CN112572185B

CN112572185B - Vehicle-mounted charging and discharging system and vehicle with same

Info

Publication number: CN112572185B
Application number: CN201910935195.1A
Authority: CN
Inventors: 杨柳; 吴昊; 刘宇; 许兴发
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2019-09-29
Filing date: 2019-09-29
Publication date: 2022-03-18
Anticipated expiration: 2039-09-29
Also published as: CN112572185A

Abstract

The invention discloses a vehicle-mounted charging and discharging system and a vehicle with the same, wherein the vehicle-mounted charging and discharging system comprises two resonant circuit modules, two rectifying circuits and a control module, wherein the first resonant circuit module is used for converting an input electric signal; the second resonance circuit module carries out conversion processing on the input electric signal; the first rectifying circuit module and the second rectifying circuit module rectify input electric signals, and the two resonant circuit modules multiplex the three-bridge-arm circuit conversion unit; the control module controls the first resonance circuit module and the first rectification circuit module during a first half period of power supply, or controls the second resonance circuit module and the second rectification circuit module during a second half period of power supply, or controls the three-bridge arm circuit conversion unit, the first rectification circuit module and the second rectification circuit module during charging of the low-voltage battery pack by the high-voltage battery pack. The system and the vehicle adopt a design without electrolytic capacitors, so that the cost can be reduced, and the stability can be improved.

Description

Vehicle-mounted charging and discharging system and vehicle with same

Technical Field

The invention relates to the technical field of vehicles, in particular to a vehicle-mounted charging and discharging system and a vehicle with the vehicle-mounted charging and discharging system.

Background

Fig. 1 is a circuit diagram of a vehicle-mounted charging and discharging system in the related art, in which one end of the system is connected to a power grid, and the other end of the system is connected to a battery pack, and the system includes a Part1 'and a Part 2' two-stage circuit. When the battery is charged in the forward direction, Part 1' realizes alternating current-direct current conversion and power factor correction, and outputs direct current voltage. Part 2' is a dc-dc converter that outputs the appropriate voltage to charge the battery pack. For the system, in order to provide stable input direct-current voltage for the later stage Part2 ', a large-capacity electrolytic capacitor C1 ' is needed between Part1 ' and Part2 ', so that the volume and the cost of the system are increased, and the electrolytic capacitor C1 ' has the problems of service life and shock resistance and is unfavorable for the reliability of the system.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art. Therefore, an object of the present invention is to provide a vehicle-mounted charging and discharging system which does not require a large-capacity electrolytic capacitor, reduces the system size, reduces the cost, and improves the system stability.

The invention also provides a vehicle adopting the vehicle-mounted charging and discharging system.

In order to solve the above problem, a vehicle-mounted charging and discharging system according to an embodiment of a first aspect of the present invention includes: the first resonant circuit module is used for converting an input electric signal, and comprises a first conversion unit, a first transformer and a three-bridge-arm circuit conversion unit, wherein the first conversion unit comprises a third switching tube and a fourth switching tube, a first end of the third switching tube is connected with a first end of the electric unit, a second end of the third switching tube is connected with a first end of the fourth switching tube, the first transformer comprises a first coil and a second coil, the first coil is connected with the first conversion unit, a first end of the second coil is connected with a first bridge arm of the three-bridge-arm circuit conversion unit, and a second end of the second coil is connected with a second bridge arm of the three-bridge-arm circuit conversion unit;

the second resonance circuit module is used for converting the input electric signal and comprises the three bridge arm circuit conversion unit, a second conversion unit and a second transformer, the third conversion unit comprises a ninth switching tube and a tenth switching tube, the first end of the ninth switching tube is connected with the second end of the electric unit, the second end of the ninth switching tube is connected with the first end of the tenth switching tube, the second end of the tenth switching tube is connected with the second end of the fourth switching tube, the second transformer includes a fifth coil and a sixth coil, the fifth coil is connected to the second conversion unit, the first end of the sixth coil is respectively connected with the second end of the second coil and the second bridge arm, a second end of the sixth coil is connected with a third bridge arm of the three-bridge-arm circuit conversion unit;

the first end of the first rectifying circuit module is connected with the secondary side of the first transformer and used for rectifying an input electric signal; a second rectifier circuit module, a first end of which is connected to a secondary side of the second transformer, for rectifying an input electrical signal;

and the control module is used for controlling the ninth switching tube and the tenth switching tube to be kept conducted during a first half period of power supply, controlling the first resonant circuit module and the first rectifying circuit module according to a time sequence signal of the first half period of power supply, or controlling the third switching tube and the fourth switching tube to be kept conducted during a second half period of power supply, and controlling the second resonant circuit module and the second rectifying circuit module according to a time sequence signal of the second half period of power supply, or controlling the three-bridge-arm circuit conversion unit, the first rectifying circuit module or the second rectifying circuit module according to a control time sequence of charging a low-voltage battery pack by a high-voltage battery pack.

According to the vehicle-mounted charging and discharging system provided by the embodiment of the invention, two resonant circuit modules are arranged, the control module controls the gating circuit module according to the power supply period signal to gate the first resonant circuit module or the second resonant circuit module, so that the signal output to the conversion circuit module by the resonant circuit module is steamed bread wave, therefore, a large-capacity electrolytic capacitor is not needed for filtering, only a small-capacity capacitor such as a film capacitor is needed, the cost and the volume of the electrolytic capacitor part are reduced, the reliability and the service life of the system are improved, the gating circuit is not needed, the number of switch tubes is reduced, the cost is reduced, the charging of a low-voltage battery pack can be realized through the first rectifying circuit module and the second rectifying circuit module, and the first resonant circuit module and the second resonant circuit module multiplex a three-bridge arm circuit conversion unit, the number of circuit devices used can be reduced, the cost is reduced, the three-bridge-arm circuit conversion unit is adopted for alternating current-direct current conversion, when different power supply periods exist, the first transformer and the second transformer can be respectively electrified, and compared with the output of one end shared by two transformer coils, the loss of the transformer is reduced, and the system efficiency is improved.

In order to solve the above problems, a vehicle according to an embodiment of the second aspect of the present invention includes a high-voltage battery pack, a low-voltage battery pack, and the vehicle-mounted charging/discharging system.

According to the vehicle provided by the embodiment of the invention, by adopting the vehicle-mounted charging and discharging system, the cost can be reduced, the reliability is improved, the anti-seismic grade is improved, the low-voltage battery pack can be charged at the same time, the transformer loss is reduced, and the system efficiency is improved.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a circuit diagram of a bidirectional vehicle-mounted charger in the related art;

fig. 2 is a functional block diagram of a vehicle-mounted charge and discharge system according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a resonant circuit output electrical signal waveform according to one embodiment of the present invention;

fig. 4 is a functional block diagram of a vehicle charging and discharging system according to another embodiment of the present invention;

fig. 5 is a functional block diagram of a vehicle charging and discharging system according to another embodiment of the present invention;

fig. 6 is a circuit diagram of a vehicle charging and discharging system according to an embodiment of the present invention;

fig. 7 is a circuit diagram of a vehicle charging and discharging system according to another embodiment of the present invention;

FIG. 8 is a block diagram of a vehicle according to one embodiment of the present invention.

Detailed Description

Embodiments of the present invention will be described in detail below, the embodiments described with reference to the drawings being illustrative, and the embodiments of the present invention will be described in detail below.

A vehicle charging and discharging system according to an embodiment of the present invention is described below with reference to fig. 2 to 7.

Fig. 2 is a block diagram of a vehicle-mounted charge and discharge system according to an embodiment of the present invention, and as shown in fig. 2, the vehicle-mounted charge and discharge system 100 according to an embodiment of the present invention includes a first resonant circuit module 10, a second resonant circuit module 20, a first rectifier circuit module 80, a second rectifier circuit module 81, and a control module 50.

The first resonant circuit module 10 is configured to perform conversion processing on an input electrical signal, and the first resonant circuit module 10 includes a first conversion unit 11, a first transformer T1, and a three-bridge circuit conversion unit 12, in an embodiment, the first conversion unit 11 may be configured to perform conversion between alternating current and alternating current, so as to implement conversion of an alternating current positive half-cycle electrical signal; the three-arm circuit converting unit 12 can realize conversion between ac-dc or dc-ac, and the first transformer T1 plays roles of signal isolation, transmission and transformation. The first conversion unit 11 includes a third switching tube Q3 and a fourth switching tube Q4, a first end of the third switching tube Q3 is connected to a first end of the electric unit 60, a second end of the third switching tube Q3 is connected to a first end of the fourth switching tube Q4, the first transformer T1 includes a first coil W1 and a second coil W2, the first coil W1 is connected to the first conversion unit 11, a first end of the second coil W2 is connected to the first leg of the three-leg circuit conversion unit 12, and a second end of the second coil W2 is connected to the second leg of the three-leg circuit conversion unit 12.

In an embodiment of the present invention, the electrical unit 60 may be an electrical grid or an electrical load, i.e. to achieve a charging operation when the electrical unit is an electrical grid, or to achieve a power battery discharging operation when the electrical unit is an electrical load.

The second resonant circuit module 20 is configured to perform conversion processing on the input electrical signal, and the second resonant circuit module 20 includes a second conversion unit 21, a second transformer T2, and a three-bridge circuit conversion unit 12, where in an embodiment, the second conversion unit 21 may be configured to perform conversion between ac and ac, so as to implement conversion of an ac negative half-cycle electrical signal; the second transformer T2 plays a role of signal isolation, transmission and transformation. The second conversion unit 12 includes a ninth switching tube Q9 and a tenth switching tube Q10, a first end of the ninth switching tube Q9 is connected to the second end of the electric unit 60, a second end of the ninth switching tube Q9 is connected to the first end of the tenth switching tube Q10, a second end of the tenth switching tube Q10 is connected to the second end of the fourth switching tube Q4, the second transformer T2 includes a fifth coil W5 and a sixth coil W6, the fifth coil W5 is connected to the second conversion unit 21, a first end of the sixth coil W6 is connected to the second end of the second coil W2 and the second arm of the three-arm circuit conversion unit 12, and a second end of the sixth coil W6 is connected to the third arm of the three-arm circuit conversion unit 12.

The first resonant circuit module 10 and the second resonant circuit module 20 multiplex the three-leg circuit conversion unit 12, so that the number of switching tubes used by circuit devices can be reduced, and the cost is reduced. By adopting the three-bridge-arm circuit conversion unit 12 and respectively connecting the first transformer T1 of the first resonant circuit module 10 and the second transformer T2 of the second resonant circuit module 20 through bridge arms, the first transformer T1 and the second transformer T2 can respectively supply current in different power supply periods, and compared with the output of the two transformer coils sharing one end, the loss of the transformer is reduced, and the system efficiency is improved.

The first end of the first rectifier circuit module 80 is connected to the secondary side of the first transformer T1, and is configured to rectify an input electrical signal, so that the rectified electrical signal can be provided to the low-voltage battery pack, so as to charge the low-voltage battery pack. The first end of the second rectifier circuit module 81 is connected to the secondary side of the second transformer T2, and is configured to rectify an input electrical signal, so that the rectified electrical signal can be provided to the low-voltage battery pack, so as to charge the low-voltage battery pack.

The control module 50 is configured to control the ninth switch Q9 and the tenth switch Q10 to remain conductive during a first half period of power supply, and control the first resonant circuit module 10 and the first rectifier circuit module 80 respectively according to a timing signal of the first half period of power supply, or control the third switch Q3 and the fourth switch Q4 to remain conductive during a second half period of power supply, and control the second resonant circuit module 20 and the second rectifier circuit module 81 according to a timing signal of the second half period of power supply. Alternatively, when the high-voltage battery pack charges the low-voltage battery pack, the control module 50 is configured to control the three-bridge circuit converting unit 12, the first rectifying circuit module 80, or the second rectifying circuit module 81 according to a charging control sequence.

Specifically, when charging, the electrical unit 60 may be a power grid, the control module 50 detects period information of alternating current output by the power grid, and outputs a first gating control signal when a first half period of power supply, for example, a positive half period, is performed, controls the ninth switching tube Q9 and the tenth switching tube Q10 to be kept conductive, a first end of the first resonant circuit module 10 is connected to a first end of the power grid, a second end of the first resonant circuit module 10 is connected to a second end of the power grid, power supply from the power grid is supplied to the first resonant circuit module 10 at the time, the control module 50 controls the first resonant circuit module 10 and the first rectifying circuit module 80 according to a timing signal of the first half period of power supply, the first converting unit 11 transmits electrical signals of the positive half period of the power grid to the first transformer T1, isolates, transforms and transmits through the first transformer T1, and converts alternating current voltage into direct current voltage through the three-arm circuit converting unit 12, and inputting the voltage to a rear-stage circuit to charge the high-voltage battery pack. And the first rectifying circuit module 81 rectifies the alternating current signal transmitted by the secondary coil of the first transformer T1, so that the rectified alternating current signal can be provided to the low-voltage battery pack to charge the low-voltage battery pack.

Similarly, when the control module 50 detects that the second half period of the power supply, for example, the negative half period, is an electrical signal, the third switching tube Q3 and the fourth switching tube Q4 are controlled to be turned on, the second end of the second resonant circuit module 20 is connected to the first end of the power grid, and the power grid power supply is provided to the second resonant circuit module 10, the control module 50 controls the second resonant circuit module 20 and the second rectifying circuit module 81 according to the timing signal of the second half period of the power supply, the second converting unit 21 converts the negative half period of the power grid signal into an ac voltage, and performs isolation, transformation and transmission through the second transformer T2, and provides the ac voltage to the three-arm circuit converting unit 12, and the three-arm circuit converting unit 12 converts the ac voltage into a dc signal, and inputs the dc signal to the rear stage circuit to charge the high voltage battery pack. And the second rectifier circuit module 81 rectifies the ac signal transmitted by the secondary coil of the second transformer T2, and then can provide the rectified ac signal to the low-voltage battery pack at the subsequent stage, thereby implementing charging of the low-voltage battery pack.

As shown in fig. 3, the electrical signal provided by the power grid 50 is as shown in (a) of fig. 3, and during the positive half-cycle, the control module 50 controls the gating circuit module 30 to conduct at the corresponding switching tube to gate the first resonant circuit module 10, the electrical signal input to the first resonant circuit module 10 is as shown in (b) of fig. 3, and the electrical signal output by the first resonant circuit module 10 is as shown in (d) of fig. 3. And, during the negative half cycle, the control module 50 controls the corresponding switch tube in the gating circuit module 30 to conduct and gate the second resonant circuit module 20, the input electrical signal of the second resonant circuit module 20 is shown in (c) of fig. 3, the output electrical signal of the second resonant circuit module 20 is shown in (e) of fig. 3, the waveform of the electrical signal provided to the subsequent circuit, which is the combined electrical signal output by the first resonant circuit module 10 and the second resonant circuit module 20, is shown in (f) of fig. 3, that is, the electrical signal provided to the subsequent circuit is a steamed bread wave, and similarly, the electrical signals provided to the subsequent circuit by the first rectifier circuit module 80 and the second rectifier circuit module 81 are also steamed bread waves, therefore, the post-stage circuit does not need to adopt a large-capacity electrolytic capacitor for filtering, and only needs to adopt a small-capacity capacitor device such as a film capacitor for filtering, so that the cost and the system volume can be reduced.

In addition, in the embodiment of the present application, the gating circuit may be omitted, and the control module 50 controls the third switching tube Q3, the fourth switching tube Q4, the ninth switching tube Q9, and the tenth switching tube Q10 according to the power supply period signal to gate the resonant circuit, so that circuit devices may be saved, and the cost may be reduced.

And, when the high voltage battery pack is discharged, when a positive half cycle is output, the first resonance circuit module 10 is gated, and the direct current output from the high voltage battery pack is converted into an alternating current signal of a positive half cycle by the first resonance circuit module 10 and supplied to the electrical unit 60, for example, an electrical load. When the negative half cycle is output, the second resonant circuit module 20 is gated, and the direct current output by the high-voltage battery pack is converted into an alternating current signal with the negative half cycle through the second resonant circuit module 20 and is provided to the electric load, so that the discharge mode of the high-voltage battery pack is realized.

And, in the embodiment of the present invention, the charging of the high-voltage battery pack to the low-voltage battery pack can also be realized by combining the first resonant circuit module 10 and the second resonant circuit module 20, and the first rectifier circuit module 80 and the second rectifier circuit module 81. Specifically, the control module 50 controls the three-leg circuit conversion unit 12, the first rectification circuit module 80 and the second rectification circuit module 81 according to a control sequence for charging the low-voltage battery pack by the high-voltage battery pack. The high voltage dc provided by the high voltage battery pack may be converted into ac power by the three-arm circuit converting unit 12, and transmitted to the secondary side of the first transformer T1 or the second transformer T2, and provided to the first rectifier circuit module 80 through the secondary side of the first transformer T1, or provided to the second rectifier circuit module 80 through the secondary side of the second transformer T2, and the control module 50 controls the switching tube of the first rectifier circuit module 80 or the second rectifier circuit module 81 to rectify and convert the ac power into dc power to be provided to the low voltage battery pack, so as to charge the low voltage battery pack with the high voltage battery pack.

According to the vehicle-mounted charging and discharging system 100 of the embodiment of the invention, by arranging two resonant circuit modules, the control module 50 controls the first resonant circuit module 10 and the second resonant circuit module 20 according to the time sequence of the corresponding power supply period, and controls the first rectifying circuit module 80 and the second rectifying circuit module 81 according to the power supply period, so that the direct current signals provided by the resonant circuit module and the rectifying circuit module to the subsequent circuit are steamed bread waves, a large-capacity filter device is not needed, a small-capacity filter device is only needed, the system volume and cost can be reduced, the electrolytic capacitor service life and the anti-seismic problem are not needed to be considered, the stability of the charging system is favorably provided, the first rectifying circuit module 80 and the second rectifying circuit module 81 are also designed, the charging of low-voltage battery packs can be simultaneously realized, and the first resonant circuit module 10 and the second resonant circuit module 20 multiplex the three-bridge arm circuit conversion unit 12, the circuit device usage amount can be reduced, the cost is reduced, and the three-bridge circuit conversion unit 12 is adopted, the first transformer T1 of the first resonance circuit module 10 and the second transformer T2 of the second resonance circuit module 20 are respectively connected through bridge arms, when power supply periods are different, the first transformer T1 and the second transformer T2 can be respectively electrified, the transformer loss is reduced, the system efficiency is improved, a gating circuit is not required to be arranged, the number of switch tubes used is reduced, and the cost is reduced.

In some embodiments, for the vehicle-mounted charging system provided with the gating circuit module, gating is realized through independent control of the switching tube in the gating circuit module, so that larger conduction loss is generated, and therefore, the system provided by the embodiment of the invention is improved on the basis.

Further, as shown in fig. 4, the vehicle-mounted charging system 100 according to the embodiment of the invention may further include a gating circuit module 30, where the gating circuit module 30 includes a first switching tube Q1 and a second switching tube Q2. A first end of the first switching tube Q1 is connected to a first end of the electrical unit 60, a second end of the first switching tube Q1 is connected to a second end of the fourth switching tube Q4 and a second end of the tenth switching tube Q10, respectively, a first end of the second switching tube Q2 is connected to a second end of the electrical unit 60, and a second end of the second switching tube Q2 is connected to a second end of the fourth switching tube Q4 and a second end of the tenth switching tube Q10, respectively; the control module 50 is further configured to, during a first half cycle of power supply, control the first switching tube Q1 to turn off, control the second switching tube Q2, the ninth switching tube Q9, and the tenth switching tube Q10 to turn on, and control the first resonant circuit module 10 and the first rectifier circuit module 80 according to a timing signal of the first half cycle of power supply; or, when the power is supplied for the second half period, the second switching tube Q2 is controlled to be turned off, the first switching tube Q1, the third switching tube Q3 and the fourth switching tube Q4 are controlled to be turned on, and the second resonant circuit module 10 and the second rectification circuit module 81 are controlled according to the timing sequence signal of the second half period of the power supply, or the third bridge arm circuit conversion unit 12, the first rectification circuit module 80 and the second rectification circuit module 81 are controlled according to the control timing sequence of the high-voltage battery pack for charging the low-voltage battery pack.

Specifically, referring to fig. 4, the switching timing of the control module 50 for the gate circuit module 30 is that, when the grid positive half-cycle signal is generated, the control module 50 controls the ninth switching tube Q9 and the tenth switching tube Q10 to be kept on, controls the first switching tube Q1 to be turned off, and controls the second switching tube Q2 to be turned on, that is, the ninth switching tube Q9 and the tenth switching tube Q10 are connected in series and then connected in parallel with the second switching tube Q2, so that the second end of the first resonant circuit module 10 can be connected to the grid, so as to gate the first resonant circuit module 10, and the resistance connected in parallel with the second switching tube Q2 after the ninth switching tube Q9 and the tenth switching tube Q10 are connected in series is reduced compared with the resistance that the second switching tube Q2 is separately controlled to be turned on, so as to reduce the conduction loss. Similarly, during the negative half cycle of the power grid, the control module 50 controls the third switching tube Q3 and the fourth switching tube Q4 to remain on, controls the first switching tube Q1 to be on, and controls the second switching tube Q2 to be off, so that the second end of the second resonant circuit module 20 is connected with the first end of the power grid, and the gating of the second resonant circuit module 20 is realized, thereby reducing the conduction loss.

Further, as shown in fig. 5, which is a block diagram of a vehicle charging and discharging system according to another embodiment of the present invention, as shown in fig. 5, the vehicle charging and discharging system 100 further includes a first dc conversion circuit module 40 and a second dc conversion circuit module 41, where the first dc conversion circuit module 40 is used for performing dc conversion on an input electrical signal, for example, reducing a dc voltage or boosting a dc voltage, and implementing power factor correction. In some embodiments, the dc conversion circuit module 40 may employ a BOOST circuit or a BUCK circuit. The first dc conversion circuit module 40 is connected to the three-bridge arm circuit conversion unit 12 and the high-voltage battery pack 70, respectively, and is configured to perform dc-dc conversion on an input electrical signal. The second dc conversion circuit module 41 is connected to the first rectifier circuit module 80, the second rectifier circuit module 81, and the low-voltage battery pack 71, respectively, and is configured to perform dc-dc conversion on the input electrical signal, so as to convert the input dc signal into an electrical signal required by the low-voltage battery pack 71, and charge the low-voltage battery pack 71.

Specifically, during the first half cycle of the power supply, the first resonant circuit module 10 outputs a dc signal to the first dc conversion circuit module 40 to charge the high-voltage battery pack 70, or during the second half cycle of the power supply, the second resonant circuit module 20 outputs a dc signal to the first dc conversion circuit module 40 to charge the high-voltage battery pack 70. The first dc conversion circuit module 40 converts the input dc electrical signal into an electrical signal required by the high voltage battery pack 70, and transmits the electrical signal to the high voltage battery pack 70, thereby charging the high voltage battery pack 70. Or, when the high-voltage battery pack 70 is discharged, during a positive half period, the first dc conversion circuit module 40 performs dc-dc conversion on the dc power of the high-voltage battery pack 70, the three-arm circuit conversion unit 12 performs dc-ac conversion, the first resonant circuit module 10 is gated and outputs the dc power to the electrical load through the first resonant circuit module 10, during a negative half period, the first dc conversion circuit module 40 performs dc-dc conversion on the dc power of the high-voltage battery pack 70, the three-arm circuit conversion unit 12 performs dc-ac conversion, and the second resonant circuit module 10 is gated and outputs the dc power to the electrical load through the second resonant circuit module 20.

In the vehicle-mounted charging and discharging system 100 according to the embodiment of the invention, the dc conversion circuit module is disposed at the rear, so that the charging voltage or the charging power output to the battery pack can be adjusted by controlling the duty ratio of the dc conversion circuit module, thereby widening the voltage range of the adaptive battery pack, shortening the charging time of the battery pack, and improving the charging efficiency of the battery pack.

The circuit structure of each module according to the embodiment of the present invention is further described below with reference to the drawings.

Fig. 6 is a circuit diagram of a vehicle charging and discharging system without a gating circuit module according to an embodiment of the present invention, and as shown in fig. 7, is a circuit diagram of a vehicle charging and discharging system including a gating circuit module according to an embodiment of the present invention, wherein, as described above, the gating circuit module 30 includes the first switching tube Q1 and the second switching tube Q2, and the control module 40 controls the gating circuit module 30 and the switching tubes that are conducted in series according to the power supply cycle signal, so as to gate the resonant circuit. As shown in fig. 7, other circuit modules such as the first resonant circuit module 10 and the second resonant circuit module 20, the first dc conversion circuit module 40, and the second dc conversion circuit module 41 have the same circuit configuration as that in fig. 6.

In an embodiment, the first resonant circuit module 10 and the second resonant circuit module 20 may employ a symmetrical half-bridge LLC resonant circuit to achieve isolation and voltage regulation, and perform ac-dc conversion on an input electrical signal.

As shown in fig. 6 or 7, the first conversion unit 11 includes a first capacitor C1, a third switching tube Q3, a fourth switching tube Q4, a second capacitor C2, and a third capacitor C3; the three-bridge arm circuit converting unit 12 includes a fifth switching tube Q5, a sixth switching tube Q6, a seventh switching tube Q7, an eighth switching tube Q8, a nineteenth switching tube Q19 and a twentieth switching tube Q20; the second converting unit 21 includes an eighth capacitor C8, a ninth switch Q9, a tenth switch Q10, a ninth capacitor C9, and a tenth capacitor C10.

A first terminal of the first capacitor C1 is connected to the first terminal of the electrical unit 60, and a second terminal of the first capacitor C1 is connected to the second terminal of the fourth switch Q4. The first capacitor C1 can filter the input electrical signal to reduce the electrical signal interference.

A first terminal of a third switching tube Q3 is connected to a first terminal of a first capacitor C1, a control terminal of a third switching tube Q3 is connected to the control module 50, a second terminal of the third switching tube Q3 is connected to a first terminal of a fourth switching tube Q4, a second terminal of a fourth switching tube Q4 is connected to a second terminal of the first capacitor C1, a control terminal of the fourth switching tube Q4 is connected to the control module 50, and a first node O1 is located between the second terminal of the third switching tube Q3 and the first terminal of the fourth switching tube Q4.

A first terminal of the second capacitor C2 is connected to the first terminal of the third switch Q3, a second terminal of the second capacitor C2 is connected to the first terminal of the third capacitor C3, a second terminal of the third capacitor C3 is connected to the second terminal of the fourth switch Q4, and a second node O2 is located between the second terminal of the second capacitor C2 and the first terminal of the third capacitor C3.

A first terminal of a first winding W1 of the first transformer T1 is connected to a first node O1 through a first inductor L1, and a second terminal of the first winding W1 is connected to a second node O2.

A first terminal of the eighth capacitor C8 is connected to the second terminal of the electrical unit 60, and a second terminal of the eighth capacitor C8 is connected to the second terminal of the tenth switching tube Q10.

A first end of the ninth switching tube Q9 is connected to a first end of the eighth capacitor C8, a control end of the ninth switching tube Q9 is connected to the control module 50, a second end of the ninth switching tube Q9 is connected to a first end of the tenth switching tube Q10, a second end of the tenth switching tube Q10 is connected to a second end of the eighth capacitor C8, a control end of the tenth switching tube Q10 is connected to the control module 50, and a sixth node O6 is provided between the second end of the ninth switching tube Q9 and the first end of the tenth switching tube Q10.

A first terminal of the ninth capacitor C9 is connected to the first terminal of the ninth switch transistor Q9, a second terminal of the ninth capacitor C9 is connected to the first terminal of the tenth capacitor C10, a second terminal of the tenth capacitor C10 is connected to the second terminal of the tenth switch transistor Q10, and a seventh node O7 is located between the second terminal of the ninth capacitor C9 and the first terminal of the tenth capacitor C10.

The second transformer T2 includes a fifth winding W5 and a sixth winding W6, a first end of the fifth winding W5 is connected to the sixth node O6 through a fifth inductor L5, a second end of the fifth winding W5 is connected to the seventh node O7, and a first end of the sixth winding W6 is connected to the second leg of the three-leg circuit converting unit 12 through a sixth inductor L6.

A first end of the fifth switching tube Q5 is connected to the first end of the first dc converting circuit module 40, a control end of the fifth switching tube Q5 is connected to the control module 50, a second end of the fifth switching tube Q5 is connected to the first end of the sixth switching tube Q6, a second end of the sixth switching tube Q6 is connected to the second end of the first dc converting circuit module 40, a control end of the sixth switching tube Q6 is connected to the control module 50, a third node O3 is located between the second end of the fifth switching tube Q5 and the first end of the sixth switching tube Q6, and the third node O3 is connected to the first end of the second coil W2 through the second inductor L2.

A first end of a seventh switching tube Q7 is connected to a first end of a fifth switching tube Q5 and a first end of the first dc converting circuit module 40, a second end of a seventh switching tube Q7 is connected to a first end of an eighth switching tube Q8, a control end of the seventh switching tube Q7 is connected to the control module 50, a second end of an eighth switching tube Q8 is connected to a second end of a sixth switching tube Q6 and a second end of the first dc converting circuit module 40, a control end of the eighth switching tube Q8 is connected to the control module 50, a fourth node O4 is provided between the second end of the seventh switching tube Q7 and the first end of the eighth switching tube Q8, the fourth node O4 is connected to a second end of the second coil W2 through a fifteenth capacitor C15, and the fourth node O4 is connected to a first end of the sixth inductor W6 through a sixth capacitor L6.

A first end of a nineteenth switching tube Q19 is connected to the first end of the seventh switching tube Q7 and the first end of the first dc converting circuit module 40, a second end of a nineteenth switching tube Q19 is connected to the first end of the twentieth switching tube Q20, a control end of the nineteenth switching tube Q19 is connected to the control module 50, a second end of the twentieth switching tube Q20 is connected to the second end of the eighth switching tube Q8 and the second end of the first dc converting circuit module 40, a control end of the twentieth switching tube Q20 is connected to the control module 50, an eighth node O8 is provided between the second end of the nineteenth switching tube Q19 and the first end of the twentieth switching tube Q20, and the eighth node O8 is connected to the second end of the sixth coil W6 through a sixteenth capacitor C16.

In the charging mode, the fifth switching tube Q5, the sixth switching tube Q6, the seventh switching tube Q7, the eighth switching tube Q8, the nineteenth switching tube Q19 and the twentieth switching tube Q20 may form a rectifying circuit structure, and in the discharging mode, the fifth switching tube Q5, the sixth switching tube Q6, the seventh switching tube Q7, the eighth switching tube Q8, the nineteenth switching tube Q19 and the twentieth switching tube Q20 may form an inverting circuit structure.

In the embodiment, the three-leg circuit converter 12 is used for ac-dc conversion, and compared with two sets of rectifier legs, the two transformers are respectively connected to current in different power supply periods, so that transformer loss can be reduced.

Specifically, when the grid voltage is a positive half-cycle during charging of the high-voltage battery pack 70, as shown in fig. 6, the control module 50 controls the ninth switching tube Q9 and the tenth switching tube Q10 to be kept conductive, or, as shown in fig. 7, controls the ninth switching tube Q9, the tenth switching tube Q10 and the second switching tube Q2 to be kept conductive, and controls the first switching tube Q1 to be turned off, so that the first resonant circuit module 10 is turned on; the grid voltage is applied to the first capacitor C1, the control module 50 turns on or off the third switching tube Q3 and the fourth switching tube Q4 at a fixed frequency and a fixed duty cycle, and the second capacitor C2 and the third capacitor C3 are charged or discharged, so that an alternating voltage is formed between a midpoint of the third switching tube Q3 and the fourth switching tube Q4, i.e., the first node O1, and a midpoint of the second capacitor C2 and the third capacitor C3, i.e., the second node O2. After being isolated and transformed by a first transformer T1, the voltage is transmitted to a rectifying circuit composed of a fifth switching tube Q5, a sixth switching tube Q6, a seventh switching tube Q7, an eighth switching tube Q8, a nineteenth switching tube Q19 and a twentieth switching tube Q20, wherein a bridge arm composed of the seventh switching tube Q7 and the eighth switching tube Q8 and a bridge arm composed of the nineteenth switching tube Q19 and the twentieth switching tube Q20 are synchronously turned on and off, and an alternating current voltage between a midpoint of the fifth switching tube Q5 and the sixth switching tube Q6, i.e., a third node O3 and a seventh switching tube Q7, and a midpoint of the eighth switching tube Q8, i.e., a fourth node O4, is converted into a direct current voltage to be output, i.e., the alternating current voltage provided to the first direct current conversion circuit module 40, thereby realizing alternating current-direct current conversion.

Specifically, when the grid voltage is a negative half-cycle during charging of the high-voltage battery pack 70, as shown in fig. 6, the control module 50 controls the third switching tube Q3 and the fourth switching tube Q4 to be kept on, or, as shown in fig. 7, controls the second switching tube Q2 to be off, controls the first switching tube Q1, the third switching tube Q3 and the fourth switching tube Q4 to be on, and controls the second resonant circuit module 20 to be turned on; the grid voltage is applied to the eighth capacitor C8, and the control module 50 controls the ninth switch Q9 and the tenth switch Q10 to be turned on or off at a fixed frequency and a fixed duty ratio, and charges or discharges the ninth capacitor C9 and the tenth capacitor C10, so that an alternating voltage is formed between a midpoint of the ninth switch Q9 and the tenth switch Q10, i.e., the sixth node O6, and a midpoint of the ninth capacitor C9 and the tenth capacitor C10, i.e., the seventh node O7. After being isolated and transformed by a second transformer T2, the voltage is transmitted to a rectifying circuit composed of a fifth switching tube Q5, a sixth switching tube Q6, a seventh switching tube Q7, an eighth switching tube Q8, a nineteenth switching tube Q19 and a twentieth switching tube Q20, wherein a bridge arm composed of the fifth switching tube Q5 and the sixth switching tube Q6 is synchronously turned on and off with a bridge arm composed of the seventh switching tube Q7 and the eighth switching tube Q8, and an alternating current voltage between a midpoint of the seventh switching tube Q7 and the eighth switching tube Q8, i.e., a fourth node O4 and the nineteenth switching tube Q19, and a midpoint of the twentieth switching tube Q20, i.e., an eighth node O8, is converted into a direct current voltage to be output, i.e., a voltage provided to the first direct current conversion circuit module 40, i.e., voltages at two ends of the sixth capacitor C6, so as to realize alternating current-direct current conversion.

As shown in fig. 6 or 7, the first dc conversion circuit module 40 includes a sixth capacitor C6, an eleventh switch Q11, a twelfth switch Q12, and a seventh capacitor C7.

A first end of the sixth capacitor C6 is connected to the first end of the nineteenth switching tube Q19, and a second end of the sixth capacitor C6 is connected to the second end of the twentieth switching tube Q20; the sixth capacitor C6 is used to filter the input dc signal, and in the embodiment of the present invention, the sixth capacitor C6 is a capacitor device with a small capacitance, such as a thin film capacitor, and an electrolytic capacitor with a large capacitance is not needed.

A first end of an eleventh switching tube Q11 is connected to the first end of the high-voltage battery pack 70, a control end of the eleventh switching tube Q11 is connected to the control module 50, a second end of an eleventh switching tube Q11 is connected to the first end of a twelfth switching tube Q12, a second end of the twelfth switching tube Q12 is connected to the second end of the sixth capacitor C6 and the second end of the high-voltage battery pack 70, respectively, a control end of a twelfth switching tube Q12 is connected to the control module 50, a fifth node O5 is located between the second end of the eleventh switching tube Q11 and the first end of the twelfth switching tube Q12, and the fifth node O5 is connected to the first end of the sixth capacitor C6 through a third inductor L3; a first end of the seventh capacitor C7 is connected to the first end of the eleventh switch tube Q11 and the first end of the high-voltage battery pack 70, respectively, and a second end of the seventh capacitor C7 is connected to the second end of the twelfth switch tube Q12 and the second end of the high-voltage battery pack 70, respectively.

In the present embodiment, the first dc conversion circuit module 40 is disposed at the rear, so that the charging voltage or the charging power output to the high-voltage battery pack 70 can be adjusted by controlling the duty ratio of the conversion circuit module 40, thereby not only widening the voltage range of the adaptive battery pack, but also shortening the charging time of the battery and the charging efficiency of the high-voltage battery pack 70.

The voltage on the sixth capacitor C6 is proportional to the absolute value of the grid voltage, and the voltage waveform is the output voltage waveform of the steamed bread wave by gating the first resonant circuit module 10 and the second resonant circuit module 20, so that a large-capacity electrolytic capacitor is not needed for filtering, and a small-capacity capacitor, such as a film capacitor, can be selected as the sixth capacitor C6.

Further, the first dc conversion circuit module 40 regulates the input dc voltage to provide to the high voltage battery pack 70. Specifically, when the twelfth switching tube Q12 is turned on, the current of the third inductor L3 increases, and as shown in fig. 6, the current flows in a → L3 → Q12 → B; the twelfth switching tube Q12 is turned off, and the current of the third inductor L3 decreases, as shown in fig. 6, and the current flows in a → L3 → Q11 → battery pack → B. The twelfth switching tube Q12 is controlled by the control module 50 to be turned on or off at a high frequency, so that the current waveform of the third inductor L3 tracks the voltage of the sixth capacitor C6, and power factor correction can be achieved, and the current amplitude of the third inductor L3 depends on the charging power.

Based on the circuit structure of the vehicle-mounted charging and discharging system 10 shown in fig. 6 or 7, the vehicle-mounted charging and discharging system can also operate in the discharging mode of the high-voltage battery pack 70, that is, the high-voltage battery pack 70 is discharged to supply power to the electric equipment, and the specific process is as follows.

When the vehicle-mounted charging and discharging system 10 works in a discharging mode, the high-voltage battery pack 70 discharges to output direct current, the first direct current conversion circuit module 40 performs direct current-direct current conversion to realize a voltage regulation function, and the control module 50 controls two switching tubes in the gating circuit module 30 to gate according to the power supply period signal so as to gate the first resonance circuit module 10 or the second resonance circuit module 20 and output power frequency alternating current to supply power for the power consumption equipment or feed back to a power grid.

Referring to fig. 6 or 7, specifically, the switching timing of the first dc conversion circuit module 40 is: when the eleventh switch tube Q11 is turned on, the current of the third inductor L3 rises, and the high-voltage battery pack 70 transfers energy to the rear-stage circuit; when the eleventh switch Q11 is turned off, the current of the third inductor L3 drops, and then flows through the twelfth switch Q12, and energy is transferred to the subsequent stage. The control module 50 regulates the output voltage, i.e., the voltage across the sixth capacitor C6, by controlling the eleventh switch Q11 to turn on and off, and the voltage amplitude depends on the switching duty cycle of the eleventh switch Q11 and the voltage of the high-voltage battery pack 70.

For the first resonant circuit module 10 and the second resonant circuit module 20, the first resonant circuit module 10 is gated on outputting a positive half cycle of the alternating current. Specifically, the fifth switching tube Q5, the sixth switching tube Q6, the seventh switching tube Q7, the eighth switching tube Q8, the nineteenth switching tube Q19 and the twentieth switching tube Q20 are controlled to be turned on or off at a fixed frequency and a fixed duty ratio, wherein a bridge arm formed by the seventh switching tube Q7 and the eighth switching tube Q8 and a bridge arm formed by the nineteenth switching tube Q19 and the twentieth switching tube Q20 are turned on or off synchronously, and an alternating current voltage is formed between a midpoint of the fifth switching tube Q5 and the sixth switching tube Q6, namely, a third node O3, a midpoint of the seventh switching tube Q7 and a midpoint of the eighth switching tube Q8, namely, a fourth node O4. After being isolated and transformed by the first transformer T1, the alternating current is transmitted to the third switching tube Q3, the fourth switching tube Q4, the second capacitor C2 and the third capacitor C3 to realize a rectification function, and alternating current voltage between the middle points of the third switching tube Q3 and the fourth switching tube Q4, namely the first node O1 and the middle points of the second capacitor C2 and the third capacitor C3, namely the second node O2 is converted into a positive half-cycle part of power frequency alternating current, namely voltages at two ends of the first capacitor C1 through the on/off of the third switching tube Q3 and the fourth switching tube Q4 and the charging or discharging of the second capacitor C2 and the third capacitor C3, so that the positive half-cycle part of the power frequency alternating current is output.

Likewise, the second resonant circuit module 20 is gated on the negative half-cycle of the alternating current output by the system. And controlling the fifth switching tube Q5, the sixth switching tube Q6, the seventh switching tube Q7, the eighth switching tube Q8, the nineteenth switching tube Q19 and the twentieth switching tube Q20 to be switched on or off at a fixed frequency and a fixed duty ratio, wherein an arm formed by the fifth switching tube Q5 and the sixth switching tube Q6 is synchronously switched on and off with an arm formed by the seventh switching tube Q7 and the eighth switching tube Q8, and alternating current voltage is formed between a midpoint of the seventh switching tube Q7 and the eighth switching tube Q8, namely a fourth node O4, a midpoint of the nineteenth switching tube Q19 and the twentieth switching tube Q20, namely an eighth node O8. After the transformation and isolation of the second transformer T2, the alternating current is transmitted to the ninth switching tube Q9, the tenth switching tube Q10, the ninth capacitor C9 and the tenth capacitor C10 to realize the rectification function, and the alternating current voltage between the midpoint of the ninth switching tube Q9 and the tenth switching tube Q10, i.e., the sixth node O6 and the midpoint of the ninth capacitor C9 and the tenth capacitor C10, i.e., the seventh node O7, is converted into the negative half-cycle of the power frequency alternating current, i.e., the voltages at the two ends of the eighth capacitor C8, by controlling the on/off of the ninth switching tube Q9 and the tenth switching tube Q10 and the charging or discharging of the ninth capacitor C9 and the eleventh capacitor C10, so as to realize the negative half-cycle output of the power frequency alternating current.

The switching timing for the gating circuit module 30 is: when the system outputs a positive half-cycle signal of alternating current, the ninth switching tube Q9 and the tenth switching tube Q10 are controlled to be kept conducted, and the first resonant circuit module 10 is gated; when the system outputs a signal of a negative half cycle of the alternating current, the third switching tube Q3 and the fourth switching tube Q4 are controlled to be kept conductive, and the second resonant circuit module 20 is gated.

Further, as shown in fig. 6 or 7, the secondary side of the first transformer T1 further includes a third coil W3 and a fourth coil W4, a second end of the third coil W3 and a first end of the fourth coil W4 are a first common end, and the first common end is connected to the first end of the second dc conversion circuit module 41.

The first rectifier circuit module 80 includes a thirteenth switching tube Q13 and a fourteenth switching tube Q14, wherein a first end of the thirteenth switching tube Q13 is connected to the first end of the third winding W3, a second end of the thirteenth switching tube Q13 is connected to the second end of the second dc converting circuit module 41, a control end of the thirteenth switching tube Q13 is connected to the control module 50, a first end of the fourteenth switching tube Q14 is connected to the second end of the fourth winding W4, a second end of the fourteenth switching tube Q14 is connected to the second end of the second dc converting circuit module 41, and a control end of the fourteenth switching tube Q14 is connected to the control module 50.

The secondary side of the second transformer T2 further includes a seventh coil W7 and an eighth coil W8, wherein a second terminal of the seventh coil W7 and a first terminal of the eighth coil W8 are a second common terminal, and the second common terminal is connected to the first terminal of the second dc conversion circuit module 41.

The second rectifying circuit module 41 includes a fifteenth switching tube Q15 and a sixteenth switching tube Q16, a first end of the fifteenth switching tube Q15 is connected to the first end of the seventh winding W7, a second end of the fifteenth switching tube Q15 is connected to the second end of the second dc conversion circuit module 41, a control end of the fifteenth switching tube Q15 is connected to the control module 50, a first end of the sixteenth switching tube Q16 is connected to the second end of the eighth winding W8, a second end of the sixteenth switching tube Q16 is connected to the second end of the second dc conversion circuit module 41, and a control end of the sixteenth switching tube Q16 is connected to the control module 50.

Further, the second dc conversion circuit module 41 includes a thirteenth capacitor C13, a seventeenth switch Q17, an eighteenth switch Q18 and a fourteenth capacitor C14.

A first end of the thirteenth capacitor C13 is connected to the first common terminal, and a second end of the thirteenth capacitor C13 is connected to the second end of the thirteenth switching tube Q13, the second end of the fourteenth switching tube Q14, the second end of the fifteenth switching tube Q15, and the second end of the sixteenth switching tube Q16, respectively.

A first end of a seventeenth switching tube Q17 is connected to the first end of the thirteenth capacitor C13 through a fourth inductor L4, a second end of the seventeenth switching tube Q17 is connected to the second end of the thirteenth capacitor C13 and the first end of the low-voltage battery pack 71, a control end of the seventeenth switching tube Q17 is connected to the control module 50, a first end of an eighteenth switching tube Q18 is connected to the fourth inductor L4 and the first end of the seventeenth switching tube Q17, a second end of the eighteenth switching tube Q18 is connected to the second end of the low-voltage battery pack 71, and a control end of the eighteenth switching tube Q18 is connected to the control module 50.

A first end of the fourteenth capacitor C14 is connected to the second end of the eighteenth switch tube Q18 and the second end of the low-voltage battery pack 71, respectively, and a second end of the fourteenth capacitor C14 is connected to the second end of the seventeenth switch tube Q17 and the first end of the low-voltage battery pack 71, respectively.

Specifically, when the grid is used for charging the battery pack, during a first half period of power supply, for example, a positive half period of the grid, the first resonant circuit module 10 is turned on, the first resonant circuit module 10 outputs a direct current to the first direct current conversion circuit 40 to charge the high-voltage battery pack 70, and at the same time, rectification is performed through on/off control of the thirteenth switching tube Q13 and the fourteenth switching tube Q14 of the first rectification circuit module 80, specifically, when the third coil W3 and the fourth coil W4 are positive and negative, the fourteenth switching tube Q14 is turned on, the thirteenth switching tube Q13 is turned off, and a direct current voltage is output; when the third coil W3 and the fourth coil W4 are in negative and positive vertical positions, the fourteenth switching tube Q14 is not conducted, the thirteenth switching tube Q13 is conducted, and a direct-current voltage is output, namely, the direct-current voltage is provided across the thirteenth capacitor C13.

Similarly, during a second half period of power supply, for example, a negative half period of the power grid, the second resonant circuit module 20 is turned on, the second resonant circuit module 20 outputs a direct current to the first dc conversion circuit 40 to charge the high-voltage battery pack 70, and at the same time, rectification is performed through the on/off control of the fifteenth switching tube Q15 and the sixteenth switching tube Q16 of the second rectifier circuit module 81, specifically, when the seventh winding W7 and the eighth winding W8 are positive and negative, the sixteenth switching tube Q16 is turned on, the fifteenth switching tube Q15 is not turned on, and a direct current voltage is output; when the seventh winding W7 and the eighth winding W8 are positive, the sixteenth switching tube Q16 is not turned on, the fifteenth switching tube Q15 is turned on, and a dc voltage is output, i.e., a dc voltage is applied across the thirteenth capacitor C13.

Further, the second dc converting circuit module 41 is a dc converting circuit such as a BOOST circuit, which can achieve power factor correction and output power regulation, wherein the eighteenth switching tube Q18 is kept conducting, specifically, when the seventeenth switching tube Q17 is conducting, the fourth inductor L4 is in the energy storage stage, and the current rises, as shown in fig. 6 or 7, and the current direction is C → L4 → the seventeenth switching tube Q17 → D; when the seventeenth switching tube Q17 is turned off, the eighteenth switching tube Q18 releases energy, and the current decreases, in the direction of C → L4 → Q18 → Q19 → low-voltage battery pack → D.

The power factor correction is realized by switching on and off the seventeenth switching tube Q17 at high frequency, so that the current waveform of the fourth inductor L4 tracks the voltage of the thirteenth capacitor C13, wherein the current amplitude of the fourth inductor L4 depends on the low-voltage battery charging power.

Based on the vehicle-mounted charge and discharge system shown in fig. 6 or 7, it is also possible to operate in a mode in which the high-voltage battery pack 70 charges the low-voltage battery pack 71. In this mode, the first dc conversion circuit 40, the secondary part of the first resonance circuit module 10, the secondary part of the second resonance circuit module 20, the first and second

rectifier circuit modules

80 and 81, and the second dc conversion circuit module 41 participate.

Specifically, when the eleventh switching tube Q11 is turned on, the current of the third inductor L3 rises, and the high-voltage battery pack 70 transfers energy to the rear-stage circuit; when the eleventh switch Q11 is turned off, the current of the third inductor L3 drops, and then flows through the twelfth switch Q12, and energy is transferred to the subsequent stage. The first dc conversion circuit module 40, for example, the buck circuit outputs a voltage across the sixth capacitor C6, and the voltage across the sixth capacitor C6 can be adjusted by adjusting the duty ratio of the eleventh switch Q11.

The switching on or off of the fifth switching tube Q5, the sixth switching tube Q6, the seventh switching tube Q7, the eighth switching tube Q8, the nineteenth switching tube Q19 and the twentieth switching tube Q20 at a certain frequency and duty cycle is controlled, wherein a bridge arm formed by the seventh switching tube Q7 and the eighth switching tube Q8 is synchronously switched on and off with a bridge arm formed by the nineteenth switching tube Q19 and the twentieth switching tube Q20, an alternating current voltage is formed between a midpoint of the fifth switching tube Q5 and the sixth switching tube Q6, namely a third node O3, and a midpoint of the seventh switching tube Q7 and the eighth switching tube Q8, namely a fourth node O4, and alternating current-alternating current conversion and isolation are realized through isolation on the secondary side of the first transformer T1.

Further, the first rectifier circuit module 80 converts the ac voltage of the third and fourth coils W3, W4 of the first transformer T1 into a dc voltage, and when the third and fourth coils W3, W4 are positive and negative, the fourteenth switching tube Q14 is turned on, the thirteenth switching tube Q13 is turned off, and the dc voltage is output; when the third coil W3 and the fourth coil W4 are turned on and off, the fourteenth switching tube Q14 is not turned on, and the thirteenth switching tube Q13 is turned on, thereby outputting a dc voltage. In this operation mode, the seventeenth switching tube Q17 in the second dc conversion circuit module 41 is kept turned off.

Or, the fifth switching tube Q5, the sixth switching tube Q6, the seventh switching tube Q7, the eighth switching tube Q8, the nineteenth switching tube Q19 and the twentieth switching tube Q20 are controlled to be turned on or off at a certain frequency and duty ratio, wherein a bridge arm formed by the fifth switching tube Q5 and the sixth switching tube Q6 and a bridge arm formed by the seventh switching tube Q7 and the eighth switching tube Q8 are turned on and off synchronously, an alternating current voltage is formed between a midpoint of the seventh switching tube Q7 and the eighth switching tube Q8, namely the fourth node O4, a midpoint of the nineteenth switching tube Q19 and the twentieth switching tube Q20, namely the eighth node O8, and the alternating current-alternating current conversion and isolation are realized through isolation on the secondary side of the second transformer T1.

Further, the ac voltages of the seventh and eighth coils W7 and W8 of the second transformer T2 are converted into dc voltages by the second rectifier circuit module 81. When the seventh coil W7 and the eighth coil W8 are positive and negative, the sixteenth switching tube Q16 is turned on, the fifteenth switching tube Q15 is turned off, and a direct-current voltage is output; when the seventh coil W7 and the eighth coil W8 are up-down negative and positive, the sixteenth switching tube Q16 is not conducted, the fifteenth switching tube Q15 is conducted, and outputs a direct-current voltage to the low-voltage battery pack 71, so that the high-voltage battery pack 70 charges the low-voltage battery pack 71. In this operating mode, in the second dc conversion circuit module 41, the seventeenth switching tube Q17 is kept off, and the eighteenth switching tube Q18 is kept on.

In the embodiment of the present invention, the switching tube may be a MOS tube or a triode or other suitable switching device.

In addition, for the Part of Part 2' in fig. 1, which is an LLC topology, when the output voltage range is wide, the switching frequency deviates from the resonant frequency more, resulting in low charging efficiency. The vehicle-mounted charging and discharging system 100 of the embodiment of the invention can adjust the duty ratio of the work of the rear-stage direct current conversion circuit module through the control module 50 so as to control the charging power, and the adaptable battery voltage range is wider.

In summary, in the vehicle-mounted charging and discharging system 100 according to the embodiment of the present invention, two resonant circuit modules are arranged, and the control module 50 gates the first resonant circuit module 10 or the second resonant circuit module 20 according to the power supply period signal, so that the signal output by the resonant circuit module to the conversion line module is a steamed bread wave, and therefore, a large-capacity electrolytic capacitor is not needed for filtering, only a small-capacity filter device, such as a thin film capacitor, is needed, the cost and the volume of the electrolytic capacitor portion are reduced, and the reliability and the service life of the product are improved. The first rectifier circuit module 80 and the second rectifier circuit module 81 are arranged to simultaneously charge the low-voltage battery pack 71, the first resonant circuit module 10 and the second resonant circuit module 20 are provided with the three-bridge-arm circuit conversion unit 12 in a multiplexing mode, the usage amount of circuit devices can be reduced, the cost is reduced, the three-bridge-arm circuit conversion unit 12 is used for alternating current-direct current conversion, two transformers are respectively connected with current in different power supply periods, the transformer loss can be reduced, a gating circuit is not needed, the cost is saved, or even if the gating circuit is arranged, the conduction loss can be reduced by controlling the series connection and the parallel connection of the switching tubes; and the working duty ratio of the direct current conversion circuit module is adjusted, so that a larger battery voltage range can be adapted, and charging power is provided.

Based on the vehicle-mounted charge and discharge system of the above embodiment, a vehicle according to an embodiment of the second aspect of the invention is described below with reference to the drawings.

FIG. 8 is a block diagram of a vehicle according to one embodiment of the present invention. As shown in fig. 8, a vehicle 1000 according to an embodiment of the present invention includes a high-voltage battery pack 70, a low-voltage battery pack 71, and the vehicle-mounted charge and discharge system 100 according to the above embodiment, wherein the composition of the vehicle-mounted charge and discharge system 100 may refer to the description of the above embodiment, and of course, the vehicle 1000 further includes other systems such as a transmission system, a power system, a steering system, and the like, which are not listed here.

According to the vehicle 1000 of the embodiment of the invention, by adopting the vehicle-mounted charging and discharging system 100 of the embodiment, the cost can be reduced, the reliability can be improved, the anti-seismic grade can be improved, and the charging of the high-voltage battery pack to the low-voltage battery pack can be realized.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example.

While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A vehicle-mounted charging and discharging system is characterized by comprising:

the first resonant circuit module is used for converting an input electric signal, and comprises a first conversion unit, a first transformer and a three-bridge-arm circuit conversion unit, wherein the first conversion unit comprises a third switching tube and a fourth switching tube, a first end of the third switching tube is connected with a first end of the electric unit, a second end of the third switching tube is connected with a first end of the fourth switching tube, the first transformer comprises a first coil and a second coil, the first coil is connected with the first conversion unit, a first end of the second coil is connected with a first bridge arm of the three-bridge-arm circuit conversion unit, and a second end of the second coil is connected with a second bridge arm of the three-bridge-arm circuit conversion unit;

the second resonance circuit module is used for converting the input electric signal and comprises the three bridge arm circuit conversion unit, a second conversion unit and a second transformer, the second conversion unit comprises a ninth switching tube and a tenth switching tube, the first end of the ninth switching tube is connected with the second end of the electric unit, the second end of the ninth switching tube is connected with the first end of the tenth switching tube, the second end of the tenth switching tube is connected with the second end of the fourth switching tube, the second transformer includes a fifth coil and a sixth coil, the fifth coil is connected to the second conversion unit, the first end of the sixth coil is respectively connected with the second end of the second coil and the second bridge arm, a second end of the sixth coil is connected with a third bridge arm of the three-bridge-arm circuit conversion unit;

the first end of the first rectifying circuit module is connected with the secondary side of the first transformer and used for rectifying an input electric signal;

a second rectifier circuit module, a first end of which is connected to a secondary side of the second transformer, for rectifying an input electrical signal;

and the control module is used for controlling the ninth switching tube and the tenth switching tube to be kept in conduction when power is supplied for a first half period, controlling the first resonant circuit module and the first rectifying circuit module according to a time sequence signal of the first half period of power supply, or controlling the third switching tube and the fourth switching tube to be kept in conduction when power is supplied for a second half period, and controlling the second resonant circuit module and the second rectifying circuit module according to a time sequence signal of the second half period of power supply, or respectively controlling the three-bridge-arm circuit conversion unit, the first rectifying circuit module or the second rectifying circuit module according to a control time sequence of charging a low-voltage battery pack by a high-voltage battery pack.

2. The vehicle-mounted charge and discharge system according to claim 1, further comprising:

the gating circuit module comprises a first switching tube and a second switching tube, wherein the first end of the first switching tube is connected with the first end of the electric unit, the second end of the first switching tube is respectively connected with the second end of the fourth switching tube and the second end of the tenth switching tube, the first end of the second switching tube is connected with the second end of the electric unit, and the second end of the second switching tube is respectively connected with the second end of the fourth switching tube and the second end of the tenth switching tube;

the control module is further configured to control the first switching tube to be turned off and control the second switching tube, the ninth switching tube and the tenth switching tube to be turned on during the first half cycle of the power supply, and controls the first resonant circuit module and the first rectifying circuit module according to a timing signal of a first half cycle of power supply, or, when the power is supplied for the second half period, the second switching tube is controlled to be turned off, and the first switching tube, the third switching tube and the fourth switching tube are controlled to be turned on, and controls the second resonant circuit module and the second rectifying circuit module according to the timing signal of the second half period of the power supply, or the three-bridge-arm circuit conversion unit, the first rectification circuit module or the second rectification circuit module are respectively controlled according to the control time sequence of charging the low-voltage battery pack by the high-voltage battery pack.

3. The vehicle-mounted charge and discharge system according to claim 1 or 2, further comprising:

the first direct current conversion circuit module is respectively connected with the three-bridge arm circuit conversion unit and the high-voltage battery pack and is used for performing direct current-direct current conversion on an input electric signal;

and the second direct current conversion circuit module is respectively connected with the first rectification circuit module, the second rectification circuit module and the low-voltage battery pack and is used for performing direct current-direct current conversion on an input electric signal.

4. The vehicle charging and discharging system according to claim 3,

the first conversion unit further comprises a first capacitor, a second capacitor and a third capacitor, the first end of the first capacitor is connected with the first end of the electric unit, the second end of the first capacitor is connected with the second end of the fourth switch tube, the first end of the third switch tube is connected with the first end of the first capacitor, the control end of the third switch tube is connected with the control module, the second end of the third switch tube is connected with the first end of the fourth switch tube, the second end of the fourth switch tube is connected with the second end of the first capacitor, the control end of the fourth switch tube is connected with the control module, a first node is arranged between the second end of the third switch tube and the first end of the fourth switch tube, the first end of the second capacitor is connected with the first end of the third switch tube, and the second end of the second capacitor is connected with the first end of the third capacitor, a second end of the third capacitor is connected with a second end of the fourth switching tube, and a second node is arranged between the second end of the second capacitor and the first end of the third capacitor;

a first end of the first coil is connected with the first node through a first inductor, and a second end of the first coil is connected with the second node;

the second conversion unit further comprises an eighth capacitor, a ninth capacitor and a tenth capacitor, wherein the first end of the eighth capacitor is connected with the second end of the electrical unit, the second end of the eighth capacitor is connected with the second end of the tenth switching tube, the first end of the ninth switching tube is connected with the first end of the eighth capacitor, the control end of the ninth switching tube is connected with the control module, the second end of the ninth switching tube is connected with the first end of the tenth switching tube, the second end of the tenth switching tube is connected with the second end of the eighth capacitor, the control end of the tenth switching tube is connected with the control module, a sixth node is arranged between the second end of the ninth switching tube and the first end of the tenth switching tube, the first end of the ninth capacitor is connected with the first end of the ninth switching tube, and the second end of the ninth capacitor is connected with the first end of the tenth capacitor, a second end of the tenth capacitor is connected with a second end of the tenth switching tube, and a seventh node is arranged between a second end of the ninth capacitor and a first end of the tenth capacitor;

a first end of the fifth coil is connected with the sixth node through a fifth inductor, a second end of the fifth coil is connected with the seventh node, and a first end of the sixth coil is connected with the second end of the second coil and the second bridge arm through a sixth inductor respectively.

5. The vehicle-mounted charging and discharging system according to claim 4, wherein the three-leg circuit switching unit comprises:

a fifth switching tube and a sixth switching tube, wherein a first end of the fifth switching tube is connected with a first end of the first dc conversion circuit module, a control end of the fifth switching tube is connected with the control module, a second end of the fifth switching tube is connected with a first end of the sixth switching tube, a second end of the sixth switching tube is connected with a second end of the first dc conversion circuit module, a control end of the sixth switching tube is connected with the control module, a third node is arranged between the second end of the fifth switching tube and the first end of the sixth switching tube, and the third node is connected with the first end of the second coil through a second inductor;

a seventh switching tube and an eighth switching tube, wherein a first end of the seventh switching tube is respectively connected with a first end of the fifth switching tube and a first end of the first dc conversion circuit module, the second end of the seventh switch tube is connected with the first end of the eighth switch tube, the control end of the seventh switch tube is connected with the control module, a second end of the eighth switching tube is respectively connected with a second end of the sixth switching tube and a second end of the first dc conversion circuit module, the control end of the eighth switching tube is connected with the control module, a fourth node is arranged between the second end of the seventh switching tube and the first end of the eighth switching tube, the fourth node is connected with the second end of the second coil through a fifteenth capacitor, and the fourth node is connected with the first end of the sixth coil through the sixth inductor;

the first end of the nineteenth switching tube is connected with the first end of the seventh switching tube and the first end of the first direct current conversion circuit module respectively, the second end of the nineteenth switching tube is connected with the first end of the twentieth switching tube, the control end of the nineteenth switching tube is connected with the control module, the second end of the twentieth switching tube is connected with the second end of the eighth switching tube and the second end of the first direct current conversion circuit module respectively, the control end of the twentieth switching tube is connected with the control module, an eighth node is arranged between the second end of the nineteenth switching tube and the first end of the twentieth switching tube, and the eighth node is connected with the second end of the sixth coil through a sixteenth capacitor.

6. The vehicle-mounted charging and discharging system according to claim 5, wherein the first direct current conversion circuit module comprises:

a first end of the sixth capacitor is connected with a first end of the nineteenth switching tube, and a second end of the sixth capacitor is connected with a second end of the twentieth switching tube;

the first end of the eleventh switch tube is connected with the first end of the high-voltage battery pack, the control end of the eleventh switch tube is connected with the control module, the second end of the eleventh switch tube is connected with the first end of the twelfth switch tube, the second end of the twelfth switch tube is respectively connected with the second end of the sixth capacitor and the second end of the high-voltage battery pack, the control end of the twelfth switch tube is connected with the control module, a fifth node is arranged between the second end of the eleventh switch tube and the first end of the twelfth switch tube, and the fifth node is connected with the first end of the sixth capacitor through a third inductor;

and a first end of the seventh capacitor is connected with the first end of the eleventh switch tube and the first end of the high-voltage battery pack respectively, and a second end of the seventh capacitor is connected with the second end of the twelfth switch tube and the second end of the high-voltage battery pack respectively.

7. The vehicle charging and discharging system according to claim 6,

the secondary side of the first transformer further comprises a third coil and a fourth coil, a second end of the third coil and a first end of the fourth coil are a first common end, and the first common end is connected with a first end of the second direct current conversion circuit module;

the first rectifying circuit module comprises a thirteenth switching tube and a fourteenth switching tube, wherein the first end of the thirteenth switching tube is connected with the first end of the third coil, the second end of the thirteenth switching tube is connected with the second end of the second direct current conversion circuit module, the control end of the thirteenth switching tube is connected with the control module, the first end of the fourteenth switching tube is connected with the second end of the fourth coil, the second end of the fourteenth switching tube is connected with the second end of the second direct current conversion circuit module, and the control end of the fourteenth switching tube is connected with the control module.

8. The vehicle charging and discharging system according to claim 7,

the secondary side of the second transformer further comprises a seventh coil and an eighth coil, wherein a second end of the seventh coil and a first end of the eighth coil are a second common end, and the second common end is connected with a first end of the second direct current conversion circuit module;

the second rectifying circuit module comprises a fifteenth switching tube and a sixteenth switching tube, wherein the first end of the fifteenth switching tube is connected with the first end of the seventh coil, the second end of the fifteenth switching tube is connected with the second end of the second direct current conversion circuit module, the control end of the fifteenth switching tube is connected with the control module, the first end of the sixteenth switching tube is connected with the second end of the eighth coil, the second end of the sixteenth switching tube is connected with the second end of the second direct current conversion circuit module, and the control end of the sixteenth switching tube is connected with the control module.

9. The vehicle-mounted charging and discharging system according to claim 8, wherein the second dc conversion circuit module includes:

a thirteenth capacitor, a first end of the thirteenth capacitor is connected to the first common terminal, and a second end of the thirteenth capacitor is connected to the second end of the thirteenth switching tube, the second end of the fourteenth switching tube, the second end of the fifteenth switching tube, and the second end of the sixteenth switching tube, respectively;

a seventeenth switching tube and an eighteenth switching tube, wherein a first end of the seventeenth switching tube is connected with a first end of the thirteenth capacitor through a fourth inductor, a second end of the seventeenth switching tube is respectively connected with a second end of the thirteenth capacitor and a first end of the low-voltage battery pack, a control end of the seventeenth switching tube is connected with the control module, a first end of the eighteenth switching tube is respectively connected with the fourth inductor and the first end of the seventeenth switching tube, and a second end of the eighteenth switching tube is connected with a second end of the low-voltage battery pack;

and a fourteenth capacitor, a first end of which is connected to the second end of the eighteenth switching tube and the second end of the low-voltage battery pack, respectively, and a second end of which is connected to the second end of the seventeenth switching tube and the first end of the low-voltage battery pack, respectively.

10. A vehicle characterized by comprising a high-voltage battery pack, a low-voltage battery pack, and the vehicle-mounted charge and discharge system according to any one of claims 1 to 9.