CN112389236A

CN112389236A - Automobile and energy conversion device

Info

Publication number: CN112389236A
Application number: CN201910755871.7A
Authority: CN
Inventors: 李吉成; 牟利; 杨峰; 谢飞跃; 宋金梦
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2019-08-15
Filing date: 2019-08-15
Publication date: 2021-02-23
Anticipated expiration: 2039-08-15
Also published as: CN112389236B

Abstract

The application discloses car and energy conversion device is applied to car technical field for adaptability and compatible poor technical problem when solving the car and charging the car. The energy conversion device comprises a first bridge arm converter, a first motor coil, a second bridge arm converter and a second motor coil, wherein an external battery, the first bridge arm converter, the first motor coil and a first external charging and discharging port form a first charging and discharging circuit; the first charge-discharge circuit and the second charge-discharge circuit work simultaneously or in a time-sharing manner.

Description

Automobile and energy conversion device

Technical Field

The application relates to the technical field of automobiles, in particular to an automobile and an energy conversion device.

Background

With the continuous popularization of electric vehicles, more and more electric vehicles enter the society and families, great convenience is brought to people going out, relevant subsidy policies built for charging stations in various regions are planned and even come out, and the quantity and distribution range of charging infrastructure are greatly improved. However, due to the limitation of the driving range of the pure electric vehicle, vehicle users are very concerned about the problem that the vehicle is stranded due to the exhaustion of the power supply, and although many vehicle manufacturing enterprises remind the vehicle driver of the information of the residual battery capacity and the information of the low battery capacity alarm through a vehicle meter or other modes, the situation that the residual battery capacity of the vehicle cannot meet the requirement of the vehicle driving to a charging facility or the situation that the driver unconsciously exhausts the vehicle battery capacity inevitably occurs.

In order to avoid the problem that the experience of a vehicle user on the use of the pure electric vehicle is influenced, and even the use and popularization of the pure electric vehicle are influenced, it is necessary to develop the requirement of supplementing the electric energy to the vehicle under the condition that the electric quantity of the vehicle is exhausted or is low to the extent that the energy storage device of the vehicle can not output any more.

With the continuous increase of the cruising ability of the electric vehicle, different voltage levels of the power battery of the automobile appear. Therefore, the car-to-car charging technology needs to meet not only the requirements of users in different areas, but also the adaptability and compatibility of cars with different voltage levels, and a highly compatible circuit is urgently needed to meet the charging requirement.

Disclosure of Invention

The embodiment of the application provides an automobile and an energy conversion device, and provides a new circuit connection structure to solve the technical problem that the adaptability and the compatibility are poor when the automobile is charged.

According to a first aspect of the present invention, an energy conversion device is provided, which includes a first bridge arm converter, a first motor coil, a second bridge arm converter and a second motor coil, wherein the first motor coil is connected to the first bridge arm converter, and the second motor coil is connected to the second bridge arm converter;

the external battery, the first bridge arm converter, the first motor coil and the first external charging and discharging port form a first charging and discharging circuit, the external battery, the second bridge arm converter, the second motor coil and the second external charging and discharging port form a second charging and discharging circuit, the first charging and discharging circuit and the second charging and discharging circuit are connected between the positive pole and the negative pole of the external battery in parallel, two ends of the first external charging and discharging port are respectively connected to the first motor coil and the external battery, and two ends of the second external charging and discharging port are respectively connected to the second motor coil and the external battery;

the first charge-discharge circuit and the second charge-discharge circuit work simultaneously or in a time-sharing manner.

According to a second aspect of the present invention, an energy conversion device is provided, which includes the energy conversion device provided in the first aspect of the present invention, and further includes an energy storage connection terminal group, a first charge-discharge port connection terminal group, and a second charge-discharge port connection terminal group;

the energy storage connecting terminal group comprises a first energy storage connecting terminal and a second energy storage connecting terminal, the first energy storage connecting terminal is connected with the anode of an external battery, and the first energy storage connecting terminal is connected with the cathode of the external battery;

the first charging and discharging port connecting end group comprises a first sub charging and discharging connecting end and a second sub charging and discharging connecting end, the first sub charging and discharging connecting end is connected with the first motor coil, and the second sub charging and discharging connecting end is connected with the second confluence end or the midpoint of the bidirectional bridge arm;

the second charging and discharging port connecting end group comprises a third sub charging and discharging connecting end and a fourth sub charging and discharging connecting end, the third sub charging and discharging connecting end is connected with the second motor coil, and the fourth sub charging and discharging connecting end is connected with the second confluence end or the midpoint of the bidirectional bridge arm.

According to a third aspect of the present invention, there is provided a vehicle comprising an energy conversion device according to the first aspect of the present invention or an energy conversion device according to the second aspect of the present invention.

The utility model provides an automobile and energy conversion device is through designing the first charge-discharge circuit that is formed by external battery, this first bridge arm converter, this first motor coil and first outside charge-discharge mouth and the second charge-discharge circuit that is formed by external battery, this second bridge arm converter, this second motor coil and second outside charge-discharge mouth for this energy conversion device and automobile can charge to outside power battery through different charge-discharge circuits, correspondingly, also can discharge to the outside through different charge-discharge circuits, this energy conversion device provides two sets of charge-discharge circuits for the automobile, make the automobile can charge and discharge through conventional mode, also can charge and discharge through the car simultaneously or timesharing, improve the charge-discharge capacity of automobile.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the description of the embodiments of the present application will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive exercise.

Fig. 1 is a block diagram of an energy conversion device according to an embodiment of the present application;

fig. 2 is a schematic circuit diagram of an energy conversion device according to a first embodiment of the present application;

fig. 3 is a schematic circuit diagram of an energy conversion device according to a second embodiment of the present application;

fig. 4 is a schematic circuit configuration diagram of an energy conversion device according to a third embodiment of the present application;

fig. 5 is a schematic circuit diagram of an energy conversion device according to a fourth embodiment of the present application;

fig. 6 is a schematic circuit diagram of an energy conversion device according to a fifth embodiment of the present application;

fig. 7 is a schematic circuit configuration diagram of an energy conversion device according to a sixth embodiment of the present application;

fig. 8 is a schematic circuit configuration diagram of an energy conversion device in a seventh embodiment of the present application;

fig. 9 is a schematic circuit configuration diagram of an energy conversion device according to an eighth embodiment of the present application;

FIG. 10 is a schematic diagram of the electrical circuit configuration of the motor winding in the first embodiment of the present application;

FIG. 11 is a schematic diagram of the electrical circuit configuration of the windings of the motor of the second embodiment of the present application;

FIG. 12 is a schematic diagram of the circuit configuration of the motor winding in the third embodiment of the present application;

FIG. 13 is a schematic diagram of the electrical circuit configuration of the winding of the motor of the fourth embodiment of the present application;

fig. 14 is a schematic diagram illustrating a current flow when the first charge/discharge circuit and the second charge/discharge circuit simultaneously perform dc charging for energy storage according to an embodiment of the present disclosure;

fig. 15 is a schematic flow diagram of current when the first charge/discharge circuit and the second charge/discharge circuit simultaneously discharge the dc charging energy storage according to an embodiment of the present application;

FIG. 16 is a schematic diagram illustrating a current flow when the first charging/discharging circuit stores the DC charging energy and the second charging/discharging circuit releases the DC charging energy according to an embodiment of the present disclosure;

FIG. 17 is a schematic diagram illustrating a current flow when the first charging/discharging circuit releases the DC charging energy and the second charging/discharging circuit releases the DC charging energy according to an embodiment of the present disclosure;

FIG. 18 is a schematic diagram illustrating a current flow when the first charging/discharging circuit stores DC charging energy and the second charging/discharging circuit releases DC discharging energy according to an embodiment of the present disclosure;

FIG. 19 is a schematic diagram illustrating a current flow when the first charging/discharging circuit stores DC charging energy and the second charging/discharging circuit releases DC discharging energy according to an embodiment of the present disclosure;

FIG. 20 is a schematic diagram illustrating a current flow when the first charging/discharging circuit stores energy by DC charging and the second charging/discharging circuit stores energy by AC charging according to an embodiment of the present disclosure;

FIG. 21 is a schematic diagram illustrating a current flow when the DC charging energy of the first charging/discharging circuit is released and the AC charging energy of the second charging/discharging circuit is released according to an embodiment of the present disclosure;

FIG. 22 is a schematic diagram illustrating a current flow when the first charging/discharging circuit DC charges the energy storage and the second charging/discharging circuit AC discharges the energy storage according to an embodiment of the present disclosure;

FIG. 23 is a schematic diagram illustrating a current flow when the first charging/discharging circuit releases the DC charging energy and the second charging/discharging circuit releases the AC discharging energy according to an embodiment of the present disclosure;

fig. 24 is a schematic diagram illustrating the current flowing in the positive half cycle of the charging energy storage during the same-phase ac charging of the third ac charging circuit according to an embodiment of the present invention;

fig. 25 is a schematic diagram illustrating the flow of current released by the charging energy stored in the positive half cycle during the same-phase ac charging performed by the third ac charging circuit according to an embodiment of the present invention;

fig. 26 is a schematic diagram illustrating the current flowing in the negative half cycle of the charging energy storage during the same-phase ac charging of the third ac charging circuit according to an embodiment of the present invention;

fig. 27 is a schematic diagram illustrating the flow of current released by the charging energy storage in the negative half cycle during the same phase control ac charging of the third ac charging circuit according to an embodiment of the present invention;

fig. 28 is a schematic current flow diagram illustrating the positive half cycle discharged energy storage during ac discharge in the third ac charging circuit according to an embodiment of the present invention;

fig. 29 is a schematic current flow diagram illustrating the discharge of the positive half-cycle discharge energy during ac discharge in the third ac charging circuit according to an embodiment of the present application;

fig. 30 is a schematic current flow diagram illustrating the negative half-cycle discharged energy storage during ac discharge in the third ac charging circuit according to an embodiment of the present invention;

fig. 31 is a schematic diagram of the current flow of the discharge energy in the negative half-cycle during ac discharge in the third ac charging circuit according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

Implementations of the present application are described in detail below with reference to the following detailed drawings:

fig. 1 is a block diagram of an energy conversion device in an embodiment of the present application, and the energy conversion device provided in accordance with the first embodiment of the present invention is described in detail below with reference to fig. 1, where the energy conversion device includes a first bridge arm converter 11, a first motor coil 12, a second bridge arm converter 21, and a second motor coil 22, the first motor coil 12 is connected to the first bridge arm converter 11, and the second motor coil 22 is connected to the second bridge arm converter 21;

the external battery 01, the first bridge arm converter 11, the first motor coil 12 and the first external charging and discharging port 13 form a first charging and discharging circuit, the external battery 01, the second bridge arm converter 21, the second motor coil 22 and the second external charging and discharging port 23 form a second charging and discharging circuit, the first charging and discharging circuit and the second charging and discharging circuit are connected between the positive pole and the negative pole of the external battery 01 in parallel, two ends of the first external charging and discharging port 13 are respectively connected to the first motor coil 12 and the external battery 01, and two ends of the second external charging and discharging port 23 are respectively connected to the second motor coil 22 and the external battery 01;

In one of them, the first charge and discharge circuit includes a first charge circuit for charging the external battery 01 and a first discharge circuit for discharging through the first external charge and discharge port 13, and the second charge and discharge circuit includes a second charge circuit for charging the external battery 01 and a second discharge circuit for discharging through the second external charge and discharge port 23;

the first charging circuit and the first discharging circuit work in the energy conversion device in a time-sharing mode, and the second charging circuit and the second discharging circuit work in the energy conversion device in a time-sharing mode.

In one embodiment, the first external charging/discharging port 13 is a first external dc charging/discharging port or a first external ac charging/discharging port, and the second external charging/discharging port 23 is a second external dc charging/discharging port or a second external ac charging/discharging port.

The embodiment adopts a double-motor scheme, double direct current charging and discharging and single-phase alternating current charging and discharging are combined, the characteristics of high direct current charging and discharging power and high current are utilized, the neutral line of the direct current charging and discharging port is adopted to be connected with a plurality of poles of the motor in parallel, the characteristics of low alternating current charging and discharging power and low current are utilized, the neutral line of the alternating current charging and discharging port is connected with a single pole of the motor, each motor coil can be led out by two neutral lines and is respectively used for an external direct current charging and discharging port and an external alternating current charging and discharging port, the embodiment can select a proper number of poles N to be led out in parallel according to the requirements of the charging power and inductance, the lead method and the control algorithm are combined, the required charging power and inductance are obtained, and the charging.

In practical use, the situation of the number of parallel poles N and the lead-out number of neutral lines may be deformed to some extent, and both belong to the scope claimed in the present application, for example, the dc charging may be performed simultaneously with the first charge-discharge circuit and the second charge-discharge circuit, as shown in fig. 13 to 14, or the dc discharging may be performed simultaneously with the first charge-discharge circuit and the second charge-discharge circuit; one of the charge and discharge circuits can be charged while the other charge and discharge circuit is DC discharged, as shown in FIG. 17 and FIG. 18; the charging can be performed by any one of the DC systems, as shown in FIGS. 19 to 22. The direct current charging and discharging and the alternating current charging and discharging are used in time sharing.

In one embodiment, as shown in fig. 10-13, the first motor coil 12 comprises a set of m₁A phase winding, the first bridge arm converter 11 comprising M₁Road bridge arm of m₁Each of the phase windings includes n₁A coil branch of n for each phase winding₁The coil branches are connected together to form a phase terminal m₁Phase end point of phase winding and M₁The middle points of each of the road bridge arms are connected in one-to-one correspondence, and the m is₁N of each of the phase windings₁One of the coil branches is also respectively connected with n of other phase windings₁One of the coil branches is connected to form n₁A connection point, n₁A connection point forming n₁A neutral point of n₁The neutral points comprise independent neutral points formed by one connecting point and/or non-independent neutral points formed by connecting at least two connecting points, and n is₁A first neutral line is led out from each neutral point, the first neutral line is connected with the first external charging and discharging port 13, each phase bridge arm of the first bridge arm converter 11 is connected in parallel to form a first bus end and a second bus end, the first bus end is connected with the positive pole of the external battery 01, the second bus end is connected with the negative pole of the external battery 01, wherein the n is₁≥1，m₁≥2，m₁＝M₁And n is₁、m₁And M₁Are all integers.

Wherein, fig. 10 is a schematic diagram of the circuit structure of the motor winding in the first embodiment of the present application, and fig. 10 shows the time when m is₁＝3，n₁When the neutral line is led out from each of the two connection points, the circuit structure of the motor is schematically shown as 2.

FIG. 11 is a schematic diagram of the circuit structure of the motor winding in the second embodiment of the present application, and FIG. 11 shows m₁＝3，n₁When the neutral line is led out from two of the four connection points, the circuit structure of the motor is schematic when the neutral line is 4.

FIG. 12 is a schematic diagram of the circuit structure of the motor winding in the third embodiment of the present application, and FIG. 12 shows m₁＝3，n₁When 4, a neutral line is drawn from two of the four connection points, and another neutral line is drawn through the other connection point.

FIG. 13 is a schematic diagram of the circuit structure of the winding of the motor in the fourth embodiment of the present application, and FIG. 13 shows m₁＝3，n₁When 4, the circuit structure of the motor is schematically shown when a neutral line is drawn from three of the four connection points.

As shown in fig. 2 and 3, the led neutral line may be individually connected to an external dc charging/discharging port, or may be simultaneously connected to the external dc charging/discharging port and external ac charging/discharging, and when the neutral line is simultaneously connected to the external dc charging/discharging port, the energy conversion device may be charged with dc through the first charging/discharging circuit and the second charging/discharging circuit simultaneously or in a time-sharing manner, or may be discharged with dc through the first charging/discharging circuit and the second charging/discharging circuit simultaneously or in a time-sharing manner.

As shown in fig. 9, the first charge/discharge circuit and the second charge/discharge circuit may be externally connected to an external ac charge/discharge port at the same time, and at this time, the first charge/discharge circuit and the second charge/discharge circuit may be ac charged at the same time or in a time-sharing manner; the first charge-discharge circuit and the second charge-discharge circuit can also discharge in an alternating current mode simultaneously or in a time-sharing mode.

As shown in fig. 6, the first charge and discharge circuit and the second charge and discharge circuit may be connected to an external dc charge and discharge port and an external ac charge and discharge port, respectively, and when the energy conversion device is connected to the external dc charge and discharge port and the external ac charge port at the same time, the energy conversion device may be dc charged by the first charge and discharge circuit and ac discharged by the second charge and discharge circuit at the same time or at different times; the direct current can be discharged through the first charge-discharge circuit, and the alternating current can be charged simultaneously or in a time-sharing manner through the second charge-discharge circuit; the alternating current charging can be carried out through the first charging and discharging circuit, and the direct current discharging can be carried out through the second charging and discharging circuit at the same time or in a time-sharing manner; the first charging and discharging circuit can be used for carrying out alternating current discharging, and the second charging and discharging circuit can be used for carrying out direct current charging simultaneously or in a time-sharing mode.

In the embodiment shown in fig. 6, the DC charging and discharging can be implemented by a DC driving system, and the ac loop can be implemented by a DC/DC bridge arm. The alternating current loop can be externally provided with an inductor, and the external inductor determines whether to be used or not according to the actual current ripple and the power grid harmonic wave condition. The embodiment can simultaneously carry out alternating current and direct current charging and discharging, can carry out direct current charging and alternating current discharging, and can also carry out alternating current charging and direct current discharging.

The time-sharing charging or discharging process does not limit which charging and discharging circuit is charged and discharged in the front and which charging and discharging circuit is charged and discharged in the back.

Fig. 7 is a schematic circuit diagram of an energy conversion device according to a sixth embodiment of the present application, and the energy conversion device shown in fig. 7 can charge and discharge both charge and discharge circuits with high dc power; the two charging and discharging circuits can be charged or discharged simultaneously by direct current; one of the charging and discharging circuits can be charged and the other charging and discharging circuit can be discharged in a direct current manner; any one of the DC charging and discharging circuits can be charged or discharged.

Fig. 8 is a schematic circuit structure diagram of an energy conversion device in a seventh embodiment of the present application, and as shown in fig. 8, a first inductor L1 may be disposed on a connection line between a first neutral line and a first end of a first external charging/discharging port, a second inductor L2 may be disposed on a connection line between a second neutral line and a second external charging/discharging port, and an external inductor is connected in series to a dc charging/discharging loop.

As shown in fig. 10 to 13, the number of phases of the first motor coil 12 or the second motor coil 22 is greater than or equal to 2 (e.g., a three-phase motor, a five-phase motor, a six-phase motor, a fifteen-phase motor, etc.), the number of arms in the corresponding arm converter is configured according to the number of phases of the motor, a neutral point of the first/second motor coil 22 may be a number of lead-out poles, the number of poles (P) of the motor coil corresponding to the motor, the number of poles n of the motor coil corresponding to the motor is a common divisor of the number of poles, the number of poles of the specific motor depends on a parallel structure of windings inside the motor coil, and the number of lead-out center lines and the number of parallel poles of the neutral line inside the motor are determined by a use condition of an actual scheme.

In the embodiment, the pole n with different led-out parallel numbers is utilized, the equivalent phase inductance of the motor is different, the current carrying capacity on the neutral line is different, the more the pole n with the same set of winding parallel connection is controlled in the same control mode, the stronger the current carrying capacity on the neutral line is, the smaller the inductance is, the larger the ripple wave on the inductance is, the pole n with the proper number is selected to be led out in parallel according to the requirements of charging power and inductance, the lead method is combined with the control algorithm to obtain the required charging power and inductance, and the charging power and the charging and discharging performance are improved simultaneously.

Through the mode, the winding connection method of the motor stator provided by the embodiment can fully utilize the inductance of the motor winding, expand the functions of the motor, reduce the existing functional devices and reduce the cost of the whole vehicle.

In one embodiment, the energy conversion device further includes a first capacitor C1, the first capacitor C1 is connected in parallel with the external battery 01, a first terminal of the first capacitor C1 is connected to the first bus terminal, and a second terminal of the first capacitor C1 is connected to the second bus terminal.

In one embodiment, the energy conversion device further includes a first switch K1, a second switch K2, a third switch K3 and a resistor R, the second switch K2 is connected in series with the resistor R and then connected in parallel with the first switch K1 between the positive electrode of the external battery 01 and the first bus terminal, and the third switch K3 is disposed between the negative electrode of the external battery 01 and the second bus terminal.

The first switch K1, the second switch K2, the third switch K3 and the resistor R form a precharge circuit for the external battery 01, the precharge circuit is connected with a direct current bus, a first bridge arm converter 11 in the first charge-discharge circuit is connected with the direct current bus, the first bridge arm converter 11 is connected with a first capacitor C1 in parallel, the first capacitor C1 is used for energy storage and filtering, the first bridge arm converter 11 is connected with the first motor coil 12 through a phase line, a first neutral line of the first motor coil 12 is connected to the positive electrode of a second capacitor C2 through a fourth switch K4, the negative electrode of the second capacitor C2 is connected to the negative electrode of the direct current bus, a first end of the first external direct current charge-discharge port is connected to the positive electrode of a second capacitor C2 through a fifth switch K5, and the first external direct current charge-discharge port is connected to the negative electrode of a second capacitor C2 through a sixth switch K6; a second bridge arm converter 21 in the second charging and discharging circuit is connected with a direct current bus, the second bridge arm converter 21 is connected with a third capacitor C3 in parallel, the third capacitor C3 is used for energy storage and filtering, the second bridge arm converter 21 is connected with a second motor coil 22 through a phase line, a second neutral line of the second motor coil 22 is connected to the positive electrode of a fourth capacitor C4 through a seventh switch K7, the negative electrode of the fourth capacitor C4 is connected to the negative electrode of the direct current bus, a first external direct current charging and discharging port is connected to the positive electrode of a fourth capacitor C4 through an eighth switch K8, and a second external direct current charging and discharging port is connected to the negative electrode of a fourth capacitor C4 through a ninth switch K9; the third external charging and discharging port 33 is connected to the first neutral line of the first motor coil 12 through a tenth switch K10, and the third external charging and discharging port 33 is connected to the second neutral line of the second motor coil 22 through an eleventh switch K11.

In one embodiment, the first external charging/discharging port 13 is a first external dc charging/discharging port, and further includes a second capacitor C2, a first end of the first external dc charging/discharging port is connected to a first end of the second capacitor C2 and the first neutral line, respectively, and a second end of the first external dc charging/discharging port is connected to a second end of the second capacitor C2 and the second bus end, respectively.

In one embodiment, the process of charging the external battery 01 by the first charging circuit includes a first dc charging energy storage process and a first dc charging energy storage release process, the current flow direction when the first charging and discharging circuit and the second charging and discharging circuit simultaneously perform dc charging energy storage is shown in fig. 14, and the current flow direction when the first charging and discharging circuit and the second charging and discharging circuit simultaneously perform dc charging energy storage release is shown in fig. 15.

In other embodiments, the third ac charging/discharging circuit can control charging in phase and can also control discharging of the external battery 01 through the third ac charging/discharging circuit, wherein the current flow of the charging energy storage in the positive half period in ac charging is controlled in phase as shown in fig. 24, the current flow of the discharging energy storage in the positive half period in ac charging is controlled in phase as shown in fig. 25, the current flow of the charging energy storage in the negative half period in ac charging is controlled in phase as shown in fig. 26, and the current flow of the discharging energy storage in the negative half period in ac charging is controlled in phase as shown in fig. 27; the flow of current of the positive half-cycle discharge energy storage during ac discharge by the third ac charging/discharging circuit is shown in fig. 28, the flow of current of the positive half-cycle discharge energy storage during ac discharge by the third ac charging/discharging circuit is shown in fig. 29, the flow of current of the negative half-cycle discharge energy storage during ac discharge by the third ac charging circuit is shown in fig. 30, and the flow of current of the negative half-cycle discharge energy storage during ac discharge by the third ac charging circuit is shown in fig. 31.

The motors in the first charge and discharge circuit and the second charge and discharge circuit may be controlled in phase, or may be staggered by a certain angle, for example, the second charge and discharge circuit and the first charge and discharge circuit are staggered by 180 °, or 90 °, or preferably 180 °.

The bridge arm switch of each set of charging and discharging circuit can adopt in-phase control and dislocation phase control respectively; the combination of the 8 th control modes in the following table (1) and the 4 th control mode in the table (2) can be formed by the permutation and combination, and the 8 th control mode in the dual-circuit simultaneous operation optimization table (1) and the 10 th or 12 th control mode in the single-circuit operation optimization table (2) can be formed.

Watch (1)

Watch (2)

The power switch control mode of the motor drive system controller can be any one or combination of the following modes: if at least one bridge arm in the inverter is selected for control, the control is flexible and simple.

The bridge arm converter adopts a synchronous control mode to synchronously switch on and switch off, so that the current in a motor coil is increased simultaneously when being switched on and is reduced simultaneously when being switched off, the motor current tends to be equal at any instant, the resultant magnetomotive force of the motor tends to be zero, the magnetic field of a stator tends to be zero, and the motor basically has no torque.

When the inductance of motor itself does not satisfy the ripple requirement, can adopt controller phase control of staggering, 360/motor phase counts are regarded as to the angle of staggering, for example three-phase staggers about 120 phase control, the positive and negative ripple of three-phase coil superposes each other like this, offset each other, thereby can make total ripple greatly reduced, for example two-phase staggers about 180 phase control, the positive and negative ripple of two-phase coil superposes each other like this, offset each other, thereby can make total ripple greatly reduced, but certain torque ripple may exist.

The motors in the double charge and discharge circuit can be two synchronous motors, two asynchronous motors or one synchronous motor and one asynchronous motor.

When the energy conversion device is in a first direct-current charging and energy storing process, the current in the first direct-current charging circuit sequentially flows through the first end of the first external direct-current charging and discharging port, the first neutral line, the winding of the first motor coil 12 connected with the first neutral line, the lower bridge arm of the first bridge arm converter 11 and the second end of the first external direct-current charging and discharging port;

when the energy conversion device is in a first dc charging energy storage release process, the current in the first dc charging circuit sequentially flows through the first end of the first external dc charging/discharging port, the first neutral line, the winding of the first motor coil 12 connected to the first neutral line, the upper bridge arm of the first bridge arm converter 11, the external battery 01, and the second end of the first external dc charging/discharging port.

In one embodiment, the energy conversion device further includes a first inductor L1, and the first inductor L1 is disposed on a connection line between the first neutral line and the first end of the first external charging/discharging port.

In one embodiment, the energy conversion device further includes a second inductor L2, and the second inductor L2 is disposed on a connection line between the second neutral line and the second external charging/discharging port.

In the embodiment, the first inductor L1 and the second inductor L2 are connected in series on the alternating current and direct current common loop, the inductance of the motor is small, the scheme that neutral wires are led out by connecting n connecting points in parallel meets the requirements of charging and discharging power, and the external inductors can be connected in series by adding the inductors under the condition that the inductance requirement is not met, so that the inductance requirement is met.

In one embodiment, the energy conversion apparatus further includes a fourth switch K4, a fifth switch K5, and a sixth switch K6, the fourth switch K4 is disposed on a connection line between the first neutral line and the second capacitor C2, the fifth switch K5 is disposed on a connection line between the second capacitor C2 and the first end of the first external dc charging/discharging port, and the sixth switch K6 is disposed between the second capacitor K2 and the second end of the first external dc charging/discharging port.

In one embodiment, the second motor coil 22 comprises a set of m₂A phase winding, the first bridge arm converter 11 comprising M₂Road bridge arm of m₂Each of the phase windings includes n₂A coil branch of n for each phase winding₂The coil branches are connected together to form a phase terminal m₂Phase end point of phase winding and M₂The middle points of each of the road bridge arms are connected in one-to-one correspondence, and the m is₂N of each of the phase windings₂One of the coil branches is also respectively connected with n of other phase windings₂One of the coil branches is connected to form n₂A connection point, n₂A connection point forming n₂A neutral point of n₂The neutral points comprise independent neutral points formed by one connecting point and/or non-independent neutral points formed by connecting at least two connecting points, and n is₂A second neutral line is led out from the neutral point, the second neutral line is connected with the second external charging and discharging port 23, the bridge arms of each phase of the second bridge arm converter 21 are connected in parallel to form a third bus end and a fourth bus end, the third bus end is connected with the positive pole of the external battery 01, the fourth bus end is connected with the negative pole of the external battery 01, wherein the n is₂≥1，m₂≥2，m₂＝M₂And is andn₂、m₂and M₂Are all integers.

In one embodiment, the energy conversion apparatus further includes a third capacitor C3, a first terminal of the third capacitor C3 is connected in parallel with a first terminal of the first capacitor C1 and then connected to the positive electrode of the external battery 01, and a second terminal of the third capacitor C3 is connected in parallel with a second terminal of the first capacitor C1 and then connected to the negative electrode of the external battery 01.

In one embodiment, the second external charging/discharging port 23 is a second external dc charging/discharging port, and further includes a fourth capacitor C4, a first end of the second external dc charging/discharging port is connected to a first end of the fourth capacitor and the second neutral line, respectively, and a second end of the second external dc charging/discharging port is connected to a second end of the fourth capacitor and the fourth bus end, respectively.

In one embodiment, the process of discharging through the first discharging circuit comprises a first direct current discharging energy storage process and a first direct current discharging energy storage releasing process;

when the energy conversion device is in a first direct current discharging and energy storing process, the current in the first direct current discharging circuit sequentially flows through the positive electrode of the external battery, the upper bridge arm of the first bridge arm converter 11, the winding of the first motor coil 12, a first neutral wire connected with the winding of the first motor coil 12, the first end of the first external direct current charging and discharging port, the second end of the first external direct current charging and discharging port and the negative electrode of the external battery;

when the energy conversion device is in a first dc discharge energy storage release process, a current in the first dc discharge circuit sequentially flows through the winding of the first motor coil 12, the first neutral line connected to the winding of the first motor coil 12, the first end of the first external dc charge-discharge port, the second end of the first external dc charge-discharge port, the lower bridge arm of the first bridge arm converter 11, and the winding of the first motor coil 12.

In one embodiment, the second charging circuit includes a second dc charging circuit, and the process of charging the external battery 01 by the second dc charging circuit includes a second charging energy storage process and a second charging energy storage release process;

when the energy conversion device is in a second charging energy storage process, the current in the second direct current charging circuit sequentially flows through the anode of the second external direct current charging and discharging port, the anode of the fourth capacitor C4, the second neutral line, the winding of the second motor coil 22 connected with the second neutral line, the lower bridge arm of the second bridge arm converter 21, and the cathode of the second external direct current charging and discharging port;

when the energy conversion device is in the second charging energy storage release process, the current in the second dc charging circuit sequentially flows through the anode of the second external dc charging/discharging port, the anode of the fourth capacitor C4, the second neutral line, the winding of the second motor coil 22 connected to the second neutral line, the upper arm of the second arm converter 21, the external battery 01, and the second end of the first external dc charging/discharging port.

In one embodiment, the second discharging circuit comprises a second direct current discharging circuit, and the process of discharging through the second direct current discharging circuit comprises a second direct current discharging energy storage process and a second direct current discharging energy storage releasing process;

when the energy conversion device is in a second dc discharge energy storage process, the current in the second dc discharge circuit sequentially flows through the first end of the third capacitor C3, the upper arm of the second arm converter 21, the winding of the second motor coil 22, the second neutral line connected to the winding of the second motor coil 22, the anode of the fourth capacitor C4, the anode of the second external dc charge-discharge port, the cathode of the second external dc charge-discharge port, and the second end of the third capacitor C3;

when the energy conversion device is in the second dc discharge energy storage release process, the current in the second dc discharge circuit sequentially flows through the winding of the second motor coil 22, the second neutral line connected to the winding of the second motor coil 22, the positive electrode of the fourth capacitor C4, the positive electrode of the second external dc charge/discharge port, the negative electrode of the second external dc charge/discharge port, the lower arm of the second arm converter 21, and the winding of the second motor coil 22.

In one embodiment, the energy conversion device further includes a seventh switch K7, an eighth switch K8, and a ninth switch K9, the seventh switch is disposed on a connection line between the second neutral line and the fourth capacitor, the eighth switch is disposed between the fourth capacitor and a positive electrode of the second external dc charging/discharging port, and the ninth switch is disposed between the fourth capacitor and a negative electrode of the second external dc charging/discharging port.

In one embodiment, the first external charging/discharging port 13 is a first external ac charging/discharging port, and further includes a first bridge arm, where the first external ac charging/discharging port includes a first ac connection end and a second ac connection end, the first ac connection end is connected to the first neutral line, the second ac connection end is connected to a midpoint of the first bridge arm, an upper bridge arm of the first bridge arm is connected to the first bus end, and a lower bridge arm of the first bridge arm is connected to the second bus end.

In one embodiment, the first charging circuit comprises a first ac charging circuit, and the process of charging the external battery 01 by the first ac charging circuit comprises a first ac charging energy storage process and a first ac charging energy storage release process;

when the energy conversion device is in a first alternating-current charging energy storage process, the current in the first alternating-current charging circuit sequentially flows through the first alternating-current connecting end, the first neutral line, the winding of the first motor coil 12 connected with the first neutral line, the upper bridge arm of the first bridge arm converter 11, the external battery, the upper bridge arm of the first bridge arm and the second alternating-current connecting end;

when the energy conversion device is in a first alternating-current charging energy storage release process, current in the first alternating-current charging circuit sequentially flows through the first alternating-current connecting end, the first neutral line, a winding of a first motor coil 12 connected with the first neutral line, an upper bridge arm of the first bridge arm converter 11, the external battery 01, a lower bridge arm of the first bridge arm 11 and the second alternating-current connecting end;

or when the energy conversion device is in a first alternating-current charging energy storage process, the current in the first alternating-current charging circuit sequentially flows through the second alternating-current connecting end, the upper bridge arm of the first bridge arm converter, the winding of the first motor coil, the first neutral line and the first alternating-current connecting end,

when the energy conversion device is in a first alternating-current charging energy storage process, the current in the first alternating-current charging circuit sequentially flows through the second alternating-current connecting end, the upper bridge arm of the first bridge arm, the lower bridge arm of the first bridge arm converter, the winding of the first motor coil, the first neutral line and the first alternating-current connecting end.

In one embodiment, the first discharge circuit comprises a first alternating current discharge circuit, and the process of discharging through the first alternating current discharge circuit comprises a first alternating current discharge energy storage process and a first alternating current discharge energy storage release process;

when the energy conversion device is in a first alternating current discharge energy storage process, the current in the first alternating current discharge circuit sequentially flows through the positive electrode of the battery, the upper bridge arm of the first bridge arm converter 11, the winding of the first motor coil 12, the first neutral wire connected with the winding of the first motor coil 12, the first external alternating current charge-discharge port, the lower bridge arm of the first bridge arm, and the negative electrode of the battery;

when the energy conversion device is in a first alternating current discharge energy storage release process, the current in the first alternating current discharge circuit sequentially flows through the winding of the first motor coil 12, a first neutral wire connected with the winding of the first motor coil, the first external alternating current charge and discharge port, the upper bridge arm of the first bridge arm converter 11 and the winding of the first motor coil 12;

or when the energy conversion device is in a first alternating current discharge energy storage process, the current in the first alternating current discharge circuit sequentially flows through the positive electrode of the battery, the upper bridge arm of the first bridge arm, the first external alternating current charge-discharge port, the first neutral wire connected with the winding of the first motor coil, the lower bridge arm of the first bridge arm converter, and the negative electrode of the battery,

when the energy conversion device is in a first alternating current discharge energy storage release process, the current in the first alternating current discharge circuit sequentially flows through the winding of the first motor coil, the upper bridge arm of the first bridge arm converter, the first external alternating current charge-discharge port, the upper bridge arm of the first bridge arm, the first neutral wire connected with the winding of the first motor coil, and the winding of the first motor coil.

In one embodiment, the energy conversion device further comprises a third inductor, and the third inductor is arranged between the second ac connection end and the midpoint of the first bridge arm.

In one embodiment, the energy conversion device further comprises an eleventh switch K12 and a thirteenth switch K13, the eleventh switch K12 being arranged between the first ac connection terminal and the first neutral line, the thirteenth switch K13 being arranged between the second ac connection terminal and the midpoint of the first leg.

In one embodiment, the second external charging/discharging port 23 is a second external ac charging/discharging port, and further includes a second bridge arm, the second external ac charging/discharging port includes a third ac connection end and a fourth ac connection end, the third ac connection end is connected to the second neutral line, the fourth ac connection end is connected to the middle point of the second bridge arm, the upper bridge arm of the second bridge arm is connected to the third bus end, and the lower bridge arm of the second bridge arm is connected to the fourth bus end.

In one embodiment, the second charging circuit comprises a second ac charging circuit, and the process of charging the external battery 01 by the second ac charging circuit comprises a fourth charging energy storage process and a fourth charging energy storage release process;

when the energy conversion device is in a fourth charging energy storage process, the current in the second alternating-current charging circuit sequentially flows through the third alternating-current connection end, the second neutral line, the winding of the second motor coil 22 connected with the second neutral line, the upper bridge arm of the second bridge arm converter 21, the upper bridge arm of the second bridge arm, and the fourth alternating-current connection end;

when the energy conversion device is in a fourth charging energy storage release process, the current in the second ac charging circuit sequentially flows through the third ac connection terminal, the second neutral line, the winding of the second motor coil 22 connected to the second neutral line, the upper bridge arm of the second bridge arm converter 21, the external battery 01, the lower bridge arm of the second bridge arm converter 21, and the fourth ac connection terminal.

In one embodiment, the second discharge circuit comprises a second ac discharge circuit, and the process of discharging through the second ac discharge circuit comprises a second ac discharge energy storage process and a second ac discharge energy storage release process;

when the energy conversion device is in a second ac discharging energy storage process, the current in the second ac discharging circuit sequentially flows through the first end of the third capacitor C3, the upper arm of the second arm converter 21, the winding of the second motor coil 22, the second neutral wire connected to the winding of the second motor coil 22, the second external ac charging and discharging port, and the second end of the third capacitor C3;

when the energy conversion device is in the second ac discharge energy storage release process, the current in the second ac discharge circuit sequentially flows through the winding of the second motor coil 22, the second external ac charge-discharge port, the upper arm of the second arm converter 21, and the winding of the second motor coil 22.

In one embodiment, the energy conversion device further comprises a fourth inductor, and the fourth inductor is arranged between the fourth ac connection terminal and the midpoint of the second bridge arm.

In one embodiment, the energy conversion device further comprises a fourteenth switch K14 and a fifteenth switch K15, the fourteenth switch K14 being arranged between the third ac connection and the second neutral line, the fifteenth switch K15 being arranged between the fourth ac connection and the midpoint of the second leg.

In one embodiment, the energy conversion device further comprises a third external ac charging and discharging port, and the third external ac charging and discharging port is respectively connected to the first neutral line and the second neutral line;

the external battery 01, the first arm converter 11, the first motor coil 12, the third external ac charging/discharging port, the second motor coil 22, and the second arm converter 21 form a third ac charging circuit for charging the external battery 01 or a third ac discharging circuit for discharging through the third external charging/discharging port 33.

In one embodiment, the energy conversion device further includes a tenth switch K10 and an eleventh switch K11, the third external charging and discharging port 33 includes a fifth ac connection terminal and a sixth ac connection terminal, the fifth ac connection terminal is connected to the first neutral line, the sixth ac connection terminal is connected to the second neutral line, the tenth switch K10 is disposed between the first neutral line and the first ac connection terminal, and the eleventh switch K11 is disposed between the second neutral line and the second ac connection terminal.

In one embodiment, the external battery 01 is charged by the in-phase control of the third ac charging circuit through the in-phase positive half-cycle charging control and the in-phase negative half-cycle charging control respectively, wherein the in-phase positive half-cycle charging control process includes an in-phase positive half-cycle charging energy storage process, an in-phase positive half-cycle charging energy storage release process, and the in-phase negative half-cycle charging control process includes an in-phase negative half-cycle charging energy storage process and an in-phase negative half-cycle charging energy storage release process;

as shown in fig. 24, when the energy conversion device is in the charging and energy storing process of the same-phase positive half-cycle, the current in the third ac charging circuit sequentially flows through the first end of the third external ac charging and discharging port, the first neutral line, the first motor coil 12, the first bridge arm converter 11, the second bridge arm converter 21, the second motor coil 22, the second neutral line, and the second end of the third external ac charging and discharging port;

as shown in fig. 25, when the energy conversion device is in the same-phase positive half-cycle charging energy storage releasing process, the current in the third ac charging circuit sequentially flows through the first end of the third external ac charging/discharging port, the first neutral line, the first motor coil 12, the first bridge arm converter 11, the external battery 01, the second bridge arm converter 21, the second motor coil 22, the second neutral line, and the second end of the third external ac charging/discharging port;

as shown in fig. 26, when the energy conversion device is in the charging and energy storing process of the same-phase negative half-cycle, the current in the third ac charging circuit sequentially flows through the first end of the third external ac charging and discharging port, the second neutral line, the second motor coil 22, the second bridge arm converter 21, the first bridge arm converter 11, the first motor coil 12, the first neutral line, and the second end of the third external ac charging and discharging port;

as shown in fig. 27, when the energy conversion device is in the releasing process of the in-phase negative half-cycle charging energy storage, the current in the third ac charging circuit sequentially flows through the first end of the third external ac charging/discharging port, the second neutral line, the second motor coil 22, the second bridge arm converter 21, the external battery 01, the first bridge arm converter 11, the first motor coil 12, the first neutral line, and the second end of the third external ac charging/discharging port.

In one embodiment, the third ac discharging circuit is controlled to discharge by the same phase positive half-cycle discharge control and the same phase negative half-cycle discharge control respectively through the same phase positive half-cycle discharge control and the same phase negative half-cycle discharge control, the same phase positive half-cycle discharge control process includes the same phase positive half-cycle discharge energy storage process and the same phase positive half-cycle discharge energy storage release process, and the same phase negative half-cycle discharge control process includes the same phase negative half-cycle discharge energy storage process and the same phase negative half-cycle discharge energy storage release process;

as shown in fig. 28, when the energy conversion device is in the discharging and energy storing process of the same phase positive half cycle, the current in the third ac charging circuit sequentially flows through the positive electrode of the external battery 01, the first bridge arm converter 11, the first motor coil 12, the first neutral line, the third external ac charging and discharging port, the second neutral line, the second bridge arm converter 21, and the negative electrode of the external battery 01;

as shown in fig. 29, when the energy conversion device is in the discharging and energy storing release process of the same phase positive half cycle, the current in the third ac charging circuit sequentially flows through the first motor coil 12, the first neutral line, the third external ac charging and discharging port, the second neutral line, the second motor coil 22, the second bridge arm converter 21, the first bridge arm converter 11, and the first motor coil 12;

as shown in fig. 30, when the energy conversion device is in the discharging and energy storing process of the same phase negative half cycle, the current in the third ac charging circuit sequentially flows through the positive electrode of the external battery 01, the second bridge arm converter 21, the second motor coil 22, the second neutral line, the third external ac charging and discharging port, the first neutral line, the first motor coil 12, the first bridge arm converter 11, and the negative electrode of the external battery 01;

as shown in fig. 31, when the energy conversion device is in the discharging and energy storing release process of the same phase negative half-cycle, the current in the third ac charging circuit sequentially flows through the second motor coil 22, the second neutral line, the third external ac charging and discharging port, the first neutral line, the first motor coil 12, the first bridge arm converter 11, the second bridge arm converter 21, and the second motor coil 22.

In one embodiment, the first motor coil and the second motor coil are coils of the same motor or coils of different motors.

Wherein, the first charge-discharge circuit and the second charge-discharge circuit can be charged and discharged at the same time or by time-sharing DC, under the state, the flow direction of the current when the first charge-discharge circuit and the second charge-discharge circuit simultaneously perform dc charge and energy storage is shown in fig. 14, the flow direction of the current when the first charge-discharge circuit and the second charge-discharge circuit simultaneously perform dc charge and energy storage release is shown in fig. 15, the flow direction of the current when the first charge-discharge circuit performs dc charge and energy storage and the second charge-discharge circuit performs dc charge and energy storage release is shown in fig. 16, the flow direction of the current when the first charge-discharge circuit performs dc charge and energy storage and the second charge-discharge circuit performs dc charge and energy storage release is shown in fig. 17, the flow direction of the current when the first charge-discharge circuit performs dc charge and energy storage and the second charge-discharge circuit performs dc discharge and energy storage release is shown in fig. 18, and the flow direction of the current when the first charge-discharge circuit performs.

In this state, the flow direction of the current when the first charge-discharge circuit stores energy through direct current charging and the second charge-discharge circuit stores energy through alternating current charging is shown in fig. 20, the flow direction of the current when the first charge-discharge circuit stores energy through direct current charging and the second charge-discharge circuit stores energy through alternating current charging is shown in fig. 21, the flow direction of the current when the first charge-discharge circuit stores energy through direct current charging and the second charge-discharge circuit stores energy through alternating current discharging is shown in fig. 22, and the flow direction schematic diagram of the current when the first charge-discharge circuit stores energy through direct current charging and the second charge-discharge circuit stores energy through alternating current discharging is shown in fig. 23.

In the scheme, the scheme of combining one synchronous motor and one asynchronous motor in the dual-motor driving system has the following efficiency characteristics that: when the asynchronous motor works at light load or close to no load, the efficiency of the induction motor is reduced at a high speed, even the efficiency can be reduced to 20%, when the induction motor runs at full load, the utilization rate of the motor is high, two motors can be switched according to working conditions during actual use, the synchronous motor is taken as the leading part during light load, the asynchronous motor is taken as the leading part during high-speed heavy load, the running efficiency of the whole system under different working conditions is improved, the efficiency corresponding to the rotating speed and torque curves of the two motors is combined for control, the whole vehicle system is controlled to be in a high-efficiency running area, the electric quantity is saved, and the endurance mileage of a battery is improved.

In one embodiment, the energy conversion device further includes a detection control module 04, the detection control module 04 is respectively connected to the first bridge arm converter 11, the second bridge arm converter 12 and all the switches, and the detection control module 04 is configured to control the on/off of the first bridge arm converter 11, the second bridge arm converter 12 and each switch, so that the energy conversion device can work in different charge and discharge states.

For the scheme of combining multiple motor drive systems, such as a four-wheel drive system and a three-wheel drive system, the control concept and the control method can be adopted for control.

As shown in fig. 14 and 15, the first bus capacitor C1 may be precharged by controlling the switches K1, K2 and K3, keeping the switches K3, K4, K5, K6, K7, K8, K9, K10 and K11 open, closing the switch K3 after precharging is completed, and opening the switch K2. When the insertion of double charge-discharge guns is detected, after a target voltage value sent by a battery manager is detected, the fourth switch K4 and the seventh switch K7 are closed, the charging control is carried out on a charging port capacitor, after the target value is reached, the voltage reduction of a sending system is completed, the fifth switch K5, the sixth switch K6, the eighth switch K8 and the ninth switch K9 are closed for charging, the target value is not reached, the voltage reduction is failed to send, and all switches are disconnected.

Fig. 14 is a schematic diagram of current flow in the process of storing energy in the inductance of the motor during the dc charging process, the detection control circuit 8 controls the switch VT2, the switch VT4, the switch VT6 to be turned on, the switch VT1, the switch VT3, the switch VT5 to be turned off, the switch VT22, the switch VT24, the switch VT26 to be turned on, the switch VT21, the switch VT23, and the switch VT25 to be turned off, and the current flow is as follows: the positive electrode of the direct current charging and discharging port 1 → the fifth switch K5 → the first end of the second capacitor C2 → the fourth switch K4 → the motor N1 line → the winding of the alternating current motor 1 → the switch VT2, the switch VT4, the switch VT6 → the sixth switch K6 → the negative electrode of the direct current charging and discharging port 1; the positive electrode of the dc charge/discharge port 2 → the eighth switch K8 → the first end of the fourth capacitor C4 → the seventh switch K7 → the motor N2 line → the winding of the ac motor 2 → the switch VT2, the switch VT4, the switch VT6 → the ninth switch K9 → the negative electrode of the dc charge/discharge port 2, and the windings of the first motor coil 12 and the second motor coil 22 are charged with energy.

As shown in fig. 15, in the dc charging process, the current flows to the schematic diagram in the process of releasing the stored energy in the inductance of the motor, the detection control circuit 8 controls the switch VT2, the switch VT4, the switch VT6, the switch VT1, the switch VT3, the switch VT5 to turn off, controls the switch VT22, the switch VT24, the switch VT26, the switch VT21, the switch VT23, and the switch VT25 to turn off, and the current flows to: the positive electrode of the dc charge and discharge port 1 → the fifth switch K5 → the first end of the second capacitor C2 → the fourth switch K4 → the first neutral line N1 → the winding of the ac motor 1 → the switch VD1, the switch VD3, the switch VD5 → the first switch K1 → the external battery → the third switch K3 → the sixth switch K6 → the negative electrode of the dc charge and discharge port 1; the positive electrode of the dc charge/discharge port 2 → the eighth switch K8 → the first end of the fourth capacitor C4 → the seventh switch K7 → the motor N2 line → the winding of the ac motor 2 → the switch VD21, the switch VD23, the switch VD25 → K1 → the external battery → the third switch K3 → the ninth switch K9 → the negative electrode of the dc charge/discharge port 2, and the stored energy is released from the windings of the first motor coil 12 and the second motor coil 22.

The control process in fig. 14 and 15 may control the vehicle alternately, and the PWM (Pulse width modulation) duty cycle magnitude of the switch VT2, the switch VT4, the switch VT6, the switch VT22, the switch VT24, and the switch VT26 are controlled to be turned on controls the magnitude of the current for charging the battery.

The current flows in the mode of controlling the double-motor driving system in a wrong phase mode as shown in figures 16 and 17. The implementation process of controlling the switches of the motor driving system 1 and the motor driving system 2 to stagger a certain angle is as follows.

The bus capacitor C1 is precharged by controlling the switch K1, the second switch K2 and the third switch K3, the third switch K3, the fourth switch K4, the fifth switch K5, the sixth switch K6, the seventh switch K7, the eighth switch K8, the ninth switch K9, the tenth switch K10 and the eleventh switch K11 are kept to be disconnected, the third switch K3 is closed after precharging is finished, and the second switch K2 is disconnected. When the insertion of double charge-discharge guns is detected, after a target voltage value sent by a battery manager is detected, the fourth switch K4 and the seventh switch K7 are closed, the charging control is carried out on a charging port capacitor, after the target value is reached, the voltage reduction of a sending system is completed, the fifth switch K5, the sixth switch K6, the eighth switch K8 and the ninth switch K9 are closed for charging, the target value is not reached, the voltage reduction is failed to send, and all switches are disconnected.

Fig. 16 dual motor drive system dc charging: in the direct current charging process, the motor inductance energy storage of the motor driving system 1 is realized, the current flow direction schematic diagram in the motor inductance energy storage releasing process of the motor driving system 2 is realized, the detection control circuit 8 controls the switch VT2, the switch VT4 and the switch VT6 to be switched on, the switch VT1, the switch VT3 and the switch VT5 to be switched off, the control switch VT22, the switch VT24, the switch VT26, the switch VT21, the switch VT23 and the switch VT25 are switched off, and the current flow direction is as follows: the positive pole of the direct current charging and discharging port 1 → the fifth switch K5 → the first end of the second capacitor C2 → the fourth switch K4 → the first neutral line N1 → the winding of the alternating current motor 1 → the switch VT2, the switch VT4, the switch VT6 → the sixth switch K6 → the negative pole of the direct current charging and discharging port 1, and the energy is stored in the winding of the alternating current motor 1; the positive electrode of the direct current charging and discharging port 2 → the eighth switch K8 → the first end of the fourth capacitor C4 → the seventh switch K7 → the motor N2 line → the winding of the alternating current motor 2 → the switch VD21, the switch VD23, the switch VD25 → the first switch → the battery → the third switch K3 → the ninth switch K9 → the negative electrode of the direct current charging and discharging port 2, and the stored energy is released from the winding of the alternating current motor 2;

fig. 17 dc charging of the two-motor drive system: the current flow direction schematic diagram of the motor inductance energy storage release process in the direct current charging process is that the detection control circuit 8 controls the switch VT2, the switch VT4 and the switch VT6, the switch VT1, the switch VT3 and the switch VT5 are turned off, the switch VT22, the switch VT24 and the switch VT26 are turned on, the switch VT21, the switch VT23 and the switch VT25 are turned off, and the current flow direction is as follows: the positive electrode of the direct current charging and discharging port 1 → the fifth switch K5 → the first end of the second capacitor C2 → the fourth switch K4 → the first neutral line N1 → the winding of the alternating current motor 1 → the switch VD1, the switch VD3, the switch VD5 → the first switch → the battery → the third switch K3 → the sixth switch K6 → the negative electrode of the direct current charging and discharging port 1, and the stored energy is released from the winding of the alternating current motor 1; the positive electrode of the dc charge/discharge port 2 → the eighth switch K8 → the first end of the fourth capacitor C4 → the seventh switch K7 → the motor N2 line → the winding of the ac motor 2 → the switch VT2, the switch VT4, the switch VT6 → the ninth switch K9 → the negative electrode of the dc charge/discharge port 2, and stores energy in the winding of the ac motor 2.

The vehicle is controlled by controlling the processes of fig. 16 and 17 alternately, the switch VT2, the switch VT4 and the switch VT6 are controlled, and the magnitude of the PWM duty ratio of the conduction of the switch VT22, the switch VT24 and the switch VT26 controls the magnitude of the current charged by the battery.

When the dc charging is performed and the dc discharging is performed, the current flows during the ac discharging as shown in fig. 18 and 19, and the energy of the dc charging can be converted into the dc power through the dc charging/discharging interface to power other electric devices.

Fig. 18 dc charging with dc discharging: the motor of the motor driving system 1 stores energy through the motor inductance, and meanwhile, the current flows to a schematic diagram in the process of releasing the motor inductance energy storage of the motor driving system 2, the switch VT2, the switch VT4 and the switch VT6 are controlled to be switched on by the detection control circuit 8, the switch VT1, the switch VT3 and the switch VT5 are switched off, the switch VT22, the switch VT24 and the switch VT26 are controlled to be switched off, the switch VT21, the switch VT23 and the switch VT25 are switched off, and the current flows to: the positive pole of the direct current charging and discharging port 1 → the fifth switch K5 → the first end of the second capacitor C2 → the fourth switch K4 → the first neutral line N1 → the winding of the alternating current motor 1 → the switch VT2, the switch VT4, the switch VT6 → the sixth switch K6 → the negative pole of the direct current charging and discharging port 1, and the energy is stored in the winding of the alternating current motor 1; alternating current motor 2 winding → motor N2 line → seventh switch K7 → first end of fourth capacitor C4 → eighth switch K8 → positive electrode of dc charge/discharge port 2 → negative electrode of dc charge/discharge port 2 → ninth switch K9 → switch VD22, switch VD24, switch VD26 → alternating current motor 2 winding, and the stored energy is released to the alternating current motor 2 winding.

Fig. 19 dc charging with dc discharging: the motor inductance energy storage of the motor driving system 1 is released, meanwhile, the motor inductance energy storage process current of the motor driving system 2 flows to a schematic diagram, the detection control circuit 8 controls the switch VT2, the switch VT4, the switch VT6, the switch VT1, the switch VT3 and the switch VT5 to be turned off, the control switch VT21, the switch VT23 and the switch VT25 to be turned on, the switch VT22, the switch VT24 and the switch VT26 to be turned off, and the current flows to: the positive electrode of the direct current charging and discharging port 1 → the fifth switch K5 → the first end of the second capacitor C2 → the fourth switch K4 → the first neutral line N1 → the winding of the alternating current motor 1 → the switch VD1, the switch VD3, the switch VD5 → the first switch → the battery → the third switch K3 → the sixth switch K6 → the negative electrode of the direct current charging and discharging port 1, and the stored energy is released from the winding of the alternating current motor 1; the first capacitor C1 dc bus positive pole → the switch VT21, the switch VT23, the switch VT25 → the ac motor 2 winding → the motor N2 line → the seventh switch K7 → the first end of the fourth capacitor C4 → the eighth switch K8 → the dc charging/discharging port 2 positive pole → the dc charging/discharging port 2 negative pole → the ninth switch K9 → C1 dc bus negative pole, and stores energy in the ac motor 2 winding.

As shown in fig. 20 and 21, the current flow direction of the dc charging and the ac charging of the first and second charging and discharging circuits can simultaneously use the energy of the dc charging and the electric energy of the ac power grid to charge the battery, and one of the switching control methods is implemented as follows.

Fig. 20 dc charging with ac charging: the motor inductance of the motor driving system 1 stores energy, and meanwhile, the motor inductance of the motor driving system 2 and the energy storage process current of the first inductance L1 flow direction schematic diagram, the detection control circuit 8 controls the switch VT2, the switch VT4 and the switch VT6 to be switched on, the switch VT1, the switch VT3 and the switch VT5 to be switched off, the control switch VT21, the switch VT23, the switch VT25, the switch VT22, the switch VT24, the switch VT26 and the switch VT8 to be switched off, the switch VT7 to be switched on, and the current flow direction is as follows: the positive pole of the direct current charging and discharging port 1 → the fifth switch K5 → the first end of the second capacitor C2 → the fourth switch K4 → the first neutral line N1 → the winding of the alternating current motor 1 → the switch VT2, the switch VT4, the switch VT6 → the sixth switch K6 → the negative pole of the direct current charging and discharging port 1, and the energy is stored in the winding of the alternating current motor 1; ac charge/discharge port → fourteenth switch K14 → second neutral line → ac motor 2 winding → switch VD21, switch VD23, switch VD25 → VT7 → first inductor L1 → fifteenth switch K15 → ac charge/discharge port, and stores energy in ac motor 2 winding and first inductor L1.

Fig. 21 dc charging while ac charging: the stored energy of the motor inductance of the motor driving system 1 is released, and simultaneously the stored energy of the motor inductance of the motor driving system 2 and the stored energy of the first inductance L1 flow to a schematic diagram, the detection control circuit 8 controls the switch VT2, the switch VT4, the switch VT6, the switch VT1, the switch VT3 and the switch VT5 to be turned off, the control switch VT21, the switch VT23, the switch VT25, the switch VT8, the switch VT22, the switch VT24, the switch VT26 and the switch VT7 are turned off, and the current flows to: the positive electrode of the direct current charging and discharging port 1 → the fifth switch K5 → the first end of the second capacitor C2 → the fourth switch K4 → the first neutral line → the winding of the alternating current motor 1 → the switch VD1, the switch VD3, the switch VD5 → the first switch → the battery → the third switch K3 → the sixth switch K6 → the negative electrode of the direct current charging and discharging port 1, and the stored energy is released to the winding of the alternating current motor 1 and the first inductor L1; the ac charging/discharging port → the fourteenth switch K14 → the second neutral line → the ac motor 2 winding → the switch VD21, the switch VD23, the switch VD25 → the switch VT7 → the first switch K1 → the external battery → the third switch K3 → VD8 → the first inductor L1 → the fifteenth switch K15 → the ac charging/discharging port, and the stored energy is released to the ac motor 2 winding and the first inductor L1;

the current flow direction during the dc charging and the ac discharging is as shown in fig. 22 and fig. 23, and the energy of the dc charging can be converted into the ac power through the ac charging and discharging interface and fed back to the power grid or used for other electric devices, wherein the implementation process of one of the switching control modes is as follows.

Fig. 22 dc charging with ac discharging: the motor inductance of the motor driving system 1 stores energy, and simultaneously the motor inductance of the motor driving system 2 and the stored energy release process current of the first inductance L1 flow to a schematic diagram, the detection control circuit 8 controls the switch VT2, the switch VT4 and the switch VT6 to be switched on, the switch VT1, the switch VT3 and the switch VT5 to be switched off, the control switch VT21, the switch VT23 and the switch VT25 to be switched on, the switch VT22, the switch VT24, the switch VT26, the switch VT7 and the switch VT8 to be switched off, and the current flow is as follows: the positive electrode of the direct current charging and discharging port 1 → the fifth switch K5 → the first end of the second capacitor C2 → the fourth switch K4 → the motor N1 line → the winding of the alternating current motor 1 → the switch VT2, the switch VT4, the switch VT6 → the sixth switch K6 → the negative electrode of the direct current charging and discharging port 1, and the energy is stored in the winding of the alternating current motor 1; ac motor 2 winding → fourteenth switch K14 → ac charging/discharging port → fifteenth switch K15 → first inductor L1 → switch VT7 → switch VT21, switch VT23, switch VT25 → ac motor 2 winding, and the stored energy is released to ac motor 2 winding and first inductor L1.

Fig. 23 dc charging with ac discharging: the stored energy of the motor inductance of the motor driving system 1 is released, and simultaneously the stored energy process current of the motor inductance of the motor driving system 2 and the stored energy process current of the first inductance L1 flow to a schematic diagram, the detection control circuit 8 controls the switch VT2, the switch VT4 and the switch VT6, the switch VT1, the switch VT3 and the switch VT5 to be turned off, the control switch VT21, the switch VT23, the switch VT25 and the switch VT8 are turned on, the switch VT22, the switch VT24, the switch VT26 and the switch VT7 are turned off, and the current flow direction is as follows: the positive electrode of the direct current charging and discharging port 1 → the fifth switch K5 → the first end of the second capacitor C2 → the fourth switch K4 → the first neutral line → the winding of the alternating current motor 1 → the switch VD1, the switch VD3, the switch VD5 → the first switch K1 → the battery → the third switch K3 → the sixth switch K6 → the negative electrode of the direct current charging and discharging port 1, and the stored energy is released from the winding of the alternating current motor 1; c1 dc bus positive pole → switch VT21, switch VT23, switch VT25 → ac motor 2 winding → second neutral line → fourteenth switch K14 → ac charging/discharging port → fifteenth switch K15 → first inductor L1 → VT8 → first capacitor C1 dc bus negative pole, and stores energy in ac motor 2 winding and first inductor L1.

According to a second embodiment of the present invention, an energy conversion apparatus is provided, which includes the energy conversion apparatus provided in the first embodiment of the present invention, and further includes an energy storage connection terminal group, a first charge-discharge port connection terminal group, and a second charge-discharge port connection terminal group;

the energy storage connecting terminal group comprises a first energy storage connecting terminal and a second energy storage connecting terminal, the first energy storage connecting terminal is connected with the anode of the external battery 01, and the first energy storage connecting terminal is connected with the cathode of the external battery 01;

the first charging and discharging port connecting end group comprises a first sub charging and discharging connecting end and a second sub charging and discharging connecting end, the first sub charging and discharging connecting end is connected with the first motor coil 12, and the second sub charging and discharging connecting end is connected with the second confluence end or the midpoint of the bidirectional bridge arm;

the second charging and discharging port connecting end group comprises a third sub charging and discharging connecting end and a fourth sub charging and discharging connecting end, the third sub charging and discharging connecting end is connected with the second motor coil 22, and the fourth sub charging and discharging connecting end is connected with the second confluence end or the midpoint of the bidirectional bridge arm.

In one embodiment, the energy conversion device further includes a third charge-discharge port connection terminal group, the third charge-discharge port connection terminal group includes a fifth sub charge-discharge connection terminal and a sixth sub charge-discharge connection terminal, the fifth sub charge-discharge connection terminal is connected to the first neutral line, and the sixth sub charge-discharge connection terminal is connected to the second neutral line.

According to a third embodiment of the present invention, there is provided an automobile including the above-described energy conversion apparatus.

The automobile provided by the embodiment comprises the energy conversion device, and is characterized in that a first charge-discharge circuit formed by an external battery, the first bridge arm converter, the first motor coil and a first external charge-discharge port and a second charge-discharge circuit formed by the external battery, the second bridge arm converter, the second motor coil and a second external charge-discharge port are designed, so that the energy conversion device and the automobile can charge an external power battery through different charge-discharge circuits and correspondingly discharge the external power battery through different charge-discharge circuits, the energy conversion device provides two sets of charge-discharge circuits for the automobile, the automobile can be charged and discharged in a conventional mode, and the automobile can be charged and discharged through the automobile at the same time or in different time, so that the charge-discharge capacity of the automobile is improved.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-mentioned functions.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should 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; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.

Claims

1. An energy conversion device is characterized by comprising a first bridge arm converter, a first motor coil, a second bridge arm converter and a second motor coil, wherein the first motor coil is connected to the first bridge arm converter, and the second motor coil is connected to the second bridge arm converter;

the external battery, the first bridge arm converter, the first motor coil and the first external charging and discharging port form a first charging and discharging circuit, the external battery, the second bridge arm converter, the second motor coil and the second external charging and discharging port form a second charging and discharging circuit, the first charging and discharging circuit and the second charging and discharging circuit are connected between the positive electrode and the negative electrode of the external battery in parallel, two ends of the first external charging and discharging port are respectively connected to the first motor coil and the external battery, and two ends of the second external charging and discharging port are respectively connected to the second motor coil and the external battery;

the first charge-discharge circuit and the second charge-discharge circuit work simultaneously or in a time-sharing mode.

2. The energy conversion device according to claim 1, wherein the first charge and discharge circuit includes a first charge circuit that charges the external battery and a first discharge circuit that discharges through the first external charge and discharge port, and the second charge and discharge circuit includes a second charge circuit that charges the external battery and a second discharge circuit that discharges through the second external charge and discharge port;

the first charging circuit and the first discharging circuit work in a time-sharing mode, and the second charging circuit and the second discharging circuit work in a time-sharing mode.

3. The energy conversion device according to claim 2, wherein the first external charging/discharging port is a first external dc charging/discharging port or a first external ac charging/discharging port, the second external charging/discharging port is a second external dc charging/discharging port or a second external ac charging/discharging port, and the operating states of the first charging/discharging circuit and the second charging/discharging circuit include:

the first charge-discharge circuit and the second charge-discharge circuit are charged by direct current at the same time or in a time-sharing manner;

the first charge-discharge circuit and the second charge-discharge circuit are charged by alternating current at the same time or in a time-sharing manner;

the first charge-discharge circuit and the second charge-discharge circuit discharge DC at the same time or in a time-sharing manner;

the first charge-discharge circuit and the second charge-discharge circuit are subjected to alternating current discharge at the same time or in a time-sharing manner;

the first charge-discharge circuit is charged by direct current, and the second charge-discharge circuit is discharged by alternating current at the same time or in a time-sharing manner;

the first charge-discharge circuit is used for direct current discharge, and the second charge-discharge circuit is used for alternating current charge at the same time or in a time-sharing manner;

the first charging and discharging circuit is charged by alternating current, and the second charging and discharging circuit is discharged by direct current at the same time or in a time-sharing manner;

the first charging and discharging circuit performs alternating current discharging, and the second charging and discharging circuit performs direct current charging at the same time or in a time-sharing manner.

4. The energy conversion device of claim 2, wherein the first motor coil comprises a set of m₁A phase winding, the first leg converter including M₁Road bridge arm, said m₁Each of the phase windings includes n₁A coil branch of n for each phase winding₁The coil branches are connected together to form a phase terminal point, m₁Phase end point of phase winding and M₁The middle points of each of the road bridge arms are connected in one-to-one correspondence, and m is₁N of each of the phase windings₁One of the coil branches is also respectively connected with n of other phase windings₁One of the coil branches is connected to form n₁A connection point, said n₁A connection point forming n₁A neutral point, said n₁The neutral points comprise independent neutral points formed by one connecting point and/or non-independent neutral points formed by connecting at least two connecting points, and n is₁A first neutral line is led out from each neutral point, the first neutral line is connected with the first external charging and discharging port, the bridge arms of each phase of the first bridge arm converter are connected in parallel to form a first bus end and a second bus end, the first bus end is connected with the anode of the external battery, the second bus end is connected with the cathode of the external battery, and the n₁≥1，m₁≥2，m₁＝M₁And n is₁、m₁And M₁Are all integers.

5. The energy conversion device of claim 4, further comprising a first capacitor connected in parallel with the external battery, a first end of the first capacitor connected to the first bus bar and a second end of the first capacitor connected to the second bus bar.

6. The energy conversion device according to claim 5, further comprising a first switch, a second switch, a third switch, and a resistor R, wherein the second switch is connected in series with the resistor R and then connected in parallel with the first switch between the positive electrode of the external battery and the first bus terminal, and the third switch is provided between the negative electrode of the external battery and the second bus terminal.

7. The energy conversion device according to claim 5, wherein the first external charging/discharging port is a first external DC charging/discharging port, and further comprising a second capacitor, a first end of the first external DC charging/discharging port is connected to a first end of the second capacitor and the first neutral line, respectively, and a second end of the first external DC charging/discharging port is connected to a second end of the second capacitor and the second bus end, respectively.

8. The energy conversion device according to claim 7, wherein the process of charging the external battery by the first charging circuit includes a first dc charging energy storage process and a first dc charging energy storage release process;

when the energy conversion device is in a first direct-current charging and energy storing process, the current in the first direct-current charging circuit sequentially flows through a first end of the first external direct-current charging and discharging port, the first neutral line, a winding of a first motor coil connected with the first neutral line, a lower bridge arm of the first bridge arm converter and a second end of the first external direct-current charging and discharging port;

when the energy conversion device is in a first direct-current charging energy storage release process, the current in the first direct-current charging circuit sequentially flows through a first end of the first external direct-current charging and discharging port, the first neutral line, a winding of a first motor coil connected with the first neutral line, an upper bridge arm of the first bridge arm converter, the external battery and a second end of the first external direct-current charging and discharging port.

9. The energy conversion device of claim 7, further comprising a first inductor disposed on a line between the first neutral line and the first end of the first external charge-discharge port.

10. The energy conversion device according to claim 7, further comprising a fourth switch provided on a connection between the first neutral line and the second capacitor, a fifth switch provided on a connection between the second capacitor and the first end of the first external direct current charging and discharging port, and a sixth switch provided between the second capacitor and the second end of the first external direct current charging and discharging port.

11. The energy conversion device of claim 5, wherein the second motor coil comprises a set of m₂A phase winding, the first leg converter including M₂A bridge arm, each of the m2 phase windings comprising n₂A coil branch of n for each phase winding₂The coil branches are connected together to form a phase terminal point, m₂Phase end point of phase winding and M₂The middle points of each of the road bridge arms are connected in one-to-one correspondence, and m is₂N of each of the phase windings₂One of the coil branches is also respectively connected with n of other phase windings₂One of the coil branches is connected to form n₂A connection point, said n₂A connection point is formedn₂A neutral point, said n₂The neutral points comprise independent neutral points formed by one connecting point and/or non-independent neutral points formed by connecting at least two connecting points, and n is₂A second neutral line is led out from each neutral point, the second neutral line is connected with the second external charging and discharging port, the bridge arms of each phase of the second bridge arm converter are connected in parallel to form a third bus end and a fourth bus end, the third bus end is connected with the anode of the external battery, the fourth bus end is connected with the cathode of the external battery, and the n₂≥1，m₂≥2，m₂＝M₂And n is₂、m₂And M₂Are all integers.

12. The energy conversion device according to claim 11, further comprising a third capacitor, wherein a first end of the third capacitor is connected to a positive electrode of the external battery after being connected in parallel with a first end of the first capacitor, and a second end of the third capacitor is connected to a negative electrode of the external battery after being connected in parallel with a second end of the first capacitor.

13. The energy conversion device according to claim 4, wherein the first external charging/discharging port is a first external AC charging/discharging port, and further comprising a first bridge arm, the first external AC charging/discharging port comprises a first AC connection end and a second AC connection end, the first AC connection end is connected to the first neutral line, the second AC connection end is connected to a midpoint of the first bridge arm, an upper bridge arm of the first bridge arm is connected to the first bus end, and a lower bridge arm of the first bridge arm is connected to the second bus end.

14. The energy conversion device of claim 13, wherein the first charging circuit comprises a first ac charging circuit, and the process of charging the external battery by the first ac charging circuit comprises a first ac charging energy storage process and a first ac charging energy storage release process;

when the energy conversion device is in a first alternating-current charging energy storage process, current in the first alternating-current charging circuit sequentially flows through the first alternating-current connecting end, the first neutral line, a winding of a first motor coil connected with the first neutral line, an upper bridge arm of the first bridge arm converter, the external battery, the upper bridge arm of the first bridge arm and the second alternating-current connecting end;

when the energy conversion device is in a first alternating-current charging energy storage release process, current in the first alternating-current charging circuit sequentially flows through the first alternating-current connecting end, the first neutral line, a winding of a first motor coil connected with the first neutral line, an upper bridge arm of the first bridge arm converter, the external battery, a lower bridge arm of the first bridge arm and the second alternating-current connecting end;

or when the energy conversion device is in a first alternating-current charging energy storage process, the current in the first alternating-current charging circuit sequentially flows through the second alternating-current connecting end, the upper bridge arm of the first bridge arm converter, the winding of the first motor coil, the first neutral line and the first alternating-current connecting end;

15. The energy conversion device of claim 13, wherein the first discharge circuit comprises a first ac discharge circuit, and the process of discharging by the first ac discharge circuit comprises a first ac discharge energy storage process and a first ac discharge energy storage release process;

when the energy conversion device is in a first alternating-current discharging energy storage process, the current in the first alternating-current discharging circuit sequentially flows through the positive electrode of the battery, the upper bridge arm of the first bridge arm converter, the winding of the first motor coil, a first neutral wire connected with the winding of the first motor coil, the first external alternating-current charging and discharging port, the lower bridge arm of the first bridge arm and the negative electrode of the battery;

when the energy conversion device is in a first alternating-current discharge energy storage release process, the current in the first alternating-current discharge circuit sequentially flows through a winding of the first motor coil, a first neutral line connected with the winding of the first motor coil, the first external alternating-current charge-discharge port, an upper bridge arm of the first bridge arm converter and a winding of the first motor coil;

or when the energy conversion device is in a first alternating-current discharge energy storage process, the current in the first alternating-current discharge circuit sequentially flows through the positive electrode of the battery, the upper bridge arm of the first bridge arm, the first external alternating-current charge-discharge port, a first neutral wire connected with the winding of the first motor coil, the lower bridge arm of the first bridge arm converter and the negative electrode of the battery;

16. The energy conversion device of claim 13, further comprising a third inductor disposed between the second ac connection end and the midpoint of the first leg.

17. The energy conversion device of claim 13 further comprising a twelfth switch disposed between the first ac connection terminal and the first neutral line and a thirteenth switch disposed between the second ac connection terminal and the midpoint of the first leg.

18. The energy conversion device of claim 11, further comprising a third external ac charging and discharging port, the third external ac charging and discharging port being connected to the first neutral line and the second neutral line, respectively;

the external battery, the first bridge arm converter, the first motor coil, the third external ac charging/discharging port, the second motor coil, and the second bridge arm converter form a third ac charging circuit that charges the external battery or a third ac discharging circuit that discharges through the third external charging/discharging port.

19. The energy conversion device of claim 18, further comprising a tenth switch and an eleventh switch, wherein the third external charge-discharge port comprises a fifth ac connection terminal and a sixth ac connection terminal, the fifth ac connection terminal is connected to the first neutral line, the sixth ac connection terminal is connected to the second neutral line, the tenth switch is disposed between the first neutral line and the first ac connection terminal, and the eleventh switch is disposed between the second neutral line and the second ac connection terminal.

20. The energy conversion device of claim 18, wherein the third ac charging circuit is controlled in phase to charge the external battery through an in-phase positive half-cycle charging control and an in-phase negative half-cycle charging control, respectively, wherein the in-phase positive half-cycle charging control process comprises an in-phase positive half-cycle charging energy storage process, an in-phase positive half-cycle charging energy storage release process, and the in-phase negative half-cycle charging control process comprises an in-phase negative half-cycle charging energy storage process and an in-phase negative half-cycle charging energy storage release process;

when the energy conversion device is in the same-phase positive half-cycle charging and energy storing process, the current in the third alternating current charging circuit sequentially flows through the first end of the third external alternating current charging and discharging port, the first neutral line, the first motor coil, the first bridge arm converter, the second motor coil, the second neutral line and the second end of the third external alternating current charging and discharging port;

when the energy conversion device is in the same-phase positive half-cycle charging energy storage release process, the current in the third alternating-current charging circuit sequentially flows through the first end of the third external alternating-current charging and discharging port, the first neutral line, the first motor coil, the first bridge arm converter, the external battery, the second bridge arm converter, the second motor coil, the second neutral line and the second end of the third external alternating-current charging and discharging port;

when the energy conversion device is in the same-phase negative half-cycle charging and energy storing process, the current in the third alternating current charging circuit sequentially flows through the first end of the third external alternating current charging and discharging port, the second neutral line, the second motor coil, the second bridge arm converter, the first motor coil, the first neutral line and the second end of the third external alternating current charging and discharging port;

when the energy conversion device is in the same-phase negative half-cycle charging energy storage release process, the current in the third alternating-current charging circuit sequentially flows through the first end of the third external alternating-current charging and discharging port, the second neutral line, the second motor coil, the second bridge arm converter, the external battery, the first bridge arm converter, the first motor coil, the first neutral line and the second end of the third external alternating-current charging and discharging port.

21. The energy conversion device of claim 18, wherein the third ac discharging circuit is controlled to discharge by an in-phase positive half-cycle discharge control and an in-phase negative half-cycle discharge control respectively in phase, wherein the in-phase positive half-cycle discharge control process comprises an in-phase positive half-cycle discharge energy storage process and an in-phase positive half-cycle discharge energy storage release process, and the in-phase negative half-cycle discharge control process comprises an in-phase negative half-cycle discharge energy storage process and an in-phase negative half-cycle discharge energy storage release process;

when the energy conversion device is in the same-phase positive half-cycle discharging and energy storing process, the current in the third alternating current charging circuit sequentially flows through the positive electrode of the external battery, the first bridge arm converter, the first motor coil, the first neutral line, the third external alternating current charging and discharging port, the second neutral line, the second bridge arm converter and the negative electrode of the external battery;

when the energy conversion device is in the discharging and energy storing release process of the same-phase positive half period, the current in the third alternating current charging circuit sequentially flows through the first motor coil, the first neutral line, the third external alternating current charging and discharging port, the second neutral line, the second motor coil, the second bridge arm converter, the first bridge arm converter and the first motor coil;

when the energy conversion device is in the discharging and energy storing process of the same-phase negative half-cycle, the current in the third alternating-current charging circuit sequentially flows through the positive electrode of the external battery, the second bridge arm converter, the second motor coil, the second neutral line, the third external alternating-current charging and discharging port, the first neutral line, the first motor coil, the first bridge arm converter and the negative electrode of the external battery;

when the energy conversion device is in the discharging and energy storing release process of the same-phase negative half-cycle, the current in the third alternating-current charging circuit sequentially flows through the second motor coil, the second neutral line, the third external alternating-current charging and discharging port, the first neutral line, the first motor coil, the first bridge arm converter, the second bridge arm converter and the second motor coil.

22. The energy conversion device of any one of claims 1 to 21, wherein the first and second motor coils are coils of the same motor or coils of different motors.

23. An energy conversion device, comprising the energy conversion device of any one of claims 1 to 21, further comprising an energy storage connection terminal group, a first charge-discharge port connection terminal group, and a second charge-discharge port connection terminal group;

the energy storage connecting end group comprises a first energy storage connecting end and a second energy storage connecting end, the first energy storage connecting end is connected with the anode of an external battery, and the first energy storage connecting end is connected with the cathode of the external battery;

24. The energy conversion device according to claim 23, further comprising a third charge-discharge port connection terminal group, wherein the third charge-discharge port connection terminal group comprises a fifth sub charge-discharge connection terminal and a sixth sub charge-discharge connection terminal, the fifth sub charge-discharge connection terminal is connected to the first neutral line, and the sixth sub charge-discharge connection terminal is connected to the second neutral line.

25. A vehicle, characterized in that the vehicle comprises an energy conversion device according to any one of claims 1 to 24.