Method for increasing driving mileage of pure electric traction vehicle

Abstract

The invention relates to a method for increasing the mileage of a pure electric traction vehicle. According to the method, a second power battery pack is additionally arranged on a trailer, and the pure electric traction vehicle can use electric energy in an original first power battery pack and the second power battery pack on the trailer, so that the energy expansion effect is achieved, and the driving mileage of the pure electric traction vehicle is increased or doubled; the second power battery pack on the trailer is connected with the pure-power traction vehicle through the high-voltage connector comprising the locking device, the high-voltage switch and the alarm, effective locking can be achieved in the vehicle starting and running process, the connection state can be monitored in real time, the high-voltage switch can be immediately switched off once abnormity occurs, meanwhile, the alarm is sent to a cab operator, and the safety of the cab is guaranteed. And the first power battery is switched to output electric energy to drive the vehicle, so that the vehicle can run safely and stably.

Description

Technical Field

[0001] The invention relates to the technical field of electric vehicles, and in particular to a method for increasing the mileage of a pure electric traction vehicle. Background Art

[0002] Currently, pure electric traction vehicles are limited by space size, and the power batteries that can be installed are small in size, small in number, and low in battery capacity. Therefore, the vehicle's operating range can only meet the needs of short-distance logistics, and cannot meet the distance requirements of medium and long-distance logistics transportation.

[0003] In order to increase the mileage of electric tractor vehicles and meet the transportation distance requirements of medium and long-distance logistics transportation, improvements are currently being made mainly in the following aspects: 1. Improving battery energy density; 2. Increasing the number of power batteries in the main storage space of the tractor vehicle; 3. Reducing the weight of the vehicle to increase the mileage. However, the feasibility of the above improvement plans is not high: 1. Due to material limitations, it is difficult to significantly improve the battery energy density; 2. There is less available space for tractor vehicles, and there is a serious lack of space for increasing the number of power batteries; 3. If the available space for tractor vehicles is completely occupied, a very serious safety accident will occur in the event of a collision; 4. Weight reduction of existing vehicle structural parts will lead to reduced strength, resulting in a high risk of component failure. If new materials are used to increase strength, the cost will increase.

[0004] Therefore, it is necessary to develop a new method for increasing the mileage of pure electric traction vehicles to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a method that can multiply the driving mileage, solve the range anxiety of pure electric traction vehicles, and meet the needs of medium and long-distance logistics transportation.

[0006] In order to achieve the above object, the present invention provides the following technical solutions: A method for increasing the mileage of a pure electric traction vehicle, applied to a pure electric traction vehicle and a trailer adapted to the pure electric traction vehicle, wherein the pure electric traction vehicle comprises a vehicle controller, a first power battery pack, a first power battery controller, a CAN bus, and a male end of a high-voltage connector, and the trailer comprises a power battery mounting frame, a second power battery pack, a second power battery controller, a second motor controller, and a female end of a high-voltage connector detachably connected to the male end of the high-voltage connector; The high-voltage connector includes a cable interface, a communication interface, a locking device, a high-voltage switch, and an alarm. The second power battery controller and the second motor controller are connected to the CAN bus through the high-voltage connector and are controlled by the vehicle controller. The method comprises: When the vehicle is started, the vehicle controller automatically detects and identifies the connection status of the high-voltage cable between the pure electric tractor and the trailer, and confirms whether it is reliably connected and whether there is leakage; After confirming that the connection of the communication interface complies with the handshake protocol, the high-voltage switch between the pure electric traction vehicle and the trailer is closed through the CAN bus, and the vehicle controller issues a command message, which is transmitted to the first power battery controller and the second power battery controller through the CAN bus, so that the first power battery pack and the second power battery pack successively relay to output electric energy for the pure electric traction vehicle to drive the vehicle to run; The signals when the vehicle shifts gears and accelerates are transmitted to the vehicle controller, and the vehicle controller issues corresponding command information, and transmits the command information to the first power battery controller, the second power battery controller, the first motor controller, the reducer, and the transmission via the CAN bus to realize vehicle operation; The signal when the vehicle decelerates or brakes is transmitted to the vehicle controller, and the vehicle controller issues corresponding command information, and transmits the command information to the first motor controller and the second motor controller respectively via the CAN bus, driving the motor to run in reverse, recovering the driving potential energy and converting it into electrical energy, which is stored in the first power battery pack and the second power battery pack respectively through the first power battery controller and the second power battery controller.

[0007] During the driving process of the vehicle, the vehicle controller can monitor the connection status of the high-voltage cables between the pure electric traction vehicle and the trailer in real time. If the communication handshake protocol between the trailer and the pure electric traction vehicle fails abnormally, the alarm will immediately sound an alarm, disconnect the high-voltage switch through the CAN bus, and at the same time transmit a signal to the instrument in the cab of the pure electric traction vehicle to warn of the connection failure of the second power battery pack, remind the driver to pay attention to the reduction of the power battery capacity (SOC), and promptly maintain the connection status between the second power battery pack and the traction vehicle.

[0008] Furthermore, the trailer also includes an electric drive axle, and the vehicle has multiple gears to choose from to meet the needs of different road conditions. When the vehicle is going uphill or driving on a muddy road, through the driver's operation, the vehicle controller sends command information to the second power battery controller, the second motor controller and the electric drive axle, and the second power battery pack outputs electrical energy to drive the electric drive axle, and outputs torque to increase auxiliary power to the pure electric traction vehicle, thereby increasing the vehicle's climbing ability and ability to escape from muddy roads.

[0009] Furthermore, in a braking phase or downhill section, under the control of the energy recovery gear, the vehicle controller issues a braking command message, and the drive motor of the pure electric traction vehicle part and the drive motor in the electric drive axle of the trailer part enter a reverse towing operation mode, converting the forward kinetic energy of the vehicle into electrical energy and recovering it into the first power battery pack and the second power battery pack.

[0010] Furthermore, the second power battery pack is detachably connected to the power battery mounting frame.

[0011] Furthermore, the second power battery is detachably connected to the power battery mounting frame.

[0012] Furthermore, the battery capacity of the second power battery pack is 1 to 2 times the battery capacity of the first power battery pack.

[0013] The beneficial effects of the present invention are: The method of the present invention can achieve the effect of energy expansion by adding a second power battery pack to the trailer, so that the pure electric traction vehicle can use the electric energy in the original first power battery pack and the second power battery pack on the trailer, thereby increasing or doubling the driving mileage of the pure electric traction vehicle; by arranging a high-voltage connector including a locking device, a high-voltage switch, and an alarm to connect the second power battery pack on the trailer with the pure power traction vehicle, the connection state can be effectively locked and monitored in real time during the start-up and operation of the vehicle, and once an abnormality occurs, the high-voltage switch can be immediately disconnected, an alarm is issued to the cab crew, and the vehicle is switched to the first power battery to output electric energy to drive the vehicle, thereby ensuring that the vehicle can travel safely and smoothly.

[0014] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, some of the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is an overall schematic diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0018] The technical solutions described in the present invention, unless otherwise specified, are all conventional solutions in the art; the accessories or parts described, unless otherwise specified, are all sourced from commercial channels.

[0019] See also Figure 1 The present invention discloses a method for increasing the mileage of a pure electric tractor, which is applied to a pure electric tractor and a trailer adapted to the pure electric tractor. The method can increase the mileage exponentially, solve the range anxiety of the pure electric tractor, and meet the needs of medium and long-distance logistics transportation. The specific process of the method is: Connect the pure electric traction vehicle to the trailer equipped with the second power battery pack, connect the male end of the high-voltage connector to the female end, ensure that the cable interface and communication interface are reliably connected, and lock the high-voltage connector through the locking device. The operating temperature range of lithium-ion batteries is generally -20℃~60℃, but in fact, temperatures below 0℃ or above 40℃ will affect the performance of lithium-ion batteries. Temperatures above 40℃ may destroy the chemical balance in the battery and cause side reactions; temperatures below 0℃ will cause the battery's discharge capacity to drop sharply. Therefore, the second power battery pack is equipped with a thermal management system to ensure that the battery operates in a reasonable temperature environment.

[0020] When the vehicle starts, the vehicle controller (VCU) automatically detects and identifies the connection status of the high-voltage cable between the pure electric tractor and the trailer to confirm whether it is reliably connected and whether there is leakage. If the connection is reliable and there is no leakage, it will start normally; if the connection is unreliable or there is leakage, the communication handshake protocol is not met and an alarm message will appear to urge the driver to check the fault. Or according to the specific situation, only the first power battery pack will be used to output power to drive the vehicle.

[0021] After confirming that the connection of the communication interface complies with the handshake protocol, the VCU issues a command message, closes the high-voltage switch between the pure electric traction vehicle and the trailer through the CAN bus, and transmits it to the first power battery controller and the second power battery controller through the CAN bus, so that the first power battery pack and the second power battery pack successively relay the output of electric energy for the pure electric traction vehicle to drive the vehicle. Because the battery capacity of the second power battery pack is 1 to 2 times that of the first power battery pack and is easy to replace, during stable driving, the VCU controls the first power battery controller and the second power battery controller to successively relay the output of power until the SOC value of the second power battery pack reaches the lower threshold.

[0022] When the vehicle shifts gears or accelerates, the shifting and acceleration signals are transmitted to the VCU, and the VCU issues corresponding command information, which is transmitted to the first power battery controller, the second power battery controller, the first motor controller, and the transmission of the pure electric traction vehicle via the CAN bus, thereby changing the electric energy output power of the two power battery groups and adjusting the gear position to achieve vehicle shifting and acceleration.

[0023] When the vehicle is going uphill or driving on a muddy road, the VCU sends command information to the second power battery controller and the electric drive axle through the driver's operation. The second power battery pack outputs electrical energy to drive the electric drive axle to output torque, thereby adding auxiliary power to the pure electric traction vehicle, increasing the vehicle's climbing ability and ability to escape from muddy roads.

[0024] During braking or when the vehicle is driving downhill, under the control of the energy recovery gear, the VCU sends out braking command information, and the motors in the pure electric traction vehicle and the electric drive axle enter the reverse drag mode, converting the vehicle's forward kinetic energy into electrical energy and recovering it into the first power battery pack and the second power battery pack, realizing energy reuse and further improving the driving mileage. At the same time, it can effectively reduce the braking distance of the vehicle, reduce the braking frequency, braking heat and wear of the brake shoe, and increase driving safety and the service life of the brake components.

[0025] During the driving process of the vehicle, the VCU monitors the connection status of the high-voltage cables of the pure electric traction vehicle and the trailer in real time. If an abnormality occurs, the alarm will immediately sound an alarm, disconnect the high-voltage switch through the CAN bus, and send command information to the first power battery controller to adjust the output power of the first power battery pack. The sudden lack of power output from the second power battery pack will cause the vehicle speed to drop, which may cause safety accidents such as collisions and rear-end collisions in situations such as obstacle avoidance and overtaking. Therefore, by increasing the output power of the first power battery pack, the total power input of the pure electric traction vehicle motor is guaranteed to remain unchanged, eliminating the safety hazards caused by the sudden drop in vehicle speed.

[0026] A spare second power battery pack can be added and placed at the charging station. The lengthy charging process can be replaced by replacing the second power battery pack, thereby improving the vehicle's medium and long-distance transportation efficiency.

[0027] In summary, the method of the present invention can achieve the effect of energy expansion by adding a second power battery pack to the trailer, so that the pure electric traction vehicle can use the electric energy in its original first power battery pack and the second power battery pack on the trailer, thereby achieving an increase or doubling of the mileage of the pure electric traction vehicle; by providing a high-voltage connector including a locking device, a high-voltage switch, and an alarm to connect the second power battery pack on the trailer to the pure power traction vehicle, the vehicle can be effectively locked and the connection status can be monitored in real time during the start-up and operation of the vehicle. Once an abnormality occurs, the high-voltage switch can be immediately closed, and an alarm can be issued to the cab crew and the output power of the first power battery can be appropriately increased to ensure that the vehicle can travel safely and smoothly.

[0028] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0029] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for increasing the mileage of a pure electric tractor vehicle, applied to a pure electric tractor vehicle and a trailer adapted to the pure electric tractor vehicle, characterized in that: The pure electric traction vehicle includes a vehicle controller, a first power battery pack, a first power battery controller, a CAN bus, and a male end of a high-voltage connector; the trailer includes a power battery mounting frame, a second power battery pack, a second power battery controller, a second motor controller, and a female end of a high-voltage connector detachably connected to the male end of the high-voltage connector; The high-voltage connector includes a cable interface, a communication interface, a locking device, a high-voltage switch, and an alarm. The second power battery controller and the second motor controller are connected to the CAN bus through the high-voltage connector and are controlled by the vehicle controller. The method comprises: When the vehicle is started, the vehicle controller automatically detects and identifies the connection status of the high-voltage cable between the pure electric tractor and the trailer, and confirms whether it is reliably connected and whether there is leakage; After confirming that the connection of the communication interface complies with the handshake protocol, the high-voltage switch between the pure electric traction vehicle and the trailer is closed through the CAN bus, and the vehicle controller issues a command message, which is transmitted to the first power battery controller and the second power battery controller through the CAN bus, so that the first power battery pack and the second power battery pack successively relay to output electric energy for the pure electric traction vehicle to drive the vehicle to run; The signals when the vehicle shifts gears and accelerates are transmitted to the vehicle controller, and the vehicle controller issues corresponding command information, and transmits the command information to the first power battery controller, the second power battery controller, the first motor controller, the reducer, and the transmission via the CAN bus to realize vehicle operation; The signal when the vehicle decelerates or brakes is transmitted to the vehicle controller, and the vehicle controller issues corresponding command information, and transmits the command information to the first motor controller and the second motor controller respectively via the CAN bus, driving the motor to run in reverse, recovering the driving potential energy and converting it into electrical energy, which is stored in the first power battery pack and the second power battery pack respectively through the first power battery controller and the second power battery controller. During the driving process of the vehicle, the vehicle controller can monitor the connection status of the high-voltage cables between the pure electric traction vehicle and the trailer in real time. If the communication handshake protocol between the trailer and the pure electric traction vehicle fails abnormally, the alarm will immediately sound an alarm, disconnect the high-voltage switch through the CAN bus, and at the same time transmit a signal to the instrument in the cab of the pure electric traction vehicle to warn of the connection failure of the second power battery pack, remind the driver to pay attention to the reduction of the power battery capacity (SOC), and promptly maintain the connection status between the second power battery pack and the traction vehicle.

2. The method for increasing the mileage of a pure electric traction vehicle according to claim 1, characterized in that: The trailer also includes an electric drive axle. The vehicle has multiple gears to choose from to meet the needs of different road conditions. When the vehicle is going uphill or driving on a muddy road, through the driver's operation, the vehicle controller sends command information to the second power battery controller, the second motor controller and the electric drive axle. The second power battery pack outputs electrical energy to drive the electric drive axle, and outputs torque to increase auxiliary power to the pure electric traction vehicle, thereby increasing the vehicle's climbing ability and ability to escape from muddy roads.

3. The method for increasing the mileage of a pure electric traction vehicle as claimed in claim 2, characterized in that: During braking or downhill sections, under the control of the energy recovery gear, the vehicle controller issues a braking command message, and the drive motor of the pure electric traction vehicle and the drive motor in the electric drive axle of the trailer enter a reverse towing operation mode, converting the vehicle's forward kinetic energy into electrical energy and recovering it into the first power battery pack and the second power battery pack.

4. The method for increasing the mileage of a pure electric traction vehicle according to claim 1, characterized in that: The second power battery pack is detachably connected to the power battery mounting frame.

5. The method for increasing the mileage of a pure electric traction vehicle as claimed in claim 1, characterized in that: The second power battery pack is detachably connected to the power battery mounting frame.

6. The method for increasing the mileage of a pure electric traction vehicle as claimed in claim 1, characterized in that: The battery capacity of the second power battery pack is 1 to 2 times the battery capacity of the first power battery pack.

Images