CN112224058B

CN112224058B - Energy conversion device, power system and vehicle

Info

Publication number: CN112224058B
Application number: CN201910582142.6A
Authority: CN
Inventors: 刘伟冬; 王超; 王兴辉
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2019-06-30
Filing date: 2019-06-30
Publication date: 2022-03-15
Anticipated expiration: 2039-06-30
Also published as: CN112224058A

Abstract

Energy conversion device, driving system and vehicle. In the application, the energy conversion device with the functions of driving and charging the motor coil, the bridge arm converter, the bidirectional bridge arm and the first capacitor set is adopted, so that the energy conversion device can work in a driving mode, a direct current charging mode and an alternating current charging mode, further the motor driving and the battery charging of a vehicle are realized by adopting the same system, the multiplexing of the capacitors can improve the power conversion efficiency and the energy utilization rate during the direct current charging, reduce the noise generated by harmonic current at the side of a power grid during the alternating current charging and the pollution to the power grid, improve the power supply quality of the power grid, and can absorb the high-frequency switching frequency and higher harmonic generated by the bridge arm converter during the motor driving, store and store energy after the bridge arm converter is boosted, ensure that the bridge arm converter has stable and pure direct current bus voltage and high multiplexing degree of components, the system has high integration level and simple structure, thereby reducing the system cost and reducing the system volume.

Description

Energy conversion device, power system and vehicle

Technical Field

The application belongs to the technical field of electronics, especially relates to an energy conversion device, driving system and vehicle.

Background

With the development and rapid popularization of electric vehicles, motor control and battery charging of electric vehicles become more and more important. At present, the motor drive, the ac charging of the battery and the dc charging of the battery of the existing electric vehicle are all separated independently, and in order to ensure the charging power or the normal operation of the drive, a capacitor is usually required to be arranged in the drive circuit, the dc charging circuit and the ac charging circuit.

However, although the above method can effectively ensure the normal operation of the motor driving and the battery charging of the vehicle, the above method has a complicated circuit structure, a low integration level, a large volume and a high cost because the motor driving circuit and the battery charging circuit are independent and irrelevant to each other and each circuit needs to be separately provided with a capacitor.

In summary, the prior art has the problems of complex overall circuit structure, low integration level, large volume and high cost of the motor driving and charging system.

Disclosure of Invention

The application aims to provide an energy conversion device, a power system and a vehicle, and aims to solve the problems of complex structure, low integration level, large size and high cost of the overall circuit of the conventional motor driving and charging system.

The energy conversion device comprises a motor coil, a bridge arm converter, a bidirectional bridge arm and a first capacitor;

the bridge arm converter is respectively connected with the motor coil and the bidirectional bridge arm;

the motor coil, the bridge arm converter and the bidirectional bridge arm are all connected with an external charging port, and the bridge arm converter and the bidirectional bridge arm are all connected with an external battery;

the first capacitor is connected with the bidirectional bridge arm in parallel;

the motor coil, the bridge arm converter, the first capacitor and an external charging port form a direct current charging circuit to charge an external battery;

the motor coil, the bridge arm converter, the bidirectional bridge arm, the first capacitor and an external charging port form an alternating current charging circuit to charge an external battery;

the motor coil, the bridge arm converter, the first capacitor and an external battery form a motor driving circuit.

Another objective of the present application is to provide a power system, which includes the above energy conversion apparatus and a control module, when the first capacitor meets the discharging condition, the control module controls the energy conversion apparatus to discharge the voltage across the first capacitor.

It is also an object of the present application to provide a vehicle including the powertrain described above.

In the application, the energy conversion device with the functions of driving and charging the motor coil, the bridge arm converter, the bidirectional bridge arm and the first capacitor set is adopted, so that the energy conversion device can work in a driving mode, a direct current charging mode and an alternating current charging mode, further the motor driving and the battery charging of a vehicle are realized by adopting the same system, the multiplexing of the capacitors can improve the power conversion efficiency and the energy utilization rate during the direct current charging, reduce the noise generated by harmonic current at the side of a power grid during the alternating current charging and the pollution to the power grid, improve the power supply quality of the power grid, and the high-frequency switching frequency and higher harmonic generated by the bridge arm converter can be absorbed during the motor driving, the energy can be stored after the bridge arm converter is boosted, the stable and pure direct current bus voltage of the bridge arm converter is ensured, and the multiplexing degree of components is high, the system integration level is high, the structure is simple, the system cost is reduced, the system size is reduced, and the problems that the existing motor driving and charging system is complex in overall structure, low in integration level, large in size and high in cost are solved.

Drawings

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

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

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

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

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

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

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

fig. 8 is a schematic circuit diagram of an energy conversion device according to an eighth embodiment of the present application;

fig. 9 is a schematic timing diagram of the operation of the bridge arm inverter of the energy conversion device shown in fig. 1 to 8;

FIG. 10 is a schematic current path diagram of an energy conversion device according to a ninth embodiment of the present application;

fig. 11 is a schematic view of another current path of an energy conversion device according to a ninth 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 shows a module structure of an energy conversion device provided in a first embodiment of the present application, and for convenience of description, only the parts related to the present embodiment are shown, and detailed description is as follows:

as shown in fig. 1, an energy conversion device 1 provided in the embodiment of the present application includes a motor coil 11, an arm converter 12, a bidirectional arm 13, and a first capacitor C1.

The bridge arm converter 12 is respectively connected with the motor coil 11 and the bidirectional bridge arm 13;

the motor coil 11, the bridge arm converter 12 and the bidirectional bridge arm 13 are all connected with an external charging port 10, and the bridge arm converter 12 and the bidirectional bridge arm 13 are all connected with an external battery 200;

a first capacitor C1 is connected in parallel with the bidirectional bridge arm 13;

specifically, the motor coil 11, the bridge arm inverter 12, the first capacitor C1 and the external charging port 10 form a dc charging circuit to charge the external battery 200;

the motor coil 11, the bridge arm converter 12, the bidirectional bridge arm 13 and the first capacitor C1 form an alternating current charging circuit with an external charging port 10 to charge an external battery 200;

motor coil 11, arm inverter 12, and first capacitor C1 form a motor drive circuit with external battery 200.

In specific implementation, when the energy conversion device 1 is used for dc charging or ac charging, the energy conversion device 1 may be connected to an external dc power supply or an external ac power supply through the charging port 10, the dc power supply may be a dc power obtained by rectifying an external ac power supply through the charging port, or a dc power input by the external dc power supply through the charging port, the ac power supply may be an ac power obtained by inverting an external dc power supply through the charging port, or an ac power input by the external ac power supply through the charging port, which is not limited herein.

In addition, when the energy conversion device operates in the dc charging mode or the ac charging mode, the first capacitor C1 may filter the voltage output by the arm converter 12 or the arm converter 12 and the bidirectional arm 13 during the dc charging process or the ac charging process of the battery 200, and may store energy according to the voltage output by the arm converter 12 or the arm converter 12 and the bidirectional arm 13, so as to complete the dc charging or the ac charging of the battery 200.

In this embodiment, the first capacitor C1 is arranged in the energy conversion device, so that the first capacitor C1 can filter the voltage output by the bridge arm converter 12 or the bridge arm converter 12 and the bidirectional bridge arm 13, and can store energy according to the voltage output by the bridge arm converter 12 or the bridge arm converter 12 and the bidirectional bridge arm 13 to complete direct current charging or alternating current charging of the battery 200, thereby ensuring that the normal charging function of the energy conversion device is ensured, and other noise waves can not interfere with the charging process; in addition, when the energy conversion device works in the motor driving mode, the first capacitor C1 can be used as a capacitor of a motor controller, so that the first capacitor C1 can be used as a PFC capacitor and can also be used as a capacitor of the motor controller for multiplexing, the utilization rate of electronic elements in the energy conversion device is improved, and the structure of the energy conversion device is simplified.

In addition, it should be noted that, during specific operation, the energy conversion apparatus 1 can operate not only in the driving mode, the dc charging mode and the ac charging mode, but also in the dc discharging mode, the ac discharging mode, the driving discharging mode, the emergency mode, and so on, which are not described herein again.

In addition, in the present application, "external battery" and "external charging port" described in the present embodiment are "external" with respect to the energy conversion device, and are not "external" of the vehicle in which the energy conversion device is located.

In the embodiment, the energy conversion device with the functions of driving and charging the motor coil, the bridge arm converter, the bidirectional bridge arm and the first capacitor set is adopted, so that the energy conversion device can work in a driving mode, a direct current charging mode and an alternating current charging mode, further motor driving and battery charging of a vehicle are realized by adopting the same system, the multiplexing of capacitors can improve the power conversion efficiency and the energy utilization rate during direct current charging, reduce noise generated by harmonic current on the side of a power grid during alternating current charging and pollution to the power grid, improve the power supply quality of the power grid, and can absorb high-frequency switching frequency and higher harmonic generated by the bridge arm converter during driving, after the bridge arm converter boosts and stores energy, the bridge arm converter is ensured to have stable and pure direct current bus voltage, the multiplexing degree of components is high, the system integration degree is high, and the structure is simple, thereby reducing the system cost and reducing the system volume.

In addition, because the charging power difference distance between current alternating current charging system and direct current charging system is great between the two, consequently two charging system's circuit topology difference is great, general two systems independent settings, multiplexing degree is lower, and the commonality of the energy conversion device that this application shows is strong, it is no matter to face direct current charging station or alternating current charging station, this energy conversion device all can charge, the system cost has been reduced, the system volume has been reduced, the problem that current alternating current charging system and direct current charging system overall structure are complicated has been solved, multiplexing degree is low.

Further, the bridge arm converter 12 can realize bidirectional current conversion, and when the energy conversion device works in a driving mode, the bridge arm converter 12 serves as a three-phase inversion function to realize the function of the motor controller. When the energy conversion device operates in the ac charging mode, the bridge arm converter 12 performs rectification and power correction functions, and when the energy conversion device operates in the dc charging mode, the bridge arm converter 12 performs a dc boosting function.

In the related art, an alternating current charging module is required for realizing alternating current charging, a direct current charging module is required for realizing direct current charging, an inverter module is required for realizing motor driving, and none of the related technologies integrates the three functions into one module, so that the circuit structure is complex, the integration level is low, the size is large, and the cost is high. The three functions are creatively integrated in the same circuit, the function multiplexing of a plurality of components is realized, and after the functions are integrated, the split type product with mutually independent current charging module, alternating current charging module and inversion module is compared.

Further, the motor coil 11, the bridge arm converter 12 and the bidirectional bridge arm 13 realize function multiplexing. In the motor driving circuit, a motor coil 11 is used for generating induced electromotive force after being electrified, and a bridge arm converter 12 is used for realizing a three-phase inversion function; in the ac charging circuit, the motor coil 11 functions as an inductor in the PFC circuit, the leg converter 12 functions as one leg in the PFC circuit, and the bidirectional leg 13 functions as the other leg in the PFC circuit; in the DC charging circuit, the motor coil 11 functions as a boost inductor in the boost DC on the one hand and reduces ripple in the circuit on the other hand, and the arm converter 12 functions as an arm in the boost DC.

In addition, in the prior art, the alternating current charging system and the direct current charging system are independently arranged, the multiplexing degree is low, the two systems are large in size and high in cost, the energy conversion device can realize the alternating current charging function and the direct current charging function, and the function multiplexing is realized, namely, the motor coil and the bridge arm converter participate in alternating current charging and direct current charging, the multiplexing of components is realized, and the problems of complex structure, low multiplexing degree, high cost and large size in the prior art are solved through the function multiplexing and the component multiplexing.

Further, since a household socket is generally used for ac charging, a power of a commonly used ac power source is generally seven kilowatts (kW), and a professional charging pile is generally used for dc charging, a power of the professional charging pile is generally 60kW to 150kW, and a rapid dc charging pile larger than 100kW is a development trend, and in addition, a power of a motor driving is generally about 100kW, it can be known from the above description that power levels of a vehicle in three cases of motor driving, dc charging, and ac charging are greatly different, and the power difference is very important for selecting a switching tube.

For the switching tubes, since the high-power switching tube is more expensive than the low-power switching tube, based on the consideration of different powers required when the energy conversion device works in the motor driving mode, the direct-current charging mode and the alternating-current charging mode, the type of the switching tube in the bridge arm converter 12 is different from that of the switching tube in the bidirectional bridge arm 13, that is, the bidirectional bridge arm 13 and the bridge arm converter 12 use switching tubes with different power levels, in one embodiment, the power level of the switching tube used by the bridge arm converter 12 is greater than that of the switching tube used by the bidirectional bridge arm 13. For example: among the same type of switching tubes, the bridge arm converter 12 adopts a high-current-level MOSFET switching tube, and the bidirectional bridge arm 13 adopts a low-current-level MOSFET switching tube; or for example: among the different types of switching tubes, the bridge arm converter 12 adopts a high-power IGBT switching tube, and the bidirectional bridge arm 13 adopts a low-power MOSFET switching tube. Specifically, in the present embodiment, since the bridge arm converter 12 is used in the high-power modes such as the dc charging and the motor driving, the bridge arm converter 12 in the present embodiment is implemented by using the high-power IGBT switching tube or the high-current MOSFET switching tube, and since the bidirectional bridge arm 13 mainly works during the ac charging, the bidirectional bridge arm 13 can be implemented by using the low-power MOSFET, so that the effective work of the energy conversion device is ensured, and the circuit cost can be reduced.

On the other hand, when ac charging is performed, the switching frequency required by the bidirectional arm 13 is high (for example, 60kHz), so that it is necessary to use a MOSFET switching tube or a silicon carbide MOSFET switching tube that can realize high-frequency operation, and since the arm converter 121 has a three-phase arm and its operation mode is three-phase interleaved control, the frequency required by the switching tube of the arm converter 12 is low, so the type of the switching tube in the arm converter 12 is different from the type of the switching tube in the bidirectional arm 13, for example: the switching tube type in the bridge arm converter 12 is an IGBT switching tube with high efficiency in low-frequency operation.

In addition, when the energy conversion device operates in an ac charging mode or a dc charging mode, the three-phase interleaved control operation mode adopted by the bridge arm converter 12 can reduce the dc-side ripple and increase the charging power when the energy conversion device is charging.

When the energy conversion device is used for testing the alternating current and direct current charging performance, the inventor proposes a design concept of improving the overall inductance of the energy conversion device to improve the charging efficiency, and finds that improving the inductance of a motor coil is one of feasible ways by researching the structure of the motor.

Further, as an embodiment of the present application, as shown in fig. 2, the motor coil includes three-phase windings, each phase winding includes N coil branches, first ends of the N coil branches in each phase winding are connected to the bridge arm converter 12 after being connected in common, second ends of the N coil branches in each phase winding are connected to second ends of the N coil branches in the other two-phase windings in a one-to-one correspondence manner, so as to form N neutral points, and the charging port 10 is connected to the M neutral points; wherein N is an integer greater than 1, and M is a positive integer less than N.

Specifically, in fig. 2, a specific structure of the motor coil 11 of the present application is described by taking an example where M is 2 and N is 4, that is, two neutral points among four neutral points are connected to the charging port 10; in the present embodiment, the number of coil branches included in each phase winding of the motor coil 11 is described by taking 4 as an example, and the number of coil branches is not limited to a specific number.

The three-phase winding of the motor coil 11 will be described in detail below by way of specific examples, as follows:

specifically, as shown in fig. 2, the motor coil 11 includes a U-phase winding, a V-phase winding, and a W-phase winding, and each of the U-phase winding, the V-phase winding, and the W-phase winding includes N coil branches.

Further, as shown in fig. 2, first ends of N coil branches in the U-phase winding are connected to a first phase bridge arm of the bridge arm converter 12 after being connected in common, first ends of N coil branches in the V-phase winding are connected to a second phase bridge arm of the bridge arm converter 12 after being connected in common, first ends of N coil branches in the W-phase winding are connected to a third phase bridge arm of the bridge arm converter 12 after being connected in common, and second ends of N coil branches in each of the U-phase winding, the V-phase winding and the W-phase winding are connected to second ends of N coil branches in other two-phase windings in one-to-one correspondence, so as to form N neutral points N1, N2 and N3., and the N neutral points may be directly connected to the charging port 10 or may be connected to the charging port 10 through other connecting circuits, which is exemplified in this embodiment by that M neutral points of the N neutral points are directly connected to the charging port 10, and the connection circuit will be described in detail later, and will not be described in detail here.

In this embodiment, compare all neutral points of motor coil and all be connected with the mouth that charges, in this embodiment, be connected partial neutral point with the mouth that charges, lead to parallelly connected motor coil to reduce, motor coil's equivalent inductance increases, and energy conversion device's whole inductance increases to charging efficiency has been promoted.

In another embodiment, the inventor comprehensively considers the factors of charging power and charging efficiency, the charging power is positively correlated with the overcurrent capacity of the motor coils, and the more the motor coils are connected in parallel, the stronger the overcurrent capacity is; the charging efficiency is inversely related to the inductance of the motor coil, and the fewer the motor coils are connected in parallel, the greater the inductance of the motor coil is. This embodiment is through adopting every phase winding all to include the motor coil 11 of N coil branch road for this energy conversion device can realize direct current charging or alternating current charging under the different power through the inductance value that changes motor coil 11, and then realizes the purpose that this energy conversion device's charging power accessible inductance value was adjusted.

Further, as an embodiment of the present application, as shown in fig. 3, the energy conversion apparatus further includes a neutral switch 130. Neutral point switch 130 controls M neutral points among N neutral points of motor coil 11 to be connected to charging port 10.

In specific implementation, the neutral point switch 130 may be implemented by N single-pole single-throw switches, or may be implemented by a plurality of single-pole double-throw switches. When the neutral point switch 130 is implemented by N single-pole single-throw switches, first ends of the N single-pole single-throw switches are connected to N neutral points of the motor coil 11 in a one-to-one correspondence, and second ends of the N single-pole single-throw switches are connected to the charging port 10. When the neutral point switch 10 is implemented by using a plurality of single-pole double-throw switches, the moving ends of the plurality of single-pole double-throw switches are all connected with the charging port 10, and the two fixed ends of each single-pole double-throw switch are correspondingly connected with two neutral points in the motor coil 11 one by one according to requirements. In addition, the neutral point switch 10 can also be implemented by a single-pole multi-throw switch, a moving end of the single-pole multi-throw switch is connected with the charging port 10, and stationary ends of the single-pole multi-throw switch are respectively connected with the neutral points in the motor coils 11 in a one-to-one correspondence manner according to requirements.

In this embodiment, the neutral point switch 130 is added to the energy conversion device, and the neutral point switch is selectively turned on and off, so that the neutral point switch 130 connects the charging port 10 with M neutral points of N neutral points of the motor coil 11, and the energy conversion device is further facilitated to turn on or off the switches of the neutral point switch 130 as required, so that different numbers of coil branches are selected from three-phase windings of the motor coil 11, and thus the adjustment of the charging power is realized.

Further, as an embodiment of the present application, as shown in fig. 4, the energy conversion apparatus further includes a switch module 14.

One end of the switch module 14 is connected to the charging port 10, the other end is connected to the motor coil 11, the bridge arm converter 12, and the bidirectional bridge arm 13, and the switch module 14 is configured to switch a driving mode, a dc charging mode, and an ac charging mode.

In this embodiment, the switch module 14 is added to the energy conversion device, so that the switch module 14 can facilitate the energy conversion device to switch among the driving mode, the dc charging mode and the ac charging mode, thereby effectively preventing the energy conversion device from failing due to the failure of the energy conversion device in accurate mode switching, and improving the reliability of the energy conversion device.

Further, as an embodiment of the present application, as shown in fig. 4, the charging port 10 includes a dc charging port 101 and an ac charging port 102; the switch module 14 includes a first switch unit 141 and a second switch unit 142.

The direct current charging port 101, the first switching unit 141, the motor coil 11, and the arm converter 12 form a direct current charging circuit for the battery 200; ac charging port 102, second switching unit 142, motor coil 11, arm converter 12, and bidirectional arm 13 form an ac charging circuit for battery 200.

In this embodiment, by using the charging port 10 formed by the dc charging port 101 and the ac charging port 102 and using the switch module 14 formed by the first switch unit 141 and the second switch unit 142, when the energy conversion device operates in the dc charging mode or the ac charging mode, the energy conversion device has charging circuits corresponding to different modes, and thus the dc charging circuit and the ac charging circuit do not interfere with each other, and the circuit has strong reliability and high stability.

Further, as an embodiment of the present application, as shown in fig. 4, the first switching unit 141 includes a first switch K1 and a second switch K2, one end of the first switch K1 is connected to the dc charging port 101, and the other end is connected to the motor coil 11; one end of the second switch K2 is connected to the dc charging port 101, and the other end is connected to the bridge arm converter 12; the second switch unit 142 includes a third switch K3 and a fourth switch K4, one end of the third switch K3 is connected to the ac charging port 102, the other end is connected to the motor coil 11, one end of the fourth switch K4 is connected to the ac charging port 102, the other end is connected to the bidirectional arm 13, and specifically, is connected to the midpoint of the bidirectional arm 13.

Specifically, referring to fig. 4 again, in this embodiment, in an implementation, the first switch K1, the second switch K2, the third switch K3, and the fourth switch K4 are implemented by single-pole single-throw switches, a first end of the first switch K1 and a first end of the second switch K2 are connected to the dc charging port 101, a second end of the first switch K1 is connected to the neutral point of the motor coil 11, and a second end of the second switch K2 is connected to the negative end of the bridge arm inverter 12. Similarly, a first terminal of the third switch K3 and a first terminal of the fourth switch K4 are connected to the ac charging port 102, a second terminal of the third switch K3 is connected to the neutral point of the motor coil 11, and a second terminal of the fourth switch K4 is connected to the midpoint of the bidirectional arm 13.

In specific implementation, when the energy conversion device works in the driving mode, the first switch K1, the second switch K2, the third switch K3 and the fourth switch K4 are all turned off, and at this time, the battery 200, the bridge arm inverter 12 and the motor coil 11 form a motor driving loop; when the energy conversion device works in a direct-current charging mode, the first switch K1 and the second switch K2 are closed, the third switch K3 and the fourth switch K4 are opened, and at the moment, the direct-current charging port 101, the first switch K1, the second switch K2, the motor coil 11 and the bridge arm converter 12 form a direct-current charging loop for the battery 200; when the energy conversion device works in an alternating current charging mode, the third switch K3 and the fourth switch K4 are closed, the first switch K1 and the second switch K2 are opened, and at the moment, the alternating current charging port 101, the third switch K3 and the fourth switch K4, the motor coil 11, the bridge arm converter 12 and the bidirectional bridge arm 13 form an alternating current charging loop for the battery 200.

Further, as another embodiment of the present application, as shown in fig. 5, the charging port 10 includes an ac/dc charging port, and the switch module 14 includes a third switch unit 143 and a fourth switch unit 144. One end of the third switching unit 143 is connected to the ac/dc charging port 103, the other end is connected to the motor coil 11, one end of the fourth switching unit 144 is connected to the ac/dc charging port 103, and the other end of the fourth switching unit 144 is connected to the bridge arm converter 12 or the bidirectional bridge arm 13.

In a specific implementation, a first end of the third switching unit 143 is connected to the ac/dc charging port 103, a second end of the third switching unit 143 is connected to the neutral point of the motor coil 11, one end of the fourth switching unit 144 is connected to the ac/dc charging port 103, and the other end of the fourth switching unit is selectively connected to the negative end of the bridge arm converter 12 or the midpoint of the bidirectional bridge arm 13.

Further, when the fourth switching unit 144 is connected to the bridge arm converter 12, the ac/dc charging port 103, the third switching unit 143, the fourth switching unit 144, the motor coil 11, and the bridge arm converter 12 form a dc charging circuit for the battery 200; when the fourth switching unit 144 is connected to the bidirectional arm 13, the ac/dc charging port 103, the third switching unit 143, the fourth switching unit 144, the motor coil 11, the arm converter 12, and the bidirectional arm 13 form an ac charging circuit for the battery.

In this embodiment, by using the charging port 10 formed by the ac/dc charging port 103 and the switch module 14 formed by the third switch unit 143 and the fourth switch unit 144, when the energy conversion device operates in the dc charging mode or the ac charging mode, the external ac power or the dc power can provide charging energy to the energy conversion device through the ac/dc charging port 10, and the fourth switch unit 144 enables the energy conversion device to have the dc charging circuit or the ac charging circuit corresponding to different modes, so that the dc charging circuit and the ac charging circuit do not interfere with each other, and the circuit reliability is high, the stability is high, and the circuit integration level is high.

Further, as an embodiment of the present application, as shown in fig. 5, the third switching unit 143 includes a fifth switch K5, one end of the fifth switch K5 is connected to the ac/dc charging port 103, and the other end is connected to the neutral point of the motor coil 11. The fourth switch unit 144 includes a single-pole double-throw switch K6, the single-pole double-throw switch K6 includes a moving end and two immobile ends, the moving end is connected with the ac/dc charging port 103, one immobile end is connected with the bridge arm converter 12, and the other immobile end is connected with the midpoint of the bidirectional bridge arm 13; alternatively, the fourth switching unit 144 includes two switches, one end of one switch is connected to the ac/dc charging port 103, and the other end is connected to the bridge arm converter 12; one end of the other switch is connected with the alternating current/direct current charging port 103, and the other end is connected with the bidirectional bridge arm 13.

It should be noted that fig. 5 illustrates that the fourth switch unit 144 is implemented by using a single-pole double-throw switch K6, and when the fourth switch unit 144 is implemented by using two single-pole single-throw switches, first ends of the two single-pole single-throw switches are both connected to the ac/dc charging port, a second end of the first single-pole single-throw switch is connected to the negative end of the bridge arm converter 12, and a second end of the second single-pole single-throw switch is connected to the midpoint of the bidirectional bridge arm 13.

In addition, in practical implementation, when the energy conversion device operates in the driving mode, the fifth switch K5 and the single-pole double-throw switch are both turned off, and at this time, the battery 200, the bridge arm inverter 12 and the motor coil 11 form a motor driving circuit; when the energy conversion device works in a direct-current charging mode, the fifth switch K5 is closed, the first fixed end of the single-pole double-throw switch K6 is closed, and at the moment, the alternating-current/direct-current charging port 103, the fifth switch K5, the single-pole double-throw switch K6, the motor coil 11, the bridge arm converter 12 and the battery 200 form a direct-current charging loop; when the energy conversion device works in an alternating current charging mode, the fifth switch K5 is closed, and the second stationary end of the single-pole double-throw switch is closed, so that the alternating current/direct current charging port 103, the fifth switch K5, the single-pole double-throw switch K6, the motor coil 11, the bridge arm converter 12, the bidirectional bridge arm 13 and the battery 200 form an alternating current charging loop.

In this embodiment, the switch K5 and the single-pole double-throw switch K6 are adopted, so that the switch K5 and the single-pole double-throw switch K6 can replace the first switch K1 to the fourth switch K4 in another embodiment, and further, when switching among the driving mode, the direct-current charging mode and the alternating-current charging mode is realized, electronic components used by the switch module 14 are reduced, so that the number of electronic components of the energy conversion device is reduced, the cost of the energy conversion device is reduced, and meanwhile, the circuit structure is simpler.

As an embodiment of the present invention, as shown in fig. 6, the switch module further includes a fifth switch unit 145, one end of the fifth switch unit 145 is connected to the battery 200, and the other end is connected to the arm converter 12 and the bidirectional arm 13, respectively.

In the present embodiment, the fifth switching unit 145 is additionally provided in the switching module, and the battery 200 is connected to the arm converter 12 and the bidirectional arm 13 through the fifth switching unit 145, so that when the front-end circuit fails (for example, when any one of the switching module 14, the motor coil 11, the arm converter 12, and the bidirectional arm 13 fails), the energy conversion device can prevent the battery 200 from being damaged by controlling the fifth switching unit 145, thereby improving the service life of the battery 200.

Further, as an embodiment of the present application, as shown in fig. 7, the fifth switching unit 145 includes a switch K7 and a switch K8. The first end of the switch K7 is connected to the positive terminal of the battery 200, the first end of the switch K8 is connected to the negative terminal of the battery 200, the second end of the switch K7 is connected to the positive terminal of the bridge arm converter 12 and the positive terminal of the bidirectional bridge arm 13, and the second end of the switch K8 is connected to the negative terminal of the bridge arm converter 12 and the negative terminal of the bidirectional bridge arm 13.

Further, as an embodiment of the present application, as shown in fig. 6, the energy conversion apparatus 1 further includes a bidirectional DC module 15, the bidirectional DC module 15 includes a first DC terminal and a second DC terminal, the first DC terminal is connected to the first electric C1 capacitor, the second DC terminal is connected to the external battery 300, and the first capacitor C1, the bidirectional DC module 15 and the battery 300 form a voltage bleeding loop to bleed the voltage across the first capacitor C1 when the first capacitor C1 satisfies the bleeding condition.

Specifically, in the embodiment of the present application, the first capacitor C1 satisfying the bleeding condition refers to a state where the vehicle is in the OFF range and just after the driving and/or just after the charging. Since a certain voltage is stored at two ends of the first capacitor C1 when the driving and/or charging is finished, and when the voltage value is higher than a preset voltage threshold, a potential safety hazard occurs, the voltage at two ends of the first capacitor C1 needs to be subjected to a discharge treatment; in addition, in implementation, the bidirectional DC module 15 may be implemented by using an existing vehicle-mounted charger.

In the embodiment, the capacitor, the bidirectional DC module and the storage battery form a voltage discharge loop to discharge the voltage at two ends of the capacitor when the capacitor meets the discharge condition, and the bidirectional DC module is implemented by using the existing vehicle-mounted charger without resetting an additional circuit to discharge the voltage of the capacitor, so that the circuit cost is reduced, the heat loss in the capacitor discharge process is eliminated, and the problems of high cost and heat loss in the existing capacitor discharge method are solved.

Further, as an embodiment of the present invention, as shown in fig. 6, the bidirectional DC module 15 includes a first converter 151, a second converter 152, and a voltage transforming unit 154, a primary side and a secondary side of the voltage transforming unit 154 are respectively connected to the first converter 151 and the second converter 152, the first converter 151 is connected in parallel to a first capacitor C1, the second converter 152 is connected in parallel to the battery 300, and the first capacitor C1, the first converter 151, the second converter 152, the voltage transforming unit 154, and the battery 300 form a voltage relief circuit.

In this embodiment, the bidirectional DC module including the first converter, the second converter, and the transforming unit enables the capacitor, the first converter, the second converter, the transforming unit, and the storage battery to form a voltage bleeding circuit, so that the capacitor is bled by voltage, and the circuit is simple in structure, easy to implement, and low in cost.

Further, as an embodiment of the present application, as shown in fig. 6, the second converter 152 includes a first sub-converter 152a, the first sub-converter 152a is connected to the secondary side of the transformer unit 154 and the battery 300, the first capacitor C1, the first converter 151, the first sub-converter 152a, the transformer unit 154 and the battery 300 form a voltage bleeding circuit, and in the voltage bleeding circuit, the first converter 151 and the first sub-converter 152a alternately operate between a first bleeding state and a second bleeding state to bleed off the voltage across the first capacitor C1.

In specific implementation, the alternating operation of the first converter 151 and the first sub-converter 152a between the first and second bleeding states means that: the first converter 151 and the first sub-converter 152a are switched to the second bleeding state after operating in the first bleeding state for a certain time, and then switched to the first bleeding state after operating in the second bleeding state for a certain time, so as to cyclically and alternately operate until the voltage across the first capacitor C1 is lower than the preset voltage threshold.

In this embodiment, the first converter and the first sub-converter alternately operate between the first discharging state and the second discharging state, so that the voltage transforming unit induces a current, and the voltage at two ends of the capacitor is discharged by charging the battery with the current, thereby increasing the discharging speed, reducing the heat loss, and improving the energy utilization rate.

Further, as an embodiment of the present application, as shown in fig. 7, the first converter 151 includes a first switching element Q3, a second switching element Q4, a third switching element Q5, a fourth switching element Q6, a first inductor L1, and a second capacitor C2; a first terminal of the first switching element Q3 is connected to a first terminal of the third switching element Q5 and a first terminal of the first capacitor C1, a second terminal of the first switching element Q3 is connected to a first terminal of the second switching element Q4 and a first terminal of the second capacitor C2, a second terminal of the third switching element Q5 is connected to a first terminal of the fourth switching element Q6 and a first terminal of the first inductor L1, a second terminal of the first inductor L1 and a second terminal of the second capacitor C2 are both connected to the primary side of the transforming unit 154, and a second terminal of the second switching element Q4 is connected to a second terminal of the fourth switching element Q6 and a second terminal of the first capacitor C1.

In a specific implementation, each of the switching elements included in the first converter may be implemented by a device capable of performing a switching operation, such as a power Transistor, a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), an Insulated Gate Bipolar Transistor (IGBT), and other switching devices.

Further, as an embodiment of the present invention, as shown in fig. 7, the first sub-converter 152a includes a fifth switching element Q11 and a sixth switching element Q12, a first end of the fifth switching element Q11, a first end of the sixth switching element Q12, and a positive terminal of the battery 300 are connected to the secondary side of the transformer unit 154, and a second end of the fifth switching element Q11 and a second end of the sixth switching element Q12 are connected to the negative terminal of the battery 300.

Similarly, in a specific implementation, the fifth switching element Q11 and the sixth switching element Q12 included in the first sub-converter may be implemented by devices capable of performing switching operations, such as a power Transistor, a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), an Insulated Gate Bipolar Transistor (IGBT), and other switching devices.

Further, as shown in fig. 7, in a specific operation, the first capacitor C1, the third switching element Q5, the second switching element Q4, the voltage transforming unit 154, the sixth switching element Q12 and the battery 300 form a first voltage bleeding circuit, the first capacitor C1, the first switching element Q3, the fourth switching element Q6, the voltage transforming unit 154, the fifth switching element Q11 and the battery 300 form a second voltage bleeding circuit, and the first voltage bleeding circuit and the second voltage bleeding circuit alternately operate to bleed off the voltage across the first capacitor C1.

In this embodiment, different voltage release loops are formed by each switching element in the existing vehicle-mounted charger and the storage battery 300, and then the voltage at the two ends of the first capacitor C1 is released, so that a release resistor and a release switch are not required to be arranged, the cost is reduced, the heat loss of a product can be reduced, and the energy utilization rate is improved.

Further, as an embodiment of the present application, as shown in fig. 6, the second converter 152 includes a second sub-converter 152b, the second sub-converter 152b is connected to the secondary side of the transformer unit 154 and the battery 300, the first capacitor C1, the first converter 151, the second sub-converter 152b, the transformer unit 154 and the battery 300 form a voltage bleeding circuit, and in the voltage bleeding circuit, the first converter 151 and the second sub-converter 152b alternately operate between a third bleeding state and a fourth bleeding state to bleed off the voltage across the capacitors.

In this embodiment, the first converter and the second sub-converter alternately operate between the third discharging state and the fourth discharging state, so that the voltage transforming unit induces a current, and the voltage at two ends of the capacitor is discharged by charging the battery with the current, thereby increasing the discharging speed, reducing the heat loss, and improving the energy utilization rate.

Further, as an embodiment of the present application, as shown in fig. 7, the second sub-converter 152b includes a seventh switching element Q13 and an eighth switching element Q14, a first end of the seventh switching element Q13, a first end of the eighth switching element Q14, and a positive end of the secondary battery 300 are connected to the secondary side of the transformer unit 154, and a second end of the seventh switching element Q13 and a second end of the eighth switching element Q14 are connected to the negative end of the secondary battery 300.

In specific implementation, the seventh switching element Q13 and the eighth switching element Q14 included in the second sub-converter may be implemented by devices capable of performing switching operations, such as a power Transistor, a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), an Insulated Gate Bipolar Transistor (IGBT), and other switching devices.

Further, as shown in fig. 7, in a specific operation, the first capacitor C1, the third switching element Q5, the second switching element Q4, the voltage transforming unit 154, the eighth switching element Q14 and the battery 300 form a third voltage bleeding circuit, the first capacitor C1, the first switching element Q3, the fourth switching element Q6, the voltage transforming unit 154, the seventh switching element Q13 and the battery 300 form a fourth voltage bleeding circuit, and the third voltage bleeding circuit and the fourth voltage bleeding circuit alternately operate to bleed off the voltage across the capacitors.

Further, as an embodiment of the present application, as shown in fig. 6, the bidirectional DC module 15 further includes a third DC terminal connected to the battery 200, and the bidirectional DC module 15 includes a third converter 153, the secondary side of the voltage transformation unit 154 is connected to the third converter 153, and the third converter 153 is connected in parallel to the battery 200.

Further, as an embodiment of the present invention, as shown in fig. 6, the switch module further includes a sixth switch unit 146, one end of the sixth switch unit 146 is connected to the third inverter 153, and the other end of the sixth switch unit 146 is connected to the battery 200.

In this embodiment, the sixth switching unit 146 is additionally arranged in the switching module, so that the sixth switching unit 146, the charging port 10, the motor coil 11 and the bidirectional DC module 15 in the energy conversion device form another ac or DC charging circuit, thereby enriching the ac/DC charging mode of the energy conversion device, and when the energy conversion device is performing DC charging, not only isolated DC charging can be performed, but also non-isolated DC charging can be performed, and further the charging process of the energy conversion device can be redundant in multiple schemes, thereby improving the safety of the energy conversion device in the ac charging process.

Further, as an embodiment of the present application, as shown in fig. 7, the sixth switching unit 146 includes a switch K9 and a switch K10. Wherein the first terminal of the switch K9 is connected to the positive terminal of the battery 200, the first terminal of the switch K10 is connected to the negative terminal of the battery 200, the second terminal of the switch K9 is connected to the third DC terminal of the bi-directional DC module 15, and the second terminal of the switch K10 is connected to the third DC terminal of the bi-directional DC module 15.

Further, as an embodiment of the present application, as shown in fig. 7, the third converter 153 includes a ninth switching element Q7, a tenth switching element Q8, an eleventh switching element Q9, a twelfth switching element Q10, a second inductor L2, and a third capacitor C3; a first terminal of the ninth switching element Q7 is connected to a first terminal of an eleventh switching element Q9 and a positive terminal of the battery 200, a second terminal of the eleventh switching element Q9 is connected to a first terminal of a twelfth switching element Q10 and a first terminal of a third capacitor C3, a second terminal of the ninth switching element Q7 is connected to a first terminal of a tenth switching element Q8 and a first terminal of a second inductor L2, a second terminal of the second inductor L2 and a second terminal of a third capacitor C3 are both connected to the primary side of the transformer unit 154, and a second terminal of the tenth switching element Q8 is connected to a second terminal of the twelfth switching element Q10 and a negative terminal of the battery 200.

In a specific implementation, each of the switching elements included in the third converter may be implemented by a device capable of performing a switching operation, such as a power Transistor, a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), an Insulated Gate Bipolar Transistor (IGBT), and other switching devices.

Further, as an embodiment of the present application, as shown in fig. 8, the energy conversion apparatus further includes a voltage inductor L, one end of which is connected to the charging port 10, and the other end of which is connected to the motor coil 11.

Specifically, as an embodiment of the present application, as shown in fig. 8, a first end of an inductor L is connected to the second end of the switch K1 and the second end of the switch K3, and the second end of the inductor L is connected to a neutral point of a three-phase winding of the motor coil 11.

Specifically, in the dc charging mode, the charging port 10, the inductor L, the motor coil 11, and the bridge arm converter 12 form a dc charging circuit for the battery 200;

in the ac charging mode, charging port 10, inductor L, motor coil 11, arm converter 12, and bidirectional arm 13 form an ac charging circuit for battery 200.

In this embodiment, when the energy conversion device operates in the ac charging mode, the inductor L and the bidirectional bridge arm 13 cooperate to convert the ac power received by the charging port 10 into the target voltage and then perform ac charging on the battery 200, that is, in the charging process of the battery 200, when an ideal voltage needs to be output to charge the battery 200, the output voltage in the charging process can be adjusted through the combined action of the inductor L and the bidirectional bridge arm 13, so as to ensure the voltage conversion function of the energy conversion device.

Further, as an embodiment of the present application, as shown in fig. 7 or fig. 8, the energy conversion apparatus further includes a switch K11 and a resistor R1, and the switch K11 and the resistor R1 form a pre-charge module to pre-charge the switch K7 and the switch K9 when the energy conversion apparatus is in operation, so as to prevent the switch K7 and the switch K9 from malfunctioning, thereby reducing the failure rate of the energy conversion apparatus.

Specifically, as shown in fig. 7 or 8, the first terminal of the switch K11 is connected to the second terminal of the switch K7, the second terminal of the switch K11 is connected to the second terminal of the switch K9 and the first terminal of the resistor R1, and the second terminal of the resistor R1 is connected to the first terminal of the switch K7, the first terminal of the switch K9, and the positive terminal of the battery 200.

Further, as an embodiment of the present invention, as shown in fig. 7 or 8, the bridge arm converter 12 in the energy conversion device includes a three-phase bridge arm formed by a first power switch cell 1 and a second power switch cell 2 connected in series, a third power switch cell 3 and a fourth power switch cell 4 connected in series, and a fifth power switch cell 5 and a sixth power switch cell 6 connected in series.

Specifically, the first end of the first power switch unit 1, the first end of the third power switch unit 3 and the first end of the fifth power switch unit 5 are connected in common to form a positive end of the bridge arm converter 12, and the positive end of the bridge arm converter 12 is connected with the positive end of the bidirectional bridge arm 13;

the second end of the second power switch unit 2, the second end of the fourth power switch unit 4 and the second end of the sixth power switch unit 6 are connected together to form a negative end of the bridge arm converter 12, and the negative end of the bridge arm converter 12 is connected with the negative end of the bidirectional bridge arm 13;

the connection point of the second end of the first power switch unit 1 and the first end of the second power switch unit 2 is connected with the first phase coil of the motor coil 11, the connection point of the second end of the third power switch unit 3 and the first end of the fourth power switch unit 4 is connected with the second phase coil of the motor coil 11, and the connection point of the second end of the fifth power switch unit 5 and the first end of the sixth power switch unit 6 is connected with the third phase coil of the motor coil 11.

In the embodiment of the present application, the plurality of power switch cells in the bridge arm converter 12 may be implemented by devices that are connected in parallel with diodes and can perform switching operations, such as power transistors, Metal-Oxide-Semiconductor Field-Effect transistors (MOSFETs), Insulated Gate Bipolar Transistors (IGBTs), and other switching devices.

Further, when the bridge arm converter 12 works, the power switch unit in the first phase bridge arm, the power switch unit in the second phase bridge arm and the power switch unit in the third phase bridge arm sequentially receive the control signals with the preset phase difference to enter a three-phase staggered control mode; it should be noted that, in the present embodiment, the preset phase is preferably 120 degrees, and the preferred angle does not limit the preset phase.

Specifically, when the bridge arm converter 12 is in operation, as can be seen from the operation timing chart shown in fig. 9, the control signal PWM1 controls the on/off of the first power switch unit 1 and the second power switch unit 2 in the first phase bridge arm in the bridge arm converter 12, and controls the first power switch unit 1 to be turned on and the second power switch unit 2 to be turned off when the control signal PWM1 is at a high level, and controls the second power switch unit 2 to be turned on and the first power switch unit 1 to be turned off when the control signal PWM1 is at a low level; after a preset phase difference from the control signal PWM1, the control signal PWM2 controls the third power switch unit 3 and the fourth power switch unit 4 in the second phase arm of the arm converter 12 to be turned on and off, and controls the third power switch unit 3 to be turned on and the fourth power switch unit 4 to be turned off at the high level of the control signal PWM2, and controls the fourth power switch unit 4 to be turned on and the third power switch unit 3 to be turned off at the low level of the control signal PWM 2; and after a preset phase difference from the control signal PWM2, the control signal PWM3 controls the fifth power switch unit 5 and the sixth power switch unit 6 in the third phase arm of the arm converter 12 to be turned on and off, controls the fifth power switch unit 5 to be turned on and the sixth power switch unit 6 to be turned off when the control signal PWM3 is at a high level, and controls the sixth power switch unit 6 to be turned on and the fifth power switch unit 5 to be turned off when the control signal PWM3 is at a low level, thereby implementing three-phase interleaved control of the arm controller 120.

In this embodiment, a three-phase interleaved control operation mode is adopted to control a three-phase bridge arm of the bridge arm converter 12, so that when the energy conversion device is charged, an equivalent inductance value is effectively increased, and further, the charging power is increased, and an inductance L does not need to be added to the energy conversion device, so that the number of electronic components in the energy conversion device is reduced, and the cost of the energy conversion device is reduced.

Further, as an embodiment of the present application, as shown in fig. 7 or fig. 8, bidirectional arm 13 in the energy conversion device includes a seventh power switch unit Q1 and an eighth power switch unit Q2 connected in series; the first end of the seventh power switch unit Q1 is the positive end of the bidirectional arm 13, the second end of the eighth power switch unit Q2 is the negative end of the bidirectional arm 13, and the connection point between the second end of the seventh power switch unit Q1 and the first end of the eighth power switch unit Q2 is the midpoint of the bidirectional arm 13.

The operation principle of the energy conversion device provided by the present application in different embodiments is specifically described below by taking the circuits shown in fig. 7 and fig. 8 as an example, and the following details are described below:

specifically, as shown in fig. 8, when the energy conversion apparatus operates in the dc charging mode, and the dc charging mode is non-isolated dc charging, the first switch K1, the second switch K2, the switch K11, the switch K7, and the switch K8 are closed, and the other switch elements K3, K4, K9, and K10 are opened, at this time, the dc voltage received by the dc charging port 101 is boosted through the inductor L, the three-phase winding U, V, W of the motor coil 11, and the arm converter 12, and then output to the battery 200 through the first capacitor C1, so as to implement dc charging of the battery 200.

Or as shown in fig. 7, when the energy conversion device operates in the dc charging mode, and the dc charging mode is non-isolated dc charging, the first switch K1, the second switch K2, the switch K11, the switch K7, and the switch K8 are closed, and the other switch elements K3, K4, K9, and K10 are opened, at this time, the dc voltage received by the dc charging port 101 is boosted by the three-phase winding U, V, W of the motor coil 11 and the arm converter 12, and then output to the battery 200 through the first capacitor C1, so as to realize dc charging of the battery 200.

In addition, when the energy conversion device operates in a dc charging mode, and the dc charging mode is isolated dc charging, as shown in fig. 8, the first switch K1, the second switch K2, the switch K9 and the switch K10 are closed, and the other switch elements K3, K4, K6, K7 and K11 are opened, at this time, the dc voltage received by the dc charging port 101 is pumped into the three-phase winding U, V, W of the motor coil 11 from the motor through the inductor L, and then is boosted through the bridge arm converter 12 to output the voltage U0, the voltage U0 is filtered through the first capacitor C1, and then is rectified through the switch tubes Q3, Q4, Q5 and Q6 to output the voltage T1, and then is inverted through the transformer T1, and rectified through the switch tubes Q7, Q8, Q9 and Q10, and then the voltage is output to the battery 200 through the filter capacitor C4 to realize the isolated dc charging of the battery 200; it should be noted that, in this embodiment, the isolated dc charging is mainly used when it is difficult to match the battery voltage of the electric vehicle with a special charging facility, and it needs to be completed through two-stage voltage regulation.

Or as shown in fig. 7, the first switch K1, the second switch K2, the switch K9 and the switch K10 are closed, and the other switch elements K3, K4, K6, K7 and K11 are opened, at this time, the dc voltage received by the dc charging port 101 is pumped from the motor into the three-phase winding U, V, W of the motor coil 11, and is boosted by the bridge arm converter 12 to output a voltage U0, the voltage U0 is filtered by the first capacitor C1, and is rectified by the switch tubes Q3, Q4, Q5 and Q6 through a full-bridge rectifier to output a value transformer T1, and is inverted by the transformer T1, rectified by the switch tubes Q7, Q8, Q9 and Q10, and then outputs a voltage to the battery 200 through the filter capacitor C4, so as to implement isolated dc charging of the battery 200.

Further, as shown in fig. 8, when the energy conversion apparatus operates in the ac charging mode, the third switch K3, the fourth switch K4, the switch K11, the switch K9, and the switch K10 are closed, and the other switch elements K1, K2, K7, and K8 are opened, at this time, one end of the ac voltage received by the ac charging port 102 enters the three-phase winding U, V, W of the motor coil 11 through the neutral line led out from the neutral point of the motor through the inductor L, and then enters the arm converter 102, and the other end passes through the bidirectional arm Q1 and Q2, and then forms a full-bridge rectified output voltage U0 through the arm converters 102 and the Q1 and Q2, the voltage U0 is rectified through the full bridge consisting of Q3 to Q6 after being filtered by the first capacitor C1, then is inverted by the transformer T1, and then passes through the arm consisting of Q7 to Q10 and then filters the output voltage to charge the battery 200 through the capacitor C4, to enable ac charging of the battery 200.

Or, when the energy conversion device operates in the ac charging mode, the third switch K3, the fourth switch K4, the switch K11, the switch K7 and the switch K8 are closed, and the other switches K1, K2, K9 and K10 are opened, at this time, one end of the ac voltage received by the ac charging port 102 enters the three-phase winding U, V, W of the motor coil 11 through the inductor L and the neutral wire led out from the neutral point of the motor, and then enters the arm converter 12, and the other end passes through the arms Q1 and Q2, and then the arms Q1 and Q2 and the arm converter 12 form a rectified output voltage U0, and the output voltage U0 is filtered by the first capacitor C1 and then charges the battery 200, so as to realize ac charging of the battery 200.

Or as shown in fig. 7, when the energy conversion device works in the alternating current charging mode, the third switch K3, the fourth switch K4, the switch K11, the switch K9 and the switch K10 are pulled in, and the other switching elements K1, K2, K7, and K8 are turned off, and at this time, one end of the ac voltage received by ac charging port 102 enters three-phase winding U, V, W of motor coil 11 from the neutral line drawn from the motor neutral point, and then enters arm converter 102, and the other end passes through first arm Q1 and Q2, further, bridge arm Q1 and Q2 and bridge arm inverter 102 form a full bridge rectified output voltage U0, the voltage U0 is rectified by a full bridge composed of Q3 to Q6 after being filtered by a first capacitor C1, inverted by a transformer T1, the voltage is rectified by a full bridge composed of Q7-Q10 and filtered by a capacitor C4 to charge the battery 200, so that the alternating current charging of the battery 200 is realized; or the third switch K3, the fourth switch K4, the switch K11, the switch K7 and the switch K8 are closed, and the other switches K1, K2, K9 and K10 are opened, at this time, one end of the alternating current voltage received by the alternating current charging port 102 enters the three-phase winding U, V, W of the motor coil 11 from a neutral line led out from a neutral point of the motor, and then enters the bridge arm converter 12, while the other end passes through the bridge arms Q1 and Q2, and then the bridge arms Q1 and Q2 and the bridge arm converter 12 form a full-bridge rectified output voltage U0, and the voltage U0 outputs a voltage to the battery 200 after being filtered by the first capacitor C1, so as to realize the alternating current charging of the battery 200.

In this embodiment, the energy conversion device provided by the present application controls on/off of each switch, so that ac power received by ac charging port 102 is ac-charged to battery 200 through inductor L, motor coil 11, bridge arm converter 12, and bidirectional bridge arm 13, and the ac charging method is not limited to a method, that is, the ac charging method of the energy conversion device is multi-scheme redundant, and the working voltage can be automatically adjusted, so that charging efficiency is improved, and the ac charging function of the energy conversion device can be effectively ensured.

Further, as shown in fig. 7, when the energy conversion device operates in the motor driving mode, the switch K11, the switch K7 and the switch K8 are closed, and the other switches K1 to K4 and K9 to K10 are opened, at this time, the battery 200 outputs high-voltage direct current, and the high-voltage direct current outputs three-phase alternating current to the three-phase winding of the motor coil 11 through the three-phase motor driving bridge of the bridge arm inverter 12, so that the driving of the motor is realized.

In the embodiment, the motor coil 11, the arm converter 12, the bidirectional arm 13 and the bidirectional DC module 15 are integrated in one circuit, so that the energy conversion device can drive the vehicle motor and perform ac charging and discharging of the vehicle battery, thereby improving the circuit integration level, reducing the circuit cost and the circuit volume, and having a simple circuit structure.

In view of the above, for the circuit shown in fig. 7 or fig. 8, no matter the circuit works in the charging mode or the driving mode, a certain amount of voltage is accumulated across the first capacitor C1 during the working process, and when the voltage across the first capacitor C1 is higher than the preset voltage threshold, that is, the voltage across the first capacitor C1 may cause a safety hazard, the capacitor across the first capacitor C1 needs to be discharged, and a specific discharging process is described below.

Specifically, when the whole vehicle is powered on, the energy conversion device firstly detects the gear position of the whole vehicle, when the gear position of the whole vehicle is in the OFF gear position, whether the vehicle is in a driving state is detected, when the vehicle is not in the driving state, the charging state of the vehicle-mounted charger is further confirmed, when the vehicle is confirmed to be in the driving end and the charging end, whether the voltage at two ends of the first capacitor C1 is higher than a preset voltage threshold value is further detected, when the preset voltage threshold value is a limit value of the human body safety voltage, and when the voltage at two ends of the first capacitor C1 is higher than the preset voltage threshold value, the voltage of the first capacitor C1 is discharged.

Further, referring to fig. 10 and fig. 11, when the voltage across the first capacitor C1 is discharged, the switching element Q5, the switching element Q4, and the switching element Q12 in the energy conversion device 1 are turned on, and the voltage across the first capacitor C1 flows through the switching element Q5, the transformer, and the switching element Q4, so that an electromotive force is induced on the secondary side of the transformer, and is rectified by the switching element Q12 to charge the battery 300, that is, the switching element Q5, the switching element Q4, the transformer, the switching element Q12, and the battery 300 form a first voltage discharging loop to discharge the voltage across the first capacitor C1, and a specific current path diagram is shown in fig. 10.

After the first voltage bleeding circuit of the energy conversion device operates for a certain time, at this time, the switching element Q3, the switching element Q6, and the switching element Q11 in the energy conversion device 1 are turned on, and at this time, the voltage across the first capacitor C1 flows through the switching element Q3, the transformer, and the switching element Q6, so that an electromotive force is induced on the secondary side of the transformer, and is rectified by the switching element Q11, and then the battery 300 is charged, that is, the switching element Q3, the switching element Q6, the transformer, the switching element Q11, and the battery 300 form a second voltage bleeding circuit to bleed the voltage across the first capacitor C1, where a specific current path diagram is shown in fig. 11.

In view of the above, the energy conversion device may alternatively operate between the first voltage bleeding circuit and the second voltage bleeding circuit to complete the voltage bleeding across the first capacitor C1 by continuously charging the battery 300, and this way has a fast bleeding speed compared with the existing way, and does not need to add an additional passive bleeding resistor, thereby reducing the cost, reducing the heat loss of the product, and improving the energy utilization rate by charging the battery 300.

Further, as another embodiment of the present invention, when the voltage across the first capacitor C1 is discharged, the switching element Q5, the switching element Q4, and the switching element Q14 in the energy conversion device 1 are turned on, and the voltage across the first capacitor C1 flows through the switching element Q5, the transformer, and the switching element Q4, and further, an electromotive force is induced on the secondary side of the transformer, and is rectified by the switching element Q14, and then, the battery 300 is charged, that is, the switching element Q5, the switching element Q4, the transformer, the switching element Q14, and the battery 300 form a third voltage discharge circuit, so that the voltage across the first capacitor C1 is discharged.

When the third voltage bleeding circuit of the energy conversion device operates for a certain time, at this time, the switching element Q3, the switching element Q6, and the switching element Q13 in the energy conversion device 1 are turned on, and at this time, the voltage across the first capacitor C1 flows through the switching element Q3, the transformer, and the switching element Q6, so that an electromotive force is induced on the secondary side of the transformer, and is rectified by the switching element Q13, and then the battery 300 is charged, that is, the switching element Q3, the switching element Q6, the transformer, the switching element Q13, and the battery 300 form a fourth voltage bleeding circuit, so as to bleed the voltage across the first capacitor C1.

It should be noted that, in this embodiment, reference may be made to the related description of the first voltage bleeding circuit and the second voltage bleeding circuit for the specific operation manner of the energy conversion device between the third voltage bleeding circuit and the fourth voltage bleeding circuit, and the specific current paths of the third voltage bleeding circuit and the fourth voltage bleeding circuit are similar to the current paths of the first voltage bleeding circuit and the second voltage bleeding circuit, respectively, and therefore reference may be made to the current path schematic shown in fig. 7 and fig. 8 specifically, and details are not repeated here.

In the present embodiment, by alternately using the switching elements Q11, Q12 and the switching elements Q13, Q14, it is possible to make any one of the switching elements Q11, Q12 and the switching elements Q13, Q14 operate for a long time, whereby the lives of the switching element Q11, the switching element Q12, the switching element Q13, and the switching element Q14 can be effectively equalized.

Further, the application also provides a power system, which comprises an energy conversion device and a control module, wherein when the first capacitor meets the discharge condition, the control module controls the energy conversion device to discharge the voltage at two ends of the first capacitor.

It should be noted that, since the energy conversion device included in the power system provided by the embodiment of the present application is the same as the energy conversion device shown in fig. 1 to 11, reference may be made to the foregoing detailed description about fig. 1 to 11 for specific working principles of the energy conversion device in the power system provided by the embodiment of the present application, and details are not repeated here

Further, the present application also provides a vehicle that includes a powertrain. It should be noted that, because the powertrain included in the vehicle provided in the embodiment of the present application is the same as the powertrain described above, reference may be made to the foregoing related description for specific operating principles of the powertrain in the vehicle provided in the embodiment of the present application, and details are not described herein again.

In the application, the vehicle provided by the application adopts the energy conversion device with the functions of driving and charging the motor coil, the bridge arm converter, the bidirectional bridge arm and the first capacitor set, so that the energy conversion device can work in a driving mode, a direct current charging mode and an alternating current charging mode, further the motor driving and the battery charging of the vehicle are realized by adopting the same system, the multiplexing of the capacitors can improve the power conversion efficiency and the energy utilization rate during the direct current charging, reduce the noise generated by harmonic current at the side of a power grid during the alternating current charging and the pollution to the power grid, improve the power supply quality of the power grid, and the high-frequency switching frequency and higher harmonic generated by the bridge arm converter can be absorbed during the motor driving, the energy is stored after the voltage is boosted by the bridge arm converter, the stable pure direct current bus voltage of the bridge arm converter is ensured, and the multiplexing degree of components is high, the system has high integration level and simple structure, thereby reducing the system cost and reducing the system volume.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. An energy conversion device is characterized by comprising a motor coil, a bridge arm converter, a bidirectional bridge arm and a first capacitor;

the first capacitor is connected with the bidirectional bridge arm in parallel;

the motor coil, the bridge arm converter, the first capacitor and an external battery form a motor driving circuit;

also included is a bidirectional DC module; the bidirectional DC module comprises a first direct current end and a second direct current end, the first direct current end is connected with the first capacitor, the second direct current end is connected with an external storage battery, and the first capacitor, the bidirectional DC module and the storage battery form a voltage release loop so as to release voltage at two ends of the first capacitor when the first capacitor meets a release condition.

2. The energy conversion device according to claim 1, wherein the bidirectional DC module includes a first converter, a second converter, and a transformation unit, a primary side and a secondary side of the transformation unit are respectively connected to the first converter and the second converter, the first converter is connected in parallel to the first capacitor, the second converter is connected in parallel to the battery, and the first capacitor, the first converter, the second converter, the transformation unit, and the battery form the voltage relief circuit.

3. The energy conversion arrangement according to claim 2, wherein the second converter comprises a first sub-converter connected to the secondary side of the transformation unit and to the battery, the first capacitor, the first converter, the first sub-converter, the transformation unit and the battery forming the voltage bleeding circuit, and in the voltage bleeding circuit the first converter and the first sub-converter operate alternately between a first bleeding state and a second bleeding state to bleed the voltage across the first capacitor.

4. The energy conversion apparatus according to claim 3, wherein the first converter includes a first switching element, a second switching element, a third switching element, a fourth switching element, a first inductance, and a second capacitance; the first end of the first switching element is connected with the first end of the third switching element and the first end of the first capacitor, the second end of the first switching element is connected with the first end of the second switching element and the first end of the second capacitor, the second end of the third switching element is connected with the first end of the fourth switching element and the first end of the first inductor, the second end of the first inductor and the second end of the second capacitor are both connected with the primary side of the transformer unit, and the second end of the second switching element is connected with the second end of the fourth switching element and the second end of the first capacitor.

5. The energy conversion apparatus according to claim 4, wherein the first sub-converter includes a fifth switching element and a sixth switching element, a first end of the fifth switching element, a first end of the sixth switching element, and a positive end of the secondary battery are connected to the secondary side of the transformer unit, and a second end of the fifth switching element and a second end of the sixth switching element are connected to a negative end of the secondary battery.

6. The energy conversion device according to claim 5, wherein the first capacitor, the third switching element, the second switching element, the transforming unit, the sixth switching element and the battery form a first voltage bleeding circuit, the first capacitor, the first switching element, the fourth switching element, the transforming unit, the fifth switching element and the battery form a second voltage bleeding circuit, the first voltage bleeding circuit bleeds in a first bleeding state, the second voltage bleeding circuit bleeds in a second state, and the first voltage bleeding circuit and the second voltage bleeding circuit work alternately to bleed off the voltage across the first capacitor.

7. The energy conversion arrangement according to claim 6, wherein the second converter comprises a second sub-converter connected to the secondary side of the transformation unit and to the battery, the first capacitor, the first converter, the second sub-converter, the transformation unit and the battery forming the voltage bleeding circuit, and in the voltage bleeding circuit the first converter and the second sub-converter operate alternately between a third bleeding state and a fourth bleeding state to bleed the voltage across the first capacitor.

8. The energy conversion apparatus according to claim 7, wherein the second sub-converter includes a seventh switching element and an eighth switching element, a first end of the seventh switching element, a first end of the eighth switching element, and a positive end of the secondary battery are connected to the secondary side of the transformer unit, and a second end of the seventh switching element and a second end of the eighth switching element are connected to a negative end of the secondary battery.

9. The energy conversion device of claim 8, wherein the first capacitor, the third switching element, the second switching element, the transformer unit, the eighth switching element, and the battery form a third voltage bleed circuit, wherein the first capacitor, the first switching element, the fourth switching element, the transformer unit, the seventh switching element, and the battery form a fourth voltage bleed circuit, wherein the third voltage bleed circuit bleeds in a third bleed state, wherein the fourth voltage bleed circuit bleeds in a fourth state, and wherein the third voltage bleed circuit and the fourth voltage bleed circuit operate alternately to bleed voltage across the first capacitor.

10. The energy conversion device of claim 1, wherein the motor coils comprise three-phase windings, each phase winding comprises N coil branches, first ends of the N coil branches in each phase winding are connected with the bridge arm converter after being connected in common, second ends of the N coil branches in each phase winding are connected with second ends of the N coil branches in the other two-phase windings in a one-to-one correspondence manner to form N neutral points, and the charging ports are connected with the M neutral points; wherein N is an integer greater than 1, and M is a positive integer less than N.

11. The energy conversion device of claim 10, further comprising a neutral switch for controlling M of the N neutral points of the motor coil to be connected to the charging port.

12. The energy conversion arrangement according to claim 9, wherein the bidirectional DC module comprises a third DC terminal, the third DC terminal being connected to the battery, the bidirectional DC module comprising a third converter, the secondary side of the transforming unit being connected to the third converter, the third converter being connected in parallel to the battery.

13. A power system comprising the energy conversion device of any of claims 1-12 and a control module that controls the energy conversion device to bleed off voltage across the first capacitor when the first capacitor meets a bleed off condition.

14. A vehicle characterized by comprising the powertrain of claim 13.