CN220544866U

CN220544866U - Drain system and vehicle

Info

Publication number: CN220544866U
Application number: CN202322208558.6U
Authority: CN
Inventors: 马先红
Original assignee: If Technology Co Ltd
Current assignee: If Technology Co Ltd
Priority date: 2023-08-16
Filing date: 2023-08-16
Publication date: 2024-02-27
Anticipated expiration: 2033-08-16

Abstract

The utility model discloses a discharge system, which is applied to a power supply system of a vehicle. The bleed system includes: the system comprises a first bleeder module, a second bleeder module, a controller and a full-bridge inverter; the controller is respectively connected with the second bleeder module and the full-bridge inverter; the first discharging module is used for continuously discharging the bus capacitor energy of the direct current bus; in response to an external power-off signal, the controller sends a first bleed signal to the second bleed module and a second bleed signal to the full-bridge inverter; the first discharging signal is used for indicating the second discharging module to be conducted so as to discharge the bus capacitor energy of the direct current bus, and the second discharging signal is used for indicating the short circuit of the full-bridge inverter so as to discharge the winding energy of the motor. The utility model can improve the safety of the vehicle.

Description

Drain system and vehicle

Technical Field

The utility model belongs to the technical field of voltage discharge, and particularly relates to a discharge system and a vehicle.

Background

Along with the continuous improvement of the intelligent degree of the automobile, higher requirements are put forward on the safety of the automobile. After the motor or the dc bus of the motor vehicle is disconnected, there is a charge on both the windings of the motor and the capacitance of the dc bus. If the active discharge is not carried out and only consumes electricity, the discharge duration is long, and a certain electric shock risk exists when a person touches the vehicle.

The utility model provides a discharging system, which reduces the risk of personnel electric shock and improves the safety level of a vehicle by discharging redundant electric quantity.

Disclosure of Invention

The embodiment of the utility model provides a discharging system and a vehicle, which are used for reducing the risk of personnel electric shock and improving the safety level of the vehicle by discharging redundant electric quantity.

A first aspect of an embodiment of the present utility model provides a bleeder system applied to a power supply system of a vehicle, the power supply system including a battery, a PDU, a full-bridge inverter and a motor connected in sequence, wherein the PDU and the full-bridge inverter are connected by a dc bus, the bleeder system including: the system comprises a first bleeder module, a second bleeder module, a controller and a full-bridge inverter;

the first discharging module and the second discharging module are connected in parallel between a positive bus and a negative bus of the direct current bus, and the controller is respectively connected with the second discharging module and the full-bridge inverter;

the first discharging module is used for continuously discharging the bus capacitor energy of the direct current bus;

in response to an external power-off signal, the controller sends a first bleed signal to the second bleed module and a second bleed signal to the full-bridge inverter;

the power-off signal is used for indicating that the vehicle is powered down, the first discharging signal is used for indicating that the second discharging module is conducted to discharge the bus capacitor energy of the direct current bus, and the second discharging signal is used for indicating that the full-bridge inverter is short-circuited to discharge the winding energy of the motor.

In one embodiment, the first bleed module includes a first power resistor.

In one embodiment, the bleed system further comprises a normally closed switch connected in series with the first power resistor.

In one embodiment, the second bleed module includes a second power resistor and a power switch connected in series;

the power switch is controlled by the controller and is switched to a conducting state when receiving the first release signal.

In one embodiment, the power switch is an IGBT switch.

In one embodiment, the bleeder system further comprises a signal amplification circuit connected between the controller and the full-bridge inverter, the signal amplification circuit being configured to amplify the second bleeder signal and to send the amplified second bleeder signal to the full-bridge inverter.

In one embodiment, the bleed system further comprises a voltage acquisition module connected to the PDU and the controller, respectively, the voltage acquisition module being configured to acquire the DC bus voltage and to send the bus voltage to the controller.

In one embodiment, the bleed system further comprises a filtering module connected between the voltage acquisition module and the controller.

In one embodiment, the full-bridge inverter is a three-phase full-bridge inverter.

A second aspect of an embodiment of the utility model provides a vehicle comprising a vent system according to any one of the first aspects above.

Compared with the prior art, the embodiment of the utility model has the beneficial effects that:

the embodiment of the utility model provides a discharge system applied to a vehicle power supply system, which is characterized in that a first discharge module is arranged to passively discharge a direct-current bus capacitor, a second discharge module is arranged to realize the active discharge of the direct-current bus capacitor, and a full-bridge inverter of the power supply system is utilized to realize the active discharge of a motor winding, so that the electric quantity of the bus capacitor on the direct-current bus of the power supply system and the surplus energy of the motor winding can be discharged, the electric shock risk of personnel is reduced, the safety level of the vehicle is improved, and the working reliability of the vehicle is ensured.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic illustration of a vent system according to an embodiment of the present utility model;

FIG. 2 is a schematic illustration of another vent system provided in accordance with an embodiment of the utility model;

FIG. 3 is a schematic illustration of a still further vent system according to an embodiment of the utility model;

FIG. 4 is a schematic illustration of a fourth vent system provided in accordance with an embodiment of the utility model;

fig. 5 is a schematic structural view of a fifth vent system provided in accordance with an embodiment of the utility model.

Detailed Description

In order to make the present solution better understood by those skilled in the art, the technical solution in the present solution embodiment will be clearly described below with reference to the accompanying drawings in the present solution embodiment, and it is obvious that the described embodiment is an embodiment of a part of the present solution, but not all embodiments. All other embodiments, based on the embodiments in this solution, which a person of ordinary skill in the art would obtain without inventive faculty, shall fall within the scope of protection of this solution.

The term "comprising" in the description of the present solution and the claims and in the above-mentioned figures, as well as any other variants, means "including but not limited to", intended to cover a non-exclusive inclusion, and not limited to only the examples listed herein. Furthermore, the terms "first" and "second," etc. are used for distinguishing between different objects and not for describing a particular sequential order.

The following detailed description of implementations of the utility model, taken in conjunction with the accompanying drawings, illustrates, for ease of explanation, only those portions of the utility model that are relevant to an embodiment of the utility model:

fig. 1 is a schematic structural diagram of a bleeder system according to an embodiment of the present utility model, as shown in fig. 1, in one embodiment of the present utility model, the bleeder system is applied to a power supply system of a vehicle, the power supply system of the vehicle includes a battery 20, a power distribution unit 21 (PowerDistributionUnit, PDU), a full-bridge inverter 22 and a motor 23 which are sequentially connected, wherein the PDU21 and the full-bridge inverter 22 are connected by a dc BUS, and the dc BUS includes a positive BUS bus+ and a negative BUS-, and a BUS capacitor is generally disposed between the positive bus+ and the negative BUS.

As shown in fig. 1, the bleed system may include a first bleed module 11, a second bleed module 12, a controller 13, and a full bridge inverter 22.

The first and second bleeder modules 11, 12 are connected in parallel between the positive BUS bar + and the negative BUS bar-of the dc BUS, and the controller 12 is connected with the second bleeder module 13 and the full bridge inverter 22, respectively.

The first discharging module 11 is used for continuously discharging the bus capacitor energy of the direct current bus.

In response to an external power down signal, the controller 13 sends a first bleed signal to the second bleed module 12 and a second bleed signal to the full bridge inverter 22.

The power-off signal is used for indicating that the vehicle is powered down, the first discharging signal is used for indicating that the second discharging module 12 is conducted to discharge the bus capacitor energy of the direct current bus, and the second discharging signal is used for indicating that the full-bridge inverter 22 is short-circuited to discharge the winding energy of the motor 23.

The first bleeder module 11 may be a power bleeder circuit formed by power devices, and in the process of powering on or powering off the vehicle, the first bleeder module 11 always bleeds the energy of the bus capacitor on the dc bus. The power consumption of the first bleeder module 11 may be preset to be a preset power, where the preset power is a power that has little influence on the working efficiency of the vehicle power supply system.

Alternatively, the second bleeder module 12 may be comprised of a controllable bleeder circuit that consumes a significant amount of power. Typically, the second bleeder module 12 is in an off state, not bleeding the bus capacitance energy of the dc bus. When the first discharging module 11 cannot meet the energy discharging requirement, or the vehicle is powered off and powered down, or the second discharging module 12 is required to discharge energy, the second discharging module 12 can be controlled to conduct to work, and the bus capacitor energy of the direct current bus is discharged at a higher speed. Wherein the power consumption of the second bleeder module 12 is larger than the power consumption of the first bleeder module 11.

In some cases, the first discharging module 11 and the second discharging module 12 simultaneously discharge the energy of the bus capacitor of the direct current bus, so that the energy of the bus capacitor can be discharged quickly, the risk of personnel electric shock is reduced, and the safety of the vehicle is improved.

In the embodiment of the present utility model, the full-bridge inverter 22 is a three-phase full-bridge inverter, and the full-bridge inverter 22 is used for converting a direct current motor of a direct current bus into a three-phase voltage and outputting the three-phase voltage to the motor 23 so as to drive the motor 23 to work. The full-bridge inverter 22 is a self-contained power controllable device in the power supply system of the vehicle.

Optionally, in the embodiment of the present utility model, the second bleed signal output by the controller 13 may control the upper bridge arm to be fully turned on and the lower bridge arm to be fully turned off in the three-phase inverter to realize active short circuit; or, the second bleed signal output by the controller 13 may control the upper bridge arm of the three-phase inverter to be fully turned off, and the lower bridge arm to be fully turned on to realize active short circuit. Or the second bleed signal output by the controller 13 can control the conduction of a single or two power tubes of the three-phase inverter to realize active short circuit. The setting can be specifically performed according to actual conditions.

Alternatively, the microcontroller (MicroController Unit, MCU) of the vehicle may send a power-off signal to the controller 13 when the vehicle is powered off. Alternatively, the controller 13 may directly monitor the power up and down condition of the vehicle.

The working process of the bleeder system provided by the embodiment of the utility model is as follows:

after receiving the power-off signal, the controller 13 may generate a first bleed-off signal and send the first bleed-off signal to the second bleed-off module 12, so as to control the second bleed-off module 12 to be turned on, and bleed the bus capacitor energy of the dc bus. The first bleed signal may be a switch control signal.

After receiving the power-off signal, the controller 13 may simultaneously generate a second bleed signal and send the second bleed signal to the full-bridge inverter 22 to control the full-bridge inverter 22 to be in a short-circuit state, and bleed the winding energy of the motor 23. The second bleed signal may be a PWM control signal.

Under the condition that the vehicle is powered off, the first discharging module 11, the second discharging module 12 and the full-bridge inverter 22 work in a discharging state at the same time, so that the bus capacitor energy of the direct current bus and the winding energy of the motor 23 can be rapidly discharged, the electric shock risk of personnel is reduced, and the safety of the vehicle is improved.

Fig. 2 is a schematic structural diagram of another bleeder system provided in an embodiment of the present utility model, as shown in fig. 2, in which the first bleeder module 11 comprises a first power resistor R1.

The first power resistor R1 is connected between a positive BUS BUS+ and a negative BUS BUS-of the direct current BUS and used for continuously discharging the BUS capacitance energy of the direct current BUS passively. The type of the first power resistor R1 may be selected according to the dc bus voltage, the capacitance of the bus capacitor, and the discharge time requirement.

For example, a 50KΩ/50W power resistor may be selected as the first power resistor R1. At a dc bus voltage of 600VDC, the actual power consumption of the first power resistor R1 is 7.2W.

The embodiment of the utility model can passively release the energy of the bus capacitor in real time by arranging the first power resistor, has lower power, has low power consumption when the power supply system of the vehicle works normally, and does not have great influence on the normal power supply of the power supply system. After the power of the vehicle is off, the energy consumption speed of the bus capacitor can be increased, and the risk of electric shock of personnel is reduced.

As shown in fig. 2, in one embodiment of the utility model, the bleed system may further comprise a normally closed switch S1 connected in series with the first power resistor. Wherein the normally closed switch S1 may be connected between the first power resistor R1 and the positive BUS bus+ of the dc BUS, or the normally closed switch S1 may be connected between the first power resistor R1 and the negative BUS-of the dc BUS.

Alternatively, the normally closed switch S1 may be controlled by the controller 13, or the MCU of the vehicle.

The normally closed switch S1 is in a default closed state, so that the energy of the bus capacitor can be continuously discharged by the first power resistor R1.

When an emergency situation is met, for example, the positive BUS BUS+ and the negative BUS BUS-are short-circuited or the output end is in fault, the normally closed switch S1 can be controlled to be disconnected, the positive BUS BUS+ and the negative BUS BUS-are prevented from being short-circuited, so that the working reliability of a relief system is ensured, and the safety of a vehicle is improved.

As shown in fig. 2, in one embodiment of the utility model, the second bleed module 12 includes a second power resistor R2 and a power switch Q1 connected in series.

The power switch Q1 is controlled by the controller 13 and switches to the on state upon receipt of the first bleed signal.

Alternatively, the power switch Q1 may be connected between the second power resistor R2 and the positive BUS bus+ of the dc BUS, or the power switch Q1 may be connected between the second power resistor R2 and the negative BUS-of the dc BUS, which may be specifically set according to practical situations.

Alternatively, the power switch Q1 may be an IGBT or a relay switch. In an embodiment of the present utility model, an IGBT may be selected as the power switch Q1.

When the controller 13 receives an external power-off signal, the power switch Q1 may send a first bleed signal to control the power switch Q1 to switch to a conducting state, so as to implement that the bus capacitor releases excessive energy through the second power resistor R2.

In the embodiment of the present utility model, the power of the second power resistor R2 is higher than that of the first power resistor R1, and therefore, the power switch Q1 needs to be configured to control discharge through the second power resistor when necessary. For example, a power resistor of 10KΩ/200W may be selected as the second power resistor R2.

According to the embodiment of the utility model, the first power resistor and the second power resistor are arranged, so that the energy of the bus capacitor can be released 1 to 3 seconds after the power of the vehicle is off, the electric shock of personnel is avoided, and the safety of the vehicle is improved.

In addition, in the embodiment of the present utility model, after the vehicle is powered on, in order to avoid that the second power resistor R2 consumes too much energy of the whole vehicle, the controller 13 may send an off signal to the power switch Q1 to control the power switch Q1 to be turned off, so as to ensure the energy of the whole vehicle, and at the same time, avoid burning out the second power resistor R2.

Fig. 3 is a schematic structural diagram of still another bleeder system according to an embodiment of the present utility model, as shown in fig. 3, in an embodiment of the present utility model, the bleeder system may further comprise a signal amplifying circuit 14 connected between the controller 13 and the full-bridge inverter 22, and the signal amplifying circuit 14 is configured to amplify the second bleeder signal and send the amplified second bleeder signal to the full-bridge inverter 22. The signal amplifying circuit 14 may be a signal isolation amplifying circuit composed of an optocoupler.

The embodiment of the utility model ensures the reliability of the transmission of the second discharge signal by arranging the signal amplifying circuit 14, and improves the working reliability of the discharge system.

Fig. 4 is a schematic structural diagram of a fourth bleeder system according to an embodiment of the present utility model, as shown in fig. 4, in an embodiment of the present utility model, the bleeder system further includes a voltage acquisition module 15 connected to the PDU21 and the controller 13, respectively, and the voltage acquisition module 15 is configured to acquire a dc bus voltage and send the bus voltage to the controller 13.

The controller 13 may determine whether to transmit the first bleed signal according to the bus voltage. When the bus voltage is too high, the controller 13 can output a first discharging signal to control the second discharging module to be in a working state, so that the energy of the bus capacitor can be rapidly released, the energy can be timely released, and the working reliability is ensured.

In the embodiment of the utility model, the vehicle MCU can also send the fault state or the motor rotation speed information of the vehicle to the controller 13, and the controller 13 can judge whether to output the first release signal or the second release signal according to the fault state and/or the motor rotation speed information so as to ensure the release of the surplus energy of the vehicle.

When the motor rotating speed is higher than the preset rotating speed and/or the vehicle is in a fault state, the controller 13 outputs a first discharge signal and a second discharge signal to the outside, so that the energy of the motor winding and the energy of the bus capacitor are released as soon as possible, the whole vehicle is prevented from being electrified, and the risk of electric shock of personnel is reduced.

Fig. 5 is a schematic structural diagram of a fifth bleeder system provided in an embodiment of the present utility model, as shown in fig. 5, and in one embodiment of the present utility model, the bleeder system further comprises a filtering module 16 connected between the voltage acquisition module 15 and the controller 13. The filtering module 16 is configured to filter the bus voltage transmitted by the voltage acquisition module, and send the filtered bus to the controller 13, so as to improve reliability of signal transmission.

In one embodiment of the utility model, the full-bridge inverter may be a three-phase full-bridge inverter. The motor 23 of the vehicle is typically implemented by a three-phase full-bridge inverter, which may include 6 switching tubes and 6 reverse freewheeling diodes, to convert direct current to alternating current. Wherein the second bleed signal may control the full bridge inverter in an active short circuit (Active short circuit, ASC) mode.

After the three-phase full-bridge inverter enters an ASC mode, because all phase bridge arms are not conducted, a direct-current end circuit and an alternating-current end circuit do not form a loop, and meanwhile, the driving motor generates reverse braking torque, and the ASC mode is reasonably applied to the running process of the electric automobile based on the characteristics to mainly play roles in the following aspects:

(1) When the whole vehicle is out of control, the ASC can be implemented to generate reverse torque, so that the vehicle is slowly braked, and safe parking is realized.

(2) When the power battery fails, the ASC is implemented to isolate the motor, the three-phase full-bridge inverter and the power battery side, so that the high-voltage safety of the whole vehicle is ensured.

(3) When the rotating speed of the driving motor is too high or abnormal in the whole vehicle driving process, the ASC can be implemented to avoid damage of too high counter potential to a power battery, a bus capacitor and other high-voltage devices.

(4) When a certain switching tube (IGBT) in the inverter circuit of the motor controller fails, the ASC can be implemented to avoid damage of uncontrollable rectification to other devices or power batteries.

In a new energy pure electric vehicle, the only power source of the vehicle is a driving motor, and most of the current motor types for electric vehicles are permanent magnet synchronous motors, once the permanent magnet of the driving motor demagnetizes or breaks away from the half shaft connection and other faults occur, the driving motor may have a runaway rotating speed to cause the runaway of the whole vehicle, so that the personal safety is endangered.

In general, a motor operating at a relatively high rotational speed (e.g., above 7000 r/min), such as directly shutting down a three-phase full-bridge inverter, will generate a significant braking torque, which is extremely dangerous for a vehicle traveling at high speeds. Compared with the torque and rotation speed characteristics of ASC and inverter shutdown, when the vehicle runs out of control or has serious faults at high speed, the vehicle enters an ASC mode in a motor high-rotation speed area (more than 5300r/min for example) and enters a three-phase full-bridge inverter shutdown mode in a motor low-speed area (less than 5300r/min for example) so as to provide effective protection measures for safe parking of the vehicle running at high speed.

In some cases, due to the characteristic of counter electromotive force existing in the running process of the motor, when the situation such as abnormal motor rotation speed, poor control and the like occurs in the running process of the vehicle, the counter electromotive force of the motor is possibly higher than the input voltage of the motor, so that the counter electromotive force is induced to flow back into the power battery through the inverter, and the power battery and related high-voltage devices are damaged. Therefore, when such a fault occurs, it is necessary to properly control the three-phase full-bridge inverter to enter the ASC mode in order to secure the safety of the vehicle.

Under a specific condition, if the rotating speed of the motor is more than 3000r/min, the counter potential is possibly higher than the input voltage, so that when the rotating speed is more than 3000r/min, the three-phase full-bridge inverter can be controlled to enter an ASC state.

It is worth noting that when the three-phase full-bridge inverter operates in the ASC mode, the phase current of the driving motor is far higher than the normal working state and possibly approaches to the peak current, so that the phase current is required to be ensured not to exceed the peak current of the motor in practical application, and damage to high-voltage devices is avoided.

Specifically, the reverse torque in the ASC state is stabilized above 3000r/min, and the phase current is 225A (the peak current of the motor is 280A) and does not exceed the peak current, so that the three-phase full-bridge inverter of the vehicle enters the ASC control mode based on the following working conditions:

(1) When the output bus voltage of the power battery of the vehicle is 240VDC, the ASC mode is entered when the motor rotating speed is more than 3000r/min in order to prevent the high back electromotive force from flowing backward to the power battery.

(2) When the output bus voltage of the power battery is 240-400 VDC, in order to prevent the high back electromotive force from flowing backwards into the power battery, the motor rotating speed is 3000-5000 r/min to cope with the voltage of the input end of the motor and counter electromotive force data, and the power battery enters an ASC mode when the counter electromotive force is higher than the voltage of the input end of the motor.

(3) When the power battery outputs the bus voltage of 400VDC, the motor speed is more than 5000r/min to enter an ASC mode in order to prevent high back electromotive force from flowing backwards to the power battery.

In addition, the driving motor is a key power assembly, and compared with other types of motors, the permanent magnet synchronous motor has the advantages of high efficiency, large torque and power density, wide constant power speed regulation range and the like, and is widely adopted. However, the permanent magnet synchronous motor adopts a permanent magnet as a rotor, and even if the MCU system is not electrified, the magnetism of the motor rotor still exists all the time, so that the permanent magnet synchronous motor can generate counter-potential when being reversely towed, and the counter-potential and the rotating speed are in a proportional relation, and the high-rotating-speed reversely towed permanent magnet synchronous motor can cause damage to high-voltage devices of a motor controller and even power batteries.

At present, most driving motors and transmission shafts do not have a disengaging device (such as a P-gear mechanism), so that a motor generates counter potential when a vehicle carrying the permanent magnet synchronous motor slides under a working condition and a driving wheel lands on a trailer, and safety threat is formed to a switching tube of a motor controller and other high-voltage devices.

Therefore, when the vehicle slides or temporarily trailes, the three-phase full-bridge inverter enters an ASC mode, the circuit connection between the motor end and the power battery end is cut off, the counter-potential electric energy is released through the motor stator winding, and the safety of the electric appliance is effectively protected.

In order to improve the working reliability of a power supply system of a vehicle, the embodiment of the utility model combines three discharging modes, can meet the functional safety requirements of ISO26262-ASIL B, and can release the energy of a bus capacitor and the energy of a motor winding in a specified time.

The embodiment of the utility model also provides a vehicle comprising the vent system of any of the embodiments above.

The above embodiments are only for illustrating the technical solution of the present utility model, and not for limiting the same; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present utility model.

Claims

1. A bleed-off system for a power supply system of a vehicle, the power supply system comprising a battery, a PDU, a full-bridge inverter and a motor connected in sequence, wherein the PDU and the full-bridge inverter are connected by a dc bus, the bleed-off system comprising: the full-bridge inverter comprises a first bleeder module, a second bleeder module, a controller and the full-bridge inverter;

the power-off signal is used for indicating that the vehicle is powered down, the first discharging signal is used for indicating that the second discharging module is conducted so as to discharge the bus capacitor energy of the direct-current bus, and the second discharging signal is used for indicating that the full-bridge inverter is short-circuited so as to discharge the winding energy of the motor.

2. The bleed system of claim 1, wherein the first bleed module comprises a first power resistor.

3. The vent system of claim 2, further comprising a normally closed switch connected in series with the first power resistor.

4. The bleed system of claim 1, wherein the second bleed module comprises a second power resistor and a power switch connected in series;

the power switch is controlled by the controller and is switched to a conducting state when the first release signal is received.

5. The vent system according to claim 4, wherein the power switch is an IGBT switch.

6. The bleeder system of claim 1, further comprising a signal amplification circuit connected between the controller and the full-bridge inverter, the signal amplification circuit for amplifying the second bleeder signal and transmitting the amplified second bleeder signal to the full-bridge inverter.

7. The vent system of claim 1, further comprising a voltage acquisition module coupled to the PDU and the controller, respectively, the voltage acquisition module configured to acquire the dc bus voltage and transmit the bus voltage to the controller.

8. The vent system of claim 7, further comprising a filtering module connected between the voltage acquisition module and the controller.

9. The bleeder system according to any one of claims 1 to 8, wherein the full-bridge inverter is a three-phase full-bridge inverter.

10. A vehicle comprising a vent system according to any one of claims 1 to 9.