Switched reluctance motor loader electric drive system based on dynamic conduction angle control

Abstract

The utility model relates to a switched reluctance motor loader electric driving system based on dynamic conduction angle control, which comprises a wheel side driving unit, a dynamic conduction angle control unit, an SRM (switched reluctance motor) controller and a switched reluctance motor, and the wheel side driving unit comprises the switched reluctance motor, a speed reducer and a brake. The engine, the three-phase asynchronous motor, the four SRM controllers and the central controller are connected in sequence; the dynamic conduction angle control unit comprises a power supply, a power converter, a driving circuit, a dynamic conduction angle controller, a current detection module, a position detection module, a speed calculation module, a load, a PI control module, a current control module, an input end of a PWM module, a power control module and four switched reluctance motors. The four switched reluctance motors are respectively connected with the speed calculation module and the PWM module, and the speed calculation module is connected with the PI control module; the utility model has obvious advantages in the aspects of improving the performance of the loader, promoting the industry development and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to engineering machinery electric drive and control field, concretely relates to a kind of switched reluctance motor loader electric drive system based on dynamic conduction angle control. BACKGROUND

[0002] Traditional loaders mostly adopt hydraulic transmission system, there are transmission efficiency low (less than 70%), high energy consumption, emission pollution and other problems.Switched reluctance motor (SRM) is regarded as the ideal choice of engineering machinery electric drive by virtue of simple structure, large starting torque, wide speed regulating range and other advantages.However, existing SRM drive system mostly adopts fixed conduction angle control strategy, it is difficult to take into account low-speed high torque and high-speed high efficiency operation requirements, leading to the decrease of system comprehensive efficiency;At the same time, traditional centralized drive architecture exists transmission chain complex, dynamic response is poor and other problems, which restricts the performance of loader under complex working conditions such as frequent start-stop, heavy load impact.

[0003] In prior art, patent CN112953249A proposes an engineering machinery drive system based on SRM, but it adopts fixed conduction angle control strategy, without considering the dynamic characteristic optimization when load mutates, leading to motor easy to stall or efficiency steep drop;Patent CN113346747A designs a wheel edge drive system, but does not involve SRM control strategy and vehicle network collaborative optimization, it is difficult to realize multi-motor real-time synchronous control.In addition, traditional CAN bus control system mostly adopts static message scheduling strategy, when facing multi-motor cooperation, working condition switching and other scenes, there are defects such as high data transmission delay, insufficient real-time, which affects the dynamic response accuracy of drive system. SUMMARY

[0004] The utility model aims at solving the problems of low efficiency, complex transmission components, poor adaptability of motor control strategy, poor working condition matching and insufficient real-time and stability of vehicle network control system existing in existing loader drive system, provides a kind of switched reluctance motor loader electric drive system based on dynamic conduction angle control, to realize the efficient, reliable, energy-saving operation of loader under various working conditions, and improve the real-time control performance of system.

[0005] The utility model provides a kind of switched reluctance motor (SRM) loader electric drive system based on dynamic conduction angle control, it includes: wheel, dynamic conduction angle control unit, engine, generator, hydraulic pump, three-phase asynchronous motor, SRM controller and switched reluctance motor, wherein:

[0006] Each wheel comprises a wheel-side driving unit, which contains a switched reluctance motor, a speed reducer and a brake, the switched reluctance motor, the speed reducer and the brake are installed in the wheel hub, the output shaft of the switched reluctance motor is engaged with the input shaft of the speed reducer through an involute spline, the brake pad of the brake is embedded in the speed reducer shell through a clamping groove, and the brake hydraulic pipeline is connected with the brake cylinder through a quick plug connector; four wheels are respectively fixed on the frame, and the wheel-side driving unit of each wheel is connected with a corresponding SRM controller; the brake is installed at the rear end of the switched reluctance motor rotor and is connected with a dynamic conduction angle controller through a shielded cable; the outlet of the hydraulic pump is connected with a DN12 high-pressure hose, the outlet of the DN12 high-pressure hose is branched through a DN10 steel pipe and is connected with the hydraulic cylinder of the working device and the four brakes respectively; the brake proportional valve is connected with the central controller through a 4-core shielded cable;

[0007] The engine is connected with the generator, and the engine and the generator are fixed on the base, the base is connected with the frame through bolts; the three-phase asynchronous motor is connected with the hydraulic pump, the hydraulic pump is connected with the working device, the engine is connected with the input shaft of the three-phase asynchronous motor through a shaft coupling, the three-phase asynchronous motor is connected with four SRM controllers through a copper bus, and the four SRM controllers are connected with the central controller respectively;

[0008] The dynamic conduction angle control unit comprises a power supply, a power converter, a drive circuit, a dynamic conduction angle controller, a current detection module, a position detection module, a speed calculation module and a load, the power supply is connected with the power converter, the input end of the power converter is connected with the drive circuit, and the output end is connected with the input end of the switched reluctance motor on the four wheels; the switched reluctance motor is bidirectionally connected with the load, the input end of the drive circuit is connected with the output end of the dynamic conduction angle controller, the output end of the switched reluctance motor on the four wheels is connected with the input end of the current detection module and the position detection module respectively, the output end of the position detection module is connected with the input end of the speed calculation module, the output ends of the current detection module, the position detection module and the speed calculation module are connected with the input end of the dynamic conduction angle controller respectively, and the input end of the dynamic conduction angle controller is connected with a command given module;

[0009] The four SRM controllers are connected with a PC through a second CAN bus, the central controller, a display and a handle are connected with the PC through a first CAN bus, and the central controller is connected with the display, the handle, a steering wheel, a pedal and a forward / reverse key respectively;

[0010] The output end of the PI control module is connected with the input end of the current control module, the output end of the current control module is connected with the input end of the PWM module, the output end of the PWM module is connected with the input end of the power control module, the output end of the power control module is connected with the four switched reluctance motors, the output end of the four switched reluctance motors is connected with the input end of the speed calculation module and the PWM module respectively, and the output end of the speed calculation module is connected with the input end of the PI control module.

[0011] In the utility model, the first CAN bus and the second CAN bus adopt shielded twisted pair wire, the sectional area is 0.75mm², and 120Ω resistance is configured at the terminal.

[0012] In the utility model, the DC bus outputs low-voltage electricity through the DC-DC conversion module (24V / 300W), and is connected to the display, the operating handle and the Hall current sensor through the flame-retardant wire, and the flame-retardant wire is fixed in the waterproof wire groove through nylon straps.

[0013] In the utility model, the display is fixed on the driver's stand through the HDMI wire and the power line, and the power converter and the SRM controller are installed in the independent heat dissipation cabin.

[0014] The utility model has the advantages that:

[0015] 1. High efficiency and energy saving: through dynamic conduction angle control and double closed loop strategy, the running state of the motor under different rotating speeds and loads is optimized, so that the motor maintains high efficiency within a wide rotating speed range (500 - 3000rpm), the efficiency is improved by more than 20% under rated working condition compared with the traditional hydraulic drive system, the energy consumption is reduced by 15%-20%, and the energy utilization efficiency is effectively improved.

[0016] 2. Precise control: based on the distributed differential control and PI control module of the CAN bus, the loader can accurately match the rotating speed of each wheel when turning, the rotating speed error is controlled within 2%, and the operation stability is significantly improved. At the same time, the motor stall protection strategy response time is less than 0.5s, which effectively avoids the damage of motor overload and guarantees the reliability of the system.

[0017] 3. Strong working condition adaptability: the three-stage double-speed ratio reducer and the multi-state switching function make the loader easily cope with the low-speed large-torque requirement in the loading operation and the high-speed low-power requirement in the transportation working condition, and adapt to various complex load changes. The integrated design of the hydraulic clutch and the brake simplifies the mechanical structure and reduces the maintenance cost.

[0018] 4. Reliability improvement: multiple sealing design and application of high-strength materials ensure that the motor can operate stably under harsh working conditions such as high voltage (513V DC bus) and high temperature (ambient temperature ≤85℃), the motor life is prolonged by 10%-15% compared with traditional motors, equipment failure and downtime are reduced, and production efficiency is improved.

[0019] In summary, the switch reluctance motor loader electric drive system based on dynamic conduction angle control has significant advantages in improving the performance of loaders and promoting industry development, and has high practical value and wide social and economic benefits. BRIEF DESCRIPTION OF DRAWINGS

[0020] Fig. 1 is a schematic diagram of the structure of the electrically driven wheel loader.

[0021] Fig. 2 is a structure block diagram of the dynamic conduction angle control unit of the utility model.

[0022] Fig. 3 is a CAN bus network diagram of the utility model.

[0023] Fig. 4 is a vehicle control unit diagram of the utility model.

[0024] In the figure, 1 is a wheel, 2 is a reducer, 3 is a brake, 4 is a switch reluctance motor (SRM), 5 is a command given module, 6 is a first SRM controller, 7 is a second SRM controller, 8 is an engine, 9 is a generator, 10 is a three-phase asynchronous motor, 11 is a hydraulic pump, 12 is a third SRM controller, 13 is a fourth SRM controller, 14 is a working device, 15 is a power supply, 16 is a power converter, 17 is a drive circuit, 18 is a dynamic conduction angle controller, 19 is a current detection module, 20 is a position detection module, 21 is a speed calculation module, 22 is a load, 23 is a central controller, 24 is a display, 25 is a handle, 26 is a PC, 27 is a steering wheel, 28 is a pedal, 29 is a forward / reverse key, and 30 is a mode switch. DETAILED DESCRIPTION

[0025] The utility model is further illustrated below by examples in combination with the drawings.

[0026] Example 1: The switch reluctance motor (SRM) loader electric drive system based on dynamic conduction angle control of the utility model realizes efficient power transmission and precise cooperative control through the architecture and example shown in the figure. Figs. 1 to 4

[0027] ​As shown in the figure, the drive wheel loader is composed of wheels 1, reducers 2, brakes 3, switched reluctance motors 4, first SRM controllers 6, second SRM controllers 7, engines 8, generators 9, three-phase asynchronous motors 10, hydraulic pumps 11, third SRM controllers 12, fourth SRM controllers 13, working devices 14, the engine 8 adopts a diesel engine, the three-phase asynchronous motor 10 adopts a three-phase alternator, the reducer 2 adopts a planetary reducer 2, and the brake 3 adopts a wet brake; the diesel engine 8 is butted with the input shaft of the three-phase alternator through a high-precision rigid coupling, the coupling is fixed at both ends through flange bolts, and power transmission is ensured without deviation. A protective cover is installed outside the coupling to prevent foreign matter from entering. The engine and the generator are fixed together on a damping base, the damping base is connected with the loader frame through high-strength bolts to reduce running vibration. The 380V alternating current output by the generator is transmitted through three copper core cables (with insulation sheath) with a cross-sectional area of 50mm², and the cable is laid along the inside of the frame to avoid mechanical damage. The rectified 513V direct current is distributed to the motors of the first SRM controller 6, the second SRM controller 7, the third SRM controller 12, the fourth SRM controller 13 and the hydraulic pump 11 through a copper bus. The copper bus outputs low-voltage electricity through a DC-DC conversion module (24V / 300W) and is connected to the display 24, the handle 25 and the Hall current sensor through flame-retardant wires. The wire bundle is fixed in the waterproof wire slot by nylon cable ties. Each switched reluctance motor 4 is fixed in the hub through a flange bolt, and the flange contact surface is coated with heat-conducting silicone grease to enhance heat dissipation. The output shaft of the switched reluctance motor 4 is engaged with the input shaft of the planetary reducer 2 through a involute spline, and the reducer 2 shell is rigidly connected with the wheel hub through a flange, and the flange bolt torque is tightened according to the standard of 120N·m. The brake pads of the wet brake 3 are embedded in the reducer 2 shell through a clamping groove, and the brake hydraulic pipeline is connected with the brake cylinder through a quick connector. The rotor rear end of the switched reluctance motor 4 is connected to the dynamic conduction angle controller 18 through a shielded cable (twisted pair with metal braid), and a magnetic ring is installed at the cable interface to suppress electromagnetic interference. The double CAN bus (CAN1 / CAN2) adopts a shielded twisted pair (cross-sectional area 0.75mm²) with a terminal resistance of 120Ω. The first CAN bus is connected with the central controller 23, the display 24, the handle 25 and the steering wheel 27, and the cable is laid along the cab wire slot with a node spacing of no more than 40m. The second CAN bus is connected with the first SRM controller 6, the second SRM controller 7, the third SRM controller 12 and the fourth SRM controller 13, and the cable is fixed along the frame longitudinal beam with a spacing of more than 30cm from the high-voltage cable to avoid cross talk.

[0028] The hydraulic pump 11 outlet is connected with a DN12 high pressure hose, the DN12 high pressure hose outlet is branched through a DN10 steel pipe, and is connected with the hydraulic cylinder of the working device 14 and four wet brakes 3 respectively. The pipe joint adopts a 24° conical surface sealing, and the tightening torque is 45 N·m. The brake proportional valve is connected with the central controller through a 4-core shielded cable (with a waterproof joint), the cable is fixed along the wire groove, and contact with high temperature components is avoided. The display is fixed on the driver's stand through an HDMI line and a power line, the handle 25 is connected with the central controller 23 through a first CAN bus and a 24V power line, and the cable is protected by a corrugated pipe. The power converter 16, the first SRM controller 6, the second SRM controller 7, the third SRM controller 12 and the fourth SRM controller 13 are installed in a separate heat dissipation cabin, the cabin body is communicated with an external fan through an air duct, and a dustproof filter screen is additionally installed at the air inlet.

[0029] The output end of the PI control module 32 is connected with the input end of the current control module 33, the output end of the current control module 33 is connected with the input end of the PWM module 34, the output end of the PWM module 34 is connected with the input end of the power control module 35, the output end of the power control module 35 is connected with the four switched reluctance motors 4, the output end of the four switched reluctance motors 4 is connected with the input end of the speed calculation module 21 and the PWM module 34 respectively, and the output end of the speed calculation module 21 is connected with the input end of the PI control module 32; the power control module 35 is connected with the three-phase asynchronous motor 10 on the line connected with the switched reluctance motor 4, and the output end of the three-phase asynchronous motor 10 is connected on the line connected with the PI control module and the current control module; the current detection module is Infineon TLI4970, the position detection module is AMS AS5048A, the speed calculation module is dsPIC33EP, and the command given module is STMicroelectronics STM32F407VGT6.

[0030] The working process of the utility model is as follows:

[0031] System startup: the engine 8 is started, the generator 9 is driven to generate electricity, and 380V alternating current is output. After the alternating current is rectified, it is distributed to the first SRM controller 6, the second SRM controller 7, the third SRM controller 12, the fourth SRM controller 13 and the hydraulic pump 11 through the copper bus. The display 24 and the handle 25 are powered by a DC-DC conversion module (24V / 300W).

[0032] Power transmission: the three-phase asynchronous motor 10 drives the hydraulic pump 11 to provide high pressure oil liquid for the working device 14 and the brake 3. The switched reluctance motor 4 of each wheel 1 drives the wheel 1 through the planetary reducer 2 to realize driving.

[0033] Signal acquisition and processing: Current detection module 19 monitors the phase current of SRM 4 in real time. Position detection module 20 obtains the rotor position, and speed calculation module 21 calculates the rotational speed. The above signals are input into dynamic conduction angle controller 18.

[0034] Data transmission and coordination: First CAN bus (CAN1) connects central controller 23, display 24, handle 25, etc., to transmit driving instructions (such as steering and acceleration) in real time. Second CAN bus (CAN2) connects first SRM controller 6, second SRM controller 7, third SRM controller 12, and fourth SRM controller 13 to synchronize the states of switched reluctance motor 4 (such as rotational speed and current). Central controller 23 coordinates the rotational speeds of each wheel through CAN bus to achieve differential control (such as the rotational speed difference between the inner and outer wheels ≤ 2% when steering).

[0035] Operation and response: The driver inputs instructions through handle 25 and steering wheel. Central controller 23 integrates CAN bus data to generate control signals. First SRM controller 6, second SRM controller 7, third SRM controller 12, and fourth SRM controller 13 adjust the torque of switched reluctance motor 4. Hydraulic pump 11 controls the action of working device 14, and brake 3 proportional valve adjusts the braking force. Display 24 displays the system status (such as efficiency and fault alarm) in real time.

Claims

1. A loader electric drive system based on a switched reluctance motor with dynamic conduction angle control, comprising wheels, a dynamic conduction angle control unit, an engine, a generator, a hydraulic pump, a three-phase asynchronous motor, an SRM controller, and a switched reluctance motor, characterized in that: Each wheel includes a wheel-side drive unit, which contains a switched reluctance motor, a reducer, and a brake. The switched reluctance motor, reducer, and brake are installed inside the wheel hub. The output shaft of the switched reluctance motor meshes with the input shaft of the reducer through an involute spline. The brake pads of the brake are embedded into the reducer housing through slots. The brake hydraulic lines of the brake are connected to the brake cylinder through quick-connect couplings. The four wheels are fixed to the frame, and the wheel-side drive unit of each wheel is connected to the corresponding SRM controller; the brake is installed at the rear end of the switched reluctance motor rotor and is connected to the dynamic conduction angle controller through a shielded cable; the outlet of the hydraulic pump is connected to a DN12 high-pressure hose, and the outlet of the DN12 high-pressure hose is branched through a DN10 steel pipe to connect to the hydraulic cylinder of the working device and the four brakes respectively; the brake proportional valve is connected to the central controller through a 4-core shielded cable. The engine is connected to the generator, and both the engine and the generator are fixed on the base, which is connected to the frame by bolts; the three-phase asynchronous motor is connected to the hydraulic pump, the hydraulic pump is connected to the working device, the engine is connected to the input shaft of the three-phase asynchronous motor through a coupling, the three-phase asynchronous motor is connected to four SRM controllers through copper busbars, and the four SRM controllers are respectively connected to the central controller. The dynamic conduction angle control unit includes a power supply, a power converter, a drive circuit, a dynamic conduction angle controller, a current detection module, a position detection module, a speed calculation module, and a load. The power supply is connected to the power converter. The input terminal of the power converter is connected to the drive circuit, and the output terminal is connected to the input terminal of the switched reluctance motors on the four wheels. The switched reluctance motors are bidirectionally connected to the load. The input terminal of the drive circuit is connected to the output terminal of the dynamic conduction angle controller. The output terminals of the switched reluctance motors on the four wheels are respectively connected to the input terminals of the current detection module and the position detection module. The output terminal of the position detection module is connected to the input terminal of the speed calculation module. The output terminals of the current detection module, the position detection module, and the speed calculation module are respectively connected to the input terminal of the dynamic conduction angle controller. The input terminal of the dynamic conduction angle controller is connected to the command setting module. Four SRM controllers are connected to the PC via the second CAN bus, and the central controller, display and gamepad are connected to the PC via the first CAN bus. The central controller is connected to the display, gamepad, steering wheel, pedals and forward / backward buttons respectively. The output of the PI control module is connected to the input of the current control module. The output of the current control module is connected to the input of the PWM module. The output of the PWM module is connected to the input of the power control module. The output of the power control module is connected to four switched reluctance motors. The outputs of the four switched reluctance motors are respectively connected to the inputs of the speed calculation module and the PWM module. The output of the speed calculation module is connected to the input of the PI control module. A three-phase asynchronous motor is connected to the line connecting the power control module and the switched reluctance motors. The output of the three-phase asynchronous motor is connected to the line connecting the PI control module and the current control module.

2. The switched reluctance motor loader electric drive system based on dynamic conduction angle control according to claim 1, characterized in that: Both the first and second CAN buses use shielded twisted-pair cables with a cross-sectional area of ​​0.75 mm², and are equipped with 120 Ω resistors at the terminals.

3. The switched reluctance motor loader electric drive system based on dynamic conduction angle control according to claim 1, characterized in that: The DC bus outputs low-voltage electricity through a DC-DC conversion module, which is then connected to the display, operating handle, and Hall current sensor via flame-retardant wires. The flame-retardant wires are secured in a waterproof cable tray using nylon cable ties.

4. The switched reluctance motor loader electric drive system based on dynamic conduction angle control according to claim 1, characterized in that: The monitor is fixed to the dashboard via an HDMI cable and a power cable, while the power converter and SRM controller are installed in a separate heat dissipation compartment.

Images