An electric wheel auxiliary transmission control method, device and storage medium

Abstract

The application relates to an auxiliary transmission control method, device and storage medium for an electric wheel mine dump truck. The method comprises the following steps: an auxiliary transmission front-end system takes power from the intermediate direct-current side of the main transmission of the electric wheel mine dump truck and converts the power into an intermediate direct-current voltage available for an auxiliary transmission rear-end system. The auxiliary transmission rear-end system mainly drives and controls various fans and water pumps to run by using the intermediate direct-current voltage converted by the auxiliary transmission front-end system, and provides cooling services for the whole vehicle. The control method can fully utilize the energy fed back to the intermediate direct-current side of the main transmission during braking operation, improves the energy efficiency of the system, reduces the oil injection amount and saves the operation cost of the system during braking operation, and the fans and water pumps in the cooling motor are AC motors, so that compared with traditional DC motors, the AC motors are simple and reliable in structure and significantly reduce the maintenance workload.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of vehicle control, and in particular to an electric wheel auxiliary transmission control method, device and storage medium. BACKGROUND

[0002] The electric wheel of the electric wheel mining dump truck generally includes a main transmission system and an auxiliary transmission system. The auxiliary transmission system needs to provide heat dissipation for the whole vehicle during normal operation of the electric wheel mining dump truck to ensure safe operation of the whole vehicle. In particular, when the electric wheel mining dump truck is running with brake braking, the braking energy is consumed on the brake resistor, causing the temperature of the brake resistor to soar in a short time. Therefore, in order to effectively dissipate heat, the corresponding brake resistor fan needs to be operated at full power to strengthen the heat dissipation of the brake resistor and keep the temperature of the brake resistor within a reasonable range. The traditional electric wheel mining dump truck provides power to the auxiliary transmission system through a diesel generator or a brake resistor voltage divider, which increases the fuel consumption of the diesel generator and increases the system operation cost. In addition, the fan of the traditional auxiliary transmission system generally uses a DC fan. The DC fan is prone to failure and thus needs regular maintenance. SUMMARY

[0003] Therefore, it is necessary to provide an electric wheel auxiliary transmission control method, device and storage medium in view of the above technical problems.

[0004] In a first aspect, an electric wheel auxiliary transmission control method is provided, which comprises:

[0005] The auxiliary transmission front-end system receives the main transmission DC voltage transmitted from the main transmission control system, and inversely converts the main transmission DC voltage into three-phase AC voltage, and then converts the three-phase AC voltage into intermediate DC voltage;

[0006] According to the given fan frequency of the cooling fan in the auxiliary transmission rear-end system, the auxiliary transmission rear-end system is subjected to current amplitude closed-loop control;

[0007] In the current amplitude closed-loop control stage, the auxiliary transmission rear-end system receives the intermediate DC voltage and the three-phase AC voltage, and the three-phase current obtained by sampling the three-phase AC voltage is converted into actual direct-axis current and actual quadrature-axis current;

[0008] After the direct-axis current and the quadrature-axis current are processed by a current regulator and then subjected to space vector pulse width modulation, six-way pulse driving of the second inverter is outputted to control the cooling fan to cool the main transmission system.

[0009] Further, the auxiliary transmission front-end system receives the main transmission DC voltage transmitted from the main transmission control system, and inversely converts the main transmission DC voltage into three-phase AC voltage, and then converts the three-phase AC voltage into intermediate DC voltage, which comprises:

[0010] The auxiliary transmission front-end system adopts voltage closed-loop control, and difference between given intermediate direct current voltage and actually sampled intermediate direct current voltage is outputted by voltage regulator to adjust pulse width modulation required input, and three-phase alternating current is outputted by six-way pulse driving first inverter.

[0011] Further, the auxiliary transmission back-end system is subjected to current amplitude closed-loop control according to given fan frequency of cooling fan in the auxiliary transmission back-end system, and the current amplitude closed-loop control comprises:

[0012] 60% of rated frequency of the cooling fan is set as judgment fan frequency, and when the given fan frequency is less than the judgment fan frequency, the current amplitude is subjected to closed-loop control, and the given fan frequency and the rotating speed of the cooling fan correspond to each other.

[0013] Further, in the current amplitude closed-loop control stage, the auxiliary transmission back-end system receives the intermediate direct current voltage and the three-phase alternating current voltage, and three-phase current sampled by the three-phase alternating current voltage is converted to obtain actual direct-axis current and actual quadrature-axis current, and the current amplitude closed-loop control comprises:

[0014] reference direct-axis current and reference quadrature-axis current are obtained according to fan characteristic curve;

[0015] the reference direct-axis current is subtracted from the actual direct-axis current, and the reference quadrature-axis current is subtracted from the actual quadrature-axis current;

[0016] the difference values after subtraction are respectively subjected to current regulator to obtain reference direct-axis voltage and reference quadrature-axis voltage.

[0017] On the other hand, the embodiment of the present application also provides an electric wheel auxiliary transmission control device, comprising:

[0018] an auxiliary transmission front-end system, which receives main transmission direct current voltage transmitted from a main transmission control system, and inversely transforms the main transmission direct current voltage into three-phase alternating current voltage, and then transforms the three-phase alternating current voltage into intermediate direct current voltage;

[0019] a closed-loop control system, which is used for subjecting the auxiliary transmission back-end system to current amplitude closed-loop control according to given fan frequency of cooling fan in the auxiliary transmission back-end system;

[0020] an auxiliary transmission back-end system, which receives the intermediate direct current voltage and the three-phase alternating current voltage in the current amplitude closed-loop control stage, and converts three-phase current sampled by the three-phase alternating current voltage to obtain actual direct-axis current and actual quadrature-axis current;

[0021] The fan cooling system is used for outputting six-way pulse to drive the second inverter after the direct-axis current and the quadrature-axis current are processed by the current regulator and outputted after space vector pulse width modulation, so as to control the cooling fan to cool the main transmission system.

[0022] Further, the auxiliary transmission front-end system comprises a front-end current conversion unit, which is used for:

[0023] In the auxiliary transmission front-end system, voltage closed-loop control is adopted, the given intermediate direct-current voltage is subtracted from the actually sampled intermediate direct-current voltage, the required input quantity of pulse width modulation is adjusted by the voltage regulator, and three-phase alternating current is outputted by the six-way pulse driving the first inverter.

[0024] Further, the closed-loop control system comprises a frequency judging unit, which is used for:

[0025] The 60% of the rated frequency of the cooling fan is set as the judging fan frequency, when the given fan frequency is less than the judging fan frequency, the current amplitude is controlled in closed loop, and the given fan frequency and the rotating speed of the cooling fan correspond to each other.

[0026] Further, the auxiliary transmission back-end system comprises a back-end reference current unit, which is used for:

[0027] The reference direct-axis current and the reference quadrature-axis current are obtained according to the fan characteristic curve;

[0028] The reference direct-axis current is subtracted from the actual direct-axis current, and the reference quadrature-axis current is subtracted from the actual quadrature-axis current;

[0029] The difference values after the subtraction are respectively converted into reference direct-axis voltage and reference quadrature-axis voltage by the current regulator.

[0030] The embodiment of the application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to realize the following steps:

[0031] The auxiliary transmission front-end system receives the main transmission direct-current voltage transmitted from the main transmission control system, and inverts the main transmission direct-current voltage into three-phase alternating voltage, and then converts the three-phase alternating voltage into intermediate direct-current voltage;

[0032] According to the given fan frequency of the cooling fan in the auxiliary transmission back-end system, the current amplitude of the auxiliary transmission back-end system is controlled in closed loop;

[0033] During the current amplitude closed-loop control stage, the auxiliary transmission back-end system receives the intermediate DC voltage and the three-phase AC voltage, and the three-phase current obtained by sampling the three-phase AC voltage is transformed to obtain the actual direct-axis current and the actual quadrature-axis current.

[0034] The direct-axis current and quadrature-axis current are processed by the current regulator and then output as six pulses after space vector pulse width modulation to drive the second inverter and control the cooling fan to cool the main transmission system.

[0035] The aforementioned electric wheel auxiliary transmission control method, equipment, and storage medium include: the auxiliary transmission front-end system draws power from the intermediate DC side of the main transmission of the electric wheel mining dump truck and converts it into an intermediate DC voltage usable at the auxiliary transmission back-end. The auxiliary back-end system mainly uses the intermediate DC voltage converted from the auxiliary transmission front-end to drive and control the operation of various fans and water pumps, providing cooling services for the entire vehicle. This control method can fully utilize the energy fed back to the intermediate DC side of the main transmission during braking, improving system energy efficiency; during braking, the use of braking energy reduces fuel injection, saving system operating costs; and since the fans and water pumps in the cooling motor use AC motors, compared to traditional DC motors, the structure is simpler and more reliable, significantly reducing maintenance workload. Attached Figure Description

[0036] Figure 1 This is a flowchart illustrating the electric wheel auxiliary transmission control method in one embodiment;

[0037] Figure 2 This is a schematic diagram of the current transformation process in the auxiliary transmission backend system in one embodiment.

[0038] Figure 3 This is a system block diagram of the electric wheel auxiliary transmission control device in one embodiment;

[0039] Figure 4 This is a schematic diagram of the circuit layout of the auxiliary transmission system equipment in one embodiment;

[0040] Figure 5 This is a schematic diagram of the circuit layout of the auxiliary transmission backend system in one embodiment. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0042] In one embodiment, such as Figure 1 As shown, an electric wheel auxiliary transmission control method is provided, the method comprising:

[0043] Step 101: The auxiliary transmission front-end system receives the main transmission DC voltage transmitted from the main transmission control system, inverts the main transmission DC voltage into a three-phase AC voltage, and then converts the three-phase AC voltage into an intermediate DC voltage.

[0044] Step 102: Perform closed-loop current amplitude control on the auxiliary transmission back-end system according to the given fan frequency of the cooling fan in the auxiliary transmission back-end system.

[0045] Step 103: In the current amplitude closed-loop control stage, the auxiliary transmission back-end system receives the intermediate DC voltage and the three-phase AC voltage, and transforms the three-phase current obtained by sampling the three-phase AC voltage to obtain the actual direct-axis current and the actual quadrature-axis current.

[0046] Step 104: After the direct-axis current and quadrature-axis current are processed by the current regulator, they are output as six pulses after space vector pulse width modulation to drive the second inverter and control the cooling fan to cool the main transmission system.

[0047] Specifically, in electric wheel mining dump trucks, the main drive system uses diesel engine excitation control. Different throttle pedal positions result in fluctuating intermediate voltage, leading to a large fluctuation range (600V-1800V). To ensure that the front-end system in the auxiliary drive system can still provide a constant intermediate DC voltage to the back-end system despite the large fluctuation range of the main drive's intermediate DC voltage, while also meeting the rated output of the isolation transformer, this embodiment proposes a control method for the auxiliary drive front-end system. Furthermore, the proposed control method for the auxiliary drive back-end system is simple and clear, ensuring the normal operation of fans and water pumps while avoiding current oscillations during low-frequency operation. In this embodiment, the auxiliary drive front-end system draws power from the intermediate DC side of the main drive of the electric wheel mining dump truck and converts it into an intermediate DC voltage usable by the auxiliary drive back-end system. The auxiliary back-end system mainly utilizes the intermediate DC voltage converted from the auxiliary drive front-end system to drive and control the operation of various fans and water pumps, providing overall vehicle cooling. This control method can make full use of the energy fed back to the DC side of the main drive during braking, thereby improving system energy efficiency. During braking, the amount of fuel injection is reduced by utilizing the energy generated by braking, thus saving system operating costs. Since the fan and water pump in the cooling motor are AC motors, compared with traditional DC motors, the structure is simple and reliable, significantly reducing maintenance workload.

[0048] In one embodiment, current conversion of the auxiliary transmission front-end system includes: the auxiliary transmission front-end system adopts voltage closed-loop control, calculates the difference between the given intermediate DC voltage and the actual sampled intermediate DC voltage, adjusts the required input amount for output pulse width modulation through a voltage regulator, and drives the first inverter to output three-phase AC power through six pulses.

[0049] Specifically, such as Figure 4As shown, the front-end system inverts the main intermediate DC voltage Udc1 into a three-phase AC voltage through inverter 1. Then, an isolation transformer steps down the output voltage, which is rectified into DC voltage by an uncontrolled rectifier. Finally, after filtering by inductors and capacitors, the required intermediate DC voltage Udc2 for the back-end system is obtained. To stabilize the back-end intermediate DC voltage Udc2, a voltage closed-loop control strategy is adopted for the front-end system control method. The difference between the given intermediate DC voltage Udc2* and the actual sampled intermediate DC voltage Udc2 is calculated. This difference is then used by a voltage regulator (such as a commonly used proportional-integral-derivative controller) to adjust the required input quantity for pulse width modulation (PWM), ultimately generating six pulses to drive the three-phase AC output of inverter 1.

[0050] In one embodiment, 60% of the rated frequency of the cooling fan is set as the judged fan frequency. When the given fan frequency is less than the judged fan frequency, the current amplitude is controlled in a closed loop. The given fan frequency and the speed of the cooling fan correspond to each other.

[0051] In one embodiment, such as Figure 2 As shown, the current conversion process in the auxiliary transmission back-end system includes:

[0052] Step 201: Obtain the reference direct-axis current and reference quadrature-axis current based on the fan characteristic curve;

[0053] Step 202: Subtract the reference direct-axis current from the actual direct-axis current, and subtract the reference quadrature-axis current from the actual quadrature-axis current;

[0054] Step 203: The difference after the operation is processed is used to obtain the reference direct-axis voltage and the reference quadrature-axis voltage through the current regulator.

[0055] Specifically, such as Figure 5The auxiliary back-end system circuit layout diagram shown includes inverter 2 and a fan. For ease of description, the fan represents all fan and pump loads in the back-end system. When the given fan frequency f* (frequency corresponds to fan speed) is less than f0, the fan uses current amplitude closed-loop control. When the given fan frequency f* is greater than f0, the fan uses voltage open-loop control. f0 is generally taken as 60% of the fan's rated frequency. In the current amplitude closed-loop control stage, the sampled three-phase currents ia, ib, and ic are converted into two voltages by three-phase AC to obtain the actual direct-axis current id and quadrature-axis current iq. The required motor angle θ* is obtained by integrating the given fan frequency f*. The reference direct-axis current id* and quadrature-axis current iq* given by the fan characteristic curve are subtracted from the actual direct-axis current id and quadrature-axis current iq, respectively, and then processed by a current regulator (such as a commonly used proportional-integral-derivative controller) to obtain the reference direct-axis voltage ud* and quadrature-axis voltage uq*. After direct-axis and quadrature-axis transformations, reference voltages uα* and uβ* are obtained and used as inputs for Space Vector Pulse Width Modulation (SVPWM). The output of six pulses drives inverter 2 to control the fan operation. During the open-loop voltage phase, the reference voltages uα* and uβ* required for SVPWM are directly given by uα* = V*cos(θ*) and uβ* = V*sin(θ*), where V is the rated voltage of the motor section.

[0056] It should be understood that although the steps in the flowchart above are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowchart above may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0057] In one embodiment, such as Figure 3 As shown, the process for sharing stored data includes:

[0058] The auxiliary transmission front-end system 301 receives the main transmission DC voltage transmitted from the main transmission control system, inverts the main transmission DC voltage into a three-phase AC voltage, and then converts the three-phase AC voltage into an intermediate DC voltage.

[0059] A closed-loop control system 302 is used to perform closed-loop current amplitude control on the auxiliary transmission back-end system based on the given fan frequency of the cooling fan in the auxiliary transmission back-end system.

[0060] In the current amplitude closed-loop control stage, the auxiliary transmission back-end system 303 receives the intermediate DC voltage and the three-phase AC voltage, and transforms the three-phase current obtained by sampling the three-phase AC voltage to obtain the actual direct-axis current and the actual quadrature-axis current.

[0061] The fan cooling system 304 is used to drive the second inverter by outputting six pulses after the direct-axis current and quadrature-axis current are processed by the current regulator and then subjected to space vector pulse width modulation, thereby controlling the cooling fan to cool the main transmission system.

[0062] In one embodiment, the auxiliary transmission front-end system 301 includes a front-end current conversion unit, the front-end current conversion unit being used for:

[0063] The auxiliary transmission front-end system adopts voltage closed-loop control, which calculates the difference between the given intermediate DC voltage and the actual sampled intermediate DC voltage, adjusts the output pulse width modulation input through the voltage regulator, and drives the first inverter to output three-phase AC power through six pulses.

[0064] In one embodiment, the closed-loop control system 302 includes a frequency determination unit, which is used for:

[0065] The rated frequency of the cooling fan is set to 60% of the judged fan frequency. When the given fan frequency is less than the judged fan frequency, the current amplitude is controlled in a closed loop. The given fan frequency and the speed of the cooling fan correspond to each other.

[0066] The auxiliary transmission backend system 303 includes a backend reference current unit, which is used for:

[0067] The reference direct-axis current and reference quadrature-axis current are obtained from the fan characteristic curve;

[0068] The difference between the reference direct-axis current and the actual direct-axis current is calculated, and the difference between the reference quadrature-axis current and the actual quadrature-axis current is calculated.

[0069] The difference after the operation is performed is used to obtain the reference direct-axis voltage and the reference quadrature-axis voltage through the current regulator.

[0070] Specific limitations regarding the electric wheel-assisted transmission control system can be found in the limitations of the electric wheel-assisted transmission control method described above, and will not be repeated here. Each module in the aforementioned electric wheel-assisted transmission control system can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0071] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0072] The auxiliary transmission front-end system receives the main transmission DC voltage transmitted from the main transmission control system, inverts the main transmission DC voltage into a three-phase AC voltage, and then converts the three-phase AC voltage into an intermediate DC voltage.

[0073] Based on the given fan frequency of the cooling fan in the auxiliary transmission back-end system, the current amplitude of the auxiliary transmission back-end system is controlled in a closed loop.

[0074] During the current amplitude closed-loop control stage, the auxiliary transmission back-end system receives the intermediate DC voltage and the three-phase AC voltage, and the three-phase current obtained by sampling the three-phase AC voltage is transformed to obtain the actual direct-axis current and the actual quadrature-axis current.

[0075] The direct-axis current and quadrature-axis current are processed by the current regulator and then output as six pulses after space vector pulse width modulation to drive the second inverter and control the cooling fan to cool the main transmission system.

[0076] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0077] The auxiliary transmission front-end system adopts voltage closed-loop control, which calculates the difference between the given intermediate DC voltage and the actual sampled intermediate DC voltage, adjusts the output pulse width modulation input through the voltage regulator, and drives the first inverter to output three-phase AC power through six pulses.

[0078] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0079] The rated frequency of the cooling fan is set to 60% of the judged fan frequency. When the given fan frequency is less than the judged fan frequency, the current amplitude is controlled in a closed loop. The given fan frequency and the speed of the cooling fan correspond to each other.

[0080] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0081] The reference direct-axis current and reference quadrature-axis current are obtained from the fan characteristic curve;

[0082] The difference between the reference direct-axis current and the actual direct-axis current is calculated, and the difference between the reference quadrature-axis current and the actual quadrature-axis current is calculated.

[0083] The difference after the operation is performed is used to obtain the reference direct-axis voltage and the reference quadrature-axis voltage through the current regulator.

[0084] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods.

[0085] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0086] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for controlling electric wheel auxiliary transmission, characterized in that, The method includes: The auxiliary transmission front-end system receives the main transmission DC voltage transmitted from the main transmission control system, inverts the main transmission DC voltage into a three-phase AC voltage, and then converts the three-phase AC voltage into an intermediate DC voltage. Based on the given fan frequency of the cooling fan in the auxiliary transmission back-end system, the current amplitude of the auxiliary transmission back-end system is controlled in a closed loop. During the current amplitude closed-loop control stage, the auxiliary transmission back-end system receives the intermediate DC voltage and the three-phase AC voltage, and the three-phase current obtained by sampling the three-phase AC voltage is transformed to obtain the actual direct-axis current and the actual quadrature-axis current. The direct-axis current and quadrature-axis current are processed by the current regulator, and then output as six pulses after space vector pulse width modulation to drive the second inverter and control the cooling fan to cool the main transmission system. The auxiliary transmission front-end system receives the main transmission DC voltage transmitted from the main transmission control system, inverts the main transmission DC voltage into a three-phase AC voltage, and then converts the three-phase AC voltage into an intermediate DC voltage, including: The auxiliary transmission front-end system adopts voltage closed-loop control, which calculates the difference between the given intermediate DC voltage and the actual sampled intermediate DC voltage, adjusts the output pulse width modulation input through the voltage regulator, and drives the first inverter to output three-phase AC power through six pulses. In the current amplitude closed-loop control stage, the auxiliary transmission backend system receives the intermediate DC voltage and the three-phase AC voltage. The three-phase current obtained by sampling the three-phase AC voltage is transformed to obtain the direct-axis current and quadrature-axis current, including: The reference direct-axis current and reference quadrature-axis current are obtained from the fan characteristic curve; The difference between the reference direct-axis current and the actual direct-axis current is calculated, and the difference between the reference quadrature-axis current and the actual quadrature-axis current is calculated. The difference after the operation is performed is used to obtain the reference direct-axis voltage and the reference quadrature-axis voltage through the current regulator.

2. The electric wheel auxiliary transmission control method according to claim 1, characterized in that, The step of performing closed-loop current amplitude control on the auxiliary transmission back-end system based on the given fan frequency of the cooling fan in the auxiliary transmission back-end system includes: The rated frequency of the cooling fan is set to 60% of the judged fan frequency. When the given fan frequency is less than the judged fan frequency, the current amplitude is controlled in a closed loop. The given fan frequency and the speed of the cooling fan correspond to each other.

3. An electric wheel auxiliary transmission control device, characterized in that, include: The auxiliary transmission front-end system receives the main transmission DC voltage transmitted from the main transmission control system, inverts the main transmission DC voltage into a three-phase AC voltage, and then converts the three-phase AC voltage into an intermediate DC voltage. A closed-loop control system is used to perform closed-loop current amplitude control on the auxiliary transmission back-end system based on the given fan frequency of the cooling fan in the auxiliary transmission back-end system. In the current amplitude closed-loop control stage, the auxiliary transmission back-end system receives the intermediate DC voltage and the three-phase AC voltage, and transforms the three-phase current obtained by sampling the three-phase AC voltage to obtain the actual direct-axis current and the actual quadrature-axis current. A fan cooling system is used to drive the second inverter by outputting six pulses after the direct-axis current and quadrature-axis current are processed by the current regulator and then subjected to space vector pulse width modulation, thereby controlling the cooling fan to cool the main transmission system. The auxiliary transmission front-end system includes a front-end current conversion unit, which is used for: The auxiliary transmission front-end system adopts voltage closed-loop control, which calculates the difference between the given intermediate DC voltage and the actual sampled intermediate DC voltage, adjusts the output pulse width modulation input through the voltage regulator, and drives the first inverter to output three-phase AC power through six pulses. The auxiliary transmission backend system includes a backend reference current unit, which is used for: The reference direct-axis current and reference quadrature-axis current are obtained from the fan characteristic curve; The difference between the reference direct-axis current and the actual direct-axis current is calculated, and the difference between the reference quadrature-axis current and the actual quadrature-axis current is calculated. The difference after the operation is performed is used to obtain the reference direct-axis voltage and the reference quadrature-axis voltage through the current regulator.

4. The electric wheel auxiliary transmission control device according to claim 3, characterized in that, The closed-loop control system includes a frequency determination unit, which is used for: The rated frequency of the cooling fan is set to 60% of the judged fan frequency. When the given fan frequency is less than the judged fan frequency, the current amplitude is controlled in a closed loop. The given fan frequency and the speed of the cooling fan correspond to each other.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method described in claim 1 or 2.

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