阅读说明：本技术 一种功能集成式车载充电机及其工作方法 (Function integrated type vehicle-mounted charger and working method thereof ) 是由 方向 陈勇 于 2020-12-01 设计创作，主要内容包括：本发明公开了一种功能集成式车载充电机及其工作方法,包括交直流切换电路、EMI滤波电路、整流桥开关电路、Boost升压电路、全桥LLC高压直流变换电路以及半桥LLC低压直流变换电路,交直流切换电路、EMI滤波电路、整流桥开关电路以及Boost升压电路顺次连接,全桥LLC高压直流变换电路分别与交直流切换电路以及Boost升压电路连接,半桥LLC低压直流变换电路与Boost升压电路连接,动力电池E1与全桥LLC高压直流变换电路连接,低压端E2与半桥LLC低压直流变换电路连接；本发明的优点在于：实现多种工作模式的功率变换控制,且集成度较高,体积和成本相对较低。(The invention discloses a functional integrated vehicle-mounted charger and a working method thereof, and the functional integrated vehicle-mounted charger comprises an alternating current-direct current switching circuit, an EMI filter circuit, a rectifier bridge switch circuit, a Boost circuit, a full-bridge LLC high-voltage direct current conversion circuit and a half-bridge LLC low-voltage direct current conversion circuit, wherein the alternating current-direct current switching circuit, the EMI filter circuit, the rectifier bridge switch circuit and the Boost circuit are sequentially connected; the invention has the advantages that: the power conversion control of multiple working modes is realized, the integration level is high, and the volume and the cost are relatively low.)

1. A functional integrated vehicle-mounted charger is characterized by comprising an AC/DC switching circuit, an EMI filter circuit, a rectifier bridge switch circuit, a Boost circuit, a full-bridge LLC high-voltage direct-current conversion circuit and a half-bridge LLC low-voltage direct-current conversion circuit, wherein the AC/DC switching circuit, the EMI filter circuit, the rectifier bridge switch circuit and the Boost circuit are sequentially connected, the full-bridge LLC high-voltage direct-current conversion circuit is respectively connected with the AC/DC switching circuit and the Boost circuit, the half-bridge LLC low-voltage direct-current conversion circuit is connected with the Boost circuit, a power battery E35 1 is connected with the full-bridge LLC high-voltage direct-current conversion circuit, and a low-voltage end E2 is connected with the half-bridge LLC low-voltage;

when the electric automobile is in an alternating current charging mode, a power grid supplies power to a power battery E1 and a low-voltage end E2, and a Boost circuit plays a role of a power factor correction circuit to realize alternating current-direct current conversion; when the electric automobile is in a driving mode, the power battery E1 is adopted to supply power to the low-voltage end E2, and the Boost conversion circuit plays a role of a DC-DC conversion circuit to realize direct-current boosting.

2. The vehicle-mounted charger according to claim 1, wherein the ac/dc switching circuit comprises a switch S1-1, a switch S1-2, a switch S2-1 and a switch S2-2, one end of the switch S1-1 is connected to one end of an ac source VS, one end of the switch S1-2 is connected to the other end of the ac source VS, one end of the switch S2-1 and one end of the switch S2-2 are both connected to a full-bridge LLC high-voltage dc conversion circuit, the other end of the switch S1-1 and the other end of the switch S2-1 share a contact a, and the other end of the switch S1-2 and the other end of the switch S2-2 share a contact B.

3. The vehicle-mounted charger with integrated functions according to claim 2, characterized in that the EMI filter circuit comprises a capacitor X1, a capacitor X2 and an inductor T3, the inductor T3 comprises a primary winding T31 and a secondary winding T32, one end of the capacitor X1 is connected with one end of the contact A and one end of the primary winding T31 respectively, and the other end of the capacitor X1 is connected with one end of the contact B and one end of the secondary winding T32 respectively; one end of the capacitor X2 is connected to the other end of the rectifier bridge switching circuit and the primary winding T31, and the other end of the capacitor X2 is connected to the other end of the rectifier bridge switching circuit and the secondary winding T32.

4. The vehicle-mounted charger according to claim 3, wherein the rectifier bridge switching circuit comprises a switch S3-1, a switch S3-2 and a rectifier bridge Br, one ac input end of the rectifier bridge Br serves as a first contact of the switch S3-1, an output positive end of the rectifier bridge Br serves as a second contact of the switch S3-1, the other ac input end of the rectifier bridge Br serves as a first contact of the switch S3-2, an output negative end of the rectifier bridge Br serves as a second contact of the switch S3-2, one end of a capacitor X2 is connected with a third contact of the switch S3-1, and the other end of the capacitor X2 is connected with a third contact of the switch S3-2.

5. The vehicle-mounted charger according to claim 4, wherein the Boost voltage Boost circuit comprises an inductor L1, an inductor L2, a MOS transistor Q1, a MOS transistor Q2, a capacitor C1, a diode D1 and a diode D2, one end of the inductor L1 and one end of the inductor L2 are both connected with an output positive terminal of the rectifier bridge Br, one end of the capacitor C1, a drain of the MOS transistor Q1 and a drain of the MOS transistor Q2 are both connected with an output negative terminal of the rectifier bridge Br, the other end of the inductor L1 is respectively connected with an anode of the diode D1 and a source of the MOS transistor Q2, and the other end of the inductor L2 is respectively connected with an anode of the diode D2 and a source of the MOS transistor Q1; the other end of the capacitor C1 is connected to the cathode of the diode D1 and the cathode of the diode D2, respectively.

6. The vehicle-mounted charger with integrated functions according to claim 5, characterized in that, the full-bridge LLC high-voltage direct-current conversion circuit comprises an MOS tube Q3, an MOS tube Q4, an MOS tube Q5, an MOS tube Q6, a resonant inductor Lr1, a resonant capacitor Cr1, a converter T1, a capacitor C2, a diode D3 and a diode D4, the converter T1 comprises a primary winding T11, a secondary winding T12 and a secondary winding T13, the source electrode of the MOS transistor Q3 and the source electrode of the MOS transistor Q5 are both connected with the cathode of the diode D1, the drain electrode of the MOS tube Q4 and the drain electrode of the MOS tube Q6 are connected with one end of a capacitor C1, the drain electrode of the MOS tube Q3, the source electrode of the MOS tube Q4 and one end of a resonant inductor Lr1 are connected, the drain electrode of the MOS tube Q5, the source electrode of the MOS tube Q6, the other end of the resonant inductor Lr1, one end of a resonant capacitor Cr1 and one end of a primary winding T11 are connected, and the other end of the resonant capacitor Cr1 is connected with the other end of the primary winding T11; the dotted terminal of the secondary winding T12 is connected with the anode of the diode D3, the dotted terminal of the secondary winding T12 is connected with the dotted terminal of the secondary winding T13, the dotted terminal of the secondary winding T13 is connected with the anode of the diode D4, one end of the capacitor C2 is connected with the cathode of the diode D3, one end of the switch S2-1 and the cathode of the diode D4, the other end of the capacitor C2 is connected with the dotted terminal of the secondary winding T12 and one end of the switch S2-2, one end of the capacitor C2 is connected with the anode of the power battery E1, and the other end of the capacitor C2 is connected with the cathode of the power battery E1.

7. The vehicle-mounted charger with integrated functions according to claim 6, characterized in that, the half-bridge LLC low-voltage direct-current conversion circuit comprises a capacitor C3, a capacitor C4, a MOS transistor Q7, a MOS transistor Q8, a resonant inductor Lr2, a resonant capacitor Cr2, a resonant capacitor Cr3, a converter T2, a MOS transistor Q9 and a MOS transistor Q10, the inverter T2 includes a primary winding T21, a secondary winding T22, and a secondary winding T23, one end of the capacitor C3 is connected with the cathode of the diode D1, the source of the MOS tube Q7 and one end of the resonant capacitor Cr2 respectively, the other end of the capacitor C3 is connected with one end of the capacitor C1, the drain of the MOS tube Q8 and one end of the resonant capacitor Cr3 respectively, the drain of the MOS tube Q7, the source of the MOS tube Q8 and one end of the resonant inductor Lr2 are connected, the other end of the capacitor Cr2, the other end of the capacitor Cr3 and one end of the primary coil T21 are connected, and the other end of the resonant inductor Lr2 is connected with the other end of the primary coil T21; the dotted terminal of the secondary coil T22 is connected with the source of the MOS tube Q9, the dotted terminal of the secondary coil T22 is connected with the dotted terminal of the secondary coil T23, the dotted terminal of the secondary coil T23 is connected with the source of the MOS tube Q10, one end of a capacitor C4 is connected with the drain of the MOS tube Q9 and the drain of the MOS tube Q10, and the other end of the capacitor C4 is connected with the dotted terminal of the secondary coil T22; one end of the capacitor C4 is connected to the positive electrode of the low voltage terminal E2, and the other end of the capacitor C4 is connected to the negative electrode of the low voltage terminal E2.

8. The working method of the functional integrated vehicle-mounted charger according to any one of claims 1 to 7, it is characterized in that when a power grid is adopted to supply power to a power battery E1 and a low-voltage end E2, when the electric automobile is in an alternating current charging mode, the alternating current and direct current switching circuit is switched to an alternating current input mode, alternating current is converted into direct current through the alternating current and direct current switching circuit, the power battery E1 is charged by the variable DC power supply converted from DC by the post full-bridge LLC high-voltage DC conversion circuit, and the power battery E2 is supplied by the low-voltage DC conversion circuit of the half-bridge LLC after the high-voltage DC is converted into low-voltage DC which is synchronously rectified.

9. The working method of the functional integrated vehicle-mounted charger according to claim 8, characterized in that when a power battery E1 is used for supplying power to a low-voltage end E2, when the electric vehicle is in a driving mode, the AC/DC switching circuit is switched to a DC input mode, DC obtained from the power battery E1 is subjected to DC conversion through an EMI filter circuit, a rectifier bridge switching circuit and a Boost circuit and then is supplied to a half-bridge LLC low-voltage DC conversion circuit, the Boost conversion circuit plays a role of a DC-DC conversion circuit at this time, the half-bridge LLC low-voltage DC conversion circuit converts high-voltage DC into low-voltage DC and supplies power to the low-voltage end E2 after synchronous rectification, and the half-bridge LLC low-voltage DC conversion circuit is supplied with power by the power battery E1 at this time.

10. The working method of the functional integrated vehicle-mounted charger according to claim 8, characterized in that when the power battery E1 or the low-voltage end E2 is charged independently by using a power grid, when the electric vehicle is in an AC charging mode, the AC/DC switching circuit is switched to an AC input mode, and the power battery E1 is charged independently by only starting the full-bridge LLC high-voltage DC conversion circuit and not starting the half-bridge LLC low-voltage DC conversion circuit;

or when the electric automobile is in an alternating current charging mode, the alternating current-direct current switching circuit is switched to an alternating current input mode, and the low-voltage end E2 is charged independently by only starting the half-bridge LLC low-voltage direct current conversion circuit and not starting the full-bridge LLC high-voltage direct current conversion circuit.

Technical Field

The invention relates to the field of electric automobiles, in particular to a functional integrated vehicle-mounted charger and a working method thereof.

Background

In recent years, new energy automobiles become an important development direction of the automobile industry in the future, and after years of development, vehicle-mounted power supply equipment has a development trend of miniaturization, integration and high power. As shown in fig. 1, which is a control schematic diagram of the vehicle-mounted power supply, when the electric vehicle is in an alternating current charging mode, the alternating current source and direct current source switching circuit is switched to an alternating current input mode, alternating current is converted into direct current and is transmitted to the high-voltage direct current conversion circuit, and at the moment, the Boost conversion circuit plays a role of a power factor correction circuit, namely, has a role of the power factor correction circuit, and realizes alternating current-direct current conversion; and when the electric automobile is in a driving mode, the alternating current source and direct current source switching circuit is switched to a direct current input mode, the obtained direct current is subjected to direct current conversion and then is supplied to a low-voltage system, and at the moment, the Boost conversion circuit plays a role of a DC-DC conversion circuit. When the electric automobile is in a driving mode, the low-voltage system is powered by the power battery pack.

The vehicle-mounted charger and the vehicle-mounted DC converter are used as electric energy conversion core components of the electric automobile, the vehicle-mounted power supply mostly works in a discrete module or physical integration mode at present, the size is large, the cost is high, how to integrate the functions of the vehicle-mounted power supply and the vehicle-mounted DC converter together reduces the cost and the size, and the improvement of the reliability of the system is crucial to the development of new energy electric automobiles in the future.

Chinese patent application No. CN201811509577.X discloses an EV vehicle-mounted charger based on a SiC power device, which comprises a main circuit and a control circuit, wherein the main circuit comprises a rectifying and filtering module and an LLC resonant DC-DC circuit; the rectification filter module adopts a totem-pole bridgeless power factor correction circuit structure and is directly connected with a three-phase alternating current input power supply; the LLC resonant DC-DC circuit consists of a first half-bridge LLC converter and a second half-bridge LLC converter which have the same topological structure, and the first half-bridge LLC converter and the second half-bridge LLC converter are connected in parallel and then connected in series between the rectifying and filtering module and the output side; the first half-bridge LLC converter and the second half-bridge LLC converter respectively comprise a half-bridge inversion module, a high-frequency transformation module and a passive rectification filtering module; the rectification filter module and the LLC resonant DC-DC circuit are respectively connected with a control circuit, and the control circuit adopts an average current control mode and a PFM control mode to realize the output of the digital control circuit. The power supply has the advantages of high power output precision, high power density, high reliability and small occupied space. But it can not realize the power conversion control of multiple operation modes, and has low integration level, relatively high volume and cost.

Disclosure of Invention

The technical problem to be solved by the invention is that the existing vehicle-mounted charger can not realize power conversion control of multiple working modes, and has low integration level and relatively high volume and cost.

The invention solves the technical problems through the following technical means: a functional integrated vehicle-mounted charger comprises an AC/DC switching circuit, an EMI filter circuit, a rectifier bridge switch circuit, a Boost circuit, a full-bridge LLC high-voltage direct-current conversion circuit and a half-bridge LLC low-voltage direct-current conversion circuit, wherein the AC/DC switching circuit, the EMI filter circuit, the rectifier bridge switch circuit and the Boost circuit are sequentially connected, the full-bridge LLC high-voltage direct-current conversion circuit is respectively connected with the AC/DC switching circuit and the Boost circuit, the half-bridge LLC low-voltage direct-current conversion circuit is connected with the Boost circuit, a power battery E1 is connected with the full-bridge LLC high-voltage direct-current conversion circuit, and a low-voltage end E2 is connected with the half-bridge LLC low-;

when the electric automobile is in an alternating current charging mode, a power grid supplies power to a power battery E1 and a low-voltage end E2, and a Boost circuit plays a role of a power factor correction circuit to realize alternating current-direct current conversion; when the electric automobile is in a driving mode, the power battery E1 is adopted to supply power to the low-voltage end E2, and the Boost conversion circuit plays a role of a DC-DC conversion circuit to realize direct-current boosting.

According to the invention, according to the electrical topological structure characteristics of the vehicle-mounted charger and the vehicle-mounted DC converter, the front-stage Boost circuit of the vehicle-mounted power supply is multiplexed to realize the functions of an active power factor correction circuit and a DC-DC conversion circuit, the front-stage circuit of the Boost circuit is multiplexed, the rear-stage full-bridge LLC high-voltage DC conversion circuit and the half-bridge LLC low-voltage DC conversion circuit are multiplexed to realize the functions of power conversion control in two working modes, and under the condition of multiplexing devices, the power conversion control in multiple working modes is realized.

Further, the alternating current-direct current switching circuit comprises a switch S1-1, a switch S1-2, a switch S2-1 and a switch S2-2, one end of the switch S1-1 is connected with one end of an alternating current source VS, one end of the switch S1-2 is connected with the other end of the alternating current source VS, one end of the switch S2-1 and one end of the switch S2-2 are connected with the full-bridge LLC high-voltage direct current conversion circuit, the other end of the switch S1-1 and the other end of the switch S2-1 share a contact A, and the other end of the switch S1-2 and the other end of the switch S2-2 share a contact B.

Furthermore, the EMI filter circuit includes a capacitor X1, a capacitor X2, and an inductor T3, where the inductor T3 includes a primary winding T31 and a secondary winding T32, one end of the capacitor X1 is connected to the contact a and one end of the primary winding T31, respectively, and the other end of the capacitor X1 is connected to the contact B and one end of the secondary winding T32, respectively; one end of the capacitor X2 is connected to the other end of the rectifier bridge switching circuit and the primary winding T31, and the other end of the capacitor X2 is connected to the other end of the rectifier bridge switching circuit and the secondary winding T32.

Furthermore, the rectifier bridge switch circuit comprises a switch S3-1, a switch S3-2 and a rectifier bridge Br, wherein one alternating current input end of the rectifier bridge Br is used as a first contact of the switch S3-1, the positive output end of the rectifier bridge Br is used as a second contact of the switch S3-1, the other alternating current input end of the rectifier bridge Br is used as a first contact of the switch S3-2, the negative output end of the rectifier bridge Br is used as a second contact of the switch S3-2, one end of a capacitor X2 is connected with a third contact of the switch S3-1, and the other end of the capacitor X2 is connected with a third contact of the switch S3-2.

Furthermore, the Boost voltage circuit comprises an inductor L1, an inductor L2, a MOS transistor Q1, a MOS transistor Q2, a capacitor C1, a diode D1, and a diode D2, wherein one end of the inductor L1 and one end of the inductor L2 are both connected to the positive output terminal of the rectifier bridge Br, one end of the capacitor C1, the drain of the MOS transistor Q1, and the drain of the MOS transistor Q2 are both connected to the negative output terminal of the rectifier bridge Br, the other end of the inductor L1 is respectively connected to the positive electrode of the diode D1 and the source of the MOS transistor Q2, and the other end of the inductor L2 is respectively connected to the positive electrode of the diode D2 and the source of the MOS transistor Q1; the other end of the capacitor C1 is connected to the cathode of the diode D1 and the cathode of the diode D2, respectively.

Furthermore, the full-bridge LLC high-voltage direct-current conversion circuit comprises a MOS transistor Q3, a MOS transistor Q4, a MOS transistor Q5, a MOS transistor Q6, a resonant inductor Lr1, a resonant capacitor Cr1, a converter T1, a capacitor C2, a diode D3, and a diode D4, wherein the converter T4 comprises a primary winding T4, a secondary winding T4, and a secondary winding T4, a source of the MOS transistor Q4 and a source of the MOS transistor Q4 are both connected to a negative electrode of the diode D4, a drain of the MOS transistor Q4 and a drain of the MOS transistor Q4 are both connected to one end of the capacitor C4, a drain of the MOS transistor Q4, a source of the MOS transistor Q4 and one end of the resonant inductor Lr 4, a drain of the MOS transistor Q4, a source of the MOS transistor Q4, the other end of the resonant inductor l 4, one end of the resonant capacitor Cr 4 and one end of the primary winding T4, and the other end of the resonant capacitor Cr 4 are connected to the primary winding T4; the dotted terminal of the secondary winding T12 is connected with the anode of the diode D3, the dotted terminal of the secondary winding T12 is connected with the dotted terminal of the secondary winding T13, the dotted terminal of the secondary winding T13 is connected with the anode of the diode D4, one end of the capacitor C2 is connected with the cathode of the diode D3, one end of the switch S2-1 and the cathode of the diode D4, the other end of the capacitor C2 is connected with the dotted terminal of the secondary winding T12 and one end of the switch S2-2, one end of the capacitor C2 is connected with the anode of the power battery E1, and the other end of the capacitor C2 is connected with the cathode of the power battery E1.

Furthermore, the half-bridge LLC low-voltage dc conversion circuit includes a capacitor C3, a capacitor C4, a MOS transistor Q7, a MOS transistor Q8, a resonant inductor Lr2, a resonant capacitor Cr2, a resonant capacitor Cr3, a converter T2, a MOS transistor Q9, and a MOS transistor Q10, where the converter T10 includes a primary coil T10, a secondary coil T10, and a secondary coil T10, one end of the capacitor C10 is connected to a cathode of the diode D10, a source of the MOS transistor Q10, and one end of the resonant capacitor Cr 10, the other end of the capacitor C10 is connected to one end of the capacitor C10, a drain of the MOS transistor Q10, and one end of the resonant capacitor Cr 10, a drain of the MOS transistor Q10, a source of the MOS transistor Q10, and one end of the resonant inductor Lr 10, the other end of the capacitor C10, the other end of the capacitor Cr 10, the other end of the primary coil Cr 10 is connected to one end of the primary coil T10; the dotted terminal of the secondary coil T22 is connected with the source of the MOS tube Q9, the dotted terminal of the secondary coil T22 is connected with the dotted terminal of the secondary coil T23, the dotted terminal of the secondary coil T23 is connected with the source of the MOS tube Q10, one end of a capacitor C4 is connected with the drain of the MOS tube Q9 and the drain of the MOS tube Q10, and the other end of the capacitor C4 is connected with the dotted terminal of the secondary coil T22; one end of the capacitor C4 is connected to the positive electrode of the low voltage terminal E2, and the other end of the capacitor C4 is connected to the negative electrode of the low voltage terminal E2.

When the electric automobile is in an alternating current charging mode, the alternating current and direct current switching circuit is switched to an alternating current input mode, alternating current is converted into direct current through the alternating current and direct current switching circuit and is transmitted to the full-bridge LLC high-voltage direct current conversion circuit through the EMI filter circuit, the rectifier bridge switch circuit and the Boost circuit, the Boost circuit plays a role of a power factor correction circuit to realize alternating current-direct current conversion, the rear-stage full-bridge LLC high-voltage direct current conversion circuit converts the direct current into a variable direct current power supply to charge the power battery E1, and the half-bridge LLC low-voltage direct current conversion circuit converts the high-voltage direct current into low-voltage direct current and supplies power to the low-voltage end E2 after synchronous rectification.

Further, when the power battery E1 is used for supplying power to the low-voltage end E2, when the electric automobile is in a driving mode, the alternating current/direct current switching circuit is switched to a direct current input mode, direct current obtained from the power battery E1 is subjected to direct current conversion through the EMI filter circuit, the rectifier bridge switch circuit and the Boost circuit and then is supplied to the half-bridge LLC low-voltage direct current conversion circuit, the Boost conversion circuit plays a role of a DC-DC conversion circuit, the half-bridge LLC low-voltage direct current conversion circuit converts high-voltage direct current into low-voltage direct current, the low-voltage direct current is subjected to synchronous rectification and then supplies power to the low-voltage end E2, and the half-bridge LLC low-voltage direct current conversion circuit is supplied with power.

Further, when the power battery E1 or the low-voltage end E2 is independently charged by adopting a power grid, when the electric automobile is in an alternating current charging mode, the alternating current-direct current switching circuit is switched to an alternating current input mode, and the power battery E1 is independently charged by only starting the full-bridge LLC high-voltage direct current conversion circuit and not starting the half-bridge LLC low-voltage direct current conversion circuit;

or when the electric automobile is in an alternating current charging mode, the alternating current-direct current switching circuit is switched to an alternating current input mode, and the low-voltage end E2 is charged independently by only starting the half-bridge LLC low-voltage direct current conversion circuit and not starting the full-bridge LLC high-voltage direct current conversion circuit.

The invention has the advantages that:

(1) according to the invention, according to the electrical topological structure characteristics of the vehicle-mounted charger and the vehicle-mounted DC converter, the front-stage Boost circuit of the vehicle-mounted power supply is multiplexed to realize the functions of an active power factor correction circuit and a DC-DC conversion circuit, the front-stage circuit of the Boost circuit is multiplexed, the rear-stage full-bridge LLC high-voltage DC conversion circuit and the half-bridge LLC low-voltage DC conversion circuit are multiplexed to realize the functions of power conversion control in two working modes, and under the condition of multiplexing devices, the power conversion control in multiple working modes is realized.

(2) The existing vehicle-mounted charger and vehicle-mounted direct-current converter are integrated in electrical function, the original electrical function of the vehicle-mounted charger and the vehicle-mounted direct-current converter is achieved, and the function of supplying power to the low-voltage end E2 when the power battery E1 is charged is additionally added.

Drawings

FIG. 1 is a prior art vehicle power control schematic;

fig. 2 is a schematic block diagram of a functional integrated vehicle-mounted charger according to an embodiment of the present invention;

fig. 3 is a schematic circuit diagram of a functional integrated vehicle-mounted charger according to an embodiment of the present invention;

fig. 4 is a schematic circuit diagram of a functional integrated vehicle-mounted charger according to an embodiment of the present invention, when a power grid is used to supply power to a power battery E1 and a low-voltage terminal E2;

fig. 5 is a schematic circuit diagram illustrating a low-voltage end E2 powered by a power battery E1 in the functional integrated vehicle-mounted charger according to the embodiment of the present invention;

fig. 6 is a schematic circuit diagram of a functional integrated vehicle-mounted charger according to an embodiment of the present invention, when a power battery E1 or a low-voltage terminal E2 is charged individually by using a power grid.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 2, a vehicle-mounted charger with integrated functions comprises an alternating current-direct current switching circuit 1, an EMI filter circuit 2, a rectifier bridge switching circuit 3, a Boost voltage Boost circuit 4, a full-bridge LLC high-voltage direct current conversion circuit 5 and a half-bridge LLC low-voltage direct current conversion circuit 6, wherein the alternating current-direct current switching circuit 1, the EMI filter circuit 2, the rectifier bridge switching circuit 3 and the Boost voltage Boost circuit 4 are sequentially connected, the full-bridge LLC high-voltage direct current conversion circuit 5 is respectively connected with the alternating current-direct current switching circuit 1 and the Boost voltage Boost circuit 4, the half-bridge LLC low-voltage direct current conversion circuit 6 is connected with the Boost voltage Boost circuit 4, a power battery E1 is connected with the full-bridge LLC high-voltage direct current conversion circuit 5, and a low-voltage end E; the low voltage terminal E2 is a low voltage battery and a low voltage load.

When the electric automobile is in an alternating current charging mode, a power grid supplies power to a power battery E1 and a low-voltage end E2, and a Boost voltage booster circuit 4 plays a role of a power factor correction circuit to realize alternating current-direct current conversion; when the electric automobile is in a driving mode, the power battery E1 is adopted to supply power to the low-voltage end E2, and the Boost conversion circuit plays a role of a DC-DC conversion circuit to realize direct-current boosting.

Referring to the specific structure of each circuit in detail, as shown in fig. 3, the ac/dc switching circuit 1 includes a switch S1-1, a switch S1-2, a switch S2-1, and a switch S2-2, wherein one end of the switch S1-1 is connected to one end of the ac source VS, one end of the switch S1-2 is connected to the other end of the ac source VS, one end of the switch S2-1 and one end of the switch S2-2 are both connected to the full-bridge LLC high-voltage dc conversion circuit 5, the other end of the switch S1-1 and the other end of the switch S2-1 share a contact a, and the other end of the switch S1-2 and the other end of the switch S2-2 share a contact B.

Continuing to refer to fig. 3, the EMI filter circuit 2 includes a capacitor X1, a capacitor X2, and an inductor T3, the inductor T3 includes a primary winding T31 and a secondary winding T32, one end of the capacitor X1 is connected to the contact a and one end of the primary winding T31, and the other end of the capacitor X1 is connected to the contact B and one end of the secondary winding T32; one end of the capacitor X2 is connected to the other ends of the rectifier bridge switch circuit 3 and the primary winding T31, and the other end of the capacitor X2 is connected to the other ends of the rectifier bridge switch circuit 3 and the secondary winding T32.

With reference to fig. 3, the rectifier bridge switch circuit 3 includes a switch S3-1, a switch S3-2, and a rectifier bridge Br, one ac input terminal of the rectifier bridge Br serves as a first contact of the switch S3-1, an output positive terminal of the rectifier bridge Br serves as a second contact of the switch S3-1, another ac input terminal of the rectifier bridge Br serves as a first contact of the switch S3-2, an output negative terminal of the rectifier bridge Br serves as a second contact of the switch S3-2, one end of a capacitor X2 is connected to a third contact of the switch S3-1, and another end of the capacitor X2 is connected to a third contact of the switch S3-2.

Continuing to refer to fig. 3, the Boost voltage circuit 4 includes an inductor L1, an inductor L2, a MOS transistor Q1, a MOS transistor Q2, a capacitor C1, a diode D1, and a diode D2, one end of the inductor L1 and one end of the inductor L2 are both connected to the positive output terminal of the rectifier bridge Br, one end of the capacitor C1, the drain of the MOS transistor Q1, and the drain of the MOS transistor Q2 are both connected to the negative output terminal of the rectifier bridge Br, the other end of the inductor L1 is connected to the positive electrode of the diode D1 and the source of the MOS transistor Q2, and the other end of the inductor L2 is connected to the positive electrode of the diode D2 and the source of the MOS transistor Q1; the other end of the capacitor C1 is connected to the cathode of the diode D1 and the cathode of the diode D2, respectively.

With reference to fig. 3, the full-bridge LLC high-voltage direct-current conversion circuit 5 includes a MOS transistor Q3, a MOS transistor Q4, a MOS transistor Q5, a MOS transistor Q6, a resonant inductor Lr1, a resonant capacitor Cr1, a converter T1, a capacitor C2, a diode D3, and a diode D4, the converter T4 includes a primary winding T4, a secondary winding T4, and a secondary winding T4, a source of the MOS transistor Q4 and a source of the MOS transistor Q4 are both connected to a cathode of the diode D4, a drain of the MOS transistor Q4 and a drain of the MOS transistor Q4 are both connected to one end of the capacitor C4, a drain of the MOS transistor Q4, a source of the MOS transistor Q4 and one end of the resonant inductor Lr 4, a drain of the MOS transistor Q4, a source of the MOS transistor Q4, the inductor Lr 4, one end of the resonant capacitor Cr 4, and one end of the primary winding T4, and the other end of the resonant capacitor T4 are connected to the primary winding T4; the dotted terminal of the secondary winding T12 is connected with the anode of the diode D3, the dotted terminal of the secondary winding T12 is connected with the dotted terminal of the secondary winding T13, the dotted terminal of the secondary winding T13 is connected with the anode of the diode D4, one end of the capacitor C2 is connected with the cathode of the diode D3, one end of the switch S2-1 and the cathode of the diode D4, the other end of the capacitor C2 is connected with the dotted terminal of the secondary winding T12 and one end of the switch S2-2, one end of the capacitor C2 is connected with the anode of the power battery E1, and the other end of the capacitor C2 is connected with the cathode of the power battery E1.

Continuing to refer to fig. 3, the half-bridge LLC low-voltage dc conversion circuit 6 includes a capacitor C3, a capacitor C4, a MOS transistor Q7, a MOS transistor Q8, a resonant inductor Lr2, a resonant capacitor Cr2, a resonant capacitor Cr3, a converter T2, a MOS transistor Q9, and a MOS transistor Q10, where the converter T10 includes a primary winding T10, a secondary winding T10, and a secondary winding T10, one end of the capacitor C10 is connected to a negative electrode of the diode D10, a source of the MOS transistor Q10, and one end of the resonant capacitor Cr 10, the other end of the capacitor C10 is connected to one end of the capacitor C10, a drain of the MOS transistor Q10, and one end of the resonant capacitor Cr 10, a drain of the MOS transistor Q10, a source of the MOS transistor Q10, and one end of the resonant inductor r 10, the other end of the capacitor C10, the other end of the primary winding Cr 10, the resonant inductor Cr 10 is connected to the other end of the primary winding T10; the dotted terminal of the secondary coil T22 is connected with the source of the MOS tube Q9, the dotted terminal of the secondary coil T22 is connected with the dotted terminal of the secondary coil T23, the dotted terminal of the secondary coil T23 is connected with the source of the MOS tube Q10, one end of a capacitor C4 is connected with the drain of the MOS tube Q9 and the drain of the MOS tube Q10, and the other end of the capacitor C4 is connected with the dotted terminal of the secondary coil T22; one end of the capacitor C4 is connected to the positive electrode of the low voltage terminal E2, and the other end of the capacitor C4 is connected to the negative electrode of the low voltage terminal E2.

As shown in fig. 4, when the electric vehicle is in an ac charging mode, one end of the switch S2-1 is not in contact with the contact a, one end of the switch S1-1 is in conduction with the contact a, one end of the switch S1-2 is in conduction with the contact B, one end of the switch S2-2 is not in contact with the contact B, a third contact of the switch S3-1 is in conduction with one ac input end of the rectifier bridge Br, a first contact of the switch S3-2 is in conduction with the other ac input end of the rectifier bridge Br, at this time, the ac/dc switching circuit 1 is switched to an ac input mode, ac power is converted into dc power through the ac/dc switching circuit 1, and the dc power is transmitted to the full-bridge LLC conversion circuit 5 through the EMI filter circuit 2, the rectifier bridge switching circuit 3 and the Boost circuit 4, at the moment, the Boost circuit 4 plays a role of a power factor correction circuit to realize alternating current-direct current conversion, the rear-stage full-bridge LLC high-voltage direct current conversion circuit 5 converts direct current into a variable direct current power supply to charge the power battery E1, and the half-bridge LLC low-voltage direct current conversion circuit 6 converts high-voltage direct current into low-voltage direct current to supply power to the low-voltage end E2 after synchronous rectification.

As shown in fig. 5, when the power battery E1 is used to supply power to the low-voltage end E2, when the electric vehicle is in a driving mode, one end of the switch S2-1 is connected to the contact a, one end of the switch S1-1 is not connected to the contact a, one end of the switch S1-2 is not connected to the contact B, one end of the switch S2-2 is connected to the contact B, the third contact of the switch S3-1 is connected to the positive output terminal of the rectifier bridge Br, the first contact of the switch S3-2 is connected to the negative output terminal of the rectifier bridge Br, the ac/DC switching circuit 1 is switched to a DC input mode, the DC obtained from the power battery E1 is DC-converted by the EMI filter circuit 2, the rectifier bridge switching circuit 3 and the Boost circuit 4 and then supplied to the half-bridge low-voltage DC conversion circuit 6, and the Boost conversion circuit functions as a DC-DC conversion circuit, the half-bridge LLC low-voltage direct-current conversion circuit 6 converts high-voltage direct current into low-voltage direct current, supplies power to a low-voltage end E2 after synchronous rectification, and the half-bridge LLC low-voltage direct-current conversion circuit 6 is supplied with power by a power battery E1.

As shown in fig. 6, when the power battery E1 or the low-voltage end E2 is charged independently by using the power grid, when the electric vehicle is in an ac charging mode, one end of the switch S2-1 is connected to the contact a, one end of the switch S1-1 is not connected to the contact a, one end of the switch S1-2 is not connected to the contact B, one end of the switch S2-2 is connected to the contact B, the third contact of the switch S3-1 is connected to the positive output terminal of the rectifier bridge Br, the first contact of the switch S3-2 is connected to the negative output terminal of the rectifier bridge Br, and at this time, the ac/dc switching circuit 1 is switched to the ac input mode, and the power battery E1 is charged independently by only enabling the LLC full-bridge high-voltage dc conversion circuit 5 and not enabling the half-bridge LLC low-voltage dc conversion circuit 6;

or, when the electric automobile is in the alternating current charging mode, the alternating current-direct current switching circuit 1 is switched to the alternating current input mode, and the low-voltage end E2 is charged independently by only starting the half-bridge LLC low-voltage direct current conversion circuit 6 and not starting the full-bridge LLC high-voltage direct current conversion circuit 5.

Through the technical scheme, the vehicle-mounted charger with integrated functions and the working method thereof provided by the invention multiplex the front-stage Boost circuit 4 of the vehicle-mounted power supply to realize the functions of an active power factor correction circuit and a DC-DC conversion circuit and multiplex the front-stage circuit of the Boost circuit 4, the rear-stage full-bridge LLC high-voltage direct-current conversion circuit 5 and the half-bridge LLC low-voltage direct-current conversion circuit 6 to multiplex the Boost circuit 4 as well as realize the power conversion control function of two working modes under the condition of multiplexing devices according to the electrical topological structure characteristics of the vehicle-mounted charger and the vehicle-mounted direct-current converter, so that the vehicle-mounted charger can realize the power conversion control of multiple working modes, reduces the using quantity of power devices and controllers through multiplexing, has higher integration level and integrates the vehicle-mounted charger and the vehicle-mounted DC converter together, the size and the cost of the vehicle-mounted power supply are effectively reduced.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.