WO2019206229A1

WO2019206229A1 - Dcdc converter, vehicle-mounted charger and electric vehicle

Info

Publication number: WO2019206229A1
Application number: PCT/CN2019/084327
Authority: WO
Inventors: 张晓彬
Original assignee: 比亚迪股份有限公司
Priority date: 2018-04-26
Filing date: 2019-04-25
Publication date: 2019-10-31
Also published as: CN110417289A

Abstract

Disclosed are a DCDC converter, a vehicle-mounted charger and an electric vehicle. The DCDC converter comprises a first adjustment module, a resonance module, a second adjustment module, and a controller. The first adjustment module is used to adjust a frequency of an input signal of the DCDC converter when a charge operation is performed, and to rectify an output signal of the resonance module when a discharge operation is performed. The resonance module is used to perform resonance processing on an output signal of the first adjustment module when the charge operation is performed, and to perform resonance processing on an output signal of the second adjustment module when the discharge operation is performed. The second adjustment module is used to adjust a frequency of an output signal of a battery module when the discharge operation is performed, and to rectify an output signal of the resonance module when the DCDC converter charges the battery module. The controller is used to control the first adjustment module and the second adjustment module according to a charge/discharge signal of the battery module so as to cause the battery module to perform a charge/discharge operation. The invention is provided with a resonance module, and thus is applicable to products with large power requirements.

Description

DCDC converter, car charger and electric vehicle

Cross-reference to related applications

The present application is based on a Chinese patent application filed on Jan. 26, 2018, the entire disclosure of which is hereby incorporated by reference.

Technical field

The present disclosure relates to the field of vehicle technology, and in particular, to a DCDC converter, and an in-vehicle charger including the DCDC converter and an electric vehicle on which the in-vehicle charger is mounted.

Background technique

With the continuous development of electric vehicles, the capacity of battery modules of electric vehicles is increasing. In order to save charging and discharging time, a large-capacity battery module requires a more powerful two-way car charger (hereinafter referred to as a car charger). At present, the mainstream car charger power level in the industry is single-phase 3.3KW/6.6KW. With the further demand of high-power car chargers, three-phase 10/20/40KW car chargers have an increasingly large market.

The main power topology of the vehicle charger generally includes PFC (Power Factor Correction) + bidirectional DCDC, PFC plays the role of power factor correction; bidirectional DCDC realizes energy controllable isolation transmission, which is the core power conversion unit of the vehicle charger. However, it is not suitable for use in high-power car chargers. With the increase of power, the design of the bidirectional DCDC module is more and more difficult. For example, the current stress is multiplied, and the semiconductor device and the magnetic device are difficult to be properly selected. The magnetic device has a large size and is difficult to adapt to the vibration requirements of the whole vehicle; The current is large, and a large-capacity filter capacitor is required; the heat generation is large, and the heat dissipation design is difficult. In view of the above problems, in the related art, a high-power bidirectional DCDC circuit is proposed, and the scheme is generally: selecting a high-power IGBT (Insulated Gate Bipolar Transistor) module, and multi-module parallel connection. However, there are some problems in paralleling multiple modules, which makes high demands on the system hardware circuit design and software algorithms.

Summary of the invention

The present disclosure aims to solve at least one of the technical problems in the related art to some extent.

To this end, an embodiment of the present disclosure is to provide a DCDC converter that is more suitable for a high-power vehicle charger, which is low in cost and simple in structure.

Yet another embodiment of the present disclosure is directed to an in-vehicle charger including the DCDC converter.

Yet another embodiment of the present disclosure is to provide an electric vehicle in which the in-vehicle charger is mounted.

In order to achieve the above object, a DCDC converter according to a first aspect of the present disclosure includes: a first adjustment module, a resonance module, a second adjustment module, and a controller, wherein the first adjustment module is configured to The battery module adjusts the frequency of the input signal of the DCDC converter when charging, or is used to rectify the output signal of the resonant module when the battery module discharges to the outside; the resonant module is used for external Resonating the output signal of the first adjustment module when charging the battery module of the vehicle, or for resonating the output signal of the second adjustment module when the battery module discharges to the outside; a second adjustment module, configured to adjust a frequency of an output signal of the battery module when the battery module of the vehicle discharges to the outside, or to output an output signal of the resonant module when the battery module is externally charged a controller, the controller is connected to a control end of the first adjustment module, and the controller is also coupled to the second adjustment mode A control terminal connected to a signal controller according to the charging and discharging of the battery module of the first regulating module and the second adjustment module is controlled to charge and discharge the battery module.

According to the DCDC converter of the embodiment of the present disclosure, the resonant module is added to provide a larger power than the conventional bidirectional full-bridge DCDC converter, and the structure is simple, and is more suitable for a high-power product, compared with the ordinary three-phase interleaved LLC. The resonant converter can resonate in two directions to achieve bidirectional energy transfer, uniform power distribution, smaller output ripple current, and low cost.

In order to achieve the above object, an in-vehicle charger of a second aspect of the present disclosure includes a three-phase PFC circuit and the DCDC converter.

According to the in-vehicle charger of the embodiment of the present disclosure, by using the DCDC converter of the embodiment of the above aspect, conversion of more power can be realized, the cost is low, and the output ripple current is small.

In order to achieve the above object, an electric vehicle according to an embodiment of the third aspect of the present disclosure includes the above-described in-vehicle charger.

According to the electric vehicle of the embodiment of the present disclosure, by installing the in-vehicle charger 1000 of the above-described embodiment, it is possible to realize conversion of more power and improve charge and discharge performance of the battery module.

DRAWINGS

1 is a circuit topology diagram of a typical two-way vehicle charger in the related art;

2 is a topological schematic diagram of a three-module parallel bidirectional DCDC circuit in the related art;

3 is a block diagram of a DCDC converter in accordance with an embodiment of the present disclosure;

4 is a circuit topology diagram of a DCDC converter in accordance with an embodiment of the present disclosure;

5 is a schematic diagram of an output ripple current waveform of a DCDC converter, in accordance with an embodiment of the present disclosure;

6 is a circuit topology diagram of a DCDC converter in accordance with an embodiment of the present disclosure;

7 is a schematic diagram of an output simulation waveform for the circuit structure of FIG. 6;

8 is a block diagram of an in-vehicle charger in accordance with an embodiment of the present disclosure;

9 is a block diagram of an electric vehicle in accordance with an embodiment of the present disclosure.

detailed description

The embodiments of the present disclosure are described in detail below, and the examples of the embodiments are illustrated in the drawings, wherein the same or similar reference numerals are used to refer to the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are illustrative, and are not intended to be construed as limiting.

Embodiments of the present disclosure are based on the inventors' knowledge and research on the following issues:

1 is a circuit topology diagram of a typical two-way vehicle charger in the related art. For the scheme shown in FIG. 1, since the IGBT module allows a lower operating frequency, a larger volume of magnetic components is required, which may result in The volume and weight of the product are greatly increased, and at the same time, the shock resistance of the large-sized magnetic device is poor. Electric vehicles have strict requirements on the weight and space of the whole vehicle, which determines that the car charger must be a small size, high power density and high reliability products. This solution is not suitable for high-power car chargers.

2 is a schematic diagram of a topology of a three-module parallel bidirectional DCDC circuit in the related art. For the scheme shown in FIG. 2, more modules are connected in parallel and the like, and there are some problems in paralleling multiple modules. For example, the cost of the device is high, and each module needs to be independent. The voltage, current sampling and drive control circuit have large redundancy, and the cost and volume are difficult to optimize. For example, the output ripple current is still difficult to solve. In order to reduce the ripple current, each module still needs a large filter capacitor. Of course, there are also multiple independent modules that phase interleaving to reduce ripple current, but also need different module time to work together. It needs to have master-slave settings and high coordination requirements, which puts high requirements on system hardware circuit design and software algorithms.

A DCDC converter according to an embodiment of the present disclosure will be described below with reference to the accompanying drawings.

3 is a block diagram of a DCDC converter according to an embodiment of the present disclosure. As shown in FIG. 3, the DCDC converter 100 of the embodiment of the present disclosure includes a first adjustment module 10, a resonance module 20, a second adjustment module 30, and a controller 40. .

The first adjustment module 10 is configured to adjust the frequency of the input signal of the DCDC converter 100 to adjust the impedance of the resonant module 20 when the battery module of the vehicle is externally charged, where the external environment may be a power grid or other power supply device. For example, the power grid charges the battery module; or, when the battery module discharges to the outside, where the external environment can be an electrical load, for example, the battery module discharges the electrical load, and the output signal of the resonant module 20 is rectified and filtered. Backend load. The battery module may be a power battery, and the external device is a device, a device, or the like that can be charged and discharged with the battery module, and is not specifically limited in the embodiment of the present disclosure.

The resonance module 20 is configured to resonate the output signal of the first adjustment module 10 to generate a high-frequency resonance current when the battery module of the vehicle is externally charged, or to the second adjustment module 30 when the battery module discharges to the outside. The output signal resonates to produce a high frequency resonant current.

The second adjusting module 30 is configured to adjust the frequency of the output signal of the battery module to adjust the impedance of the resonant module 20 when the battery module of the vehicle discharges to the outside, or to adjust the impedance of the resonant module 20 when the battery module is externally charged. The output signal is rectified, and the high-frequency resonant current is changed to direct current to be supplied to the battery module to charge the battery module.

The controller 40 is connected to the control end of the first adjustment module 10, and the controller 40 is also connected to the control end of the second adjustment module 30. The controller 40 is configured to pair the first adjustment module 10 and the second according to the charge and discharge signals of the battery module. The adjustment module 30 performs control to charge the battery module or discharge the battery module to the outside. The charge and discharge signal of the battery module includes a charging signal and a discharge signal of the battery module.

According to the DCDC converter 100 of the embodiment of the present disclosure, the resonant module 20 is added to provide a larger power than the conventional bidirectional full-bridge DCDC converter, and the structure is simple, and is more suitable for a high-power product than the ordinary three-phase. The interleaved LLC resonant converter, the resonant module 20 can resonate bidirectionally, realizes energy bidirectional transmission, and has uniform power distribution, smaller output ripple current, and low cost.

In an embodiment of the present disclosure, the resonance module 20 may include N primary LC cells, N phase transformation cells, and N secondary LC cells. Where N is a positive integer greater than 1, for example, N may be 2, 3, 4, or the like. In order to facilitate the description of the present disclosure, in the following embodiments, N is equal to 3 as an example for description.

4 is a circuit topology diagram of a DCDC converter according to an embodiment of the present disclosure. As shown in FIG. 4, the resonance module 20 includes three primary LC units 21, a three-phase transformer unit 22, and three secondary units. LC unit 23.

When the battery module is externally charged, the three primary LC units 21 and the three-phase transformer unit 22 are used to resonate the output signal of the first adjustment module 10 to generate a high-frequency current, and the high-frequency current passes through the second adjustment module 30. After rectification and filtering, it becomes DC power, and can be supplied to the battery module of the vehicle to realize charging of the battery module; when the battery module discharges to the outside, the three-way secondary LC unit 23 and the three-phase transformer unit 22 are used for the second adjustment. The output signal of the module 30 resonates to generate a high-frequency current, and the high-frequency current is rectified and filtered by the first adjustment module 10 to become a direct current, and the direct current can be supplied to subsequent components for processing, thereby powering the load to realize the battery module of the vehicle. Discharge.

In some embodiments of the present disclosure, as shown in FIG. 4, the first adjustment module 10 includes a first three-phase bridge circuit, and the second adjustment module 30 includes a second three-phase bridge circuit, wherein each of the primary LC units 21 One end is connected to a phase connection point of a corresponding phase bridge arm of the first three-phase bridge circuit 10, and the same end of the primary coil of the three-phase transformer unit 22 is respectively connected to the other end of the corresponding primary LC unit 21, and the three-phase transformer unit The synonyms of the primary coils of 22 are joined together to form a Y-connection. The same-name ends of the secondary coils of the three-phase transformer unit 22 are respectively connected to one ends of the corresponding secondary LC units 23, and the different-name ends of the secondary coils of the three-phase transformer unit 22 are connected together to form a Y-type connection. The Y-type connection method is beneficial to the automatic current sharing of the three-phase bridge circuit, and avoids uneven power distribution due to device parameter deviation of the three-phase bridge circuit.

The phase line connection point of each phase leg of the second three-phase bridge circuit 30 is connected to the other end of the corresponding secondary LC unit 23.

The controller 40 is respectively connected to the control end of the switch tube of the first three-phase bridge circuit 10 and the control end of the switch tube of the second three-phase bridge circuit 30 for the first three-phase according to the charge and discharge signals of the battery module of the vehicle. The switching circuits of the bridge circuit 10 and the second three-phase bridge circuit 30 are controlled to charge and discharge the battery module.

In the embodiment of the present disclosure, the three-phase transformer unit 22 may adopt three independent magnetic cores or may be wound by the same magnetic core.

In an embodiment, when charging the battery module of the vehicle, each primary LC unit 21 and the primary coil of the corresponding transformer unit 22 may constitute a corresponding input resonant cavity, and the controller 40 performs the first three-phase bridge circuit 10. The high frequency resonance control and the rectification control of the second three-phase bridge circuit 30, the first three-phase bridge circuit 10 and the three primary LC units 21 and the primary coil of the three-phase transformer unit 22 form a three-phase interleaved LLC to operate at a high frequency The resonant state outputs a high-frequency current, and the high-frequency current is rectified by the second three-phase bridge circuit 30 to become a direct current output, which can charge the entire vehicle battery module of the electric vehicle.

When the battery module of the vehicle is discharged, each secondary LC unit 23 and the secondary coil of the corresponding transformer unit 22 may constitute a corresponding input resonant cavity, and the controller 40 performs high frequency resonance control on the second three-phase bridge circuit 30. And performing rectification control on the first three-phase bridge circuit 10, the second three-phase bridge circuit 10 and the three-way secondary LC unit 23 and the secondary coil of the three-phase transformer unit 22 form a three-phase interleaved LLC to operate in a high-frequency resonance state And outputting a high-frequency current, which is rectified by the first three-phase bridge circuit 10 to become a direct current output, and discharge of the battery module can be realized.

According to the DCDC converter 100 of the embodiment of the present disclosure, the output ripple current is small, as shown in FIG. 5, P1 is an ordinary full-bridge circuit output ripple current curve, and P2 is an output ripple current curve of the structure of the present application, which is compared with a common full-bridge circuit. Comparing, under the condition of the same output current I ₀ , the ordinary full-bridge circuit outputs ripple current I _ripple = πI ₀ /2=1.57I ₀ , and based on the circuit of the present application, the output ripple current is

Obviously, the output ripple current is smaller, and the smaller ripple current is more conducive to saving the output filter capacitor.

According to the DCDC converter 100 of the embodiment of the present disclosure, the resonant unit is added to the primary secondary side of the transformer unit to form a three-phase resonant full bridge, which can provide more power, simple structure and more than the ordinary bidirectional full-bridge DCDC converter. Applicable to high-power products, compared with the ordinary three-phase interleaved LLC resonant converter, the secondary side of the transformer unit adds a resonant unit, which can realize bidirectional resonance, realize energy bidirectional transmission, uniform power distribution, and smaller output ripple current. ,low cost.

The respective units of the present disclosure and their connection relationships will be further described below with reference to the accompanying drawings. Wherein, the first three-phase bridge circuit 10 and the second three-phase bridge circuit 30 may be constituted by a switching tube such as a MOS tube or an IGBT or other components to form a three-phase bridge structure, the LC unit may include a capacitor and an inductor, and the transformer unit may be a transformer structure achieve.

In some embodiments of the present disclosure, as shown in FIG. 4, the first three-phase bridge circuit 10 includes a first one-phase bridge arm, a first two-phase bridge arm, and a first three-phase bridge arm. The first phase bridge arm includes a first switch tube Q1 and a second switch tube Q2. One end of the first switch tube Q1 is connected to one end of the second switch tube Q2, and one end of the first switch tube Q1 and the second switch tube Q2 There is a first phase line connection point Z1 between one end; the first two-phase bridge arm includes a third switch tube Q3 and a fourth switch tube Q4, one end of the third switch tube Q3 is connected to one end of the fourth switch tube Q4, and the third A second phase line connection point Z2 is formed between one end of the switch tube Q3 and one end of the fourth switch tube Q4; the first three bridge arm includes a fifth switch tube Q5 and a sixth switch tube Q6, and one end of the fifth switch tube Q5 is One end of the sixth switch tube Q6 is connected, and one end of the fifth switch tube Q5 and one end of the sixth switch tube Q6 have a third phase line connection point Z3; the other end of the first switch tube Q1 and the third switch tube Q3 The other end is connected to the other end of the fifth switching transistor Q5 to form a first end point S11 of the first three-phase bridge circuit, the other end of the second switching tube Q2, the other end of the fourth switching tube Q4, and the sixth switch The other ends of the tube Q6 are connected together to form a second end point S12 of the first three-phase bridge circuit 10, the first end point S11 and Two end points S12 may be connected to other input or output modules.

As shown in FIG. 4, the first three-phase bridge circuit 10 further includes a first capacitor C1. One end of the first capacitor C1 is connected to the first end point S11 of the first three-phase bridge circuit 10, and the other end of the first capacitor C1 is The second terminal S12 of the first three-phase bridge circuit 10 is connected to filter the output or input of the first three-phase bridge circuit 10.

As shown in FIG. 4, the three-way primary LC unit 21 includes a first primary LC unit, a second primary LC unit, and a third primary LC unit. The first primary LC unit includes a second capacitor C2 and a first inductor L1. One end of the second capacitor C2 is connected to the first phase line connection point Z1, and the other end of the second capacitor C2 is connected to one end of the first inductor L1. The other end of the inductor L1 is connected to the same end of the primary coil of the corresponding phase shifting unit 22; the second primary LC unit includes a third capacitor C3 and a second inductor L2, and one end of the third capacitor C3 is connected to the second phase line Z2 Connected, the other end of the third capacitor C3 is connected to one end of the second inductor L2, the other end of the second inductor L2 is connected to the same end of the primary coil of the corresponding phase shifting unit 22; the third primary LC unit includes a fourth capacitor C4. Connected to the third inductor L3, one end of the fourth capacitor C4 is connected to the third phase line connection point Z3, the other end of the fourth capacitor C4 is connected to one end of the third inductor L3, and the other end of the third inductor L3 is corresponding to the phase change. The same name end of the primary coil of the press unit 22 is connected.

In the embodiment of the present disclosure, as shown in FIG. 4, the three-phase transformation unit 22 includes a first phase transformation unit T1, a second phase transformation unit T2, and a third phase transformation unit T3.

The first phase transformation unit T1 includes a first primary coil and a first secondary coil, and the same end of the first primary coil is connected to the other end of the first inductor L1, and the same name end of the first secondary coil and the corresponding secondary One end of the LC unit 23 is connected; the second phase transforming unit T2 includes a second primary coil and a second secondary coil, the same end of the second primary coil is connected to the other end of the second inductor L2, and the second secondary coil has the same name The end is connected to one end of the corresponding secondary LC unit 23; the third phase transforming unit T3 includes a third primary coil and a third secondary coil, and the same end of the third primary coil is connected to the other end of the third inductor L3, and the third The same-name end of the secondary coil is connected to one end of the corresponding secondary LC unit 23; the different-name end of the first primary coil, the different-name end of the second primary coil, and the different-name end of the third primary coil are connected together, for example, to the NP To form a Y-connection, the different end of the first secondary coil, the different end of the second secondary coil, and the different end of the third secondary coil are connected together, for example, to the NS to form a Y-connection. law. By adopting the Y-connection method, the three-phase bridge can be automatically balanced to avoid uneven power distribution due to the parameter deviation of the three-phase bridge device.

As shown in FIG. 4, the second three-phase bridge circuit 30 includes a second one-phase bridge arm, a second two-phase bridge arm, and a second three-phase bridge arm.

The second phase bridge arm includes a seventh switch tube Q7 and an eighth switch tube Q8. One end of the seventh switch tube Q7 is connected to one end of the eighth switch tube Q8, and one end of the seventh switch tube Q7 and the eighth switch tube There is a fourth phase line connection point Z4 between one end of the Q8; the second two-phase bridge arm includes a ninth switch tube Q9 and a tenth switch tube Q10, and one end of the ninth switch tube Q9 is connected to one end of the tenth switch tube Q10, A fifth phase line connection point Z5 is formed between one end of the ninth switch tube Q9 and one end of the tenth switch tube Q10; the second three-phase bridge arm includes an eleventh switch tube Q11 and a twelfth switch tube Q12, the eleventh One end of the switch tube Q11 is connected to one end of the twelfth switch tube Q12, and one end of the eleventh switch tube Q11 and one end of the twelfth switch tube Q12 have a sixth phase line connection point Z6; the seventh switch tube Q7 At the other end, the other end of the ninth switch tube Q9 and the other end of the eleventh switch tube Q11 are connected together to form a first end point S21 of the second three-phase bridge circuit 30, and the other end of the eighth switch tube Q8 The other end of the ten switch tube Q10 and the other end of the twelfth switch tube Q12 are connected together to form a second three-phase The second end 30 of the circuit S22. The first endpoint S21 and the second endpoint S22 can be connected to other modules for input or output.

As shown in FIG. 4, the second three-phase bridge circuit 30 further includes a fifth capacitor C5. One end of the fifth capacitor C5 is connected to the first end point S21 of the second three-phase bridge circuit 30, and the other end of the fifth capacitor C5 is The second end point S22 of the second three-phase bridge circuit 30 is connected. The fifth capacitor C5 can filter the output or input of the second three-phase bridge circuit 30.

In some embodiments of the present disclosure, as shown in FIG. 4, the three-way secondary LC unit 23 includes a first secondary LC unit, a second secondary LC unit, and a third secondary LC unit.

The first secondary LC unit includes a fourth inductor L4 and a sixth capacitor C6. One end of the fourth inductor L4 is connected to the same end of the first secondary coil, and the other end of the fourth inductor L4 and one end of the sixth capacitor C6. Connected, the other end of the sixth capacitor C6 is connected to the fourth phase line connection point Z4; the second secondary LC unit includes a fifth inductor L5 and a seventh capacitor C7, and one end of the fifth inductor L5 has the same name as the second secondary coil The other end of the fifth inductor L5 is connected to one end of the seventh capacitor C7, the other end of the seventh capacitor C7 is connected to the fifth phase line connection point Z5, and the third secondary LC unit includes a sixth inductor L6 and the eighth The capacitor C8, one end of the sixth inductor L6 is connected to the same end of the third coil, the other end of the sixth inductor L6 is connected to one end of the eighth capacitor C8, and the other end of the eighth capacitor C8 is connected to the sixth phase line Z6. Connected.

In some embodiments, the first three-phase bridge circuit 10 is connected to the charging input, and the second three-phase bridge circuit 30 is connected to the battery module of the electric vehicle. For forward charging, the second capacitor C2, the first inductor L1 and the first The primary coil constitutes a resonant cavity of the first one-phase bridge arm, the third capacitor C3, the second inductor L2 and the second primary coil constitute a resonant cavity of the first two-phase bridge arm, a fourth capacitor C4, a third inductor L3 and a third The primary coil constitutes a resonant cavity of the first three-phase bridge arm. Wherein, in some embodiments, the second capacitor C2, the third capacitor C3, and the fourth capacitor C4 are referred to as primary resonant capacitors, and the first inductor L1, the second inductor L2, and the third inductor L3 are referred to as primary resonant inductors.

When the battery module is charged by the outside, each phase bridge arm of the first three-phase bridge arm circuit 10 and its corresponding resonance module form a three-phase interleaved LLC and operate in a high-frequency resonance state, and the controller 40 controls the first switch tube Q1. And the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4, the fifth switch tube Q5 and the sixth switch tube Q6 are respectively alternately switched at a preset duty ratio, for example, 50%, to control the first switch tube Q1. The phase between the third switch tube Q3 and the fifth switch tube Q5 is 120°, respectively, and the phase difference between the second switch tube Q2, the fourth switch tube Q4 and the sixth switch tube Q6 is 120°, and the The two-phase bridge circuit 30 performs rectification control, and the second three-phase bridge circuit 30 functions as a secondary three-phase rectifier bridge. The high-frequency current is rectified by the diode in the switching body of the second three-phase bridge circuit 30, and then converted into direct current and supplied to the DC power. The high-voltage battery module of the whole vehicle, wherein, as shown in FIG. 4 in general, each of the switch tubes includes a diode element, which may be referred to as a switch body diode. If the drive signal is applied to the switching tube of the second three-phase bridge circuit 30, the second three-phase bridge circuit 30 will form a synchronous rectification circuit, further improving product efficiency.

In some embodiments, the first three-phase bridge circuit 10 is connected to the power side, and the second three-phase bridge circuit 30 is connected to the battery module of the electric vehicle. For the reverse discharge, the sixth capacitor C6, the fourth inductor L4, and the A secondary coil constitutes a resonant cavity of the second phase bridge arm, and the seventh capacitor C7, the fifth inductor L5 and the second secondary coil constitute a resonant cavity of the second two-phase bridge arm, and the eighth capacitor C8 and the sixth inductor L6 And the third secondary coil constitutes a resonant cavity of the second three-phase bridge arm. In some embodiments, the sixth capacitor C6, the seventh capacitor C7, and the eighth capacitor C8 are referred to as secondary resonant capacitors, and the fourth inductor L4, the fifth inductor L5, and the sixth inductor L6 are referred to as secondary resonances. inductance.

When the battery module discharges to the outside, each phase bridge arm of the second three-phase bridge arm circuit 30 and its corresponding resonance module form a three-phase interleaved LLC and operate in a high-frequency resonance state, and the controller 40 controls the seventh switch tube Q7. And the eighth switch tube Q8, the ninth switch tube Q9 and the tenth switch tube Q10, the eleventh switch tube Q11 and the twelfth switch tube Q12 are respectively alternately switched at a preset duty ratio, for example, 50%, to control the seventh switch tube Q7, the ninth switch tube Q9 and the eleventh switch tube Q11 have a phase difference of 120°, respectively, and control the phase between the eighth switch tube Q8, the tenth switch tube Q10 and the twelfth switch tube Q12 to be 120° respectively. And rectifying the first three-phase bridge circuit 10, the first three-phase bridge circuit 30 acts as a discharge output three-phase rectifier bridge, and the high-frequency current is converted into a diode in the switching body of the first three-phase bridge circuit 30, and then converted into The direct current is supplied to the module on the power output side. If the drive signal is applied to the switch tube of the first three-phase bridge circuit 10, the first three-phase bridge circuit 10 will form a synchronous rectification circuit to further improve product efficiency.

The following is an example of a 20KW three-phase interleaved LLC bidirectional DCDC converter. Among them, the design requirements are: the input voltage and output voltage rating of the DCDC converter are both 750V, and the full load power in both the charging direction and the discharging direction is 20KW. For the cavity parameter setting: since the forward charging voltage and the power are equal, the resonant cavity corresponding to the first three-phase bridge circuit 10, for example, the resonant cavity of the primary resonant cavity and the corresponding second three-phase bridge circuit 30 is called, for example. The parameters of the secondary resonator are the same. Assuming that the resonant frequency of the circuit is 150KHZ, according to the relevant calculation formula of the three-phase interleaved LLC circuit, the primary resonant capacitor C2=C3=C4=secondary resonant capacitor C5=C6=C7=80nF, primary Resonant inductance L1=L2=L3=Secondary resonant inductance L4=L5=L6=14μH, three-phase transformer unit 22匝 ratio T1=T2=T3=1:1, the inductance of the primary coil of the three-phase transformer unit 22 T _1-1 =T _2-1 =T _3-1 = Sensitivity of the secondary coil = T _1-2 = T _2-2 = T _3-2 = 70 μH, depending on current, voltage requirements, and heat dissipation requirements It is considered that the switch tubes Q1-Q12 are 1200V/40mΩ silicon oxide MOS (metal oxide semiconductor) tubes, as shown in FIG. 6 . Fig. 7 is a simulation waveform diagram of an output waveform based on the circuit configuration of the DCDC converter shown in Fig. 6, in which the output current has a maximum value of 28 A, a peak value of 56 A, a switching frequency of 150 kHz, and a load of 20 kW.

In the DCDC converter 100 of the embodiment of the present disclosure, compared with the ordinary bidirectional full-bridge DCDC converter, the primary transformer side and the secondary transformer side each add a resonance unit, thereby forming a three-phase resonance full bridge, and the operating frequency of each phase is uniform. The phase is shifted by 120°; compared with the ordinary three-phase full-bridge DCDC converter, three resonant units are added on the transformer secondary side, and the second three-phase bridge circuit 30 uses a controllable switch. Among them, bidirectional resonance can realize bidirectional transmission of energy, and bidirectional transmission works in soft switching mode; forming a three-phase interleaved LLC can realize greater power conversion, and can save power switching tube compared with ordinary three-phase interleaved LLC, and The three-phase transformer unit 22 adopts a Y-connection method, which can realize automatic current sharing of the three-phase bridge circuit, avoid uneven power distribution, and the circuit structure of the DCDC converter 100 based on the embodiment of the present disclosure, and the output ripple current is more Smaller, smaller ripple currents save output filter capacitors, which is more conducive to cost reduction and product size reduction.

Based on the DCDC converter of the embodiment of the above aspect, an in-vehicle charger according to an embodiment of the present disclosure will be described below with reference to the drawings.

8 is a block diagram of an in-vehicle charger according to an embodiment of the present disclosure. As shown in FIG. 8, the in-vehicle charger 1000 of the embodiment of the present disclosure includes a three-phase PFC circuit 200 and the DCDC converter 100 of the above embodiment, a three-phase PFC circuit. 200 functions as a power factor correction. The DCDC converter 100 implements controllable isolated transmission of energy. The specific structure and operation of the DCDC converter 100 are described with reference to the above embodiments.

According to the in-vehicle charger 100 of the embodiment of the present disclosure, by employing the DCDC converter 100 of the above-described embodiment, conversion of more power can be realized with low cost and small output ripple current.

9 is a block diagram of an electric vehicle according to an embodiment of the present disclosure. As shown in FIG. 9, an electric vehicle 10000 of an embodiment of the present disclosure includes the in-vehicle charger 1000 of the above-described embodiment.

According to the electric vehicle 10000 of the embodiment of the present disclosure, by installing the in-vehicle charger 1000 of the above-described embodiment, it is possible to realize conversion of more power and improve charge and discharge performance of the battery module.

In the description of the present specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like means a specific feature described in connection with the embodiment or example. A structure, material, or feature is included in at least one embodiment or example of the present disclosure. In the present specification, the schematic representation of the above terms is not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, various embodiments or examples described in the specification, as well as features of various embodiments or examples, may be combined and combined.

While the embodiments of the present disclosure have been shown and described above, it is understood that the foregoing embodiments are illustrative and are not to be construed as limiting the scope of the disclosure The embodiments are subject to variations, modifications, substitutions and variations.

Claims

A DCDC converter, comprising: a first adjustment module, a resonance module, a second adjustment module, and a controller, wherein

The first adjustment module is configured to adjust a frequency of an input signal of the DCDC converter when the battery module of the vehicle is externally charged, or for outputting the resonance module when the battery module discharges to the outside Signal rectification;

The resonance module is configured to resonate an output signal of the first adjustment module when the battery module of the vehicle is externally charged, or for the second adjustment module when the battery module discharges to the outside The output signal is resonant;

The second adjustment module is configured to adjust a frequency of an output signal of the battery module when the battery module of the vehicle discharges to the outside, or to use the resonance module when the battery module is externally charged The output signal is rectified;

a controller, the controller is connected to a control end of the first adjustment module, the controller is also connected to a control end of the second adjustment module, and the controller is configured to be based on a charge and discharge signal of the battery module The first adjustment module and the second adjustment module are controlled to charge the battery module or the battery module discharges to the outside.
The DCDC converter of claim 1 wherein said resonant module comprises N primary LC cells, N phase transformer cells, and N secondary LC cells, wherein N is a positive integer greater than one.
The DCDC converter according to claim 1 or 2, wherein the resonance module comprises three primary LC units, three-phase transformer units, and three secondary LC units, wherein

The three-way primary LC unit and the three-phase transformer unit are configured to resonate an output signal of the first adjustment module to generate a high-frequency current when the battery module is externally charged;

The three-way secondary LC unit and the three-phase transformer unit are configured to resonate an output signal of the second adjustment module to generate a high-frequency current when the battery module discharges to the outside.
The DCDC converter according to claim 3, wherein the first adjustment module comprises a first three-phase bridge circuit, and the second adjustment module comprises a second three-phase bridge circuit, wherein

One end of each primary LC unit is connected to a phase connection point of a corresponding phase bridge arm of the first three-phase bridge circuit, and the same end of the primary coil of the three-phase transformer unit is respectively connected with the other end of the corresponding primary LC unit Connected, the synonyms of the primary coils of the three-phase transformer unit are connected together, and the same-name ends of the secondary coils of the three-phase transformer unit are respectively connected to one end of the corresponding secondary LC unit, and the three-phase change The different ends of the secondary coils of the pressing unit are connected together;

a phase line connection point of each phase bridge arm of the second three-phase bridge circuit is connected to another end of the corresponding secondary LC unit;

The controller is respectively connected to a control end of the switch tube of the first three-phase bridge circuit and a control end of the switch tube of the second three-phase bridge circuit.
The DCDC converter of claim 4 wherein said first three phase bridge circuit comprises:

a first one-phase bridge arm, the first one-phase bridge arm circuit includes a first switch tube and a second switch tube, and one end of the first switch tube is connected to one end of the second switch tube, the first a first phase line connection point between one end of the switch tube and one end of the second switch tube;

a first two-phase bridge arm, the first two-phase bridge arm includes a third switch tube and a fourth switch tube, one end of the third switch tube is connected to one end of the fourth switch tube, and the third switch a second phase line connection point between one end of the tube and one end of the fourth switch tube;

a first three-phase bridge arm, the first three-bridge arm includes a fifth switch tube and a sixth switch tube, one end of the fifth switch tube is connected to one end of the sixth switch tube, and the fifth switch tube a third phase line connection point between one end of the sixth switch tube and one end of the sixth switch tube;

The other end of the first switch tube, the other end of the third switch tube, and the other end of the fifth switch tube are connected together to form a first end point of the first three-phase bridge circuit, The other end of the second switch, the other end of the fourth switch, and the other end of the sixth switch are coupled together to form a second end of the first three-phase bridge circuit.
The DCDC converter of claim 5, wherein the first three-phase bridge circuit further comprises:

a first capacitor, one end of the first capacitor is connected to a first end of the first three-phase bridge circuit, and the other end of the first capacitor is connected to a second end of the first three-phase bridge circuit.
A DCDC converter according to claim 5 or claim 6, wherein said three-way primary LC unit comprises:

a first primary LC unit, the first primary LC unit includes a second capacitor and a first inductor, one end of the second capacitor is connected to the first phase line connection point, and the other end of the second capacitor is One end of the first inductor is connected, and the other end of the first inductor is connected to the same end of the primary coil of the corresponding phase transformer unit;

a second primary LC unit, the second primary LC unit includes a third capacitor and a second inductor, one end of the third capacitor is connected to the second phase line connection point, and the other end of the third capacitor is One end of the second inductor is connected, and the other end of the second inductor is connected to the same end of the primary coil of the corresponding phase transformer unit;

a third primary LC unit, wherein the third primary LC unit includes a fourth capacitor connected to the third inductor, one end of the fourth capacitor is connected to the third phase line connection point, and the other end of the fourth capacitor is One end of the third inductor is connected, and the other end of the third inductor is connected to the same end of the primary coil of the corresponding phase transformer unit.
The DCDC converter of claim 7 wherein said three-phase transformer unit comprises:

a first phase transformation unit, the first phase transformation unit includes a first primary coil and a first secondary coil, and a same end of the first primary coil is connected to another end of the first inductor, the first The same name end of a secondary coil is connected to one end of the corresponding secondary LC unit;

a second phase transformation unit, the second phase transformation unit includes a second primary coil and a second secondary coil, and the same end of the second primary coil is connected to the other end of the second inductor, the first The same name end of the second secondary coil is connected to one end of the corresponding secondary LC unit;

a third phase transformation unit, the third phase transformation unit includes a third primary coil and a third secondary coil, the same end of the third primary coil being connected to the other end of the third inductor, the first The same name end of the three secondary coils is connected to one end of the corresponding secondary LC unit;

a different end of the first primary coil, a different end of the second primary coil, and a different end of the third primary coil are connected together, the different end of the first secondary coil, the The opposite end of the second secondary coil is coupled to the opposite end of the third secondary coil.
The DCDC converter of claim 8 wherein said second three phase bridge circuit comprises:

a second phase bridge arm, the second one phase bridge arm includes a seventh switch tube and an eighth switch tube, and one end of the seventh switch tube is connected to one end of the eighth switch tube, and the seventh switch a fourth phase line connection point between one end of the tube and one end of the eighth switch tube;

a second two-phase bridge arm, the second two-phase bridge arm includes a ninth switch tube and a tenth switch tube, one end of the ninth switch tube is connected to one end of the tenth switch tube, and the ninth switch a fifth phase line connection point between one end of the tube and one end of the tenth switch tube;

a second three-phase bridge arm, the second three-phase bridge arm includes an eleventh switch tube and a twelfth switch tube, one end of the eleventh switch tube is connected to one end of the twelfth switch tube, a sixth phase line connection point between one end of the eleventh switch tube and one end of the twelfth switch tube;

The other end of the seventh switch tube, the other end of the ninth switch tube and the other end of the eleventh switch tube are connected together to form a first end point of the second three-phase bridge circuit. The other end of the eighth switch tube, the other end of the tenth switch tube, and the other end of the twelfth switch tube are connected together to form a second end point of the second three-phase bridge circuit.
The DCDC converter of claim 9 wherein said second three-phase bridge circuit further comprises:

And a fifth capacitor, one end of the fifth capacitor is connected to the first end of the second three-phase bridge circuit, and the other end of the fifth capacitor is connected to the second end of the second three-phase bridge circuit.
The DCDC converter of claim 9 or 10, wherein the three secondary LC units comprise:

a first secondary LC unit, the first secondary LC unit includes a fourth inductor and a sixth capacitor, one end of the fourth inductor being connected to a same end of the first secondary coil, the fourth inductor The other end is connected to one end of the sixth capacitor, and the other end of the sixth capacitor is connected to the fourth phase line connection point;

a second secondary LC unit, the second secondary LC unit includes a fifth inductor and a seventh capacitor, one end of the fifth inductor being connected to a same end of the second secondary coil, the fifth inductor The other end is connected to one end of the seventh capacitor, and the other end of the seventh capacitor is connected to the fifth phase line connection point;

a third secondary LC unit, the third secondary LC unit includes a sixth inductor and an eighth capacitor, one end of the sixth inductor is connected to the same end of the third coil, and the sixth inductor is One end is connected to one end of the eighth capacitor, and the other end of the eighth capacitor is connected to the sixth phase line connection point.
The DCDC converter according to claim 11, wherein said controller switches said first three-phase bridge circuit and said second three-phase bridge circuit according to a charge and discharge signal of a battery module of the vehicle Control is used,

Controlling the first switch tube and the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, and the sixth switch tube when charging the battery module Switching between the first switch tube, the third switch tube and the fifth switch tube by a switch of 120°, respectively controlling the second switch tube by the preset duty ratio a phase difference between the fourth switch tube and the sixth switch tube is 120°, and the second three-phase bridge circuit is rectified and controlled;

Controlling the seventh switch tube and the eighth switch tube, the ninth switch tube and the tenth switch tube, the eleventh switch tube, and the twelfth when the battery module discharges to the outside The switch tubes are respectively alternately switched at a preset duty ratio, and the phase difference between the seventh switch tube, the ninth switch tube and the eleventh switch tube is controlled by 120°, and the eighth switch tube is controlled. And a phase difference between the tenth switch tube and the twelfth switch tube is 120°, and the first three-phase bridge circuit is rectified and controlled.
An in-vehicle charger comprising a three-phase PFC circuit and a DCDC converter according to any of claims 1-12.
An electric vehicle comprising the on-board charger of claim 13.