CN206067514U - Underground coal mine four motorized wheels brake energy recovering system of electric vehicle - Google Patents

Abstract

The utility model relates to a braking energy recovery system for four-wheel independently driven electric vehicles in underground mines. The left front wheel hub motor driver, the right front wheel hub motor driver, the left rear wheel hub motor driver, and the right rear wheel hub motor driver are electrically connected for independent driving; the left front wheel hub motor driver, the right front wheel hub motor driver, the left rear wheel The hub motor driver and the right rear wheel hub motor driver are electrically connected to the DC high-voltage bus. It solves the problem of short driving range of electric vehicles in existing coal mines.

Description

Braking energy recovery system for four-wheel independent drive electric vehicle in coal mine

technical field

The utility model belongs to the field of braking energy recovery of electric vehicles, in particular to a braking energy recovery system for four-wheel independently driven electric vehicles in coal mines.

Background technique

The existing diesel locomotives in underground coal mines have serious pollution, loud noise, and large dust blown by exhaust. The introduction of electric vehicles into underground coal mines, the advantages of zero emission and low noise of electric vehicles will play a positive role in realizing clean and efficient coal mine transportation. However, the road conditions in coal mines are complex, requiring frequent starting, braking, acceleration and deceleration, uphill and downhill, emergency braking, etc., so that the regenerative braking control system has practical significance. Coupled with the long distance of the mine ramp, the electric energy feedback research of electric vehicles in coal mines can significantly increase the cruising range of vehicles.

However, most of the existing underground electric vehicles in coal mines are driven by a single motor, and the recovery efficiency of braking energy for a single motor is not very high. Compared with a single motor, the driving force is decomposed into four independently driven wheel hub motors. . At the same time, coal mine underground electric vehicles using four-wheel independent drive technology generally have a large amount of information transmission that may cause network congestion. Many electric vehicles use the method of increasing the physical number of transmission buses. The signal transmission speed still lags behind. At present, the energy transmission between the power consumption part and the energy supply part of most electric vehicles is basically through the corresponding point-to-point line. The concept of DC-BUS, a DC online interactive power supply system, is introduced into the four-wheel independent underground coal mine. The drive braking energy recovery system can transfer energy efficiently.

Therefore, the existing electric vehicle technology cannot meet the needs of efficient recovery of electric vehicle braking energy in coal mines.

Utility model content

The utility model aims to solve the problem of short driving mileage of electric vehicles in underground coal mines, and proposes a braking energy recovery system and method for four-wheel independent driving electric vehicles in underground coal mines.

For this reason, the technical scheme of the utility model is: a kind of braking energy recovery system of four-wheel independent drive electric vehicle under the coal mine is provided, comprises the hub motor of right front wheel, the hub motor of left front wheel, the hub motor of left rear wheel, the rear right wheel Wheel hub motors, super capacitors, lithium batteries, DC high-voltage busbars, and CAN bus, the right front wheel hub motors, left front wheel hub motors, left rear wheel hub motors, and right rear wheel Wheel hub motor driver, right front wheel hub motor driver, left rear wheel hub motor driver, right rear wheel hub motor driver are electrically connected for independent drive; left front wheel hub motor driver, right front wheel hub motor driver, left rear wheel hub motor driver 1. The right rear wheel hub motor driver is electrically connected to the DC high-voltage bus; and is electrically connected to the vehicle controller interface through the CAN bus; the supercapacitor is electrically connected to the DC high-voltage bus through the first DC/DC converter, and the lithium battery is connected through the second The DC/DC converter is electrically connected to the DC high-voltage bus; the first DC/DC converter and the second DC/DC converter are respectively electrically connected to the CAN bus interface; the super capacitor and the lithium battery are electrically connected to the CAN bus interface through the battery manager .

The supercapacitor is electrically connected with the lithium battery through a bidirectional DC/DC converter.

The vehicle controller is electrically connected to a sensor signal processor through a CAN bus, and the sensor signal processor is electrically connected to a brake sensor, an acceleration sensor, and a vehicle speed sensor through an interface respectively, and the vehicle controller receives a braking signal through the sensor signal processor. The signals collected by sensors, acceleration sensors, and vehicle speed sensors.

The vehicle controller is connected with a vehicle low-energy early warning device.

Beneficial effects of the utility model: the braking energy recovery system of four-wheel independent driving electric vehicles in underground coal mines provided by the utility model utilizes the mine's small-angle, long-distance road characteristics to absorb braking with high efficiency during the braking process of electric vehicles Feedback energy, and can fully store the feedback energy generated by the braking of four independently driven hub motors, improve the efficiency of regenerative braking energy recovery, and provide sufficient power demand during the start, acceleration and climbing stages of electric vehicles; the system reduces The maximum current that the lithium battery needs to provide increases the cycle life of the lithium battery, thereby increasing the mileage of the electric vehicle in the coal mine; at the same time, the regenerative braking control based on CAN bus communication and synchronous rectification technology can control the four-wheel Independently drive electric vehicles for real-time and effective control. The utility model improves the power, economy and system stability of the four-wheel independently driven electric vehicle in the coal mine, and promotes the application of the electric vehicle in the coal mine.

The utility model will be described in further detail below in conjunction with the accompanying drawings.

Description of drawings

Figure 1 is a schematic diagram of the structure of the four-wheel independent drive electric vehicle braking energy recovery system in the coal mine;

Figure 2 is a state diagram of braking freewheeling in synchronous rectification technology;

Figure 3 is a diagram of the braking charging state of the synchronous rectification technology;

Figure 4 is a flow chart of the design of the regenerative braking control module.

Description of reference signs: 1. Left front wheel hub motor; 2. Right front wheel hub motor; 3. Left rear wheel hub motor; 4. Right rear wheel hub motor; 5. Left front wheel hub motor driver; 6. Right front Wheel hub motor driver; 7. Left rear wheel hub motor driver; 8. Right rear wheel hub motor driver; 9. Super capacitor; 10. Lithium battery; 11. Bidirectional DC/DC converter; 12. First DC/DC conversion 13. The second DC/DC converter; 14. Battery manager; 15. Brake sensor; 16. Acceleration sensor; 17. Vehicle speed sensor; 18. Sensor signal processor; 19. Vehicle low-energy early warning device; 20. Vehicle controller; 21. DC high-voltage bus; 22. CAN bus.

detailed description

As shown in Figure 1, a braking energy recovery system for four-wheel independently driven electric vehicles in underground coal mines, including a right front wheel hub motor 1, a left front wheel hub motor 2, a left rear wheel hub motor 3, and a right rear wheel hub motor 4 , supercapacitor 9, lithium battery 10, DC high-voltage bus 21, CAN bus 22, the described right front wheel hub motor 1, left front wheel hub motor 2, left rear wheel hub motor 3, right rear wheel hub motor 4 are composed of Corresponding left front wheel hub motor driver 6, right front wheel hub motor driver 5, left rear wheel hub motor driver 7, right rear wheel hub motor driver 8 are electrically connected for independent driving; left front wheel hub motor driver 6, right front wheel The hub motor driver 5, the left rear wheel hub motor driver 7, and the right rear wheel hub motor driver 8 are electrically connected to the DC high-voltage bus 21; and are respectively electrically connected to the vehicle controller 20 interface through the CAN bus 22; the supercapacitor 9 passes through the first The DC/DC converter 12 is electrically connected to the DC high-voltage bus 21, and the lithium battery 10 is electrically connected to the DC high-voltage bus 21 through the second DC/DC converter 13; the first DC/DC converter 12 and the second DC/DC converter 13 are respectively electrically connected to the CAN bus 22 interface; the supercapacitor 9 and the lithium battery 10 are electrically connected to the CAN bus 22 interface through the battery manager 14 .

The hub motor driver 6 of the left front wheel, the hub motor driver 5 of the right front wheel, the hub motor driver 7 of the left rear wheel, and the hub motor driver 8 of the right rear wheel adopt the synchronous interval regenerative braking control mode based on the continuous current phase rectifier technology to Reduce the pressure drop of the circuit and realize the efficient driving of the hub motor.

As shown in Figure 2 and Figure 3, taking the conduction braking of the motor A-phase winding and B-phase winding as an example, in the freewheeling phase of the interval from 0 to 2π/3, the modulation conduction T ₄ is conduction at the same time as T ₆ , instead of D ₆ is used as a freewheeling circuit, and the current circuit is A phase → T ₄ → T ₆ → B phase winding. In the interval 2π/3～4π/3 and 4π/3～2π is the charging stage, the modulation turns off T ₄ and turns on T ₁ at the same time, replacing D ₁ as the charging loop, the current loop is A-phase winding → T ₁ → power supply positive pole → power supply Negative pole → T ₆ → B-phase winding. When using this regenerative braking control method, the pump voltage must be monitored in real time. If the pump voltage is higher than the DC bus voltage, T ₁ can be modulated and turned on during the charging phase to replace D ₁ as the charging circuit to reduce the voltage drop. If the pumping voltage is lower than the DC bus voltage, T ₁ must be switched off during the charging phase. Using the one-way conductivity of the diode, the cut-off current is reversed to ensure that the electromagnetic torque is still braking.

The supercapacitor 9 is electrically connected to the lithium battery 10 through a bidirectional DC/DC converter 11, and the bidirectional DC/DC converter 11 can adjust the direction of energy transfer according to the remaining power of the supercapacitor 9 and the lithium battery 10. The two energy sources can fully mobilize and store energy in roads with different power requirements in underground coal mines, and achieve efficient energy utilization in the different operating processes of electric vehicles such as starting, braking, acceleration and deceleration, uphill and downhill, and emergency braking, and The cycle life of the lithium battery is extended, and the mileage of the electric vehicle under the coal mine is improved. The supercapacitor 9 is also called an electric double layer capacitor, which belongs to the known technology.

As shown in Figure 1, the vehicle controller 20 is electrically connected to the sensor signal processor 18 through the CAN bus 22, and the sensor signal processor 18 is electrically connected to the brake sensor 15, the acceleration sensor 16, and the vehicle speed sensor 17 through interfaces respectively. The controller 20 receives the signals collected by the brake sensor 15 , the acceleration sensor 16 and the vehicle speed sensor 17 through the sensor signal processor 18 . The vehicle controller 20 is connected with a vehicle low-energy early warning device 19 . The vehicle low-energy early warning device is used to detect the electric energy of the vehicle battery, and belongs to the known technology.

As shown in Figure 4, a method for recovering braking energy of an underground four-wheel independently driven electric vehicle in a coal mine at least includes the following steps:

Step 400, the program starts;

Step 401, detecting sensor signal,

Step 402, detecting the angle signal of the brake pedal through the brake sensor 15, and detecting the speed signal of the electric vehicle through the vehicle speed sensor 17;

Step 403, when there is a signal from the brake pedal, the vehicle controller 20 calculates the required power of the electric vehicle through the vehicle speed and the angle of the brake pedal;

Step 404, judging whether the required power of the electric vehicle is greater than the drive power of the four in-wheel motors, if greater, the program returns to step 401 by the return command 408; if less, the program continues to enter step 414;

Step 414, judging whether the supercapacitor 9 is fully charged; yes, the program continues to enter step 415, no, the program continues to enter step 416;

Step 415, judging whether the lithium battery 10 is fully charged, if yes, the program returns to step 401; no, the program returns to step 416;

Step 416, the vehicle controller 20 controls the first DC/DC converter 12 to charge the supercapacitor 9, until the charging is completed, the program returns to step 401 by the return command 408;

Step 405, when there is no signal from the brake pedal, the angle signal of the accelerator pedal is detected by the acceleration sensor 16, and the speed signal of the electric vehicle is detected by the vehicle speed sensor 17;

Step 406, the vehicle controller 20 calculates the required power of the electric vehicle through the signal obtained in step 405;

Step 407, judge whether the power required by the electric vehicle is greater than the drive power of the four hub motors, if less, the program goes to step 412; if it is greater, the program continues to step 409;

Step 412, judging whether the supercapacitor 9 or the lithium battery 10 is fully charged? Yes, the program is returned to step 401 by the return instruction 408; no, the program continues to enter step 413;

In step 413, energy regulation is performed between the supercapacitor 9 and the lithium battery 10, and the program returns to step 401.

Step 409, is the power required by the electric vehicle less than the maximum power output value of the lithium battery? Yes, enter step 410, no, enter step 411;

Step 410, the second DC/DC converter 13 adjusts the output power of the lithium battery 10 to supply power independently, and the program returns to step 401;

Step 411, the second DC/DC converter 13 and the first DC/DC converter 12 adjust the output power of the lithium battery 10 to supply power.

When energy feedback occurs, the sum of the maximum braking torque and the minimum duty cycle at the current speed needs to be performed first. Then detect the bus voltage to determine whether the voltage is higher than the voltage at both ends of the battery. If it is higher than the voltage at both ends of the supercapacitor or lithium battery, it means that the energy can be fed back to the energy source, otherwise it cannot.

In addition, in order to protect the system from running better, the torque is detected and calculated. If the current torque is greater than the maximum braking torque, it means that there is an external mechanical brake, and the maximum braking torque should be assigned to the current torque. Otherwise, It is electrical braking, fuzzy control, and output duty cycle. If the duty cycle at this time is greater than the minimum duty cycle, the PWM wave can be output, otherwise, the duty cycle should be set to 0.

The parts that are not described in detail in this embodiment are commonly known and commonly used means in this industry, and will not be described here one by one. The above examples are only illustrations of the utility model, and do not constitute a limitation to the protection scope of the utility model. All designs identical or similar to the utility model all belong to the protection scope of the utility model.

Claims (4)

1. Braking energy recovery system for four-wheel independent drive electric vehicles in coal mines, including hub motors for the right front wheel (1), hub motors for the left front wheel (2), hub motors for the left rear wheel (3), and hub motors for the right rear wheel ( 4), supercapacitor (9), lithium battery (10), DC high voltage busbar (21), CAN bus (22), said right front wheel hub motor (1), left front wheel hub motor (2), left The rear wheel hub motor (3) and the right rear wheel hub motor (4) are respectively composed of the corresponding left front wheel hub motor driver (6), right front wheel hub motor driver (5), left rear wheel hub motor driver (7), The right rear wheel hub motor driver (8) is electrically connected for independent driving; the left front wheel hub motor driver (6), the right front wheel hub motor driver (5), the left rear wheel hub motor driver (7), the right rear wheel hub motor The driver (8) is electrically connected to the DC high-voltage bus (21); and is electrically connected to the interface of the vehicle controller (20) through the CAN bus (22); the supercapacitor (9) passes through the first DC/DC converter (12) It is electrically connected with the DC high-voltage bus (21), and the lithium battery (10) is electrically connected with the DC high-voltage bus (21) through the second DC/DC converter (13); the first DC/DC converter (12) and the second DC The /DC converter (13) is electrically connected to the CAN bus (22) interface respectively; the supercapacitor (9) and the lithium battery (10) are electrically connected to the CAN bus (22) interface through the battery manager (14). 2. The braking energy recovery system for four-wheel independent driving electric vehicles in coal mines according to claim 1, characterized in that: the supercapacitor (9) is connected to the lithium battery (10) through a bidirectional DC/DC converter (11) ) electrical connection. 3. The brake energy recovery system for underground four-wheel independent drive electric vehicles in coal mines according to claim 1, characterized in that: the vehicle controller (20) is electrically connected to a sensor signal processor through a CAN bus (22) (18), the sensor signal processor (18) is electrically connected with the brake sensor (15), the acceleration sensor (16), the vehicle speed sensor (17) respectively through the interface, and the vehicle controller (20) is connected through the sensor signal processor (18) ) to receive signals collected by the brake sensor (15), the acceleration sensor (16), and the vehicle speed sensor (17). 4. The braking energy recovery system for four-wheel independently driven electric vehicles in coal mines according to claim 1, characterized in that: the vehicle controller (20) is connected with a vehicle low-energy early warning device (19).