Distributed motor power system and control method

Abstract

The invention relates to the technical field of mining dump trucks, in particular to a distributed motor power system and a control method.The control method of the distributed motor power system comprises the steps that the running state of a vehicle is judged; when the driving state is constant-speed driving, a single-motor set driving strategy is executed; when the driving state is accelerated driving, a double-motor-set driving strategy is executed; when the driving state is deceleration driving, an energy recovery strategy is executed; and executing a power control strategy based on the battery pack electric quantity and the driving motor demand value. Distributed power arrangement is adopted in the hundred-ton mine truck for the first time, and when the hundred-ton mine truck runs at a constant speed, the truck does not need too large power and is driven by a single motor set; when the vehicle is driven in an accelerated mode, the vehicle needs large power, and double motor sets are adopted for driving. The two generator sets are adopted for range extending, the purchasing problem of a high-horsepower engine is effectively solved, the first wheel edge motor set and the second wheel edge motor set are matched for driving, and the power requirement of the hundred-ton mine truck is effectively met.

Description

Technical Field

[0001] The present application relates to the technical field of mining dump trucks, and in particular to a distributed motor power system and a control method. Background Art

[0002] Hundred-ton mining vehicles refer to mining transport vehicles with a carrying capacity of 100 tons or more. They are heavy-duty vehicles specially used for transportation in large engineering sites such as mines. Their powerful carrying capacity and high transportation efficiency make them an indispensable equipment in mining.

[0003] However, at present, 100-ton mining vehicles are generally centrally driven, such as Figure 2 As shown, a power system using a high-power engine to drive a generator set and an asynchronous drive motor in conjunction with a gearbox has a long procurement cycle and high cost. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems in the prior art or related art that the current 100-ton mining vehicles are generally centrally driven, using a high-power engine to drive a generator set and an asynchronous drive motor in conjunction with a gearbox, and that the power system has a long procurement cycle and high cost.

[0005] To this end, the present application provides a distributed motor power system control method, which adopts a distributed power layout for the first time in a 100-ton mining vehicle. By judging the driving state and executing the corresponding strategy, the first wheel side motor group and the second wheel side motor group can work in coordination. When driving at a constant speed, the vehicle does not need too much power and is driven by a single motor group; when accelerating, the vehicle requires greater power and is driven by a dual motor group. The use of two sets of generator sets for range extension effectively solves the problem of purchasing high-horsepower engines, and cooperates with the first wheel side motor group and the second wheel side motor group for driving, effectively meeting the power requirements of 100-ton mining vehicles.

[0006] The present application also provides a distributed motor power system including the above control method.

[0007] A distributed motor power system control method provided in accordance with an embodiment of the first aspect of the present application includes: judging a driving state of a vehicle, the driving state includes at least one of: uniform speed driving, accelerated driving or decelerated driving, and the vehicle includes at least: a first wheel motor group, a second wheel motor group and two generator groups; when the driving state is uniform speed driving, executing a single motor group drive strategy, and the single motor group drive strategy is used to control the first wheel motor group or the second wheel motor group to drive; when the driving state is accelerated driving, executing a dual motor group drive strategy, and the dual motor group drive strategy is used to control the first wheel motor group and the second wheel motor group to drive simultaneously; when the driving state is decelerated driving, executing an energy recovery strategy, and the energy recovery strategy is used to control the first wheel motor group and / or the second wheel motor group to recover energy; obtaining a battery pack power and a drive motor demand value, the battery pack power is the remaining power value of the battery pack, and the drive motor demand value is the current value required when the drive motor is running; based on the battery pack power and the drive motor demand value, executing a power control strategy, and the power control strategy is used to control the generator group to generate electricity.

[0008] Optionally, judging the driving state of the vehicle includes: obtaining driving information, the driving information including at least: one or more of vehicle speed, slope value, accelerator pedal state, and brake pedal state; when a change in vehicle speed within a preset time is less than a speed threshold, and the slope value is less than the slope threshold, and the accelerator pedal state and the brake pedal state are in an un-stepped state, judging the driving state to be uniform speed driving; when the accelerator pedal state is in a stepped state, judging the driving state to be accelerated driving; when the brake pedal state is in a stepped state, judging the driving state to be decelerated driving.

[0009] Optionally, a single motor group driving strategy includes: obtaining a first motor temperature and a second motor temperature, the first motor temperature being the highest temperature of the two driving motors in the first wheel motor group, and the second motor temperature being the highest temperature of the two driving motors in the second wheel motor group; when the first motor temperature is less than a first temperature threshold, and the second motor temperature is greater than or equal to the first temperature threshold, using the first wheel motor group for driving; when the first motor temperature is greater than or equal to the first temperature threshold, and the second motor temperature is less than the first temperature threshold, using the second wheel motor group for driving; when both the first motor temperature and the second motor temperature are less than the first temperature threshold, using the first wheel motor group and the second wheel motor group for driving alternately with a preset period.

[0010] Optionally, a dual-motor group driving strategy includes: obtaining demand power, which is the power required for vehicle acceleration when the accelerator pedal is in a stepped state; obtaining motor speed, which is the rotation speed of the drive motor; when the motor speed is less than a preset speed, converting the demand power into motor output torque; when the motor output torque is greater than the preset torque, using the first wheel side motor group and the second wheel side motor group to drive simultaneously; when the motor speed is greater than or equal to the preset speed, converting the demand power into motor output power; when the motor output power is greater than the preset power, using the first wheel side motor group and the second wheel side motor group to drive simultaneously.

[0011] Optionally, an energy recovery strategy includes: obtaining a first motor temperature and a second motor temperature, the first motor temperature being the highest temperature of the two drive motors in the first wheel motor group, and the second motor temperature being the highest temperature of the two drive motors in the second wheel motor group; when the first motor temperature is less than a second temperature threshold, and the second motor temperature is greater than or equal to the second temperature threshold, using the first wheel motor group for energy recovery; when the first motor temperature is greater than or equal to the second temperature threshold, and the second motor temperature is less than the second temperature threshold, using the second wheel motor group for energy recovery; when both the first motor temperature and the second motor temperature are less than the second temperature threshold, using the first wheel motor group and the second wheel motor group for energy recovery at the same time.

[0012] Optionally, the power control strategy includes: when the battery pack power is less than a first power threshold, using two generator sets to charge the battery pack simultaneously; when the battery pack power is between the first power threshold and the second power threshold, using one generator set to charge the battery pack; based on the battery pack power, calculating the maximum current value provided by the battery pack; when the drive motor demand value is greater than the maximum current value provided by the battery pack, executing a parallel power supply strategy, the parallel power supply strategy includes allowing the generator set and the battery pack to power the drive motor simultaneously.

[0013] Optionally, the parallel power supply strategy includes: determining whether the sum of the current value provided by a group of generator sets and the maximum current value is greater than the required current value; if so, using a group of generator sets and battery packs to power the drive motor at the same time; if not, using two groups of generator sets and battery packs to power the drive motor at the same time.

[0014] A distributed motor power system provided in an embodiment of the second aspect of the present application includes: at least two generator sets, the generator sets include: an engine, the engine is used to drive a number of generators to generate electricity; at least two wheel-side motor sets, the wheel-side motor sets include: two drive motors, the two drive motors are respectively arranged next to the two wheels of the same axle, and the drive motors are used to drive the corresponding wheels; an energy recovery unit, the energy recovery unit is connected to the drive motor, and is used to recover the electric energy generated by the drive motor during braking or sliding and store it in a battery pack; a distribution unit, the distribution unit includes: a charging bus, the generator set charges the battery pack through the charging bus; a power supply bus, the battery pack supplies power to the wheel-side motor set through the power supply bus; a power supply branch, the generator set directly supplies power to the wheel-side motor set through the power supply branch; the generator set, the battery pack and the wheel-side motor set use the same voltage platform; a main controller is configured to execute a distributed motor power system control method of the first aspect.

[0015] Optionally, the power distribution unit also includes: a voltage acquisition module, used to collect the power generation voltage value of the generator set; a voltage loop control module, used to compare the collected power generation voltage value and generate a voltage control instruction; the voltage control instruction is used to control the generator set so that the power generation voltage value is within a preset range.

[0016] Optionally, the power distribution unit also includes: a current acquisition module, used to collect the first current value of the battery pack and the second current value of the power supply branch; a current loop control module, used to compare the first current value with the second current value and generate a current control instruction; the current control instruction is used to control the battery pack and the generator set so that the sum of the first current value and the second current value is within a preset range.

[0017] One of the above technical solutions has at least the following advantages or beneficial effects:

[0018] A distributed motor power system control method provided in an embodiment of the present application includes: judging the driving state of a vehicle, the driving state includes at least one of: uniform speed driving, accelerated driving or decelerated driving, and the vehicle includes at least: a first wheel motor group, a second wheel motor group and two generator groups; when the driving state is uniform speed driving, executing a single motor group drive strategy, and the single motor group drive strategy is used to control the first wheel motor group or the second wheel motor group to drive; when the driving state is accelerated driving, executing a dual motor group drive strategy, and the dual motor group drive strategy is used to control the first wheel motor group and the second wheel motor group to drive simultaneously; when the driving state is decelerated driving, executing an energy recovery strategy, and the energy recovery strategy is used to control the first wheel motor group and / or the second wheel motor group to recover energy; obtaining the battery pack power and the drive motor demand value, the battery pack power is the remaining power value of the battery pack, and the drive motor demand value is the current value required when the drive motor is running; based on the battery pack power and the drive motor demand value, executing a power control strategy, and the power control strategy is used to control the generator group to generate electricity. For the first time, a distributed power layout is used in a 100-ton mining vehicle. By judging the driving state and executing the corresponding strategy, the first-wheel side motor group and the second-wheel side motor group can work in coordination. When driving at a constant speed, the vehicle does not need too much power and is driven by a single motor group; when accelerating, the vehicle requires greater power and is driven by dual motor groups. The use of two sets of generator sets for range extension effectively solves the problem of purchasing high-horsepower engines, and cooperates with the first-wheel side motor group and the second-wheel side motor group for driving, effectively meeting the power requirements of 100-ton mining vehicles.

[0019] A distributed motor power system provided in an embodiment of the present application is provided with the above-mentioned control method. Since the control method has the above-mentioned technical effects, a distributed motor power system provided with the control method should also have corresponding technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0021] Figure 1 A schematic diagram of the structure of a distributed motor power system provided in an embodiment of the present application is shown;

[0022] Figure 2 A schematic diagram of the structure of a central drive arrangement power system is shown;

[0023] Figure 3 A schematic diagram showing the principle of a power distribution unit provided in an embodiment of the present application is shown;

[0024] Figure 4 A schematic diagram showing the principle of a voltage loop control module provided in an embodiment of the present application is shown;

[0025] Figure 5 A schematic diagram showing the principle of a current loop control module provided in an embodiment of the present application is shown;

[0026] Figure 6 A schematic diagram of a flow chart of a distributed motor power system control method provided in an embodiment of the present application is shown;

[0027] Figure 7 A schematic diagram of a process flow of a single motor group driving strategy provided in an embodiment of the present application is shown;

[0028] Figure 8 A schematic diagram of the process flow of the dual-motor group driving strategy provided in an embodiment of the present application is shown;

[0029] Fig. 9 A schematic diagram of the process flow of the energy recovery strategy provided by an embodiment of the present application is shown;

[0030] Fig.10 A schematic diagram of a flow chart of a power supply control strategy provided in an embodiment of the present application is shown;

[0031] Fig.11 A working curve of a driving motor is shown. DETAILED DESCRIPTION

[0032] In order to better explain the present application and facilitate understanding, the present application is described in detail below through specific implementation methods in conjunction with the accompanying drawings.

[0033] As mentioned above, the current 100-ton mining vehicles are generally centrally driven. Figure 2 As shown in the figure, the power system uses a QST30-C1050 high-horsepower engine to drive the generator set, an asynchronous drive motor and an 86100RS-R gearbox. Among them, the QST30-C1050 high-horsepower engine and the 86100RS-R gearbox have procurement problems, long procurement cycles and high costs; moreover, the asynchronous drive motor needs to use a 1200-1500V high-voltage platform, the electronic control technology is difficult, the supply channels are few, the cost is high, and there is a problem of low efficiency under high-speed and low-torque conditions.

[0034] In order to solve at least one of the technical problems existing in the prior art or related technology, the present application provides a distributed motor power system and a control method, the distributed motor power system control method comprising: judging the driving state of the vehicle, the driving state comprising at least one of: uniform speed driving, accelerated driving or decelerated driving, the vehicle comprising at least: a first wheel motor group, a second wheel motor group and two generator groups; when the driving state is uniform speed driving, executing a single motor group drive strategy, the single motor group drive strategy is used to control the first wheel motor group or the second wheel motor group to drive; when the driving state is accelerated driving, executing a dual motor group drive strategy, the dual motor group drive strategy is used to control the first wheel motor group and the second wheel motor group to drive simultaneously; when the driving state is decelerated driving, executing an energy recovery strategy, the energy recovery strategy is used to control the first wheel motor group and / or the second wheel motor group to recover energy; obtaining the battery pack power and the drive motor demand value, the battery pack power is the remaining power value of the battery pack, and the drive motor demand value is the current value required when the drive motor is running; based on the battery pack power and the drive motor demand value, executing a power control strategy, the power control strategy is used to control the generator group to generate electricity. For the first time, a distributed power layout is used in a 100-ton mining vehicle. By judging the driving state and executing the corresponding strategy, the first-wheel side motor group and the second-wheel side motor group can work in coordination. When driving at a constant speed, the vehicle does not need too much power and is driven by a single motor group; when accelerating, the vehicle requires greater power and is driven by dual motor groups. The use of two sets of generator sets for range extension effectively solves the problem of purchasing high-horsepower engines, and cooperates with the first-wheel side motor group and the second-wheel side motor group for driving, effectively meeting the power requirements of 100-ton mining vehicles.

[0035] The following describes a distributed motor power system according to some embodiments provided by the present application with reference to the accompanying drawings.

[0036] See also Figures 1 to 11 , a distributed motor power system control method provided by an embodiment of the first aspect of the present application includes:

[0037] S100: Determine the driving state of the vehicle, where the driving state includes at least one of uniform speed driving, accelerated driving or decelerated driving, and the vehicle includes at least a first wheel-side motor set, a second wheel-side motor set and two generator sets.

[0038] Generally, the driving state of a vehicle can be divided into uniform driving, accelerated driving or decelerated driving. Different driving states have different power requirements. For example, in a uniform driving state, the vehicle needs to maintain a certain speed, so the drive motor needs to provide a stable power output. At the same time, due to the inertia of the vehicle, the energy consumption of the drive motor is relatively low, so that the power output of the drive motor and the driving resistance of the vehicle reach a balance state, and excessive energy loss needs to be avoided. In the accelerated driving state, the vehicle needs to increase the speed quickly, so the drive motor needs to provide a larger power output in order to increase the speed of the vehicle to the required level in a short time. At this time, the drive motor needs to output a large amount of power and torque in a short time. In the decelerated driving state, the vehicle needs to reduce the speed, so the drive motor can enter the regenerative braking mode, that is, the energy recovery mode, to convert the mechanical energy of the vehicle into electrical energy and store it in the battery pack. This can not only reduce the energy loss of the vehicle, but also extend the battery life.

[0039] In an illustrative implementation, determining the driving state of a vehicle includes:

[0040] S100-1: Acquire driving information, where the driving information includes at least one or more of vehicle speed, slope value, accelerator pedal status, and brake pedal status.

[0041] The vehicle speed can generally be obtained through the speedometer on the vehicle. The speedometer is also called the odometer or the speedometer. It is a basic and important instrument on the car. It is usually located on the dashboard of the cab and can display the current speed of the vehicle in real time. The slope value can be obtained through the gyroscope or angle sensor on the vehicle. The gyroscope can be used to measure the inclination angle of the vehicle to calculate the slope value. Generally, when the slope value is positive, it means that the vehicle is going uphill; when the slope value is negative, it means that the vehicle is going downhill. The accelerator pedal state can output the corresponding electrical signal through the pedal angle of the accelerator pedal. For example, the accelerator pedal is calibrated. When the accelerator pedal is not stepped on, the electrical signal 0 is output; when the accelerator pedal is stepped on to the bottom, the electrical signal 100 is output; when the accelerator pedal is stepped on to the middle, the corresponding value in the electrical signal 0-100 is output according to the pedal angle. The brake pedal state has the same principle as the accelerator pedal state, which will not be repeated here.

[0042] S100-2: When the vehicle speed change value within the preset time is less than the speed threshold, and the slope value is less than the slope threshold, and the accelerator pedal state and the brake pedal state are in the un-pressed state, the driving state is judged to be uniform speed driving.

[0043] Constant speed driving means that the speed of the vehicle remains stable within a certain time window, that is, the speed change value within the preset time is less than the speed threshold. At the same time, the vehicle is not in an uphill or downhill state, that is, the slope value is less than the slope threshold, and the accelerator and brake are not stepped on, that is, the accelerator pedal state and the brake pedal state are not stepped on, then it can be judged that the vehicle is in a constant speed driving state. For example, when the speed change value within 10 seconds is less than 3km / h, the slope value is less than 2 degrees, the accelerator pedal state is 0, and the brake pedal state is 0, the driving state is judged to be constant speed driving.

[0044] S100-3: When the accelerator pedal is in the stepped state, the driving state is determined to be accelerating.

[0045] The accelerator pedal is in a stepped state, for example, the accelerator pedal state is 50, indicating that the driver wants the vehicle to accelerate and needs the drive motor to output a large amount of power and torque in a short period of time. At this time, the driving state is accelerated. It can be understood that when the vehicle is in an uphill state, even if the vehicle speed does not change, it can be judged that the driving state is accelerated.

[0046] S100-4: When the brake pedal is in the stepped state, the driving state is determined to be decelerating.

[0047] The brake pedal state is in a stepped state, for example, the brake pedal state is 30, indicating that the driver wants the vehicle to decelerate and needs to drive the motor to enter the energy recovery mode. At this time, the driving state is deceleration. It can be understood that when the vehicle is in a downhill state, even if the vehicle speed does not change, it can be judged that the driving state is deceleration.

[0048] S210: When the driving state is uniform speed driving, a single motor group driving strategy is executed, and the single motor group driving strategy is used to control the first wheel side motor group or the second wheel side motor group to drive.

[0049] When driving at a constant speed, the power output of the drive motor does not need to be too large to avoid excessive energy loss, so a set of wheel-side motors can be used for driving.

[0050] In an illustrative embodiment, Figure 7 As shown, the single motor drive strategy includes:

[0051] S210 - 1 : Acquire a first motor temperature and a second motor temperature, wherein the first motor temperature is the highest temperature of the two drive motors in the first wheel-side motor group, and the second motor temperature is the highest temperature of the two drive motors in the second wheel-side motor group.

[0052] like Figure 1As shown, the wheel-side motor group includes two drive motors. The temperature of the drive motor can be obtained through the motor controller (Microcontroller Unit, MCU), and the highest temperature of the two drive motors is used as the temperature of the wheel-side motor group. For example, the temperatures of the two drive motors in the first wheel-side motor group are 70°C and 65°C respectively, and the temperature of the first motor is 70°C; the temperatures of the two drive motors in the second wheel-side motor group are 80°C and 85°C respectively, and the temperature of the second motor is 85°C.

[0053] S210-2: When the temperature of the first motor is lower than the first temperature threshold, and the temperature of the second motor is higher than or equal to the first temperature threshold, the first wheel-side motor group is used for driving.

[0054] The first temperature threshold is the upper limit temperature of the drive motor. When the temperature of the drive motor exceeds the first temperature threshold, it is regarded as an overload state, which may cause the life of the drive motor to be seriously shortened. In this application, the drive motor is a permanent magnet synchronous motor, and the normal operating temperature range is 100-120°C. Therefore, the first temperature threshold can be set at 120-130°C. When the temperature of the first motor is less than the first temperature threshold, it means that the drive motors in the first wheel motor group are all within a reasonable operating temperature range and can be driven normally; when the temperature of the second motor is greater than or equal to the first temperature threshold, it means that the drive motors in the second wheel motor group are not within a reasonable operating temperature range and need to stop driving for cooling.

[0055] S210-3: When the temperature of the first motor is greater than or equal to the first temperature threshold, and the temperature of the second motor is less than the first temperature threshold, use the second wheel-side motor group for driving.

[0056] Similarly, when the temperature of the first motor is greater than or equal to the first temperature threshold, it means that the drive motor in the first wheel motor group is not within a reasonable operating temperature range and needs to be stopped for cooling; when the temperature of the second motor is less than the first temperature threshold, it means that the drive motors in the second wheel motor group are within a reasonable operating temperature range and can be driven normally.

[0057] S210-4: When the first motor temperature and the second motor temperature are both lower than the first temperature threshold, the first wheel-side motor group and the second wheel-side motor group are used to drive alternately with a preset period.

[0058] When the first motor temperature and the second motor temperature are both lower than the first temperature threshold, it indicates that the drive motors in the first wheel motor group and the second wheel motor group are within a reasonable operating temperature range and can be driven normally. At this time, the two wheel motor groups are driven in rotation to ensure that both wheel motor groups are used evenly, thereby reducing energy consumption and improving overall efficiency. At the same time, each wheel motor group has a chance to rest and cool down, thereby reducing excessive wear and heat accumulation.

[0059] S220: When the driving state is acceleration, a dual-motor group driving strategy is executed, where the dual-motor group driving strategy is used to control the first wheel side motor group and the second wheel side motor group to drive simultaneously.

[0060] When accelerating, the vehicle needs to increase its speed quickly, so a greater power output is needed to increase the vehicle's speed to the required level in a short time. The dual-motor drive strategy allows the drive motor to output a large amount of power and torque in a short time, which can meet the power output requirements.

[0061] In an illustrative embodiment, Figure 8 As shown, the dual motor drive strategy includes:

[0062] S220-1: Obtaining required power, where the required power is the power required for vehicle acceleration when the accelerator pedal is in a stepped state.

[0063] When the accelerator pedal is in the stepped state, it means that the driver wants the vehicle to accelerate. At this time, the power required for vehicle acceleration is determined based on a preset algorithm and the current operating state of the vehicle.

[0064] S220-2: Get the motor speed, which is the rotation speed of the drive motor.

[0065] The motor speed of the drive motor can be obtained through the motor controller. Since the drive motor works in a constant torque area and a constant power area, such as Fig.11 As shown, when the motor speed is less than the preset speed, the motor operates in the constant torque zone. In the constant torque zone, no matter how the speed changes, the drive motor can provide a constant torque output, and the power increases linearly with the increase of speed. Because power is the product of torque and speed, the constant torque zone is suitable for medium and low speed driving conditions, such as general road driving; when the motor speed is greater than or equal to the preset speed, the motor enters the constant power zone. In the constant power zone, as the speed increases, the torque of the motor decreases nonlinearly to keep the power constant, because the reduction in torque is offset by the increase in speed. The constant power zone is suitable for conditions requiring high power output, such as climbing, accelerating and high-speed driving.

[0066] S220-3: When the motor speed is lower than the preset speed, the required power is converted into the motor output torque; when the motor output torque is higher than the preset torque, the first wheel side motor group and the second wheel side motor group are used for driving simultaneously.

[0067] When the motor speed is less than the preset speed, the motor works in the constant torque zone. At this time, the required power needs to be converted into the motor output torque to control the output power of the drive motor; when the motor output torque is greater than the preset torque, it means that the output power required to be provided by the drive motor is large, and a single wheel-side motor group cannot meet it, and the first wheel-side motor group and the second wheel-side motor group need to be used for driving at the same time. It can be understood that if the motor output torque is less than the preset torque, it means that the output power required to be provided by the drive motor can be met by a single wheel-side motor group, and a single motor group drive strategy can be adopted at this time.

[0068] S220-4: When the motor speed is greater than or equal to the preset speed, the required power is converted into the motor output power; when the motor output power is greater than the preset power, the first wheel side motor group and the second wheel side motor group are used to drive simultaneously.

[0069] Similarly, when the motor speed is greater than or equal to the preset speed, the motor works in the constant power zone. At this time, the required power needs to be converted into the motor output power to control the output power of the drive motor; when the motor output power is greater than the preset power, it means that the output power required to be provided by the drive motor is large, and a single wheel-side motor group cannot meet it, and the first wheel-side motor group and the second wheel-side motor group need to be used for driving at the same time. It is understandable that if the motor output power is less than the preset power, it means that the output power required to be provided by the drive motor can be met by a single wheel-side motor group, and a single motor group drive strategy can be adopted at this time.

[0070] S230: When the driving state is deceleration, an energy recovery strategy is executed, and the energy recovery strategy is used to control the first wheel-side motor group and / or the second wheel-side motor group to recover energy.

[0071] When decelerating, the vehicle needs to reduce speed. At this time, the drive motor does not need to output power, but will switch to regenerative braking mode, that is, energy recovery mode, to convert the vehicle's mechanical energy into electrical energy and store it in the battery pack. This not only reduces the vehicle's energy loss, but also extends the battery's range.

[0072] In an illustrative embodiment, Fig. 9 As shown, the energy recovery strategy includes:

[0073] S230-1: Acquire a first motor temperature and a second motor temperature, wherein the first motor temperature is the highest temperature of the two drive motors in the first wheel-side motor group, and the second motor temperature is the highest temperature of the two drive motors in the second wheel-side motor group.

[0074] The principle of step S230 - 1 is the same as that of step S210 - 1 and will not be repeated here.

[0075] S230-2: When the temperature of the first motor is lower than the second temperature threshold and the temperature of the second motor is higher than or equal to the second temperature threshold, use the first wheel-side motor group to recover energy.

[0076] The second temperature threshold is the upper limit temperature of the operation when the drive motor is used as a generator. When the temperature of the drive motor exceeds the second temperature threshold, it is regarded as an overload state, which may cause the life of the drive motor to be seriously shortened. In this application, the drive motor is a permanent magnet synchronous motor. When used as a generator, the normal operating temperature range is 80-100°C. Therefore, the second temperature threshold can be set at 100-110°C. When the temperature of the first motor is less than the second temperature threshold, it means that the drive motors in the first wheel-side motor group are all within a reasonable operating temperature range and energy recovery can be performed normally; when the temperature of the second motor is greater than or equal to the second temperature threshold, it means that the drive motors in the second wheel-side motor group are not within a reasonable operating temperature range and energy recovery needs to be stopped for cooling.

[0077] S230-3: When the temperature of the first motor is greater than or equal to the second temperature threshold, and the temperature of the second motor is less than the second temperature threshold, use the second wheel-side motor group to recover energy.

[0078] Similarly, when the temperature of the first motor is greater than or equal to the second temperature threshold, it means that the drive motor in the first wheel-side motor group is not within a reasonable operating temperature range, and energy recovery needs to be stopped for cooling; when the temperature of the second motor is less than the second temperature threshold, it means that the drive motors in the second wheel-side motor group are within a reasonable operating temperature range and energy recovery can be performed normally.

[0079] S230-4: When the first motor temperature and the second motor temperature are both lower than the second temperature threshold, the first wheel-side motor group and the second wheel-side motor group are used to recover energy simultaneously.

[0080] When the first motor temperature and the second motor temperature are both lower than the second temperature threshold, it indicates that the drive motors in the first wheel motor group and the second wheel motor group are within a reasonable operating temperature range and can perform energy recovery normally. At this time, the first wheel motor group and the second wheel motor group can perform energy recovery simultaneously to increase the efficiency of energy recovery.

[0081] S300: Obtaining a battery pack power and a drive motor demand value, where the battery pack power is the remaining power value of the battery pack, and the drive motor demand value is the current value required for the drive motor to run.

[0082] The remaining power value of the battery pack can be accurately obtained through the battery management system, and the current value required when the drive motor is running can be obtained through the motor controller. In this application, the generator set, battery pack and drive motor use the same voltage platform, and the voltage platform can be 600V-800V. Compared with the 1200-1500V high-voltage platform, the 600V-800V voltage platform can save the AC / DC conversion device for high-voltage boost, and the 600V-800V voltage platform motor and electronic control technology are less difficult, and industrialized mass production has been achieved, with a short procurement cycle and low cost. At the same time, since the generator set, battery pack and drive motor use the same voltage platform, the generator set can be used to directly power the drive motor.

[0083] S400: Execute a power control strategy based on the battery pack power and the drive motor demand value, where the power control strategy is used to control the generator set to generate electricity.

[0084] In an illustrative embodiment, Fig.10 As shown, the power control strategy includes:

[0085] S410: When the battery power is less than a first power threshold, two generator sets are used to charge the battery set simultaneously.

[0086] The first power threshold is the lower limit of the battery pack power. For example, the first power threshold is 30%. When the battery pack power is less than the first power threshold, it means that the battery pack power is insufficient and needs to be charged as soon as possible. At this time, using two generator sets to charge the battery pack at the same time can ensure that the battery pack can quickly and effectively restore power.

[0087] S420: When the power level of the battery pack is between the first power level threshold and the second power level threshold, use a group of generator sets to charge the battery pack.

[0088] The second power threshold is the upper limit threshold of the battery pack power. For example, the first power threshold is 80%. When the battery pack power is between the first power threshold and the second power threshold, it means that the battery pack power can still meet the usage needs. At this time, only one set of generator sets is needed to charge the battery pack, which can meet the charging needs without causing energy waste.

[0089] When the battery power is greater than the second power threshold, it means that the battery power is sufficient, and there is no need to use the generator set for charging, thus saving energy.

[0090] S430: Calculate the maximum current value provided by the battery pack based on the battery pack power.

[0091] S440: When the demand value of the driving motor is greater than the maximum current value provided by the battery pack, a parallel power supply strategy is executed, where the parallel power supply strategy includes enabling the generator set and the battery pack to supply power to the driving motor simultaneously.

[0092] When the battery pack is low on power, the maximum current value provided by the battery pack will also decrease. Since the present application adopts a 600V-800V voltage platform, compared to a 1200-1500V high-voltage platform, a larger current value is required to drive the motor at the same power. Using only the battery pack may not be able to provide sufficient current. In this case, a generator set and a battery pack can be used to power the drive motor at the same time.

[0093] In an exemplary embodiment, the parallel power supply strategy includes:

[0094] Determine whether the sum of the current value provided by a group of generator sets and the maximum current value is greater than the required current value;

[0095] If so, a generator set and a battery set are used to power the drive motor simultaneously;

[0096] If not, two generator sets and battery sets are used to power the drive motor simultaneously.

[0097] When the current provided by one group of generators can meet the needs of the drive motor, one group of generator sets is used to power the drive motor, so that the other group of generator sets can continue to charge the battery pack; when the current provided by one group of generators cannot meet the needs of the drive motor, two groups of generator sets are used to power the drive motor, giving priority to meeting the power supply needs of the drive motor. Generally, the drive motor is required to output a larger power only in the accelerated driving state, and the accelerated driving state will not last for a long time, so the impact on the generator set charging the battery pack will be very small.

[0098] Furthermore, when the battery pack fails to supply power, the limp home strategy is executed, which is used to control the generator set to directly supply power to the drive motor. The battery pack may stop working due to unexpected factors, such as low temperature or failure. At this time, the generator set can be used to directly supply power to the drive motor, which can ensure the minimum operation of the vehicle even when the battery pack fails, thereby improving the reliability and safety of the vehicle.

[0099] Based on the distributed motor power system control method provided in the above embodiment, the second aspect of the present application also provides a distributed motor power system, such as Figure 1 As shown, including:

[0100] At least two generator sets, the generator sets include: an engine, the engine is used to drive a number of generators to generate electricity;

[0101] At least two wheel-side motor groups, the wheel-side motor groups include: two drive motors, the two drive motors are respectively arranged next to two wheels of the same axle, and the drive motors are used to drive the corresponding wheels; an energy recovery unit, the energy recovery unit is connected to the drive motor, and is used to recover the electric energy generated by the drive motor during braking or sliding and store it in a battery pack;

[0102] The power distribution unit includes: a charging bus, through which the generator set charges the battery pack; a power supply bus, through which the battery pack supplies power to the wheel-side motor set; a power supply branch, through which the generator set directly supplies power to the wheel-side motor set; the generator set, the battery set and the wheel-side motor set use the same voltage platform;

[0103] The main controller is configured to execute the above-mentioned distributed motor power system control method.

[0104] In this application, the engine can use two 16 / 17L displacement engines, which are easier to purchase and have low cost compared to the QST30-C1050 high-horsepower engine with a displacement of 30L, and can achieve the same technical effect. This application adopts a distributed power layout for the first time in a 100-ton mining vehicle, that is, a wheel-side motor drive mode. The drive motor is set next to the wheel, which can save the gearbox and also does not require a differential. The drive wheel speed torque distribution is achieved by calculating the drive motor speed. The drive motor torque is controlled by calculating the adhesion and the drive wheel speed, and the wheel side can be prevented from slipping.

[0105] The drive motor uses a permanent magnet synchronous motor. Compared with the asynchronous drive motor, the permanent magnet synchronous motor has a higher efficiency value under high-speed and low-torque conditions. Moreover, the permanent magnet synchronous motor can use a 600V-800V voltage platform, while the asynchronous drive motor needs to use a 1200-1500V high-voltage platform. The 600V-800V voltage platform motor and electronic control technology are less difficult and have been industrialized and mass-produced, with a short procurement cycle and low cost. At the same time, since the generator set, battery pack and drive motor use the same voltage platform, the generator set can be used to directly power the drive motor, effectively solving the problem of insufficient battery power supply.

[0106] Further, if Figure 3As shown, the battery pack includes at least two power batteries, which are configured in parallel. Two power batteries can achieve more flexible battery management, optimize energy use through the battery management system, and improve overall efficiency. When the battery management system detects a power battery failure, it can automatically switch to another power battery, thereby avoiding the sudden power outage of the vehicle and improving driving safety; in high or low temperature environments, the two power batteries can be independently temperature controlled to prevent the battery from overheating or overcooling, extending battery life and improving safety; and when driving at a constant speed, the battery management system can use only one power battery for power supply, and when accelerating or requiring high power output, it enables two power batteries to optimize power use.

[0107] In an illustrative embodiment, Figure 4 As shown, the power distribution unit also includes: a voltage acquisition module, which is used to acquire the power generation voltage value of the generator set; a voltage loop control module, which is used to compare the acquired power generation voltage value and generate a voltage control instruction; the voltage control instruction is used to control the generator set so that the power generation voltage value is within a preset range.

[0108] The voltage loop control module is responsible for monitoring and adjusting the output voltage of the generator set to ensure that it is stable within a given set value range. The voltage loop control module first measures the actual output voltage of the generator set through the voltage acquisition module; compares the measured actual voltage with the set reference voltage to calculate the voltage error; inputs the voltage error into the proportional integral controller, and outputs a control signal by adjusting the controller parameters, the proportional coefficient Kp and the integral coefficient Ki; the control signal acts on the generator controller (Generator Control Unit, GCU) of the generator set to adjust the excitation current or speed, thereby changing the output voltage of the generator set; through continuous monitoring and adjustment, the voltage loop control module can stabilize the output voltage of the generator set within the set value range.

[0109] In an illustrative embodiment, Figure 5 As shown, the power distribution unit also includes: a current acquisition module, used to acquire the first current value of the battery pack and the second current value of the power supply branch; a current loop control module, used to compare the first current value with the second current value and generate a current control instruction; the current control instruction is used to control the battery pack and the generator set so that the sum of the first current value and the second current value is within a preset range.

[0110] The main function of the current loop control module is to ensure the stability of the power supply current of the drive motor when the battery pack and the generator set are powered at the same time. The current loop control module monitors the output current of the battery pack and the generator set in real time through the current acquisition module, and compares it with the set reference current; if there is a deviation, the battery management system and the generator controller are used to change the output current so that it is close to or reaches the reference current. This process ensures the stability and accuracy of the power supply current and avoids the impact of current fluctuations on the performance of the drive motor.

[0111] In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the feature. In the description of the present application, "plurality" means two or more, unless otherwise clearly and specifically defined.

[0112] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "exemplary embodiment", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0113] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A distributed motor power system control method, characterized in that: include: Determine the driving state of the vehicle, the driving state includes at least one of: uniform speed driving, accelerated driving or decelerated driving, the vehicle includes at least: a first wheel-side motor group, a second wheel-side motor group and two generator groups; When the driving state is uniform speed driving, a single motor group driving strategy is executed, and the single motor group driving strategy is used to control the first wheel side motor group or the second wheel side motor group to drive; When the driving state is acceleration driving, a dual motor group driving strategy is executed, wherein the dual motor group driving strategy is used to control the first wheel side motor group and the second wheel side motor group to drive simultaneously; When the driving state is deceleration, an energy recovery strategy is executed, and the energy recovery strategy is used to control the first wheel-side motor group and / or the second wheel-side motor group to recover energy; Obtaining the battery pack power and the drive motor demand value, wherein the battery pack power is the remaining power value of the battery pack, and the drive motor demand value is the current value required when the drive motor is running; Based on the battery power and the driving motor demand value, a power control strategy is executed, and the power control strategy is used to control the generator set to generate electricity.

2. A distributed motor power system control method as claimed in claim 1, characterized in that: The determining of the driving state of the vehicle includes: Acquiring driving information, the driving information including at least one or more of: vehicle speed, slope value, accelerator pedal state, and brake pedal state; When the vehicle speed change value within the preset time is less than the speed threshold, and the slope value is less than the slope threshold, and the accelerator pedal state and the brake pedal state are in the un-stepped state, the driving state is determined to be uniform speed driving; When the accelerator pedal is in a stepped state, determining that the driving state is accelerated driving; When the brake pedal is in a stepped state, the driving state is determined to be decelerating driving.

3. A distributed motor power system control method as claimed in claim 1, characterized in that: The single motor drive strategy includes: Acquire a first motor temperature and a second motor temperature, wherein the first motor temperature is the highest temperature of the two drive motors in the first wheel-side motor group, and the second motor temperature is the highest temperature of the two drive motors in the second wheel-side motor group; When the temperature of the first motor is lower than a first temperature threshold, and the temperature of the second motor is higher than or equal to the first temperature threshold, the first wheel-side motor group is used for driving; When the temperature of the first motor is greater than or equal to the first temperature threshold, and the temperature of the second motor is less than the first temperature threshold, the second wheel-side motor group is used for driving; When the first motor temperature and the second motor temperature are both lower than the first temperature threshold, the first wheel-side motor group and the second wheel-side motor group are driven alternately with a preset period.

4. A distributed motor power system control method as claimed in claim 1, characterized in that: The dual-motor drive strategy includes: Obtaining required power, where the required power is the power required for vehicle acceleration when the accelerator pedal is in a stepped state; Obtaining a motor speed, where the motor speed is the rotation speed of the drive motor; When the motor speed is less than a preset speed, the required power is converted into motor output torque; When the motor output torque is greater than the preset torque, the first wheel-side motor group and the second wheel-side motor group are used to drive simultaneously; When the motor speed is greater than or equal to a preset speed, the required power is converted into motor output power; When the output power of the motor is greater than the preset power, the first wheel-side motor group and the second wheel-side motor group are used to drive simultaneously.

5. A distributed motor power system control method as claimed in claim 1, characterized in that: The energy recovery strategy comprises: Acquire a first motor temperature and a second motor temperature, wherein the first motor temperature is the highest temperature of the two drive motors in the first wheel-side motor group, and the second motor temperature is the highest temperature of the two drive motors in the second wheel-side motor group; When the temperature of the first motor is lower than a second temperature threshold, and the temperature of the second motor is higher than or equal to the second temperature threshold, using the first wheel-side motor group for energy recovery; When the temperature of the first motor is greater than or equal to the second temperature threshold, and the temperature of the second motor is less than the second temperature threshold, using the second wheel-side motor group to recover energy; When the first motor temperature and the second motor temperature are both lower than the second temperature threshold, the first wheel-side motor group and the second wheel-side motor group are used to perform energy recovery simultaneously.

6. A distributed motor power system control method as claimed in claim 1, characterized in that: The power control strategy includes: When the power level of the battery pack is less than a first power level threshold, using two generator sets to charge the battery pack simultaneously; When the power level of the battery pack is between the first power level threshold and the second power level threshold, using a group of generator sets to charge the battery pack; Based on the power of the battery pack, calculating the maximum current value provided by the battery pack; When the demand value of the driving motor is greater than the maximum current value provided by the battery pack, a parallel power supply strategy is executed, wherein the parallel power supply strategy includes enabling the generator set and the battery pack to supply power to the driving motor simultaneously.

7. A distributed motor power system control method as claimed in claim 6, characterized in that: The parallel power supply strategy includes: Determining whether the sum of the current value provided by a group of generator sets and the maximum current value is greater than the required current value; If so, a generator set and a battery set are used to power the drive motor simultaneously; If not, two generator sets and battery sets are used to power the drive motor simultaneously.

8. A distributed motor power system, characterized in that: include: At least two generator sets, the generator sets comprising: an engine, the engine being used to drive a plurality of generators to generate electricity; At least two wheel-side motor groups, the wheel-side motor groups include: two drive motors, the two drive motors are respectively arranged beside two wheels of the same axle, the drive motors are used to drive the corresponding wheels; an energy recovery unit, the energy recovery unit is connected to the drive motors, and is used to recover the electric energy generated by the drive motors during braking or sliding and store it in a battery pack; A power distribution unit, the power distribution unit comprising: a charging bus, through which the generator set charges the battery set; a power supply bus, through which the battery set supplies power to the wheel-side motor set; a power supply branch, through which the generator set directly supplies power to the wheel-side motor set; the generator set, the battery set and the wheel-side motor set use the same voltage platform; A main controller is configured to execute a distributed motor power system control method as described in any one of claims 1-7.

9. A distributed motor power system as claimed in claim 8, characterized in that: The power distribution unit further comprises: A voltage acquisition module, used to acquire the power generation voltage value of the generator set; The voltage loop control module is used to compare the collected power generation voltage values ​​and generate voltage control instructions; the voltage control instructions are used to control the generator set so that the power generation voltage value is within a preset range.

10. A distributed motor power system as claimed in claim 8, characterized in that: The power distribution unit further comprises: A current acquisition module, used for acquiring a first current value of the battery pack and a second current value of the power supply branch; The current loop control module is used to compare the first current value with the second current value and generate a current control instruction; the current control instruction is used to control the battery pack and the generator set so that the sum of the first current value and the second current value is within a preset range.

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