12-28 | 2021-12-28 | Isolated bidirectional DC/DC conversion circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN216721182U (en) |
-
2021
- 2021-12-28 CN CN202123370256.6U patent/CN216721182U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10958180B2 (en) | DC-DC converter for wide input voltage | |
| CN109217681B (en) | Bidirectional resonant converter | |
| CN101527520B (en) | Single-stage single-phase AC-DC convertor based on LLC series resonance | |
| CN101505107B (en) | Low voltage stress single-stage AC-DC converter based on LLC series resonance | |
| TWI672898B (en) | Bidirectional DC-DC converter | |
| CN114301301A (en) | Wide-range resonant soft-switching bidirectional direct-current converter and control method thereof | |
| CN110224599A (en) | A kind of multiphase buck-boost alternation parallel DC/DC translation circuit | |
| CN108988634B (en) | Three-phase interleaved bidirectional large-transformation-ratio DCDC converter and control method thereof | |
| US10243455B2 (en) | Bidirectional DC-DC converter | |
| CN105939107A (en) | Hybrid type quasi-switch voltage-boosting DC-DC converter | |
| CN217087777U (en) | Wide-range resonant soft-switching bidirectional direct-current converter | |
| CN117691887A (en) | Super-capacitor energy-storage type high-overload single-phase inverter circuit and control method thereof | |
| CN114244104A (en) | High-gain zero-ripple passive clamping type Boost converter and control method thereof | |
| CN108667301B (en) | Full-bridge converter with follow current path | |
| CN109818494A (en) | A kind of quasi- source Y DC-DC converter of high gain voltage type | |
| CN110729899B (en) | Wide-input wide-output three-phase high-gain direct current converter and control method | |
| CN114825663B (en) | SP type double-output independently adjustable wireless power transmission system and control method thereof | |
| CN108429452B (en) | Quadratic multi-bootstrap DC-DC converter for photovoltaic system | |
| CN216721182U (en) | Isolated bidirectional DC/DC conversion circuit | |
| CN216774624U (en) | High-voltage gain soft switching DC-DC converter | |
| CN114900029A (en) | Single-phase single-stage coupling inductance type split source boost inverter and method thereof | |
| CN113938003A (en) | Bidirectional common-current DC/DC converter and method using coupling inductor | |
| CN109149954A (en) | It is a kind of width loading range Sofe Switch current mode recommend DC converter | |
| CN209184488U (en) | A kind of Buck-Boost DC-DC converter having high gain boost ability | |
| CN106787721B (en) | Three-level Buck converter of zero-voltage switch and control method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |