Mine car braking method and device and readable storage medium

Abstract

The invention provides a mine car braking method and device and a readable storage medium, a mine car comprises a driving motor, a braking resistor, a high-voltage loop, a temperature detection module, a mechanical braking mechanism and a driving motor control system, and the method comprises the steps that slope data and battery electric quantity data of the mine car and state data of the driving motor control system are obtained; when the battery electric quantity data meets a preset electric quantity condition, the slope data meets a downhill judgment condition and the state data of the driving motor control system is that a fault exists, the working power of a braking resistor required by braking is determined according to the fault state of the driving motor control system; controlling the brake resistor to access a high-voltage loop based on the working power of the brake resistor; controlling a temperature detection module to obtain temperature detection data of the brake resistor; and when the temperature detection data reach a temperature threshold value, the working power of the brake resistor is reduced, and the mechanical brake mechanism is controlled to intervene in braking. Power can be reduced at high temperature, mechanical braking can be linked, and insufficient braking redundancy is avoided.

Description

Technical Field

[0001] This invention relates to the technical field of mine car braking systems, and more specifically, to a braking method, device, and readable storage medium for a mine car. Background Technology

[0002] In related technologies, some models of large electric engineering vehicles, such as electric mining trucks, cannot be equipped with retarders due to limitations in their power structure layout. Their braking systems rely solely on regenerative braking and mechanical braking. Regenerative braking fails when the drive motor control system malfunctions, leaving the entire vehicle's braking load to be handled by mechanical braking. Under conditions requiring continuous braking, such as downhill driving, mechanical braking is prone to overheating and failure, potentially leading to safety accidents. Furthermore, high-intensity use can accelerate wear and tear. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0004] Therefore, the first aspect of the present invention provides a braking method for a mining car.

[0005] A second aspect of the present invention provides a braking device for a mining car.

[0006] A third aspect of the present invention provides another braking device for a mining car.

[0007] The fourth aspect of this application proposes a readable storage medium.

[0008] In view of the above, a first aspect of the present invention provides a braking method for a mining car, the mining car including a drive motor, a braking resistor, a high-voltage circuit, a temperature detection module, a mechanical braking mechanism, and a drive motor control system. The method includes: acquiring slope data, battery power data, and status data of the drive motor control system; determining that the mining car is in a redundant braking working state when the battery power data meets a preset power condition, the slope data meets a downhill determination condition, and the status data of the drive motor control system indicates a fault; in the redundant braking working state, determining the required operating power of the braking resistor based on the fault status of the drive motor control system; controlling the braking resistor to connect to the high-voltage circuit based on the operating power of the braking resistor; controlling the temperature detection module to acquire temperature detection data of the braking resistor; and reducing the operating power of the braking resistor and controlling the mechanical braking mechanism to intervene in braking when the temperature detection data reaches a temperature threshold.

[0009] This application addresses the core technical challenges of transversely arranged power structures and electric axle / electric axle mining cars without drive shafts (where retarders cannot be installed). It proposes a multi-mode braking system that implements all steps of the aforementioned mining car braking methods, filling the gap in braking redundancy during high-risk downhill conditions when regenerative braking fails (drive motor control system malfunction). It replaces the retarder to distribute braking force, avoiding the mining car's reliance solely on mechanical braking. Secondly, it achieves precise matching of braking resistor power, adapting braking force according to the drive motor control system malfunction, ensuring the redundant braking effect matches the mining car's operating conditions. Thirdly, it provides dual protection for both the braking resistor's hardware and the mining car's braking safety. Through temperature detection and high-temperature linkage with mechanical braking, it prevents overheating damage to the braking resistor and avoids insufficient braking effect due to reduced braking resistor power, thus reducing the intensity of mechanical braking use and extending the service life of the mechanical braking mechanism.

[0010] In some technical solutions of this application, the braking method of the mine car further includes: determining that the mine car is in a normal braking working state when the battery power data, slope data and drive motor control system status data do not simultaneously meet the determination conditions for redundant braking working state; and determining the braking mode of the mine car based on the battery power data and drive motor control system status data when the mine car is in a normal braking working state, the braking mode includes electro-regenerative braking mode, braking resistor braking mode and mechanical braking mode.

[0011] In some technical solutions of this application, in the regenerative braking mode, the drive motor is controlled to enter the power generation state.

[0012] In some technical solutions of this application, in the braking resistor braking mode, the braking resistor is controlled to be connected to the high-voltage circuit.

[0013] In some technical solutions of this application, in mechanical braking mode, the mechanical braking mechanism is controlled to engage braking, and the drive motor is controlled to enter the power generation state and / or the braking resistor is controlled to connect to the high-voltage circuit.

[0014] In some technical solutions of this application, the operating power of the braking resistor required for braking is determined according to the fault state of the drive motor control system, including: when the drive motor control system is in a single-module fault, the braking resistor is controlled to operate at a limited power, which is the regenerative braking power matched to a single drive motor; when the drive motor control system is in a dual-module fault, the braking resistor is controlled to operate at full load power.

[0015] In some technical solutions of this application, reducing the operating power of the braking resistor includes: controlling the on / off duty cycle of the power transistor in the high-voltage circuit to reduce the operating power of the braking resistor; wherein the power transistor is a high-voltage resistant insulated-gate bipolar transistor and is connected in series with the braking resistor in the high-voltage circuit.

[0016] A second aspect of the present invention provides a braking device for a mining car. The device is applied to a mining car, which includes a drive motor, a braking resistor, a high-voltage circuit, a temperature detection module, a mechanical braking mechanism, and a drive motor control system. The device includes: a data acquisition unit, a state determination unit, a power determination unit, a circuit control unit, a temperature detection unit, and a braking control unit. The data acquisition unit is used to acquire slope data, battery power data, and state data of the drive motor control system of the mining car. The state determination unit is used to determine that the mining car is in a redundant braking working state when the battery power data meets a preset power condition, the slope data meets a downhill determination condition, and the state data of the drive motor control system shows a fault. The power determination unit is used to determine the working power of the braking resistor required for braking in the redundant braking working state based on the fault state of the drive motor control system. The circuit control unit is used to control the braking resistor to connect to the high-voltage circuit based on the working power of the braking resistor. The temperature detection unit is used to control the temperature detection module to acquire temperature detection data of the braking resistor. The braking control unit is used to reduce the working power of the braking resistor and control the mechanical braking mechanism to intervene in braking when the temperature detection data reaches a temperature threshold.

[0017] A third aspect of the present invention provides a braking device for a mine car, comprising: a processor and a memory, wherein the memory stores a program or instructions, and the processor, when executing the program or instructions in the memory, implements the steps of the mine car braking method as described in any of the above-described technical solutions. Therefore, the braking device for the mine car possesses all the beneficial effects of the mine car braking method as described in any of the above-described technical solutions.

[0018] A fourth aspect of the present invention provides a readable storage medium storing a program or instructions, which, when executed by a processor, implement the steps of the mine car braking method as described in any of the above-described technical solutions. Therefore, the readable storage medium possesses all the beneficial effects of the mine car braking method as described in any of the above-described technical solutions.

[0019] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0021] Figure 1 This is one of the schematic flowcharts of a braking method for a mining car according to an embodiment of the present invention;

[0022] Figure 2 This is a second schematic flowchart of a braking method for a mine car according to an embodiment of the present invention;

[0023] Figure 3 One of the circuit diagrams of the braking system of a mine car according to an embodiment of the present invention;

[0024] Figure 4 A second circuit diagram of the braking system of a mine car according to an embodiment of the present invention;

[0025] Figure 5 This is a third circuit diagram of the braking system of a mine car according to an embodiment of the present invention;

[0026] Figure 6 The fourth circuit diagram of the braking system of a mine car according to an embodiment of the present invention;

[0027] Figure 7 The fifth is a circuit diagram of the braking system of a mine car according to an embodiment of the present invention;

[0028] Figure 8 Sixth circuit diagram of the braking system of a mine car according to an embodiment of the present invention;

[0029] Figure 9 This is one of the schematic block diagrams of a braking device for a mine car according to an embodiment of the present invention;

[0030] Figure 10 This is a second schematic block diagram of a braking device for a mine car according to an embodiment of the present invention. Detailed Implementation

[0031] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0032] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0033] The following reference Figures 1 to 10 A braking method, apparatus, and readable storage medium for a mining car according to some embodiments of the present invention are described.

[0034] like Figure 1 As shown, an embodiment of this application provides a braking method for a mining car. The mining car includes a drive motor, a braking resistor, a high-voltage circuit, a temperature detection module, a mechanical braking mechanism, and a drive motor control system. The method includes the following steps:

[0035] Step 102: Obtain the slope data, battery power data, and status data of the drive motor control system of the mining truck;

[0036] Step 104: When the battery power data meets the preset power conditions, the slope data meets the downhill judgment conditions, and the status data of the drive motor control system shows a fault, the mine car is determined to be in a redundant braking working state.

[0037] Step 106: Under redundant braking operation, determine the operating power of the braking resistor required for braking based on the fault status of the drive motor control system.

[0038] Step 108: Based on the operating power of the braking resistor, control the connection of the braking resistor to the high-voltage circuit;

[0039] Step 110: Control the temperature detection module to acquire the temperature detection data of the braking resistor;

[0040] Step 112: When the temperature detection data reaches the temperature threshold, reduce the working power of the braking resistor and control the mechanical braking mechanism to intervene in braking.

[0041] In this application, the drive motor is the core actuator providing power for the mine car's movement. It can also switch to a generator state during braking, converting the mine car's mechanical energy into electrical energy. It is the core component of regenerative braking, essentially the mine car's main drive motor, adapting to the mine car's high-power, high-torque driving and braking requirements. The braking resistor is an energy-consuming component connected to the mine car's high-voltage circuit. Based on Joule's law, it converts electrical energy into heat energy, consuming the DC high-voltage electricity generated by the drive motor. This heat energy replaces the retarder to distribute braking force, making it the core component in the redundant braking and conventional braking modes of this application. The high-voltage circuit is the circuit system in the mine car that carries high-voltage electrical transmission and control. One end is connected to the bus capacitor of the drive motor control system, and the other end is connected to the braking resistor. It is the hardware carrier for realizing the on / off control and power regulation of the braking resistor, integrating components such as power transistors, contactors, and fuses. The temperature detection module is a temperature sensing component closely attached to the braking resistor. It can collect the operating temperature of the braking resistor in real time, converting the temperature signal into an electrical signal and transmitting it to the mine car's overall controller. It is the sensing component for the high-temperature protection of the braking resistor. The mechanical braking mechanism is the component of the mining car that achieves braking through mechanical friction. It dissipates the mechanical energy of the mining car through friction between the brake pads and the brake disc, serving as the final guarantee for braking. It is the core execution component for the redundant braking high-temperature linkage and conventional braking mechanical mode of this application. The drive motor control system is a control unit (MCU) used to control the start, operation, power generation, and stop of the drive motor. It can receive commands from the vehicle controller and report its own fault status. One control module corresponds to one drive motor, and the mining car can be configured with one or two modules. The gradient data is the road gradient information collected by the onboard gradient sensor, including the gradient magnitude and direction. It is the core data for determining whether the mining car is in a downhill condition. Specifically, the downhill determination threshold can be a gradient less than 20°. The battery charge data is the remaining charge information of the mining car's power battery, collected by the battery management system (BMS). It is the core data for determining whether the regenerative braking is ready to operate. The preset charge condition is preferably a remaining charge ≤90% (not reaching the full charge threshold). The status data refers to the self-operating status information fed back by the drive motor control system to the vehicle controller, including two states: normal operation and fault existence. The fault state can be further subdivided into single-module fault and dual-module fault. The preset battery charge condition is the criterion for determining that the remaining charge of the mine car's power battery has not reached the full charge threshold. This is a prerequisite for the normal operation of regenerative braking and one of the triggering conditions for redundant braking operation. It is calibrated by the vehicle controller based on the power battery performance. The downhill judgment condition is the criterion for determining that the mine car's driving gradient reaches the preset downhill threshold. This is one of the triggering conditions for redundant braking operation and is calibrated by the vehicle controller based on the mine area road conditions and the mine car's braking performance. The redundant braking operation state is the braking state of the mine car when the battery charge meets the preset condition, it is in a downhill condition, and the drive motor control system is faulty. This is the high-risk emergency braking state designed for mine cars without retarders in this application, with the braking resistor as the core actuator.The fault status refers to the number of drive motor control systems in the mine car that are in a fault state, categorized as single-module faults and dual-module faults. It is the core basis for matching the operating power of the braking resistor. Operating power is the actual power consumed by the braking resistor after it is connected to the high-voltage circuit, determined by the vehicle controller based on the fault status of the drive motor control system, and is divided into limited power and full-load power. The drive motor control system includes at least the drive motor and its control system. Fault status includes any fault affecting regenerative braking, specifically motor faults, controller faults, wiring faults, and system faults.

[0042] Temperature detection data refers to the real-time operating temperature of the braking resistor collected by the temperature detection module. This data is crucial for determining whether the braking resistor is operating at a high temperature. The temperature threshold is the maximum permissible operating temperature of the braking resistor, calibrated by its material and performance. It is the critical value that triggers the braking resistor to reduce power and engage the mechanical braking mechanism.

[0043] This application addresses the core technical challenges of transversely arranged power structures and electric axle / electric axle mining cars without drive shafts (where retarders cannot be installed). It proposes a multi-mode braking system that implements all steps of the aforementioned mining car braking methods, filling the gap in braking redundancy during high-risk downhill conditions when regenerative braking fails (drive motor control system malfunction). It replaces the retarder to distribute braking force, avoiding the mining car's reliance solely on mechanical braking. Secondly, it achieves precise matching of braking resistor power, adapting braking force according to the drive motor control system malfunction, ensuring the redundant braking effect matches the mining car's operating conditions. Thirdly, it provides dual protection for both the braking resistor's hardware and the mining car's braking safety. Through temperature detection and high-temperature linkage with mechanical braking, it prevents overheating damage to the braking resistor and avoids insufficient braking effect due to reduced braking resistor power, thus reducing the intensity of mechanical braking use and extending the service life of the mechanical braking mechanism.

[0044] First, the vehicle controller of the mining truck acquires slope data, battery power data, and drive motor control system status data through onboard sensors, the battery management system, and the drive motor control system, respectively, to complete the data acquisition for determining the redundant braking working state. Second, the vehicle controller performs logical judgments on the three types of data. When the battery power data meets the preset power condition (regenerative braking could work), the slope data meets the downhill judgment condition (the mining truck is in a high-risk condition of descending a long slope), and the drive motor control system status data shows a fault (regenerative braking failure), the vehicle controller determines that the mining truck has entered the redundant braking working state. This judgment process accurately identifies the high-risk failure condition of the mining truck's braking system, providing a basis for subsequent braking control. Third, based on the fault status of the drive motor control system and the regenerative braking power of a single drive motor, the vehicle controller determines the working power of the braking resistor. If it is a single-module fault, a limited power is matched; if it is a dual-module fault, full-load power is matched. This process achieves precise matching between the braking resistor power and the missing regenerative braking force of the mining truck, ensuring braking effectiveness. Then, the vehicle controller sends a control command to the high-voltage circuit, controlling the braking resistor to connect to the high-voltage circuit based on the determined operating power. The braking resistor begins to consume the DC high-voltage electricity generated by the drive motor, replacing the retarder to distribute braking force and filling the braking gap after the failure of the regenerative braking. This avoids the mine car relying solely on mechanical braking, achieving the first layer of braking safety protection. Simultaneously, the vehicle controller controls the temperature detection module to acquire the temperature data of the braking resistor in real time, continuously monitoring its operating status. Finally, when the temperature data reaches the temperature threshold, the vehicle controller immediately sends a power reduction command to the high-voltage circuit, reducing the operating power of the braking resistor, decreasing its heat generation, and preventing damage due to overheating, thus achieving hardware protection for the braking resistor. At the same time, the vehicle controller sends an intervention command to the mechanical braking mechanism, controlling it to intervene and take on part of the braking force, ensuring the mine car's braking effect does not diminish, achieving the second layer of braking safety protection. This solves the problem of insufficient braking redundancy in mine cars without retarders, achieves dual protection of braking components and mine car braking safety, and significantly reduces the usage intensity of the mechanical braking mechanism, extending its service life.

[0045] In some embodiments of this application, the braking method for the mine car further includes: determining that the mine car is in a normal braking state when the battery power data, slope data, and drive motor control system status data do not simultaneously meet the determination conditions for redundant braking operation; and determining the braking mode of the mine car based on the brake pedal opening data, battery power data, and drive motor control system status data when the mine car is in a normal braking state, including an electro-regenerative braking mode, a braking resistor braking mode, and a mechanical braking mode.

[0046] In the above embodiments, the conventional braking state is the braking state of the mining truck when the battery power data, gradient data, and drive motor control system status data do not simultaneously meet the redundancy braking state determination conditions. This is the primary braking state during daily operation and includes three braking modes: regenerative braking, reluctance braking, and mechanical braking. Brake pedal opening data, collected by the brake pedal position sensor, is the travel information of the driver's brake pedal. It is one of the core data points for determining the braking mode under conventional braking conditions. Specifically, non-mechanical braking is prioritized when the pedal opening is ≤70%, and mechanical braking is activated when the opening is >70%. The braking mode is the braking method selected by the mining truck under conventional braking conditions based on driving conditions and braking requirements. It includes regenerative braking, reluctance braking, and mechanical braking. These three modes dynamically switch based on brake pedal opening data, battery power data, and drive motor control system status data. Regenerative braking is the braking mode under conventional braking conditions that uses the drive motor to generate electricity, converting the mining truck's mechanical energy into electrical energy to recharge the power battery. It is the most energy-efficient braking mode. The braking resistor braking mode is a braking mode that relies on the energy dissipation of the braking resistor under normal braking conditions. It consumes the high-voltage DC electricity generated by the drive motor and serves as an alternative braking mode when the electro-regenerative braking mode is not working. The mechanical braking mode is a braking mode that relies on mechanical friction under normal braking conditions. It is the last resort for the conventional braking of the mine car and can be used in conjunction with the electro-regenerative and braking resistor braking modes.

[0047] First, after collecting gradient data, battery charge data, and drive motor control system status data, the vehicle controller of the mining truck first determines the redundant braking operating state. When the three types of data do not simultaneously meet the redundant braking determination conditions, the vehicle controller determines that the mining truck has entered the normal braking operating state. This determination logic achieves comprehensive coverage of the mining truck's braking conditions, ensuring the continuity of braking control. Second, the vehicle controller collects brake pedal opening data through the brake pedal position sensor, and combines it with the collected battery charge data and drive motor control system status data to form three core data for determining the normal braking mode. Then, the vehicle controller performs a comprehensive logical determination on the three types of data according to preset determination rules. When the brake pedal opening is small, the battery charge is below the full charge threshold, and the drive motor control system is normal, it is determined to be in regenerative braking mode. When the brake pedal opening is small, the battery charge is at the full charge threshold, or the drive motor control system is faulty, it is determined to be in regenerative braking mode. When the brake pedal opening is large, it is determined to be in mechanical braking mode. This process realizes intelligent determination and switching of braking modes, maximizing the selection of energy-saving non-mechanical braking modes. Finally, the vehicle controller sends control commands to the corresponding actuators based on the determined braking mode, and activates the corresponding braking mode. The whole process realizes intelligent and efficient braking control under normal braking conditions, which not only ensures the braking effect, but also reduces the use of mechanical braking, achieving the dual effects of energy saving and wear reduction.

[0048] The braking method and device for mine cars disclosed in this application effectively solves the problem of insufficient braking redundancy in mine cars where space constraints prevent the installation of retarders through the coordinated and precise control of components such as the drive motor, braking resistor, and high-voltage circuit. The braking resistor is compatible with the DC high-voltage power supply of the high-voltage circuit, has a wide applicable voltage range, and does not require stringent layout conditions; it can be installed in an area with good heat dissipation, significantly improving the flexibility of the overall vehicle layout. In redundant braking operation, the working power of the braking resistor is matched according to the number of faults in the drive motor control system. In the event of a single module failure, limited power intervention occurs; in the event of a dual module failure, full-load power intervention occurs, precisely compensating for the missing regenerative braking force. At the same time, the braking resistor directly dissipates energy after the drive motor generates and rectifies the power and before the energy is recharged to the power battery, reducing the number of charge and discharge cycles of the power battery and effectively extending the service life of the power battery. The temperature detection module monitors the braking resistor temperature in real time. When the temperature reaches a threshold, the power is reduced and the mechanical braking mechanism is activated. This achieves both hardware protection for the braking resistor and ensures the continuity of braking effect. Simultaneously, the energy consumption of the braking resistor effectively prevents the high-voltage circuit bus voltage from rising uncontrollably, maintaining the bus voltage stable near the rated value and avoiding overvoltage damage to high-voltage components, thus protecting the high-voltage circuit and related devices. Under normal braking conditions, the braking mode is dynamically switched according to the priority of regenerative braking, braking resistor braking, and mechanical braking, maximizing the use of non-contact braking, significantly reducing the frequency of use and friction intensity of the mechanical braking mechanism, reducing its wear, and extending its service life. Furthermore, the braking resistor can be equipped with an air-cooled or liquid-cooled system. The heat absorbed by the liquid-cooled system can be recovered and reused for power battery heating or vehicle interior heating, achieving rational energy utilization. This application, through a dual redundancy design of hardware and control, not only compensates for the limitations of regenerative braking but also replaces the retarder to improve the braking force distribution of the mine car braking system, significantly improving the performance, reliability, and safety of the mine car braking system. This allows the mine car to achieve smooth and safe braking under various working conditions, combining braking energy saving and economic efficiency.

[0049] In one embodiment, the preset rule for determining the braking mode in normal braking operation is as follows: When the driver depresses the brake pedal, the brake pedal opening data is ≤70%, the battery charge data is ≤90%, and the drive motor control system status data is normal, the vehicle controller determines it to be in regenerative braking mode. When the driver depresses the brake pedal, the brake pedal opening data is ≤70%, the battery charge data is >90%, or the drive motor control system status data indicates a fault, the vehicle controller determines it to be in regenerative braking mode. When the driver depresses the brake pedal and the brake pedal opening data is >70%, the vehicle controller determines it to be in mechanical braking mode.

[0050] In some embodiments of this application, in the regenerative braking mode, the drive motor is controlled to enter the power generation state.

[0051] In the above embodiment, the power generation state is the working state in which the drive motor is disconnected from the power output state, the rotor rotates under the inertia of the mine car, and the mechanical energy of the mine car is converted into electrical energy through electromagnetic induction. This is the core working state of the electric regenerative braking mode, and the generated electrical energy can be recharged to the power battery.

[0052] When the mine car's overall controller determines that it is in regenerative braking mode under normal braking conditions, it immediately sends a power generation control command to the drive motor control system. Upon receiving the command, the drive motor control system adjusts the drive motor's operating mode, causing the drive motor to disengage from power output mode and enter power generation mode. The inertia of the mine car during travel drives the rotor of the drive motor to rotate. The drive motor converts the mine car's mechanical energy into electrical energy through electromagnetic induction. The generated electrical energy is transmitted to the power battery through a high-voltage circuit, completing energy recovery. Simultaneously, the counter-torque generated by the drive motor during power generation acts on the mine car's wheels, achieving braking and deceleration. The entire process requires no mechanical friction, achieving both braking and energy recovery while avoiding wear on mechanical braking mechanisms, thus achieving the dual benefits of braking and energy saving.

[0053] In one embodiment, the regenerative braking mode is implemented as follows: the vehicle controller (VCU) sends a negative torque request command to the drive motor control system. Upon receiving the command, the drive motor control system controls the drive motor to output torque in the opposite direction of travel, causing the drive motor to enter a generator state. The generated three-phase AC power is rectified into high-voltage DC power by the drive motor control system, regulated by the bus capacitor, and then recharged to the power battery. In another embodiment, the regenerative braking mode is implemented as follows: the vehicle controller (VCU) sends a negative torque request command to the drive motor control system. Upon receiving the command, the drive motor control system controls the drive motor to output torque in the opposite direction of rotation, causing the drive motor to enter a generator state, converting the mechanical energy of the vehicle's operation into electrical energy.

[0054] The core prerequisite for the drive motor to enter the generator state is that the direction of the motor's output torque is opposite to the direction of rotation, rather than controlling the drive motor to reverse. Specifically, this includes two operating conditions (with the forward movement of the entire vehicle defined as the positive direction):

[0055] When the motor rotates forward (the vehicle moves forward), the vehicle controller sends a negative torque request command to the drive motor control system, controlling the drive motor to output a negative torque that opposes forward rotation, thereby realizing regenerative braking and power generation during forward movement.

[0056] When the motor reverses (the vehicle is reversing), the vehicle controller sends a positive torque request command to the drive motor control system, controlling the drive motor to output a positive torque that opposes the reverse rotation, thereby realizing regenerative braking and power generation during the reversing process.

[0057] The three-phase AC power generated by the drive motor is rectified into DC high voltage by the drive motor control system, and then recharged to the power battery after being stabilized by the bus capacitor, thus completing braking and energy recovery.

[0058] In some embodiments of this application, in the braking resistor braking mode, the braking resistor is controlled to be connected to the high-voltage circuit.

[0059] In the above embodiment, when the mine car's overall controller determines that it is in braking resistor braking mode under normal braking operation, it immediately sends a closing command to the contactor in the high-voltage circuit. Upon receiving the command, the contactor closes, connecting the braking resistor to the high-voltage circuit. Driven by the mine car's inertia, the drive motor enters a power generation state, generating high-voltage DC electricity which is transmitted to the braking resistor through the high-voltage circuit. The braking resistor, based on Joule's law, converts electrical energy into heat energy, consuming excess electrical energy. Simultaneously, the counter-torque generated by the drive motor and the energy consumption of the braking resistor work together to achieve braking and deceleration of the mine car. Throughout this process, the braking resistor consumes the excess electrical energy generated by the drive motor, preventing damage to the power battery due to overcharging and preventing excessively high bus voltage in the high-voltage circuit, thus protecting the mine car's high-voltage electrical components. It also achieves non-mechanical braking, reducing wear on the mechanical braking mechanism.

[0060] In one embodiment, the braking resistor braking mode is implemented as follows: the vehicle controller sends a closing command to the contactor in the high-voltage circuit and an enable command to the power transistor. After receiving the command, the power transistor is turned on, and the braking resistor is connected to the high-voltage circuit. The DC high-voltage electricity generated by the drive motor is transmitted to the braking resistor through the bus capacitor, contactor, and power transistor, and the braking resistor begins to consume energy.

[0061] In some embodiments of this application, in mechanical braking mode, the mechanical braking mechanism is controlled to engage braking, and the drive motor is controlled to enter the power generation state and / or the braking resistor is controlled to connect to the high-voltage circuit.

[0062] In the above embodiment, when the vehicle controller of the mining truck determines that it is in mechanical braking mode under normal braking operation, it immediately sends an intervention command to the mechanical braking mechanism. After receiving the command, the mechanical braking mechanism controls the brake pads to engage with the brake disc, generating braking force through mechanical friction to achieve braking and deceleration of the mining truck. Simultaneously, the vehicle controller determines whether to activate regenerative braking and / or regenerative braking based on battery power data and the status data of the drive motor control system. If the battery power is below the full charge threshold and the drive motor control system is normal, the drive motor is simultaneously controlled to enter generator mode, achieving regenerative braking assistance. If the battery power reaches the full charge threshold or the drive motor control system malfunctions, the braking resistor is simultaneously connected to the high-voltage circuit, achieving regenerative braking assistance. If both non-mechanical braking conditions are met, both regenerative braking and regenerative braking assistance are activated simultaneously. Assisted braking reduces the friction intensity of the mechanical braking mechanism and lowers its wear by generating counter-torque or dissipating energy to share part of the braking force. The entire process achieves coordinated operation of mechanical and non-mechanical braking, ensuring braking effect under high braking demand, reducing wear on the mechanical braking mechanism, and improving the smoothness of the braking process.

[0063] In one embodiment, when the brake pedal opening is greater than 70%, the vehicle controller activates the mechanical braking mechanism. Simultaneously, if the battery charge is ≤90% and the drive motor control system status is normal, the drive motor enters generator mode, with regenerative braking as a supplement. If the battery charge is greater than 90%, the braking resistor is connected to the high-voltage circuit, with regenerative braking as a supplement. These two auxiliary braking methods share the braking force, reducing the friction intensity of the mechanical braking mechanism by 30%-50%.

[0064] In some embodiments of this application, the operating power of the braking resistor required for braking is determined according to the fault state of the drive motor control system, including: when the drive motor control system is in a single-module fault, controlling the braking resistor to operate at a limited power, wherein the limited power is the regenerative braking power matched to a single drive motor; and when the drive motor control system is in a dual-module fault, controlling the braking resistor to operate at full load power.

[0065] In the above embodiments, a single-module failure refers to a failure where only one of the two drive motor control systems in the mine car is faulty, while the other is operating normally. In this case, the mine car still has some regenerative braking force. The limited power is the operating power of the braking resistor when the drive motor control system experiences a single-module failure; its value is equal to the regenerative braking power of a single drive motor, used to precisely match the missing regenerative braking force of the mine car. A double-module failure refers to a failure where both drive motor control systems in the mine car are faulty; in this case, the mine car completely loses its regenerative braking force. The full-load power is the maximum design power of the braking resistor, the operating power of the braking resistor when both drive motor control systems experience a double-module failure, used to completely replace the missing regenerative braking force of the mine car.

[0066] Once the mine car's overall controller determines that the mine car is in a redundant braking state, it first obtains the fault status of the drive motor control system and determines the fault type. If it is determined to be a single-module fault, it means that one drive motor control system of the mine car is still working normally and still has some regenerative braking force. The overall controller sets the operating power of the braking resistor to a limited power, which is consistent with the regenerative braking power of a single drive motor, precisely matching the missing portion of regenerative braking force of the mine car. If it is determined to be a dual-module fault, it means that the mine car has completely lost regenerative braking force. The overall controller sets the operating power of the braking resistor to full-load power, using the maximum braking force of the braking resistor to completely replace the regenerative braking. Then, the overall controller sends a control command to the high-voltage circuit according to the determined operating power, controlling the braking resistor to connect to the high-voltage circuit with the corresponding power. The braking resistor consumes electrical energy according to the matched power, providing precise braking force. The entire process achieves precise matching of the braking resistor power, ensuring braking effect while achieving energy-saving operation of the braking resistor and reducing heat generation.

[0067] In one embodiment, when a single drive motor control system fails, the vehicle controller's power transistor operates with a 50% duty cycle, and the braking resistor operates at 50% full-load power (limited power), which is consistent with the regenerative braking power of a single drive motor. When both drive motor control systems fail, the vehicle controller's power transistor operates with a 100% duty cycle, and the braking resistor operates at 100% full-load power, completely replacing the regenerative braking force.

[0068] In some embodiments of this application, reducing the operating power of the braking resistor includes: controlling the on / off duty cycle of the power transistor in the high-voltage circuit to reduce the operating power of the braking resistor; wherein the power transistor is a high-voltage resistant insulated-gate bipolar transistor and is connected in series with the braking resistor in the high-voltage circuit.

[0069] In the above embodiments, the power transistor is a semiconductor device connected in series in the high-voltage circuit, used to control the on / off state of the braking resistor and regulate its power. It is the core control component of the high-voltage circuit. The duty cycle is the ratio of the power transistor's on-time to the total cycle time in one working cycle. It is a core parameter for adjusting the working power of the braking resistor; the higher the duty cycle, the greater the working power of the braking resistor. A high-voltage resistant insulated-gate bipolar transistor (IGBT) is a power transistor that combines the high input impedance of an insulated-gate field-effect transistor with the low conduction loss of a bipolar transistor. It can withstand the high voltage of the mine car's high-voltage circuit and is an optional type of power transistor in the high-voltage circuit of this application.

[0070] When the vehicle controller of the mining truck detects that the temperature data of the braking resistor has reached the temperature threshold, it initiates the braking resistor power reduction control process. First, the vehicle controller determines the required power reduction ratio based on the difference between the temperature data and the temperature threshold, and then calculates the corresponding duty cycle of the power transistor. Next, the vehicle controller sends a duty cycle control command to the power transistor in the high-voltage circuit. After receiving the command, the power transistor cycles through conduction and cutoff according to the set duty cycle. Since the power transistor and the braking resistor are connected in series in the high-voltage circuit, the conduction time of the power transistor determines the energization time of the braking resistor. A lower duty cycle reduces the energization time of the braking resistor, thereby reducing the actual operating power and heat generation. Throughout the process, the duty cycle of the power transistor can be smoothly adjusted, and the operating power of the braking resistor changes smoothly accordingly, avoiding braking force fluctuations caused by sudden power changes and ensuring the stability of the mining truck's braking process. Simultaneously, the high-voltage resistant insulated-gate bipolar transistor can stably withstand the high voltage of the mining truck's high-voltage circuit, ensuring the accuracy of power regulation and the reliability of the high-voltage circuit.

[0071] In one embodiment, when the temperature detection data of the braking resistor reaches the temperature threshold (e.g., 120°C), the vehicle controller adjusts the duty cycle of the power transistor from 100% to 30%-50%, thereby reducing the operating power of the braking resistor to 30%-50% of the full load power, significantly reducing heat generation, and ensuring that the temperature of the braking resistor gradually decreases. This embodiment clearly defines the specific duty cycle adjustment range for power reduction, enabling those skilled in the art to implement it directly.

[0072] like Figure 2 As shown, the braking method of this application further includes the following steps:

[0073] Step 202: Determine whether the brake pedal is responding with a high level and whether the brake pedal opening is less than or equal to 70%. If yes, proceed to step 204; if no, proceed to step 210.

[0074] Step 204: Is the slope less than -20 degrees and does it meet the redundancy control requirements? If yes, proceed to step 212; if no, proceed to step 206.

[0075] Step 206: Is the mine car status SOC less than or equal to 90% or a motor system fault? If yes, proceed to step 208; if no, proceed to step 212.

[0076] Step 208: Is the slope less than -20 degrees and does it meet the redundancy control requirements? If yes, proceed to step 212; if no, proceed to step 214.

[0077] Step 210: Braking resistor braking, electro-regenerative braking, mechanical braking;

[0078] Step 212, braking with braking resistor;

[0079] Step 214, regenerative braking.

[0080] Here, SOC refers to the battery capacity.

[0081] like Figure 3 As shown, Figure 3This diagram illustrates the basic design of the high-voltage circuit for the braking resistor. The core of this application integrates the high-voltage circuit into the drive motor control system (i.e., MCU1 and MCU2) or a multi-functional controller. The core hardware involved includes the drive motor control system (MCU), the main drive motors (TM, i.e., TM1 and TM2), the bus capacitor C, the braking resistor, the contactor, the fuse, the power transistor VT, and the freewheeling diode VD. Specifically, the drive motor control system is the core unit controlling the operation and power generation of the main drive motor. The mine car is equipped with dual-module adapters for dual main drive motors and is the core control component for regenerative braking. The main drive motor, i.e., the drive motor, can enter a power generation state during the braking phase to convert mechanical energy into electrical energy. The bus capacitor C is located on the DC bus of the drive motor control system to stabilize the bus voltage and reduce voltage fluctuations. The braking resistor is an energy-consuming component connected to the high-voltage circuit. Based on Joule's law, it consumes the DC high-voltage electricity generated by the main drive motor and is the core execution component for redundant braking and braking resistor braking modes. The contactor is the on / off switch for the high-voltage circuit, receiving commands from the vehicle controller (VCU) to connect and disconnect the braking resistor. The fuse is an overcurrent protection component for the high-voltage circuit. It melts in the event of overcurrent or short circuit, protecting the entire high-voltage circuit and related hardware. The power transistor VT can be a high-voltage resistant insulated-gate bipolar transistor (IGBT), connected in series with the braking resistor in the high-voltage circuit. It is the core component for power regulation, and the operating power of the braking resistor can be adjusted by the duty cycle. The freewheeling diode VD is connected in reverse parallel with the power transistor VT, forming a freewheeling circuit at the moment the power transistor is turned off. This dissipates the delayed current caused by Lenz's law, preventing damage to the power transistor due to overvoltage. The specific connection relationship of each hardware component is as follows: power is drawn from the positive and negative terminals of the bus capacitor C of the drive motor control system, connected in series with the contactor, fuse, and power transistor VT, and then connected to one end of the braking resistor. The other end of the braking resistor is connected to the negative terminal of the bus capacitor C, forming a complete high-voltage power supply and control circuit. The freewheeling diode VD is connected in parallel across the power transistor VT, with its anode connected to the connection between the power transistor and the braking resistor, and its cathode connected to the connection between the power transistor and the fuse. The above circuit is linked to the control scheme of the braking method for the mine car described in this application. Specifically, when the mine car is determined to enter a redundant braking state, the vehicle controller determines the working power of the braking resistor based on the fault status, sends a closing command to the contactor, and sends an enable command with the corresponding duty cycle to the power transistor VT. The power transistor VT conducts according to the command, and the braking resistor is connected to the high-voltage circuit with the set power, completing the execution of redundant braking. When the braking resistor temperature reaches a threshold and power reduction is required, the vehicle controller adjusts the on / off duty cycle of the power transistor VT to reduce the actual working power of the braking resistor, achieving high-temperature protection. U1, V1, W1, U2, V2, and W2 are all three-phase terminals of the main drive motor.Meanwhile, the braking resistor in the above circuit draws power directly from the bus of the drive motor control system, consuming the DC high-voltage power after rectification by the main drive motor. The energy consumption is completed before the power energy is returned to the power battery, which not only avoids the unlimited rise of the bus voltage and protects the high-voltage components, but also reduces the number of charge and discharge cycles of the power battery and extends the life of the power battery.

[0082] like Figure 4 As shown, Figure 4 This is another core integrated form of the braking resistor high-voltage circuit, integrating the high-voltage circuit into the vehicle's high-voltage distribution box (BDU, or high-voltage box for short). Its hardware composition is similar to... Figure 3 The hardware is consistent with the original, including core components such as contactors, fuses, power transistors VT, freewheeling diodes VD, and braking resistors. This embodiment changes the integration location and power supply method of the high-voltage circuit, making it an adaptable application of the control scheme for the braking method of the mine car in this application under different hardware integration forms. The hardware connection relationship of the circuit is as follows: power is drawn from the high-voltage bus of the vehicle's high-voltage box, and then connected in series with the contactor, fuse, and power transistor VT to one end of the braking resistor. The other end of the braking resistor is connected to the negative bus of the vehicle's high-voltage box. The freewheeling diode VD is still connected in reverse parallel with the power transistor VT, forming a complete high-voltage circuit. The generator end of the drive motor control system is connected to the high-voltage bus of the vehicle's high-voltage box through a high-voltage wiring harness. The electrical energy generated by the main drive motor is transmitted to the vehicle's high-voltage box, and then the high-voltage circuit supplies power to the braking resistor. The above integration method is identical to the control logic of the mine car's braking method, differing only slightly in the transmission path of the control commands. In one embodiment, the vehicle controller sends control commands to the power transistor VT and contactor within the vehicle's high-voltage box to achieve the connection and power adjustment of the braking resistor. This also enables power matching and execution for redundant braking, as well as high-temperature power reduction control of the braking resistor. Compared to... Figure 3 This design integrates the high-voltage circuit into the vehicle's high-voltage box, facilitating centralized power distribution and management of the mine truck's high-voltage system. It adapts to the modular layout requirements of mine trucks for high-voltage components, and the braking resistor's placement is more flexible. It only needs to be connected to the vehicle's high-voltage box via a high-voltage wiring harness, without relying on the drive motor control system, making it more suitable for the spatial layout of the mine truck chassis. Simultaneously, the above circuit also achieves the design of the braking resistor dissipating energy before the power battery is charged, effectively maintaining the stability of the vehicle's bus voltage and solving the problem of high voltage damaging high-voltage components.

[0083] like Figure 5 As shown, Figure 5 Is Figure 3 The expanded design, with the addition of a pre-charging circuit, fundamentally addresses the issue of high-current surges impacting the hardware during high-voltage circuit power-on, providing more reliable hardware support for the control scheme of the mine car's braking method. Figure 3Based on the existing hardware, two new hardware components are added: a pre-charge contactor K1 and a pre-charge resistor R1. The pre-charge contactor K1 is the on / off switch for the pre-charge circuit, connected in parallel with the main contactor, and receives commands from the vehicle controller to start and stop the pre-charge circuit. The pre-charge resistor R1 is a current-limiting resistor, connected in series in the pre-charge circuit, used to limit the current during the pre-charge process and prevent instantaneous large currents from impacting capacitive components in the high-voltage circuit. The hardware connection relationship of the circuit is as follows: Figure 3 Based on the existing high-voltage circuit, the pre-charge contactor K1 and pre-charge resistor R1 are connected in series and then in parallel across the two ends of the main contactor. One end of the pre-charge circuit is connected to the input terminal of the main contactor (between the positive terminal of the bus capacitor C and the contactor), and the other end is connected to the output terminal of the main contactor (between the contactor and the fuse). The remaining hardware connections are the same as those in the circuit. Figure 3 The circuit is completely consistent with the mine car's braking method. Before the braking resistor is connected to the high-voltage circuit, a pre-charging process for energizing the high-voltage circuit is added: the vehicle controller first controls the main contactor to open and the pre-charging contactor K1 to close. The high-voltage current, after being current-limited by the pre-charging resistor R1, pre-charges the bus capacitor C, braking resistor, and other capacitive components with a small current. After the high-voltage circuit voltage stabilizes, the pre-charging contactor K1 is then controlled to open and the main contactor to close, completing the normal energization of the high-voltage circuit. Subsequently, the braking resistor is controlled to operate at the set power, and then power adjustment is completed. The addition of the pre-charging circuit avoids the impact of the large current at the moment of high-voltage circuit energization on hardware such as the power transistor VT, contactor, and bus capacitor C, reducing electrical stress on the hardware, extending the service life of each component in the high-voltage circuit, and further improving the hardware reliability of the braking system during execution. U1, V1, W1, U2, V2, and W2 are all three-phase terminals of the main drive motor.

[0084] like Figure 6 As shown, the braking resistor power supply and control circuit (two power transistors in parallel, designed within the motor controller or multi-function controller). Figure 6 Is Figure 3 Based on the existing design, this paper extends the configuration of the power transistors by using a parallel connection of two power transistors to meet the braking requirements of mine cars with high-power braking resistors and high operating currents. This is an important extension of the power transistor structure in this application. Figure 3 Based on the existing hardware, the single power transistor VT is replaced with two power transistors VT1 and VT2 connected in parallel, along with two freewheeling diodes VD1 and VD2. The hardware specifications are as follows: Power transistors VT1 and VT2 are high-voltage resistant insulated-gate bipolar transistors (IGBTs) as described in this application, connected in parallel to share the large current in the high-voltage circuit. Freewheeling diodes VD1 and VD2 are connected in reverse parallel with power transistors VT1 and VT2, respectively, and their function is... Figure 3The freewheeling diode VD is the same as that used in the circuit, and is used to protect the corresponding power transistor. The hardware connection of this circuit is as follows: power is drawn from the positive terminal of the bus capacitor C, connected in series with a contactor and a fuse, and then connected to the positive terminals of the parallel-connected power transistors VT1 and VT2. The negative terminals of power transistors VT1 and VT2 are connected together and then connected to one end of the braking resistor. The other end of the braking resistor is connected to the negative terminal of the bus capacitor C. The freewheeling diodes VD1 and VD2 are connected in reverse parallel across the two ends of power transistors VT1 and VT2, respectively. The remaining connections are the same as those in the circuit. Figure 3 Consistent. This circuit is deeply adapted to the control scheme of this application: For the scenario in this application where the braking resistor needs to operate at full load power when the dual-drive motor control system fails, the parallel connection of the two power transistors can effectively share the large current, reduce the current carrying capacity of a single power transistor, prevent damage to the power transistor due to overcurrent, and ensure the stability of the braking resistor operating at full load power. During the power regulation process of this application, the vehicle controller sends synchronous on / off duty cycle commands to the two power transistors, causing them to turn on and off synchronously, achieving smooth regulation of the braking resistor's operating power. Simultaneously, temperature and current acquisition modules are installed on the power transistors to monitor their operating status in real time. If any abnormalities such as over-temperature or over-current occur, feedback is immediately sent to the vehicle controller, achieving real-time protection of the power transistors. Furthermore, the freewheeling diodes VD1 and VD2 in this design utilize existing diodes packaged in the drive motor control system, eliminating the need for additional modifications to the motor controller's power module, reducing hardware modification costs. Simultaneously, a freewheeling loop is formed at the moment the power transistors are turned off, consuming delayed current and further protecting the power transistors. Among them, U1, V1, W1, U2, V2, and W2 are all three-phase terminals of the main drive motor.

[0085] like Figure 7 As shown, Figure 7 Is Figure 6 This further optimizes the power transistor configuration scheme based on the existing design. The core utilizes a dual-transistor parallel design using IGBTs packaged in the drive motor control system. This eliminates the need for any modification to the IGBT package structure of the motor controller, maximizing hardware resource utilization. It represents an adaptation of the power transistor structure of this application to the hardware of a mining truck. The core hardware consists of multiple IGBTs already packaged in the drive motor control system. Two IGBTs, VT1 and VT2, are selected as the power transistors for the braking resistor. Other hardware includes contactors, fuses, braking resistors, etc. Figure 3 The above circuit's hardware connection is as follows: power is drawn from the positive terminal of the bus capacitor C, connected in series with a contactor and a fuse, and then connected to the positive terminals of the two selected IGBT transistors VT1 and VT2. The negative terminals of VT1 and VT2 are connected together and then connected to one end of the braking resistor. The other end of the braking resistor is connected to the negative terminal of the bus capacitor C, forming a complete high-voltage circuit. Unselected IGBT transistors do not participate in the control of the braking resistor. This circuit is consistent with the control logic of this application. Figure 6The vehicle controller sends synchronized control commands to VT1 and VT2 to connect the braking resistor and adjust its power, meeting the power matching requirements of redundant braking and the power reduction control requirements at high temperatures in this application. Its core advantage lies in its IGBT-based motor controller, eliminating the need for additional power transistors and significantly reducing the cost of modifying the braking system. Furthermore, the parallel connection of the two transistors still allows for high current sharing, adapting to the operating requirements of high-power braking resistors. The two sets of power transistors also form a mutual emergency relationship; if one set fails, the other can independently handle the power control of the braking resistor, ensuring the continuity of the braking system and further improving the reliability of the redundant braking scheme in this application. U1, V1, W1, U2, V2, and W2 are all three-phase terminals of the main drive motor.

[0086] like Figure 8 As shown, Figure 8 This is the highest redundancy design scheme for the power transistors. Similarly, based on the four IGBTs packaged in the drive motor control system, a diagonal redundancy backup configuration is used to design the power transistor structure, providing a higher level of hardware redundancy for the redundant braking scheme of this application. It represents a high-end extension of the power transistor structure of this application. Its core hardware consists of the four IGBTs VT1, VT2, VT3, and VT4 originally packaged in the drive motor control system. Other hardware includes contactors, fuses, braking resistors, etc. Figure 3The connections of the hardware are consistent. Two diagonal IGBT transistors, VT1 and VT4, are selected as the primary power transistors, while another diagonal pair, VT2 and VT3, serve as redundant backup power transistors. Power is drawn from the positive terminal of the bus capacitor C, connected in series with a contactor and a fuse, and then connected to the positive terminals of VT1 and VT4. The negative terminals of VT1 and VT2 are shared, as are the negative terminals of VT3 and VT4. The positive terminals of VT2 and VT3 are shared and then connected to one end of the braking resistor. The other end of the braking resistor is connected to the negative terminal of the bus capacitor C, forming a complete high-voltage circuit. Each of the four IGBT transistors is equipped with a freewheeling diode to protect its corresponding power transistor. This circuit forms a deep redundant linkage with the control scheme of this application: Under normal operating conditions, the vehicle controller sends control commands to the primary power transistors VT1 and VT4, matching the working power of the braking resistor according to the scheme of this application and adjusting the power according to the scheme of this application. The redundant backup power transistors VT2 and VT3 are in the off state. When the primary power transistor VT1 or VT4 fails and reports it to the vehicle controller, the vehicle controller immediately stops sending commands to the faulty power transistor and simultaneously sends synchronous control commands to the redundant backup power transistors VT2 and VT3. VT2 and VT3 quickly turn on, replacing the primary power transistor to complete the connection and power regulation of the braking resistor. The entire switching process is time-free, and the operating power of the braking resistor remains stable, ensuring the continuity of the redundant braking operation in this application and preventing braking failure due to power transistor failure. This design achieves cost-free redundant backup of the power transistors without additional modifications through the IGBT packaging of the motor controller, significantly improving the reliability of the high-voltage circuit. The diagonal power transistor configuration effectively distributes large currents, adapting to the high-power, high-reliability braking requirements of mining trucks. Together with the redundant braking scheme of this application, it forms dual redundancy in hardware and control, further enhancing the overall reliability of the mining truck braking system. U1, V1, W1, U2, V2, and W2 are all three-phase terminals of the main drive motor.

[0087] In one embodiment, this application also designs supporting expansion structures such as a cooling system and a high-temperature warning system for the braking resistor, which are linked with the redundant braking control scheme of this application to improve the overall design of the braking system and enhance the system's reliability and human-machine interaction. The cooling system is adapted to the braking resistor of this application and comes in two forms: air-cooled fan and liquid-cooled device. The air-cooled fan is directly installed on the heat dissipation fins of the braking resistor, with the power supply end connected to the low-voltage power supply of the mine car and the control end connected to the vehicle controller. Each braking resistor corresponds to one air-cooled fan. When this application controls the braking resistor to operate in the high-voltage circuit, the vehicle controller synchronously starts the air-cooled fan. The fan dissipates heat from the braking resistor at maximum power; the higher the temperature, the faster the fan speed. The fan shuts off after a delay when the braking resistor stops working. The liquid-cooled device arranges liquid-cooled pipes in the heat dissipation channel of the braking resistor, forming a circulation loop with the coolant pump and radiator. After the coolant absorbs the heat energy of the braking resistor, it can be used to heat the power battery in winter or to warm the mine car cab, achieving secondary utilization of heat energy. The cooling system design effectively controls the operating temperature of the braking resistor, providing temperature protection for the redundant braking scheme and power regulation scheme of this application, and preventing the braking resistor from degrading due to long-term high-temperature operation. The high-temperature warning system consists of a temperature detection module (the core sensing component in this application) and a mine car display terminal (vehicle instrument). The temperature detection module is closely attached to the braking resistor, collecting the temperature data of the braking resistor in real time and transmitting it to the vehicle controller. When this application determines that the temperature of the braking resistor has reached the threshold and controls the power reduction and mechanical braking intervention, the vehicle controller simultaneously sends a high-temperature warning command to the mine car display terminal. The display terminal provides feedback to the driver through text prompts (such as "braking resistor high temperature"), light prompts (flashing red fault light), and sound prompts (buzzer sound), reminding the driver to control the brake pedal opening and reduce the vehicle speed, so as to achieve smooth braking of the mine car in conjunction with the mechanical braking mechanism. This realizes human-machine interaction of the braking system's working status and further improves the safety of the redundant braking scheme of this application.

[0088] This application also clarifies the design principles for the power and quantity of braking resistors, adapting to the redundant braking and conventional braking operating states of this application. The power and quantity of the braking resistors are designed differently based on their functional positioning: if the braking resistor is used for conventional braking, participating in the daily braking force distribution of the mine car and replacing the conventional function of the retarder, then it is designed for full-load power, with the power and quantity determined according to the daily braking force distribution capacity of the mine car. If the power of a single unit is insufficient, multiple braking resistors can be connected in parallel. Figures 6 to 8 The high-power circuit design; if the braking resistor is only used as a backup for the redundant braking in this application, and only intervenes in high-risk operating conditions where the regenerative braking fails, then it is designed to compensate for the braking force of the mine car's missing retarder, without full-load power. Under the premise of ensuring braking redundancy, the braking resistor can be lightweighted and miniaturized, adapting to... Figures 3 to 5 The basic circuit design is as follows. Simultaneously, the number of braking control modules corresponds one-to-one with the number of braking resistors. Each braking resistor is controlled by an independent control module for power adjustment and on / off control, ensuring the accuracy and independence of braking resistor control. This matches the aforementioned circuit design, ensuring that the power and quantity design of the braking resistors perfectly meets the actual braking needs of the mine car, balancing the reliability and economy of the braking system.

[0089] like Figure 9 As shown in some embodiments of this application, a braking device 300 for a mining car is provided. The device is applied to a mining car, which includes a drive motor, a braking resistor, a high-voltage circuit, a temperature detection module, a mechanical braking mechanism, and a drive motor control system. The device includes: a data acquisition unit 310, a state determination unit 320, a power determination unit 330, a circuit control unit 340, a temperature detection unit 350, and a braking control unit 360. The data acquisition unit 310 is used to acquire the slope data, battery power data, and state data of the drive motor control system of the mining car. The state determination unit 320 is used to determine the braking device when the battery power data meets a preset power condition and the slope data meets a preset power condition. When the downhill judgment condition is met and the status data of the drive motor control system indicates a fault, the mine car is determined to be in a redundant braking state. The power determination unit 330 is used to determine the required braking power of the braking resistor based on the fault status of the drive motor control system in the redundant braking state. The circuit control unit 340 is used to control the braking resistor to connect to the high-voltage circuit based on the working power of the braking resistor. The temperature detection unit 350 is used to control the temperature detection module to acquire the temperature detection data of the braking resistor. The braking control unit 360 is used to reduce the working power of the braking resistor and control the mechanical braking mechanism to intervene in braking when the temperature detection data reaches the temperature threshold.

[0090] The braking device 300 of the mine car in this application achieves accurate determination and full-process control of the redundant braking working state of the mine car through the coordinated cooperation of various functional units: the data acquisition unit 310 provides comprehensive and accurate basic data for braking state determination; the state determination unit 320 can accurately lock high-risk braking conditions where the battery power is up to standard, the mine car is going downhill, and the drive motor control system is faulty; the power determination unit 330 can match the working power of the braking resistor according to the fault state of the drive motor control system to ensure that the braking force is adapted to the missing electro-regenerative braking force of the mine car; the circuit control unit 340 controls the braking resistor to connect to the high-voltage circuit according to the matched power, effectively filling the braking redundancy gap after the failure of the electro-regenerative braking of the mine car without a retarder; the temperature detection unit 350 obtains the braking resistor temperature data in real time to provide a basis for hardware protection; and the braking control unit 360 reduces the power in time and links the mechanical braking mechanism to intervene when the braking resistor is at high temperature, which not only realizes the high temperature protection of the braking resistor, but also ensures the continuous braking effect of the mine car. Therefore, the braking device of the mine car effectively solves the technical problems of insufficient braking redundancy and easy braking failure and severe wear caused by relying solely on mechanical braking in high-risk downhill conditions where regenerative braking fails, which are limited by space and cannot be equipped with retarders. It can also maintain the stability of the high-voltage circuit bus voltage of the mine car, protect high-voltage components from overvoltage damage, greatly improve the reliability and safety of the mine car braking system, and extend the service life of mechanical braking mechanism, power battery and other components.

[0091] like Figure 10 As shown, an embodiment of this application provides a braking device 400 for a mine car, including a processor 402 and a memory 404. The memory 404 stores a program or instructions. When the processor 402 executes the program or instructions in the memory 404, it implements the steps of the mine car braking method as described in any of the above embodiments. Therefore, the mine car braking device 400 possesses all the beneficial effects of the mine car braking method as described in any of the above embodiments.

[0092] Embodiments of this application provide a readable storage medium storing a program or instructions that, when executed by a processor, implement the steps of the mine car braking method as described in any of the above embodiments. Therefore, the readable storage medium possesses all the beneficial effects of the mine car braking method as described in any of the above embodiments.

[0093] In the claims, description, and accompanying drawings of this invention, the term "plural" refers to two or more. Unless otherwise explicitly defined, the terms "upper," "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and simplifying the descriptive process, and are not intended to indicate or imply that the device or element referred to must have the described specific orientation, or be constructed and operated in a specific orientation. Therefore, these descriptions should not be construed as limiting the invention. The terms "connected," "installed," "fixed," etc., should be interpreted broadly. For example, "connected" can be a fixed connection between multiple objects, a detachable connection between multiple objects, or an integral connection; it can be a direct connection between multiple objects or an indirect connection between multiple objects through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this invention can be understood based on the specific circumstances described above.

[0094] In the claims, description, and accompanying drawings of this invention, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In the claims, description, and accompanying drawings of this invention, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0095] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A braking method for a mine car, characterized in that, The mining car includes a drive motor, a braking resistor, a high-voltage circuit, a temperature detection module, a mechanical braking mechanism, and a drive motor control system. The method includes: Acquire data on the slope of the mining truck, battery level, and status of the drive motor control system; When the battery power data meets the preset power condition, the slope data meets the downhill determination condition, and the status data of the drive motor control system indicates a fault, the mine car is determined to be in a redundant braking working state. In the redundant braking operation state, the operating power of the braking resistor required for braking is determined according to the fault state of the drive motor control system. Based on the operating power of the braking resistor, control the connection of the braking resistor to the high-voltage circuit; The temperature detection module is controlled to acquire the temperature detection data of the braking resistor; When the temperature detection data reaches the temperature threshold, the operating power of the braking resistor is reduced, and the mechanical braking mechanism is controlled to engage braking.

2. The braking method for a mine car according to claim 1, characterized in that, Also includes: If the battery power data, the slope data, and the status data of the drive motor control system do not simultaneously meet the determination conditions for redundant braking operation, the mine car is determined to be in normal braking operation. When the mine car is in normal braking operation, the braking mode of the mine car is determined based on the battery power data and the status data of the drive motor control system. The braking mode includes electro-regenerative braking mode, braking resistor braking mode and mechanical braking mode.

3. The braking method for a mine car according to claim 2, characterized in that, In the regenerative braking mode, the drive motor is controlled to enter the power generation state.

4. The braking method for a mine car according to claim 2, characterized in that, In the braking resistor braking mode, the braking resistor is controlled to be connected to the high-voltage circuit.

5. The braking method for a mine car according to claim 2, characterized in that, In the mechanical braking mode, the mechanical braking mechanism is controlled to engage braking, and the drive motor is controlled to enter the power generation state and / or the braking resistor is controlled to connect to the high-voltage circuit.

6. The braking method for a mine car according to claim 1, characterized in that, Determining the operating power of the braking resistor required for braking based on the fault state of the drive motor control system includes: When the drive motor control system experiences a single-module failure, the braking resistor is controlled to operate at a limited power, which is the regenerative braking power matched to a single drive motor. When the drive motor control system experiences a dual-module failure, the braking resistor is controlled to operate at full load power.

7. The braking method for a mine car according to claim 1, characterized in that, The reduction of the operating power of the braking resistor includes: Controlling the on / off duty cycle of the power transistor in the high-voltage circuit reduces the operating power of the braking resistor; The power transistor is a high-voltage resistant insulated-gate bipolar transistor and is connected in series with the braking resistor in the high-voltage circuit.

8. A braking device for a mine car, characterized in that, The device is applied to a mining car, which includes a drive motor, a braking resistor, a high-voltage circuit, a temperature detection module, a mechanical braking mechanism, and a drive motor control system. The device includes: The data acquisition unit is used to acquire slope data, battery power data, and status data of the drive motor control system of the mining truck. The status determination unit is used to determine that the mine car is in a redundant braking working state when the battery power data meets the preset power condition, the slope data meets the downhill determination condition, and the status data of the drive motor control system is faulty. A power determination unit is used to determine the operating power of the braking resistor required for braking based on the fault state of the drive motor control system under the redundant braking operating state. A circuit control unit is used to control the connection of the braking resistor to a high-voltage circuit based on the operating power of the braking resistor. A temperature detection unit is used to control the temperature detection module to acquire temperature detection data of the braking resistor; The braking control unit is used to reduce the operating power of the braking resistor and control the mechanical braking mechanism to engage braking when the temperature detection data reaches the temperature threshold.

9. A braking device for a mine car, characterized in that, include: processor; A memory storing programs or instructions, wherein the processor, when executing the programs or instructions in the memory, implements the steps of the braking method for the mine car as described in any one of claims 1 to 7.

10. A readable storage medium, characterized in that, The readable storage medium stores a program or instructions that, when executed by a processor, implement the steps of the braking method for the mine car as described in any one of claims 1 to 7.

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