CN114701362A - Electric slow-moving control system and heavy-load mine car - Google Patents

Abstract

The invention discloses an electric slow-moving control system and a heavy-load mine car, which comprise a controller, a power system, an electric drive system, a brake resistor, a frequency converter, a cooling fan and a driving motor, wherein the power system is connected with the electric drive system; the electric drive system is respectively connected with the controller, the power system, the brake resistor and the drive motor, the drive motor is connected with the controller, the brake resistor is connected with the frequency converter, and the frequency converter is connected with the cooling fan. The invention utilizes the electrical characteristics of the motor to apply reverse torque to the motor to convert the kinetic energy of the vehicle into electric energy, thereby realizing the speed reduction function of the vehicle speed of the heavy-duty mine car, and the converted energy is consumed by the brake resistor. The cooling fan of the brake resistor adopts an alternating current motor, the alternating current motor controller is integrated in the brake resistor, when the brake resistor is used, energy is provided by the voltage of the resistor end, the normal operation of the cooling fan is ensured, and meanwhile, the rotating speed of the fan and the angle of the fan can be adjusted according to the working condition, so that the control of the cooling air quantity is realized.

Description

A kind of electric retarding control system and heavy-duty mine car

technical field

The invention relates to an electric retarding control system and a heavy-duty mining car, belonging to the technical field of heavy-duty mining car control.

Background technique

In the field of large-scale open-pit mine transportation, heavy-duty mining trucks are the main means of transportation, which are mainly divided into mechanical transmission and electric transmission mining trucks. Electric transmission mining trucks occupy an absolutely dominant position. Power generation, providing power for subsequent equipment, no complicated gear train, low maintenance cost. In the early stage of the development of electric drive mine cars, the DC drive system was the mainstay. With the development of electronic switching devices and their control technology, AC drive cars began to gradually occupy the main market share, but DC motors are still used for braking resistors. Drive the fan to dissipate heat for the braking resistor.

Due to the characteristics of the mine transportation line, half of the working cycle must be in the braking state, so the braking resistor is an important part of the electric drive mine car, and its importance is particularly prominent. However, the structure of the DC motor currently used is complex, requires regular maintenance, and has a high failure rate, which is a major shortcoming of the electric drive mine car. The current solution is to replace the DC motor with an AC motor, and add a loop to the DC bus to control the AC motor. Flexibility, high cost, and significant increase in vehicle cost. If the motor in the braking resistor and its controller can be integrated according to the operating characteristics of the braking resistor, the structure will be greatly simplified and the cost will be reduced.

SUMMARY OF THE INVENTION

In view of the problems existing in the above-mentioned prior art, the present invention provides an electric retarding control system and a heavy-duty mining car.

In order to achieve the above purpose, an electric retarding control system adopted in the present invention includes a controller, and also includes a power system, an electric drive system, a braking resistor, a frequency converter, a cooling fan and a drive motor;

The electric drive system is respectively connected with a controller, a power system, a braking resistor and a drive motor, the drive motor is connected with the controller, the braking resistor is connected with a frequency converter, and the frequency converter is connected with a cooling fan.

As an improvement, the electric drive system includes a rectifier, a DC bus, an inverter and a chopper circuit, and the braking resistor is connected to the electric drive system through the chopper circuit.

As an improvement, the braking resistor is connected to the electric drive system through a DC chopper circuit.

As an improvement, the power supply of the frequency converter is connected in parallel in a braking resistor branch, and the parallel position is adjusted to change the terminal voltage of the frequency converter and its output voltage as required.

As an improvement, the frequency converter is two-level or three-level.

As an improvement, the frequency converter calculates the cooling demand according to the voltage value and the existence time of the resistance terminal voltage, and controls the rotation speed of the cooling fan.

As an improvement, the braking resistor measures the ventilation volume during operation, and adjusts the angle of the cooling fan according to the calculated cooling demand and the measured ventilation volume of the braking resistor.

As an improvement, the motor of the cooling fan adopts an AC motor.

As an improvement, the driving motor includes a driving motor 1 and a driving motor 2 which are connected in parallel.

Finally, the present invention also provides a heavy-duty mining cart, on which the electric retarding control system is installed.

Compared with the prior art, the present invention utilizes the electrical characteristics of the motor, applies reverse torque to it, converts the kinetic energy of the vehicle into electrical energy, and can realize the function of reducing the speed of the heavy mining truck, and the converted energy is consumed by the braking resistor. The cooling fan of the braking resistor adopts an AC motor, and the AC motor controller is integrated into the braking resistor. During braking, the voltage of the resistor terminal provides energy to ensure the normal operation of the cooling fan. At the same time, the fan speed and speed can be adjusted according to the working conditions. The angle of the fan, so as to realize the control of the cooling air volume.

Description of drawings

Fig. 1 is the principle schematic diagram of the present invention;

Fig. 2 is the schematic diagram of fan speed control of the present invention;

In the picture: 1. Controller, 2. Power system, 3. Electric drive system, 4. Braking resistor, 5. Frequency converter, 6. Cooling fan, 7. Drive motor one, 8. Drive motor two.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail below. However, it should be understood that the specific embodiments described herein are only used to explain the present invention, and not to limit the scope of the present invention.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present invention, and the terms used herein in the description of the present invention are only for describing specific implementations The examples are not intended to limit the invention.

As shown in Figures 1 and 2, an electric retarding control system includes a controller 1, a power system 2, an electric drive system 3, a braking resistor 4, a frequency converter 5, a cooling fan 6 and a drive motor;

The electric drive system 3 is connected with the controller 1 through the CAN bus, and the electric drive system 3 is connected with the power system 2, the drive motor one 7 and the drive motor two 8 respectively through the three-phase alternating current, and the drive motor one 7 and the drive motor two are respectively connected. 8 are respectively connected with the controller 1, and the driving motor one 7 and the driving motor two 8 transmit speed and current signals to the controller; the electric drive system 3 is connected with the braking resistor 4, and the braking resistor 4 is connected with the frequency converter. 5 is connected, the frequency converter 5 is connected with the cooling fan 6. During traction, power system 2 and electric drive system 3 provide energy, and drive motor 1 7 and drive motor 2 8 run; during braking, drive motor 1 7 and drive motor 2 8 input energy to electric drive system 3, and electric drive system 3 The braking resistor 4 is supplied with energy, and at the same time, the inverter 5 is supplied with energy to control the operation of the cooling fan 6 , and the cooling fan 6 provides cooling airflow to the braking resistor 4 . In addition, during braking, the heat dissipation capacity of the braking resistor 4 is adjusted by the fan speed and the fan angle, which can maximize the cooling air volume and improve the heat dissipation capacity. Braking power and reliability.

As an improvement of the embodiment, the electric drive system 3 includes a rectifier, a DC bus, an inverter and a chopper circuit, the braking resistor 4 is connected to the electric drive system 3 through a DC chopper circuit, and the braking resistor 4 It can be divided into several branches according to the braking requirements of the mine car, and different branches can be closed according to the requirements to achieve different braking power requirements.

As an improvement of the embodiment, the inverter power supply is connected in parallel in a braking resistor branch, and the parallel position can be adjusted as required to change the inverter terminal voltage and its output voltage to meet the needs of different power cooling fans. The inverter 5 can be two-level or three-level, which is determined according to the voltage of the parallel resistor. If it is connected in parallel at both ends of the braking resistor branch, selecting a three-level inverter can reduce the voltage level of the IGBT in the inverter. It is connected in parallel in the middle of the braking resistor branch, and a two-level inverter is selected.

As an improvement of the embodiment, the frequency converter 5 can calculate the heat dissipation requirement according to the voltage value and the existence time of the resistance terminal voltage, and control the speed of the heat dissipation fan to ensure the effectiveness and efficiency of the heat dissipation of the braking resistor under different working conditions.

As an improvement of the embodiment, the braking resistor 4 measures the ventilation volume during operation, and adjusts the angle of the cooling fan according to the calculated cooling demand and the measured ventilation volume of the braking resistor, so as to realize the closed-loop control of the system, and the cooling fan The angle controller of 6 is integrated in frequency converter 5.

As an improvement of the embodiment, the motor of the cooling fan 6 adopts an AC motor, which reduces the use cost and has higher reliability than using a DC motor.

Finally, the present invention also provides a heavy-duty mining cart, on which the electric retarding control system is installed.

Specific working process:

When the power is slow, the motor changes from the electric state to the feeding state, and flows into the DC bus through diode rectification. When the DC bus voltage is greater than the set value, it discharges to the braking resistor 4 through the DC chopper circuit. When the DC bus voltage drops to the set value, When the value is set low, the chopper circuit is turned off. During the working process of the chopper circuit, the inverter of the cooling fan adjusts the motor speed and the fan angle according to the voltage and working time of the resistor branch, so as to realize the precise heat dissipation of the braking resistor 4 and ensure the effectiveness and efficiency of the braking system. .

According to the electric retarding demand of the vehicle, the inverter power supply can be connected in parallel at both ends of the resistor branch or in the middle of the resistor to realize the control requirements for motors of different power levels. The inverter can also select two-level or three-level according to the voltage cost. The cooling fan angle controller is integrated in the inverter, and the air flow and flow rate can be adjusted by adjusting the fan angle, and a wide range of cooling capacity can be obtained by using the same system.

Example 1

An electric drive mine car, comprising a controller 1, a power system 2, an electric drive system 3, a braking resistor 4, a frequency converter 5, a cooling fan 6 and a drive motor;

In the braking deceleration stage, the characteristics of the traction motor are used to make the traction motor work in the feeding state. After the energy is rectified, it is consumed by the braking resistance grid. The heat of the braking resistance is forced air cooling through the cooling fan 6. Drive, the AC motor speed is controlled by the inverter 5 integrated on the braking resistor 4; the braking resistor 4 is connected to the electric drive system 3 through a cable, and the inverter 5 is connected in parallel to a branch of the braking resistor 4 through a cable, and the controller 1 is connected to the AC motor through a cable, and the AC motor is connected to the cooling fan 6;

During braking, the electric drive system 3 discharges the braking resistor 4 through the chopper circuit, and the inverter 5 connected in parallel with a resistor branch accurately calculates the heat dissipation requirement according to the resistor terminal voltage and voltage action time, and adjusts the speed of the AC fan and the cooling fan. The angle is adjusted to realize the heat dissipation of the resistor.

During the whole working process, the energy fed back by the motor during braking is used to drive the fan to dissipate heat, which realizes the recovery and utilization of braking energy and achieves the purpose of saving energy. system reliability.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement or improvement made within the spirit and principle of the present invention shall be included in the protection of the present invention. within the range.

Claims (10)

1. An electric slow-moving control system comprises a controller (1), and is characterized by further comprising a power system (2), an electric driving system (3), a brake resistor (4), a frequency converter (5), a heat-radiating fan (6) and a driving motor;

the electric drive system (3) is respectively connected with the controller (1), the power system (2), the brake resistor (4) and the driving motor, the driving motor is connected with the controller (1), the brake resistor (4) is connected with the frequency converter (5), and the frequency converter (5) is connected with the heat dissipation fan (6).

2. An electric creep control system according to claim 1, characterized in that the electric drive system (3) comprises a rectifier, a dc bus, an inverter and a chopper circuit, and the braking resistor (4) is connected to the electric drive system (3) via the chopper circuit.

3. An electric creep control system according to claim 2, characterized in that the braking resistor (4) is connected to the electric drive system (3) via a dc chopper circuit.

4. An electric creep control system as claimed in claim 1, characterized in that the power supply of the frequency converter (5) is connected in parallel in a brake resistor branch, and the voltage at the end of the frequency converter and its output voltage are changed by adjusting the parallel position as required.

5. An electric creep control system according to claim 1, characterized in that the frequency converter (5) is two-level or three-level.

6. An electric creep control system as claimed in claim 1, characterized in that the frequency converter (5) calculates the heat dissipation requirement according to the voltage value and the voltage existing time of the resistor terminal, and controls the rotation speed of the heat dissipation fan (6).

7. An electric creep control system according to claim 1, characterized in that the brake resistor (4) measures the ventilation during operation and the angle of the cooling fan (6) is adjusted according to the calculated cooling demand and the measured ventilation of the brake resistor.

8. An electric creep control system according to claim 1, characterized in that the motor of the cooling fan (6) is an ac motor.

9. An electric creep control system according to claim 1, wherein the drive motor comprises a first drive motor (7) and a second drive motor (8) connected in parallel.

10. A heavy-duty mining vehicle, characterized in that the electric creep control system according to any one of claims 1 to 9 is mounted on the heavy-duty mining vehicle.

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