CN117087435A - Electric vehicle trailer working condition circuit protection device and method - Google Patents

Electric vehicle trailer working condition circuit protection device and method Download PDF

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Publication number
CN117087435A
CN117087435A CN202210515476.3A CN202210515476A CN117087435A CN 117087435 A CN117087435 A CN 117087435A CN 202210515476 A CN202210515476 A CN 202210515476A CN 117087435 A CN117087435 A CN 117087435A
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CN
China
Prior art keywords
voltage
trailer
unit
low
hysteresis
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CN202210515476.3A
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Chinese (zh)
Inventor
范佳伦
焦民胜
于海燕
黄炜
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Jee Automation Equipment Shanghai Co ltd
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Jee Automation Equipment Shanghai Co ltd
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Priority to CN202210515476.3A priority Critical patent/CN117087435A/en
Publication of CN117087435A publication Critical patent/CN117087435A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L3/00—Electric devices on electrically-propelled vehicles for safety purposes; Monitoring operating variables, e.g. speed, deceleration or energy consumption
    • B60L3/0023—Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L3/00—Electric devices on electrically-propelled vehicles for safety purposes; Monitoring operating variables, e.g. speed, deceleration or energy consumption
    • B60L3/0023—Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train
    • B60L3/0061—Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train relating to electrical machines
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L3/00—Electric devices on electrically-propelled vehicles for safety purposes; Monitoring operating variables, e.g. speed, deceleration or energy consumption
    • B60L3/12—Recording operating variables ; Monitoring of operating variables

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  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Sustainable Energy (AREA)
  • Power Engineering (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Electric Propulsion And Braking For Vehicles (AREA)

Abstract

The invention discloses a circuit protection device and method for the working condition of an electric vehicle trailer. Comprising the following steps: the low-voltage state monitoring unit is used for receiving the low-voltage signal, monitoring the low-voltage state of the low-voltage system of the electric vehicle, and sending a logic signal for starting the working condition of the trailer to the trailer enabling circuit unit when the low-voltage side is powered down due to the failure of the low-voltage system; the trailer enabling circuit unit is used for controlling whether the electric vehicle enters a trailer working condition, and opening trailer protection logic after receiving a logic signal for starting the trailer working condition sent by the low-voltage state monitoring unit; and the hysteresis comparison unit is used for directly controlling the on or off of the driving unit when the trailer enabling circuit unit turns on the trailer protection logic. The method can simplify the hardware execution logic, improve the reliability, improve the security level of the system, and has the advantages of high logic adaptability, low design cost and the like.

Description

Electric vehicle trailer working condition circuit protection device and method
Technical Field
The invention relates to the technical field of electric vehicle safety, in particular to an electric vehicle trailer working condition circuit protection device and method.
Background
With the rapid development of the modern electric automobile technology, the output power and the safety level of the electric automobile are higher and higher, and the safety protection requirements under fault conditions are also more and more severe, including overvoltage faults, overcurrent faults, overspeed faults and the like. At present, most of the motors for vehicles adopt a permanent magnet synchronous structure, and when faults occur and the rotating speed of the motors still exists, the motors generate certain back electromotive force, and the back electromotive force needs to be eliminated through three-phase active short circuit of the motors. When the rotation speed of the motor is low, a certain braking torque is generated by executing the active short circuit, which is contrary to the safety requirement of the automobile, so that the controller can execute the full closing pipe when the motor is in low speed and execute the active short circuit when the motor is in high speed when the motor is in failure.
At present, the controller adopts a high-low voltage isolation power supply mode, and when the low-voltage power supply is powered down or the vehicle fails in the running process of the vehicle, and the low-voltage power supply falls off and needs to be used for a trailer working condition, the system requires the controller to realize dual safety of torque and high voltage.
The current controller design adopts sampling high-voltage side busbar voltage and rotational speed signal more, and the isolated transmission is carried out to the low-voltage side and is monitored, and this requires the controller to carry out backup power supply to low-voltage main control unit, and when taking place low-voltage power down, the logic control function of MCU (Motor Control Unit ) still can reliably be operated.
The circuit structure in the prior art needs to design a low-voltage full-backup power supply, and the low-voltage backup power supply can be stably switched when the low-voltage side is powered off, so that the power supply structure is complex. Meanwhile, bus voltage and rotating speed signals are monitored, driving signals of IGBT (Insulated Gate Bipolar Transistor ) are transmitted to the high-voltage side from the low-voltage side for safety control, and when an actual vehicle breaks down, the integrity of a signal link is difficult to guarantee.
Disclosure of Invention
In order to at least partially solve the technical problems in the prior art, the inventor makes the invention, and aims to realize simplified and reliable low-voltage power-down safety protection, the rotating speed information is indirectly obtained through monitoring the bus voltage, the logic protection is directly carried out on the high-voltage side, and the invention provides a device and a method for protecting the working condition circuit of the electric vehicle trailer through a specific embodiment.
In a first aspect, an embodiment of the present invention provides a circuit protection device for an electric vehicle trailer working condition, including a driving unit, where the driving unit includes a plurality of IGBT power modules, and further includes:
the low-voltage state monitoring unit is electrically connected with the trailer enabling circuit unit and is used for isolating high voltage from low voltage, receiving a low-voltage signal, controlling the high-voltage signal, monitoring the low-voltage state of the low-voltage system of the electric vehicle, and sending a logic signal for starting the working condition of the trailer to the trailer enabling circuit unit when the low-voltage system fails to cause power failure of the low-voltage side or the low-voltage signal is abnormal;
the trailer enabling circuit unit is positioned at the high-voltage side and is electrically connected with the low-voltage state monitoring unit, the hysteresis comparison unit and the driving unit and used for controlling whether the electric vehicle enters a trailer working condition or not, and after receiving a logic signal for starting the trailer working condition sent by the low-voltage state monitoring unit, the trailer enabling circuit unit opens trailer protection logic;
and the hysteresis comparison unit is positioned at the high-voltage side and is electrically connected with the trailer enabling circuit unit and used for directly controlling the on or off of the driving unit when the trailer enabling circuit unit turns on the trailer protection logic.
Optionally, the low-voltage state monitoring unit is further configured to send a logic signal to close the trailer to the trailer enable unit when the low-voltage system is normal.
Optionally, the trailer enabling circuit unit is further configured to receive a logic signal for closing the trailer sent by the low-voltage state monitoring unit when the low-voltage system is normal, wherein the switch electrically connected to the driving unit of the trailer enabling circuit unit is disconnected, and the trailer enabling circuit unit performs a function of prohibiting the hardware trailer.
Optionally, the driving unit is used for executing the torque control logic under the normal working condition when the trailer enabling circuit unit executes the function of disabling the hardware trailer.
Optionally, the method further comprises: and the bus voltage sampling unit is positioned at the high-voltage side, is electrically connected with the hysteresis comparison unit, and is used for monitoring the bus voltage value and transmitting the bus voltage value to the hysteresis comparison unit.
Optionally, the hysteresis comparison unit is further configured to receive the bus voltage value sent by the bus voltage sampling unit, and switch an execution state according to the bus voltage value at different high-voltage points, where the execution state includes a full-closed tube and an active short circuit.
Optionally, the hysteresis comparison unit is specifically configured to execute a lower three-bridge active short-circuit logic when the electric vehicle enters a trailer working condition and the driving unit is in a full-closed tube, and when the bus voltage value received by the hysteresis comparison unit reaches a preset high voltage V2.
Optionally, the hysteresis comparison unit is specifically configured to, when the electric vehicle enters a trailer working condition and the driving unit is in a fully closed tube, and when the bus voltage value received by the hysteresis comparison unit is lower than a preset high-voltage point V1, enter a fully closed tube execution state.
Optionally, the hysteresis comparison unit is further configured to set a hysteresis voltage interval according to a high voltage point corresponding to the execution state switching, and when the bus voltage value received by the hysteresis comparison unit is within the hysteresis voltage interval, the hysteresis comparison unit maintains the execution state.
In a second aspect, an embodiment of the present invention provides a method for protecting a working condition circuit of an electric vehicle trailer, including the following steps:
setting a low-voltage state monitoring unit to isolate high voltage from low voltage, receiving a low-voltage signal by using the low-voltage state monitoring unit, controlling the high-voltage signal, and monitoring the low-voltage state of the low-voltage system of the electric vehicle;
a trailer enabling circuit unit and a hysteresis comparison unit are arranged on the high-voltage side;
forming a driving unit by a plurality of IGBT power modules;
the trailer enabling circuit unit is electrically connected with the low-voltage state monitoring unit, the hysteresis comparison unit and the driving unit respectively;
when the low-voltage system fails and the low-voltage side is powered down or the low-voltage signal is abnormal, the low-voltage state monitoring unit sends a logic signal for starting the working condition of the trailer to the trailer enabling circuit unit;
when the trailer enabling circuit unit receives the logic signal for starting the working condition of the trailer sent by the low-voltage state monitoring unit, the trailer enabling circuit unit starts the trailer protection logic, and the hysteresis comparison unit directly controls the on or off of the driving unit.
Optionally, when the low voltage system fails to cause the low voltage side to fail or the low voltage signal is abnormal, the low voltage state monitoring unit sends a logic signal for starting the working condition of the trailer to the trailer enabling circuit unit, and the method further includes the following steps:
when the low-voltage system is normal, the low-voltage state monitoring unit sends a logic signal for closing the trailer to the trailer enabling unit, the switch electrically connected with the trailer enabling circuit unit and the driving unit is disconnected, the trailer enabling circuit unit performs the function of prohibiting the hardware trailer, and the driving unit performs torque control logic under normal working conditions.
Optionally, the method further comprises the following steps:
a bus voltage sampling unit is arranged at the high-voltage side, and the bus voltage sampling unit is electrically connected with the hysteresis comparison unit;
monitoring a bus voltage value by using the bus voltage sampling unit, and sending the bus voltage value to the hysteresis comparison unit;
and receiving the bus voltage value sent by the bus voltage sampling unit by using the hysteresis comparison unit, and switching the execution state according to the bus voltage value at different high-voltage points, wherein the execution state comprises a full-closed tube and an active short circuit.
Optionally, the switching the execution state at different high-voltage points according to the bus voltage value includes the following steps:
when the electric vehicle enters a trailer working condition and the driving unit is in a full-closed tube, and when the bus voltage value received by the hysteresis comparison unit reaches a preset high-voltage V2, the hysteresis comparison unit executes a lower three-bridge active short circuit logic;
when the electric vehicle enters a trailer working condition and the driving unit is in a full-closed pipe, and when the bus voltage value received by the hysteresis comparison unit is lower than a preset high-voltage point V1, the hysteresis comparison unit enters a full-closed pipe execution state.
Optionally, the switching of the execution state is performed at different high-voltage points according to the bus voltage value, and the method further includes the following steps:
setting a hysteresis voltage interval according to a corresponding high-voltage point when the state switching is executed;
and when the bus voltage value received by the hysteresis comparison unit is within the hysteresis voltage interval, the hysteresis comparison unit maintains an execution state.
The technical scheme provided by the embodiment of the invention has the beneficial effects that at least:
by arranging the hardware trailer enabling circuit, safety protection in a normal state and protection logic switching in a trailer state are realized, hardware execution logic is simplified, and reliability is improved; the whole set of trailer logic can be realized by the high-voltage side unit circuit automatically, so that the logic link range in a fault state is reduced, and the stability of the whole system is improved; furthermore, the monitoring of the motor rotating speed is indirectly realized through the monitoring of the bus voltage, the problem of loss of motor rotating speed monitoring under low-voltage power failure is solved, and the system safety is higher; the state switching setting of different switching points is realized through the hysteresis comparison unit, so that the complex trailer protection logic can be realized, and the cost of devices is greatly reduced. A certain hysteresis voltage interval is set, so that the problem of frequent execution of state switching actions is avoided. The trailer logic circuit is built at the high-voltage side, the monitoring of the rotating speed of the motor is indirectly carried out by adopting the monitoring of the bus voltage, the failure risk of a monitoring path in a fault state is reduced, the operation and the forbidden operation of the trailer circuit are flexibly realized through the arrangement of the trailer enabling circuit, and the safety level of a system is improved; compared with the prior art, the technical scheme provided by the invention simplifies the hardware execution logic, improves the reliability, realizes the execution of the trailer strategy by the hardware unit, and has the advantages of high logic adaptability, low design cost and the like.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings.
The technical scheme of the invention is further described in detail through the drawings and the embodiments.
Drawings
The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate the invention and together with the embodiments of the invention, serve to explain the invention. In the drawings:
FIG. 1 is a block diagram of a circuit protection device for the working condition of an electric vehicle trailer in an embodiment of the invention;
FIG. 2 is a schematic diagram of a circuit unit according to an embodiment of the invention;
fig. 3 is a flowchart of a method for protecting a circuit under the working condition of an electric vehicle trailer according to an embodiment of the invention.
Detailed Description
Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
In order to solve the problems in the prior art, the embodiment of the invention provides a circuit protection device and a method for the working condition of an electric vehicle trailer.
Example 1
An embodiment of the present invention provides a circuit protection device for a working condition of an electric vehicle trailer, the structure of which is shown in fig. 1, and the circuit protection device includes a driving unit 104, wherein the driving unit 104 includes a plurality of IGBT power modules, and further includes:
the low-voltage state monitoring unit 101 is electrically connected with the trailer enabling circuit unit 102 and is used for isolating high voltage from low voltage, receiving a low-voltage signal, controlling the high-voltage signal, performing low-voltage state monitoring on the low-voltage system of the electric vehicle, and when the low-voltage system fails to cause power failure on the low-voltage side or the low-voltage signal is abnormal, the low-voltage state monitoring unit 101 sends a logic signal for starting the working condition of the trailer to the trailer enabling circuit unit 102;
the trailer enabling circuit unit 102 is located at the high-voltage side and is electrically connected with the low-voltage state monitoring unit 101, the hysteresis comparison unit 103 and the driving unit 104, the trailer enabling circuit unit 102 is used for controlling whether the electric vehicle enters a trailer working condition, and after receiving a logic signal for starting the trailer working condition sent by the low-voltage state monitoring unit 101, the trailer enabling circuit unit 102 opens trailer protection logic;
and the hysteresis comparison unit 103 is positioned at the high voltage side and is electrically connected with the trailer enabling circuit unit 102, and is used for directly controlling the on or off of the driving unit 104 when the trailer enabling circuit unit 102 turns on the trailer protection logic.
Optionally, the low-voltage status monitoring unit 101 is further configured to, when the low-voltage system is normal, send a logic signal to the trailer enable unit 102 to shut down the trailer.
Optionally, the trailer enabling circuit unit 102 is further configured to receive a logic signal for closing the trailer sent by the low voltage status monitoring unit 101 when the low voltage system is normal, where the switch that the trailer enabling circuit unit 102 is electrically connected to the driving unit 104 is opened, and the trailer enabling circuit unit 102 performs a function of disabling the hardware trailer.
Optionally, the driving unit 104 is configured to execute the torque control logic under the normal operating condition when the trailer enabling circuit unit 102 executes the disabled hardware trailer function.
Optionally, the method further comprises: and a bus voltage sampling unit 105, which is located at the high voltage side, is electrically connected with the hysteresis comparison unit 103, and is used for monitoring the bus voltage value and transmitting the bus voltage value to the hysteresis comparison unit 103.
Optionally, the hysteresis comparing unit 103 is further configured to receive the bus voltage value sent by the bus voltage sampling unit 105, and switch an execution state according to the bus voltage value at different high voltage points, where the execution state includes a full-closed tube and an active short circuit.
Optionally, the hysteresis comparison unit 103 is specifically configured to, when the electric vehicle enters a trailer working condition and the driving unit 104 is in a full-closed tube, and when the bus voltage value received by the hysteresis comparison unit 103 reaches a preset high voltage V2, execute a lower three-bridge active short-circuit logic by the hysteresis comparison unit 103.
Optionally, the hysteresis comparing unit 103 is specifically configured to, when the electric vehicle enters a trailer working condition and the driving unit 104 is in a full-closed tube, and when the bus voltage value received by the hysteresis comparing unit 103 is lower than a preset high-voltage point V1, the hysteresis comparing unit 103 enters a full-closed tube executing state.
Optionally, the hysteresis comparing unit 103 is further configured to set a hysteresis voltage interval according to a high voltage point corresponding to the execution state switching, and when the bus voltage value received by the hysteresis comparing unit is within the hysteresis voltage interval, the hysteresis comparing unit maintains the execution state.
For example, as shown in FIG. 2,the low voltage state monitoring unit 101 sends a state signal to the trailer enabling circuit unit 102 to start the trailer execution logic when the low voltage system fails to cause the low voltage side to be powered down or the low voltage signal is abnormal. Under normal conditions, the trailer enable circuit unit 102 performs the disable hardware trailer function and the drive unit 104 performs normal torque control logic. When a low voltage power down condition abnormality occurs, the trailer enable circuit unit 102 turns on the trailer protection logic by directly controlling the on-state communication of the high voltage side of the drive unit 104And (3) executing the instructions of switching on and switching off the IGBT. The controller is in the trailer state after the low voltage is powered down, and at the moment, if the IGBT is under the full-closed tube, the counter electromotive force of the motor is in direct proportion to the rotating speed, and the rotating speed state of the motor can be indirectly obtained through monitoring the voltage value of the bus. According to the torque safety requirement, the controller is required to execute the full closing pipe at a low speed in a trailer state, and is required to execute the active short circuit at a high speed, namely, the active short circuit is required to be executed when the bus voltage monitoring requirement reaches a high voltage point V2, the full closing pipe is executed when the bus voltage monitoring requirement is lower than the high voltage point V1, a certain hysteresis voltage interval is arranged between the V1 and the V2, and the problem of frequent action of a state switching point is avoided. The hysteresis comparison unit 103 is used for realizing state switching setting of different switching points, and when the trailer enabling circuit is effective, the on-off control of the driving unit 104 is directly controlled.
In the method of the embodiment, the safety protection in the normal state and the protection logic switching in the trailer state are realized by arranging the hardware trailer enabling circuit, so that the hardware execution logic is simplified, and the reliability is improved; the whole set of trailer logic can be realized by the high-voltage side unit circuit automatically, so that the logic link range in a fault state is reduced, and the stability of the whole system is improved; furthermore, the monitoring of the motor rotating speed is indirectly realized through the monitoring of the bus voltage, the problem of loss of motor rotating speed monitoring under low-voltage power failure is solved, and the system safety is higher; the state switching setting of different switching points is realized through the hysteresis comparison unit, so that the complex trailer protection logic can be realized, and the cost of devices is greatly reduced. A certain hysteresis voltage interval is set, so that the problem of frequent execution of state switching actions is avoided. The trailer logic circuit is built at the high-voltage side, the monitoring of the rotating speed of the motor is indirectly carried out by adopting the monitoring of the bus voltage, the failure risk of a monitoring path in a fault state is reduced, the operation and the forbidden operation of the trailer circuit are flexibly realized through the arrangement of the trailer enabling circuit, and the safety level of a system is improved; compared with the prior art, the technical scheme provided by the invention simplifies the hardware execution logic, improves the reliability, realizes the execution of the trailer strategy by the hardware unit, and has the advantages of high logic adaptability, low design cost and the like.
Example two
The second embodiment of the invention provides a circuit protection method for the working condition of an electric vehicle trailer, which has a flow shown in fig. 3 and comprises the following steps:
step S201: setting a low-voltage state monitoring unit to isolate high voltage from low voltage, receiving a low-voltage signal by using the low-voltage state monitoring unit, controlling the high-voltage signal, and monitoring the low-voltage state of the low-voltage system of the electric vehicle; a trailer enabling circuit unit and a hysteresis comparison unit are arranged on the high-voltage side; forming a driving unit by a plurality of IGBT power modules;
step S202: the trailer enabling circuit unit is electrically connected with the low-voltage state monitoring unit, the hysteresis comparison unit and the driving unit respectively;
step S203: when the low-voltage system fails and the low-voltage side is powered down or the low-voltage signal is abnormal, the low-voltage state monitoring unit sends a logic signal for starting the working condition of the trailer to the trailer enabling circuit unit;
optionally, when the low voltage system fails to cause the low voltage side to fail or the low voltage signal is abnormal, the low voltage state monitoring unit sends a logic signal for starting the working condition of the trailer to the trailer enabling circuit unit, and the method further includes the following steps:
when the low-voltage system is normal, the low-voltage state monitoring unit sends a logic signal for closing the trailer to the trailer enabling unit, the switch electrically connected with the trailer enabling circuit unit and the driving unit is disconnected, the trailer enabling circuit unit performs the function of prohibiting the hardware trailer, and the driving unit performs torque control logic under normal working conditions.
Step S204: when the trailer enabling circuit unit receives the logic signal for starting the working condition of the trailer sent by the low-voltage state monitoring unit, the trailer enabling circuit unit starts the trailer protection logic, and the hysteresis comparison unit directly controls the on or off of the driving unit.
Step S205: a bus voltage sampling unit is arranged at the high-voltage side, and the bus voltage sampling unit is electrically connected with the hysteresis comparison unit; monitoring a bus voltage value by using the bus voltage sampling unit, and sending the bus voltage value to the hysteresis comparison unit; and receiving the bus voltage value sent by the bus voltage sampling unit by using the hysteresis comparison unit, and switching the execution state according to the bus voltage value at different high-voltage points, wherein the execution state comprises a full-closed tube and an active short circuit.
Optionally, the switching the execution state at different high-voltage points according to the bus voltage value includes the following steps:
when the electric vehicle enters a trailer working condition and the driving unit is in a full-closed tube, and when the bus voltage value received by the hysteresis comparison unit reaches a preset high-voltage V2, the hysteresis comparison unit executes a lower three-bridge active short circuit logic;
when the electric vehicle enters a trailer working condition and the driving unit is in a full-closed pipe, and when the bus voltage value received by the hysteresis comparison unit is lower than a preset high-voltage point V1, the hysteresis comparison unit enters a full-closed pipe execution state.
Optionally, the switching of the execution state is performed at different high-voltage points according to the bus voltage value, and the method further includes the following steps:
setting a hysteresis voltage interval according to a corresponding high-voltage point when the state switching is executed;
and when the bus voltage value received by the hysteresis comparison unit is within the hysteresis voltage interval, the hysteresis comparison unit maintains an execution state.
For example, as shown in FIG. 2,and representing a low-voltage signal, performing low-voltage state monitoring by adopting an isolation chip, and when a low-voltage system fails to cause power failure of a low-voltage side or the low-voltage signal is abnormal, sending a state signal to a trailer enabling circuit unit by a low-voltage state monitoring unit, and starting the trailer to execute logic. Under normal conditions, the trailer enabling circuit unit performs the function of disabling the hardware trailer, and the drive unit performs normal torque control logic. When the low-voltage power-down state is abnormal, the trailer enabling circuit unit turns on the trailer protection logic, and directly controls the high voltage of the driving unitAnd the side turn-on signal is used for executing the turn-on and turn-off instructions of the IGBT. The controller is in the trailer state after the low voltage is powered down, and at the moment, if the IGBT is under the full-closed tube, the counter electromotive force of the motor is in direct proportion to the rotating speed, and the rotating speed state of the motor can be indirectly obtained through monitoring the voltage value of the bus. According to the torque safety requirement, the controller is required to execute the full closing pipe at a low speed in a trailer state, and is required to execute the active short circuit at a high speed, namely, the active short circuit is required to be executed when the bus voltage monitoring requirement reaches a high voltage point V2, the full closing pipe is executed when the bus voltage monitoring requirement is lower than the high voltage point V1, a certain hysteresis voltage interval is arranged between the V1 and the V2, and the problem of frequent action of a state switching point is avoided. The state switching setting of different switching points is realized through the hysteresis comparison unit, and when the trailer enabling circuit is effective, the on-off control of the driving unit is directly controlled.
In the embodiment, the safety protection in the normal state and the protection logic switching in the trailer state are realized by arranging the hardware trailer enabling circuit, so that the hardware execution logic is simplified, and the reliability is improved; the whole set of trailer logic can be realized by the high-voltage side unit circuit automatically, so that the logic link range in a fault state is reduced, and the stability of the whole system is improved; furthermore, the monitoring of the motor rotating speed is indirectly realized through the monitoring of the bus voltage, the problem of loss of motor rotating speed monitoring under low-voltage power failure is solved, and the system safety is higher; the state switching setting of different switching points is realized through the hysteresis comparison unit, so that the complex trailer protection logic can be realized, and the cost of devices is greatly reduced. A certain hysteresis voltage interval is set, so that the problem of frequent execution of state switching actions is avoided. The trailer logic circuit is built at the high-voltage side, the monitoring of the rotating speed of the motor is indirectly carried out by adopting the monitoring of the bus voltage, the failure risk of a monitoring path in a fault state is reduced, the operation and the forbidden operation of the trailer circuit are flexibly realized through the arrangement of the trailer enabling circuit, and the safety level of a system is improved; compared with the prior art, the technical scheme provided by the invention simplifies the hardware execution logic, improves the reliability, realizes the execution of the trailer strategy by the hardware unit, and has the advantages of high logic adaptability, low design cost and the like.

Claims (11)

1. The utility model provides an electric motor car trailer operating mode circuit protection device, includes drive unit, drive unit includes a plurality of IGBT power module, its characterized in that still includes:
the low-voltage state monitoring unit is electrically connected with the trailer enabling circuit unit and is used for isolating high voltage from low voltage, receiving a low-voltage signal, controlling the high-voltage signal, monitoring the low-voltage state of the low-voltage system of the electric vehicle, and sending a logic signal for starting the working condition of the trailer to the trailer enabling circuit unit when the low-voltage system fails to cause power failure of the low-voltage side or the low-voltage signal is abnormal;
the trailer enabling circuit unit is positioned at the high-voltage side and is electrically connected with the low-voltage state monitoring unit, the hysteresis comparison unit and the driving unit and used for controlling whether the electric vehicle enters a trailer working condition or not, and after receiving a logic signal for starting the trailer working condition sent by the low-voltage state monitoring unit, the trailer enabling circuit unit opens trailer protection logic;
and the hysteresis comparison unit is positioned at the high-voltage side and is electrically connected with the trailer enabling circuit unit and used for directly controlling the on or off of the driving unit when the trailer enabling circuit unit turns on the trailer protection logic.
2. The apparatus as recited in claim 1, further comprising: and the bus voltage sampling unit is positioned at the high-voltage side, is electrically connected with the hysteresis comparison unit, and is used for monitoring the bus voltage value and transmitting the bus voltage value to the hysteresis comparison unit.
3. The apparatus of claim 2, wherein the hysteresis comparison unit is further configured to receive the bus voltage value sent by the bus voltage sampling unit, and switch an execution state according to the bus voltage value at different high voltage points, where the execution state includes a full-closed tube and an active short circuit.
4. The device of claim 2, wherein the hysteresis comparison unit is specifically configured to execute a lower three-bridge active short circuit logic when the electric vehicle enters a trailer condition and the driving unit is in a full-closed state, and when the bus voltage value received by the hysteresis comparison unit reaches a preset high voltage V2.
5. The device of claim 2, wherein the hysteresis comparison unit is specifically configured to, when the electric vehicle enters a trailer condition and the driving unit is in a fully closed state, and when the bus voltage value received by the hysteresis comparison unit is lower than a preset high voltage point V1, enter the fully closed state.
6. The apparatus according to any one of claims 3 to 5, wherein the hysteresis comparing unit is further configured to set a hysteresis voltage interval according to a corresponding high voltage point when the state switching is performed, and the hysteresis comparing unit maintains the execution state when the bus voltage value received by the hysteresis comparing unit is within the hysteresis voltage interval.
7. The working condition circuit protection method for the electric vehicle trailer is characterized by comprising the following steps of:
setting a low-voltage state monitoring unit to isolate high voltage from low voltage, receiving a low-voltage signal by using the low-voltage state monitoring unit, controlling the high-voltage signal, and monitoring the low-voltage state of the low-voltage system of the electric vehicle;
a trailer enabling circuit unit and a hysteresis comparison unit are arranged on the high-voltage side;
forming a driving unit by a plurality of IGBT power modules;
the trailer enabling circuit unit is electrically connected with the low-voltage state monitoring unit, the hysteresis comparison unit and the driving unit respectively;
when the low-voltage system fails and the low-voltage side is powered down or the low-voltage signal is abnormal, the low-voltage state monitoring unit sends a logic signal for starting the working condition of the trailer to the trailer enabling circuit unit;
when the trailer enabling circuit unit receives the logic signal for starting the working condition of the trailer sent by the low-voltage state monitoring unit, the trailer enabling circuit unit starts the trailer protection logic, and the hysteresis comparison unit directly controls the on or off of the driving unit.
8. The method of claim 7, wherein the low voltage condition monitoring unit sends a logic signal to the trailer enable circuit unit to turn on the trailer when the low voltage system fails to cause a low voltage side power loss or a low voltage signal to be abnormal, further comprising the steps of:
when the low-voltage system is normal, the low-voltage state monitoring unit sends a logic signal for closing the trailer to the trailer enabling unit, the switch electrically connected with the trailer enabling circuit unit and the driving unit is disconnected, the trailer enabling circuit unit performs the function of prohibiting the hardware trailer, and the driving unit performs torque control logic under normal working conditions.
9. The method of claim 7, further comprising the step of:
a bus voltage sampling unit is arranged at the high-voltage side, and the bus voltage sampling unit is electrically connected with the hysteresis comparison unit;
monitoring a bus voltage value by using the bus voltage sampling unit, and sending the bus voltage value to the hysteresis comparison unit;
and receiving the bus voltage value sent by the bus voltage sampling unit by using the hysteresis comparison unit, and switching the execution state according to the bus voltage value at different high-voltage points, wherein the execution state comprises a full-closed tube and an active short circuit.
10. The method of claim 9, wherein said switching of the execution state at different high voltage points according to the bus voltage value comprises the steps of:
when the electric vehicle enters a trailer working condition and the driving unit is in a full-closed tube, and when the bus voltage value received by the hysteresis comparison unit reaches a preset high-voltage V2, the hysteresis comparison unit executes a lower three-bridge active short circuit logic;
when the electric vehicle enters a trailer working condition and the driving unit is in a full-closed pipe, and when the bus voltage value received by the hysteresis comparison unit is lower than a preset high-voltage point V1, the hysteresis comparison unit enters a full-closed pipe execution state.
11. The method according to claim 9 or 10, wherein the switching of the execution state at different high voltage points according to the bus voltage value further comprises the steps of:
setting a hysteresis voltage interval according to a corresponding high-voltage point when the state switching is executed;
and when the bus voltage value received by the hysteresis comparison unit is within the hysteresis voltage interval, the hysteresis comparison unit maintains an execution state.
CN202210515476.3A 2022-05-11 2022-05-11 Electric vehicle trailer working condition circuit protection device and method Pending CN117087435A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210515476.3A CN117087435A (en) 2022-05-11 2022-05-11 Electric vehicle trailer working condition circuit protection device and method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210515476.3A CN117087435A (en) 2022-05-11 2022-05-11 Electric vehicle trailer working condition circuit protection device and method

Publications (1)

Publication Number Publication Date
CN117087435A true CN117087435A (en) 2023-11-21

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Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210515476.3A Pending CN117087435A (en) 2022-05-11 2022-05-11 Electric vehicle trailer working condition circuit protection device and method

Country Status (1)

Country Link
CN (1) CN117087435A (en)

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