An all-electric emergency control system and method for special vehicles

Abstract

This invention proposes an emergency control system and method for all-electric special vehicles. The system consists of a composite energy storage power module, an energy management control module, a brake controller, a brake resistor, and a drive motor. According to the operating requirements of the special vehicle, corresponding protection voltage, stable voltage, and limit voltage are set. Based on the relationship between the engine voltage and the above three voltages, the system determines the working state of different modules, effectively preventing vehicle malfunctions and accidental damage to other electrical equipment caused by generator failure in electromechanical composite transmissions or all-electric special vehicles with low energy storage power.

Description

Technical Field

[0001] This invention relates to an all-electric emergency control system and method for special vehicles, belonging to the field of automatic control. Background Technology

[0002] With the development of electrification, electromechanical hybrid transmission special vehicles and all-electric special vehicles have developed rapidly. The application of high-power drive motors and actuator motors has not only improved the mobility of the vehicle but also enabled intelligent control of the actuation equipment and optimized the information management of the entire vehicle. Typically, transmission special vehicles use an engine-driven generator grid topology, with the generator providing the necessary electrical energy to the vehicle's electrical equipment. When the generator or engine fails and stops outputting power while the vehicle is traveling at high speed, the vehicle's electrical equipment can only be powered by the high-voltage battery pack. Due to the compact design of special vehicles, the capacity of the high-voltage battery pack is relatively small, and its discharge power cannot meet the electrical energy requirements for high-speed driving, potentially leading to over-discharge of the high-voltage battery pack and causing safety hazards. Therefore, it is urgent to design a composite energy storage circuit and control strategy to effectively prevent unexpected and serious failures of the high-voltage energy storage power supply, high-voltage power distribution equipment, and high-voltage electrical equipment in electromechanical hybrid transmission armored vehicles when the engine or generator fails, given the relatively low power of the composite energy storage power supply. Summary of the Invention

[0003] In view of this, in order to address the emergency control of the vehicle drive motor when a generator fails in an emergency situation in an all-electric special vehicle, this invention proposes an emergency control system and method for all-electric special vehicles. This system effectively prevents vehicle malfunctions and accidental damage to other electrical equipment caused by generator failures in electromechanical composite transmissions or all-electric special vehicles with low energy storage power.

[0004] The technical solution for achieving the present invention:

[0005] An all-electric emergency control system for special vehicles includes a composite energy storage power module, an energy management control module, a brake controller, a braking resistor, and a drive motor;

[0006] The power management control module collects the vehicle generator voltage and determines whether the generator voltage is greater than a preset limit voltage. If it is greater, it sends a conduction command to the braking resistor; otherwise, it sends a disconnection command to the braking resistor and determines whether the generator voltage is less than a preset protection voltage. If it is less, it sends a control command to the brake controller and the drive motor; otherwise, it determines whether the generator voltage is greater than a preset stable voltage. If it is greater, it sends a capacitor command to the power module; otherwise, it sends a battery command to the power module.

[0007] The composite energy storage power module, connected in parallel to the vehicle bus, includes: a capacitor, a high-voltage bidirectional power conversion device, and a high-voltage battery pack. When a capacitor command is received, the capacitor discharges to the vehicle bus. When a battery command is received, the high-voltage battery pack discharges to the vehicle bus through the high-voltage bidirectional power conversion device.

[0008] When the brake controller receives a control command, it performs braking control.

[0009] The braking resistor is connected in parallel to the vehicle bus. When a conduction command is received, it is connected to the vehicle bus; when a disconnection command is received, it is disconnected from the vehicle bus.

[0010] The drive motor is connected in parallel to the vehicle busbar. When it receives a control command, it enters the braking mode.

[0011] Furthermore, the capacitor's withstand voltage is not less than 900V.

[0012] Furthermore, the limiting voltage is no greater than 900V.

[0013] Furthermore, the value of the stable voltage is 80V lower than the limiting voltage.

[0014] An emergency control method for all-electric special vehicles includes the following steps:

[0015] Step 1: Set the protection speed, protection voltage, stable voltage, and limit voltage in the power management control module, and collect the generator voltage;

[0016] Step 2: The power management control module determines whether the generator voltage is greater than the preset limit voltage. If it is greater, it sends a conduction command to the braking resistor; otherwise, it sends a disconnection command to the braking resistor and determines whether the generator voltage is less than the protection voltage. If it is greater, it executes Step 3; if it is less, it sends a control command to the braking control module and the drive motor and executes Step 4.

[0017] Step 3: The power management control module determines whether the generator voltage is greater than the stable voltage. If it is greater, the capacitor is turned on to discharge to the vehicle bus. If it is less than the stable voltage, the high-voltage battery pack is turned on to discharge to the vehicle bus through the high-voltage bidirectional power conversion device, and then Step 2 is executed.

[0018] Step 4: When the drive motor receives the control command, it enters the braking mode. When the brake controller receives the control command, it brakes the vehicle until it stops.

[0019] Beneficial effects:

[0020] First, this system is configured with three voltages, from lowest to highest: protection voltage, stable voltage, and limit voltage. The limit voltage is generally set to the same value as the vehicle's operating voltage, protecting the system from damage due to excessive voltage during malfunctions. The stable voltage is generally close to the vehicle's normal operating voltage. However, because this system incorporates a supercapacitor with a withstand voltage greater than 900V, which has a strong discharge capacity, the difference between it and the limit voltage can be set to around 80V. By setting the stable voltage, the vehicle's engine voltage is divided into two ranges, which are then used to access the capacitor and battery pack respectively, resulting in a more scientific approach and better voltage stabilization. The protection voltage is set primarily to address situations where the system encounters emergencies. Due to the special nature of special vehicles, the small-power composite energy storage power supply may not be sufficient to meet power supply needs. To ensure vehicle safety, a protection voltage is set so that the system can promptly access the drive motor system for auxiliary power supply in emergency situations, ensuring the vehicle can complete the final emergency braking.

[0021] Secondly, compared with the control system of traditional special vehicles, this system, while ensuring the high compactness of the system and the small capacity of the high-voltage battery pack, adds a drive motor to assist in power supply, which avoids the discharge power being unable to meet the power demand of vehicle operation and avoids the over-discharge of the high-voltage battery pack, thus improving safety.

[0022] Third, the composite energy storage power module has a 900V supercapacitor and a high-voltage bidirectional power conversion device working together to maintain the vehicle grid voltage when the voltage fluctuates within a small range, ensuring the normal operation of the equipment. A braking resistor is also added to this system. When the system voltage exceeds the limit voltage, the braking resistor is activated to discharge overvoltage and control the 900V bus voltage within a reasonable range, preventing overvoltage breakdown and damage to the electrical equipment. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a system control block diagram;

[0025] Figure 2 This is a schematic diagram of the control principle of part of the system; Detailed Implementation

[0026] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0027] This embodiment proposes an all-electric emergency control system and method for special vehicles. The system control block diagram is attached. Figure 1 As shown, it includes a composite energy storage power module, an energy management and control module, a brake controller, a drive motor, and a brake resistor. It also includes the vehicle's engine, generator, and brake motor. In this embodiment, the vehicle speed is controlled by the brake controller and the EMT controller working together. The high-voltage battery pack used in this embodiment is a 600V battery pack. The main function of the high-voltage bidirectional power conversion device is to convert the 600V voltage to 900V voltage. Because the voltage is too high, a safety protection device is added.

[0028] As attached Figure 1 As shown, the parts connected to the power management and control module by the dashed line all transmit information through the bus in the vehicle system. The parts connected by the solid line are directly connected to the components and transmit control signals, including the composite energy storage power module and the braking resistor. The composite energy storage power module includes: a capacitor (a 900V supercapacitor is used in this embodiment), a high-voltage bidirectional power conversion device, and a high-voltage battery pack (a 600V battery pack is used in this embodiment).

[0029] The schematic diagram of the system principle involved in this control method in this embodiment is attached. Figure 2 As shown, the wiring methods of the DC 28V power supply, DC 900V power supply and bus are illustrated. The components include the generator, power control manager, drive motor, EMT control box and brake controller, brake motor, engine and brake resistor. The DC 28V power supply provides power to the control circuits in each component. The 900V bus is the vehicle's main power grid system, mainly connected to the generator, drive motor, brake motor and brake resistor. Taking the drive motor as an example: when the power manager sends a control command to the drive motor through the bus, the drive motor control circuit controls the drive motor to connect to the 900V and power it for braking.

[0030] The main functions of the system shown in this embodiment are as follows: (1) To enable the supercapacitor, high-voltage bidirectional power conversion device and high-voltage battery pack to maintain grid balance under small fluctuations in grid voltage when the generator or engine fails. (2) To enable the drive motor to enter braking mode when the generator or engine fails (generally manifested as abnormal engine speed or large voltage fluctuations). (3) To enable the braking resistor to be connected to the control and the braking motor to perform braking control when the generator or engine fails.

[0031] An all-electric emergency control system for special vehicles includes a composite energy storage power module, an energy management control module, a brake controller, a braking resistor, and a drive motor;

[0032] The power management control module collects the vehicle generator voltage and sends it to the power module. It determines whether the generator voltage is greater than the preset limit voltage (900V). If it is greater, it sends a conduction command to the braking resistor; otherwise, it sends a disconnection command to the braking resistor. It also determines whether the generator voltage is less than the preset protection voltage (750V). If it is less, it sends a control command to the brake controller and the drive motor; otherwise, it determines whether the generator voltage is greater than the preset stable voltage (820V). If it is greater, it sends a capacitor command to the power module; if it is less, it sends a battery command to the power module.

[0033] In this embodiment, when the vehicle is traveling at high speed, the bus voltage is generally maintained at 900V, which is the same as the generator's output voltage. If the composite energy storage module detects that the generator voltage is greater than 900V, it sends a conduction command to the braking resistor. The braking resistor is connected in parallel to the bus for overvoltage discharge, controlling the 900V generator voltage within a reasonable range to prevent overvoltage breakdown and damage to electrical equipment. When the generator voltage is not greater than 900V, the composite energy storage power module sends a disconnection command to the braking resistor, and the braking resistor disconnects from the bus voltage.

[0034] When the vehicle is traveling at high speed, if the engine or generator fails, or the generator speed drops below 2200 rpm, the 900V bus voltage drops, causing fluctuations in the power grid. At this time, the power management control module determines whether the generator voltage is lower than the preset protection voltage (750V). If it is lower, it sends a control command to the brake controller and drive motor, causing the drive motor to operate in braking mode (i.e., generator mode). The side drive of the special vehicle drives the drive motor to rotate, causing the drive motor to generate electricity in reverse, providing power to the 900V power grid. This ensures the normal operation of the water pump motor of the 900V power auxiliary system, the transmission oil pump motor of the electromechanical composite transmission system, the brake motor of the brake control system, and other electrically actuated equipment. At the same time, it sends an emergency braking signal to the brake controller and EMT control box to the brake motor, which controls the vehicle speed to gradually decrease and stop slowly.

[0035] If the generator voltage is greater than 750V, it is determined whether the generator voltage is greater than the preset stable voltage (820V). If the generator voltage is greater than 820V, a capacitor command is sent to the power module, and the power management control module controls the capacitor to conduct, and the 900V supercapacitor passively discharges to supplement the 900V grid. If the voltage is less than 820V, a battery command is sent to the power module, and the power management control module controls the battery pack to conduct. When the 900V grid fluctuates greatly and the supercapacitor is insufficient to provide instantaneous supplementation or the generator output voltage is lower than 820V, the high-voltage battery pack discharges at high power through high-voltage power changes and safety protection devices. The discharge power and duration are determined according to the high-voltage battery pack's carrying capacity, effectively preventing safety accidents caused by over-discharge of the high-voltage battery pack. The composite energy storage power module is connected in parallel to the vehicle bus and includes: a capacitor, a high-voltage bidirectional power conversion device and a high-voltage battery pack. When the capacitor receives a command, it discharges to the vehicle bus. When the battery receives a command, the high-voltage battery pack discharges to the vehicle bus through the high-voltage bidirectional power conversion device. Normally, it is not directly connected to the 900V vehicle bus. The power management control module determines whether the capacitor or the battery pack is connected to the vehicle bus.

[0036] When the brake controller receives a control command, it performs braking control by sending a braking control command to the brake motor via the bus. The brake motor then performs deceleration braking control to adjust the vehicle speed.

[0037] The braking resistor is connected in parallel to the vehicle bus. When a conduction command is received, it is connected to the vehicle bus; when a disconnection command is received, it is disconnected from the vehicle bus.

[0038] The drive motor is connected in parallel to the vehicle busbar. When it receives a control command, it enters the braking mode.

[0039] An emergency control method for all-electric special vehicles includes the following steps:

[0040] Step 1: The power management and control module sets the protection speed, protection voltage, and limit voltage, collects the generator voltage and sends it to the composite energy storage power module, and sets the stable voltage in the composite energy storage power module.

[0041] Step 2: The power management control module determines whether the generator voltage is greater than the preset limit voltage. If it is greater, it sends a conduction command to the braking resistor. If it is less, it sends a disconnection command to the braking resistor and determines whether the generator voltage is less than the protection voltage. If it is greater, it sends a control command to the composite energy storage power module and executes Step 3. If it is less, it sends a control command to the braking control module and the drive motor and executes Step 4.

[0042] Step 3: The composite energy storage power module determines whether the generator voltage is greater than the stable voltage. If it is greater, the capacitor discharges to the vehicle bus. If it is less, the high-voltage battery pack discharges to the vehicle bus through the high-voltage bidirectional power conversion device and then proceeds to Step 2.

[0043] Step 4: When the drive motor receives the control command, it enters the braking mode. When the brake controller receives the control command, it brakes the vehicle until it stops.

[0044] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A fully electric emergency control system for special vehicles, characterized in that, It includes a composite energy storage power module, an energy management and control module, a brake controller, a brake resistor, and a drive motor; The power management and control module collects the vehicle generator voltage and determines whether the generator voltage is greater than a preset limit voltage. If it is greater, it sends a conduction command to the braking resistor; otherwise, it sends a disconnection command to the braking resistor and determines whether the generator voltage is less than a preset protection voltage. If it is less, it sends a control command to the brake controller and the drive motor; otherwise, it determines whether the generator voltage is greater than a preset stable voltage. If it is greater, it sends a capacitor command to the composite energy storage power module; otherwise, it sends a battery command to the composite energy storage power module. The composite energy storage power module, connected in parallel to the vehicle bus, includes: a capacitor, a high-voltage bidirectional power conversion device, and a high-voltage battery pack. When a capacitor command is received, the capacitor discharges to the vehicle bus. When a battery command is received, the high-voltage battery pack discharges to the vehicle bus through the high-voltage bidirectional power conversion device. When the brake controller receives a control command, it performs braking control. The braking resistor is connected in parallel to the vehicle bus. When a conduction command is received, it is connected to the vehicle bus; when a disconnection command is received, it is disconnected from the vehicle bus. The drive motor is connected in parallel to the vehicle busbar. When it receives a control command, it enters the braking mode.

2. The system as described in claim 1, characterized in that, The capacitor's withstand voltage is not less than 900V.

3. The system as described in claim 1, characterized in that, The limiting voltage is no greater than 900V.

4. The system as described in any one of claims 1-3, characterized in that, The value of the stable voltage is 80V lower than the limiting voltage.

5. A fully electric emergency control method for special vehicles based on the system described in any one of claims 1-4, characterized in that, Includes the following steps: Step 1: Set the protection speed, protection voltage, stable voltage, and limit voltage in the power management control module, and collect the generator voltage; Step 2: The power management control module determines whether the generator voltage is greater than the preset limit voltage. If it is greater, it sends a conduction command to the braking resistor; otherwise, it sends a disconnection command to the braking resistor and determines whether the generator voltage is less than the protection voltage. If it is greater, it executes Step 3; if it is less, it sends a control command to the braking control module and the drive motor and executes Step 4. Step 3: The power management control module determines whether the generator voltage is greater than the stable voltage. If it is, the capacitor is turned on and discharged to the vehicle bus. If it is less than the stable voltage, the high-voltage battery pack is turned on and discharged to the vehicle bus through the high-voltage bidirectional power conversion device. Then, step 2 is executed. Step 4: When the drive motor receives the control command, it enters the braking mode. When the brake controller receives the control command, it brakes the vehicle until it stops.

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