Vehicle driving device and vehicle

Abstract

The invention provides a vehicle driving device and a vehicle. The vehicle driving device comprises at least one first branch, a main road, at least one second branch and a third branch, wherein the first branch comprises an engine, a generator and a first converter; wherein the engine drives the generator to output alternating current, the first converter converts the alternating current into direct current and outputs the direct current to the main circuit, the main circuit is communicated with the first branch circuit, the second branch circuit and the third branch circuit, and the second branch circuit converts the direct current of the main circuit into the alternating current and is used for driving a vehicle. And the third branch stores the electric energy from the main road or releases the electric energy to the main road. According to the technical scheme, the third branch is arranged to store the electric energy from the main road or release the electric energy to the main road, so that the fuel consumption of the engine is reduced to a great extent, and the purpose of improving the fuel utilization rate is achieved.

Description

[0001] This application is a divisional application of the Chinese patent application with an application date of December 16, 2020, application number "202011483229.7", and invention name "Vehicle drive device, driving method, vehicle, driving device and storage medium", and all its contents are incorporated into this application by reference. Technical Field

[0002] The present invention relates to the technical field of vehicles, and in particular to a vehicle drive device and a vehicle. Background Art

[0003] At present, in the power system of electric wheel dump trucks, a high-power engine drives a generator, which transmits electrical energy to the electric motor of the rear wheel through the electronic control system to drive the vehicle forward. However, the procurement and maintenance costs of the high-power engine are high. Summary of the Invention

[0004] The present invention aims to solve at least one of the above technical problems.

[0005] To this end, a first object of the present invention is to provide a vehicle drive device.

[0006] A second object of the present invention is to provide a vehicle driving method.

[0007] A third object of the present invention is to provide a vehicle.

[0008] A fourth object of the present invention is to provide a vehicle drive device.

[0009] A fifth object of the present invention is to provide a computer-readable storage medium.

[0010] To achieve the first purpose of the present invention, an embodiment of the present invention provides a vehicle drive device, comprising: at least one first branch, a main road, at least one second branch and a third branch, the first branch comprising an engine, a generator and a first converter; wherein the engine drives the generator to output alternating current, the first converter converts the alternating current into direct current, and outputs the direct current to the main road, the main road connects the first branch, the second branch and the third branch, the second branch converts the direct current of the main road into alternating current for driving the vehicle, and the third branch stores electrical energy from the main road or releases electrical energy to the main road.

[0011] By setting up a third branch to store electricity from the main road or release electricity to the main road, the engine's fuel consumption is greatly reduced, thereby achieving the goal of improving fuel utilization.

[0012] In addition, the technical solutions provided by the above embodiments of the present invention may also have the following additional technical features:

[0013] In the above technical solution, the second branch includes: a drive motor and a second converter; wherein the second converter converts the DC power of the main circuit into AC power and outputs the AC power to the drive motor.

[0014] The second converter converts the DC power of the main road into AC power and outputs it to the drive motor. The drive motor drives the vehicle and provides power for the vehicle to move forward or backward.

[0015] In any of the above technical solutions, the third branch includes: a third converter and a battery; wherein the third converter converts the DC power of the main line into DC power suitable for the battery, and the battery stores electrical energy; or, the battery releases electrical energy, and the electrical energy is output to the main line through the third converter.

[0016] The battery collects excess energy from the generator set when the vehicle is idling and at low power, or when the vehicle is waiting, as well as the electrical energy generated when the vehicle's drive motor converts it into electric braking during downhill driving. When the vehicle is reloaded and in high-power demand conditions, the battery releases electrical energy, thereby reducing the engine's fuel consumption.

[0017] In any of the above technical solutions, when there are multiple first branches, the first branch further includes: a control switch, which is provided on the first branch and is used to control the connection or disconnection of the first branch with the main road.

[0018] When any of the first branches fails, the first branch is disconnected from the main trunk by disconnecting the control switch.

[0019] In any of the above technical solutions, the vehicle drive device further includes: a fourth branch, the fourth branch includes a fourth converter and a braking resistor, the fourth converter converts the DC power of the main line into DC power suitable for the braking resistor, and outputs it to the braking resistor.

[0020] When the stored energy in the third branch reaches the upper limit, a braking resistor is set to consume the excess energy in the main branch.

[0021] To achieve the second purpose of the present invention, an embodiment of the present invention provides a vehicle driving method, which is used for the vehicle driving device in any embodiment of the present invention, including: based on the vehicle accelerator pedal depth being less than or equal to a depth threshold, controlling the engine speed to a first speed, driving the vehicle through the second branch, and when the engine power is greater than the vehicle traction power requirement, controlling the third branch to store electrical energy through the main road; based on the vehicle accelerator pedal depth being greater than the depth threshold, controlling the engine speed to a second speed, driving the vehicle through the second branch, and when the engine power is less than the vehicle traction power requirement, controlling the third branch to release electrical energy to the main road, so that the sum of the engine power and the electrical energy released by the third branch meets the vehicle traction power requirement.

[0022] According to the different power required by the vehicle load, the engine is set to two working states with the same speed, and the third branch is used to store or release electrical energy to reduce the engine's fuel consumption and achieve the purpose of improving fuel utilization.

[0023] In addition, the technical solutions provided by the above embodiments of the present invention may also have the following additional technical features:

[0024] In the above technical solution, the vehicle driving method further includes: after the electric energy stored in the third branch is fully charged, the electric energy is consumed through a braking resistor.

[0025] When the stored energy in the third branch reaches the upper limit, the excess energy in the main branch is consumed through the braking resistor.

[0026] To achieve the third objective of the present invention, an embodiment of the present invention provides a vehicle, comprising: a vehicle body and a vehicle drive device as in any embodiment of the present invention; wherein the vehicle drive device is provided on the vehicle body.

[0027] The vehicle provided by the embodiment of the present invention includes the vehicle drive device as in any embodiment of the present invention, and thus has all the beneficial effects of the vehicle drive device as in any embodiment of the present invention, which will not be described in detail here.

[0028] To achieve the fourth purpose of the present invention, an embodiment of the present invention provides a vehicle driving device, including: a memory and a processor, the memory stores a computer program, and the processor executes the computer program; wherein, when the processor executes the computer program, it implements the steps of the vehicle driving method as any embodiment of the present invention.

[0029] The vehicle driving device provided by the embodiment of the present invention implements the steps of the vehicle driving method of any embodiment of the present invention, and thus has all the beneficial effects of the vehicle driving method of any embodiment of the present invention, which will not be repeated here.

[0030] To achieve the fifth objective of the present invention, an embodiment of the present invention provides a computer-readable storage medium, which stores a computer program. When the computer program is executed, the steps of the vehicle driving method of any of the above embodiments are implemented.

[0031] The computer-readable storage medium provided by the embodiment of the present invention implements the steps of the vehicle driving method as in any embodiment of the present invention, and thus has all the beneficial effects of the vehicle driving method as in any embodiment of the present invention, which will not be repeated here.

[0032] Additional aspects and advantages of the invention will become apparent from the description which follows, or may be learned by practice of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0034] Figure 1 A schematic diagram of a driving method of an electric wheel dump truck in the related art;

[0035] Figure 2 A schematic diagram of a vehicle drive device according to an embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of the composition of the first branch according to an embodiment of the present invention;

[0037] Figure 4 This is a schematic diagram of the composition of the second branch according to an embodiment of the present invention;

[0038] Figure 5 This is a schematic diagram of the composition of the third branch according to an embodiment of the present invention;

[0039] Figure 6 This is a second schematic diagram of the composition of the first branch according to an embodiment of the present invention;

[0040] Figure 7 This is a schematic diagram of the fourth branch circuit according to an embodiment of the present invention;

[0041] Figure 8 This is a second schematic diagram of the composition of the fourth branch according to an embodiment of the present invention;

[0042] Figure 9 A vehicle driving method process according to an embodiment of the present invention is as follows Figure 1 ;

[0043] Figure 10 A vehicle driving method process according to an embodiment of the present invention is as follows Figure 2 ;

[0044] Figure 11 A schematic diagram of a vehicle composition according to an embodiment of the present invention;

[0045] Figure 12 A schematic diagram of the composition of a vehicle drive device according to an embodiment of the present invention;

[0046] Figure 13 A schematic structural diagram of a vehicle drive device according to an embodiment of the present invention;

[0047] Figure 14 A schematic diagram of a vehicle driving device according to an embodiment of the present invention;

[0048] Figure 15 This is a schematic diagram of an engine fuel consumption curve and speed selection according to an embodiment of the present invention.

[0049] in, Figure 1 The corresponding relationship between the reference numerals and component names is as follows:

[0050] 100': diesel engine, 110': generator, 120': AC / DC rectifier module, 130': DC / AC inverter module, 140': wheel motor.

[0051] in, Figures 2 to 15 The corresponding relationship between the reference numerals and component names is as follows:

[0052] 100: Vehicle drive device, 110: First branch, 112: Engine, 114: Generator, 116: First converter, 120: Main road, 130: Second branch, 132: Drive motor, 134: Second converter, 140: Third branch, 142: Third converter, 144: Battery, 150: Control switch, 160: Fourth branch, 162: Fourth converter, 164: Braking resistor, 166: First generator set, 168: Second Generator set, 170: First rectifier, 172: Second rectifier, 178: First rectifier system, 180: Second rectifier system, 182: First drive motor, 184: First inverter unit, 186: Second drive motor, 188: Second inverter unit, 190: Chopper, 194: Charger / discharger, 196: Battery pack, 200: Vehicle, 210: Vehicle body, 300: Vehicle drive equipment, 310: Memory, 320: Processor. DETAILED DESCRIPTION

[0053] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other.

[0054] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0055] Refer to the following Figures 1 to 15 A vehicle driving apparatus 100 , a vehicle driving method, a vehicle 200 , a vehicle driving device 300 , and a computer-readable storage medium according to some embodiments of the present invention are described.

[0056] Electric-wheel dump trucks are characterized by high transport capacity and high efficiency. They account for nearly 70% of the transport equipment used in large open-pit mines with annual production exceeding tens of millions of tons, mining and transporting 40% of the world's coal and the vast majority of iron ore. The current powertrain technology for electric-wheel dump trucks utilizes a high-power engine driving a generator, which, through an electronic control system, transmits electricity to the rear-wheel electric motors to propel the vehicle forward. However, these high-power engines are typically imported, resulting in high procurement and maintenance costs. Furthermore, due to the operational characteristics of open-pit mine transport equipment, the engine's effective operating time is only 20%-35%, with the remainder primarily spent on downhill braking, waiting, and loading and unloading. This leaves significant room for improvement in engine fuel efficiency.

[0057] like Figure 1 As shown, the existing technology route of electric wheel dump trucks is to use an imported high-horsepower engine 100' and an imported main generator 110'. The generator 110' generates alternating current, which is converted into controllable electric energy through an AC / DC rectifier module 120' and multiple DC / AC inverter modules 130', thereby driving multiple wheel motors 140' to provide forward and reverse power for the vehicle.

[0058] In summary, the present embodiment aims to solve at least one of the following problems:

[0059] (1) The purchase and maintenance costs of the high-power engine 100' are high;

[0060] (2) The high-power engine 100' has low fuel efficiency.

[0061] Example 1:

[0062] like Figure 2 and Figure 3 As shown, this embodiment provides a vehicle drive device 100, including: at least one first branch 110, a main road 120, at least one second branch 130 and a third branch 140, the first branch 110 includes an engine 112, a generator 114 and a first converter 116; wherein, the engine 112 drives the generator 114 to output alternating current, the first converter 116 converts the alternating current into direct current, and outputs the direct current to the main road 120, the main road 120 connects the first branch 110, the second branch 130 and the third branch 140, the second branch 130 converts the direct current of the main road 120 into alternating current for driving the vehicle 200, and the third branch 140 stores electrical energy from the main road 120 or releases electrical energy to the main road 120.

[0063] For example, the vehicle 200 in this embodiment may be an electric wheel dump truck, and the weight of the electric wheel dump truck is 100 tons to 363 tons.

[0064] In this embodiment, when the number of the first branch 110 is one, an engine 112 and a generator 114 are used to meet the power requirements of the vehicle 200 .

[0065] When there are multiple first branches 110, the total power of the multiple engines 112 meets the power requirements of the vehicle 200. The engine 112 of the first branch 110 drives the generator 114 to output AC power. The first converter 116 converts the AC power into DC power, connects the DC power to the grid, and outputs it to the main road 120. By using a combination of multiple engines 112 and multiple generators 114 to replace high-power engines and generators, the manufacturing cost and maintenance cost of the vehicle 200 are reduced, and the performance of the vehicle 200 is not reduced.

[0066] In this embodiment, the number of the second branches 130 can be two, which are used to drive the vehicle 200 .

[0067] This embodiment provides a third branch 140 to store electrical energy from the main road 120 or release electrical energy to the main road 120 , thereby greatly reducing the fuel consumption of the engine and achieving the purpose of improving fuel utilization.

[0068] Example 2:

[0069] like Figure 4 As shown, in addition to the technical features of the above embodiment, this embodiment further includes the following technical features:

[0070] The second branch 130 includes a drive motor 132 and a second converter 134 . The second converter 134 converts the DC power of the main branch 120 into AC power and outputs the AC power to the drive motor 132 .

[0071] The second converter 134 converts the DC power of the main road 120 into AC power and outputs the AC power to the drive motor 132 . The drive motor 132 drives the vehicle 200 and provides power for the vehicle 200 to move forward or backward.

[0072] Example 3:

[0073] like Figure 5 As shown, in addition to the technical features of the above embodiment, this embodiment further includes the following technical features:

[0074] The third branch 140 includes: a third converter 142 and a battery 144; wherein the third converter 142 converts the DC power of the main line 120 into DC power suitable for the battery 144, and the battery 144 stores the electrical energy; or, the battery 144 releases the electrical energy, and the electrical energy is output to the main line 120 through the third converter 142.

[0075] In this embodiment, the battery 144 may be a battery pack.

[0076] The battery 144 collects excess energy from the generator set when the vehicle 200 is idling and at low power or when the vehicle 200 is waiting, as well as the electrical energy generated when the vehicle 200 drives the motor 132 to convert it into electric braking during downhill operation. The generator set refers to the engine 112 and the generator 114. When the vehicle 200 is in a condition with high power requirements, the battery 144 releases electrical energy, thereby reducing the fuel consumption of the engine 112.

[0077] Example 4:

[0078] like Figure 6 As shown, in addition to the technical features of the above embodiment, this embodiment further includes the following technical features:

[0079] When there are multiple first branches 110 , the first branch 110 further includes a control switch 150 . The control switch 150 is provided on the first branch 110 and is used to control the connection or disconnection between the first branch 110 and the main road 120 .

[0080] When multiple first branches 110 are used, a control switch 150 is provided on each first branch 110 . When a first branch 110 fails, the control switch 150 is disconnected to disconnect the first branch 110 from the main line 120 .

[0081] Example 5:

[0082] like Figure 7 and Figure 8 As shown, in addition to the technical features of the above embodiment, this embodiment further includes the following technical features:

[0083] The vehicle driving device 100 further includes a fourth branch 160 , which includes a fourth converter 162 and a braking resistor 164 . The fourth converter 162 converts the DC power of the main line 120 into DC power suitable for the braking resistor 164 and outputs the DC power to the braking resistor 164 .

[0084] For example, when the electric energy stored in the third branch 140 reaches an upper limit, the braking resistor 164 is provided to consume the excess electric energy in the main branch 120 .

[0085] Example 6:

[0086] like Figure 9 As shown, this embodiment provides a vehicle driving method, which is used in the vehicle driving device 100 in any embodiment of the present invention, and includes the following steps:

[0087] Step S102: Based on the vehicle's accelerator pedal depth being less than or equal to a depth threshold, the engine speed is controlled to a first speed, the vehicle is driven via the second branch, and when the engine power exceeds the vehicle's traction power requirement, the third branch is controlled to store electrical energy via the main road.

[0088] In step S104, based on the fact that the depth of the vehicle's accelerator pedal is greater than the depth threshold, the engine speed is controlled to be a second speed, and the vehicle is driven through the second branch. When the engine power is less than the vehicle's traction power requirement, the third branch is controlled to release electrical energy to the main road, so that the sum of the engine power and the electrical energy released by the third branch meets the vehicle's traction power requirement.

[0089] In this embodiment, the engine is set to two operating states with the same speed according to the different powers required by the load of the vehicle 200, namely a high-power optimal economic speed (second speed) and a low-power fuel-saving speed (first speed).

[0090] For example, the throttle depth threshold of vehicle 200 can be set to 30% of the throttle depth, i.e., the throttle depth range of 0% to 30% corresponds to 800 rpm to 1400 rpm, and 30% to 100% corresponds to 1400 rpm to 1800 rpm. The first speed can be set to 800 rpm to 1400 rpm, and the second speed can be set to 1400 rpm to 1800 rpm.

[0091] When the accelerator pedal depth of vehicle 200 is less than or equal to the depth threshold, the speed of engine 112 is controlled to be a first speed, that is, a low-power fuel-saving speed, and the third branch 140 stores electrical energy through the main road 120. When the accelerator pedal depth of vehicle 200 is greater than the depth threshold, the speed of engine 112 is controlled to be a second speed, that is, a high-power optimal economic speed, and the third branch 140 releases electrical energy to the main road 120. The released electrical energy drives the drive motor 132, thereby meeting the high power requirements of vehicle 200.

[0092] By setting a high-power optimal economic speed and a low-power fuel-saving speed, and coordinating the third branch 140 to store or release electrical energy, the fuel consumption of the engine 112 is reduced, thereby achieving the purpose of improving fuel utilization.

[0093] Example 7:

[0094] like Figure 10 As shown, in addition to the technical features of the above embodiment, this embodiment further includes the following technical features:

[0095] The vehicle driving method further includes the following steps:

[0096] Step S202: After the electric energy stored in the third branch is fully charged, the electric energy is consumed through the braking resistor.

[0097] When the electric energy stored in the third branch 140 reaches an upper limit, the excess electric energy in the main branch 120 is consumed through the braking resistor 164 .

[0098] Example 8:

[0099] like Figure 11 As shown, this embodiment provides a vehicle 200 , comprising: a vehicle body 210 and a vehicle drive device 100 as in any embodiment of the present invention; wherein the vehicle drive device 100 is disposed on the vehicle body 210 .

[0100] Example 9:

[0101] like Figure 12 As shown, this embodiment provides a vehicle driving device 300, including: a memory 310 and a processor 320, the memory 310 stores a computer program, and the processor 320 executes the computer program; wherein, when the processor 320 executes the computer program, it implements the steps of the vehicle driving method as any embodiment of the present invention.

[0102] Example 10:

[0103] This embodiment provides a computer-readable storage medium, which stores a computer program. When the computer program is executed, the steps of the vehicle driving method of any of the above embodiments are implemented.

[0104] The main objectives of this embodiment are: (1) to provide a technical solution to the high cost of purchasing and using high-power engines and generators used in electric wheel dump trucks with a load capacity of 100 tons to 363 tons. (2) to provide a technology to reduce the fuel consumption of electric wheel dump trucks with a load capacity of 100 tons to 363 tons.

[0105] To achieve the above objectives, this embodiment provides a vehicle drive device 100 that can utilize multiple low-power generator sets (2, 3, 4, ... n sets) to replace the high-power engine and generator combination of an electric wheel dump truck, wherein the generator set includes an engine and a generator. Furthermore, an energy control device (i.e., third branch 140) is provided. This device is used to collect the kinetic energy and potential energy of the vehicle when descending a slope and braking, as well as the excess electrical energy of the power module (i.e., first branch 110) when the vehicle 200 is unloaded or waiting. All collected energy is used to meet the energy needs of the vehicle 200 when it is heavily loaded.

[0106] In order to achieve the above-mentioned purpose, this embodiment provides a vehicle driving method, namely, a control method for multiple engines 112. According to the different power required by the vehicle 200 load, the multiple engines 112 are set to two working states with the same speed, namely, a high-power optimal economic speed and a low-power fuel-saving speed.

[0107] For example, the vehicle driving device 100 of this embodiment uses two or more small generator sets (i.e., a combination of an engine 112 and a generator 114) to replace imported high-horsepower engines and generators while achieving the power required by a dump truck. This significantly reduces the manufacturing cost of the dump truck without reducing the performance of the dump truck. Figure 13 As shown, the first first branch 110 includes a first generator set 166 and a first rectifier 170, and the second first branch 110 includes a second generator set 168 and a second rectifier 172, wherein the first generator set 166 and the second generator set 168 are first rectified by the first rectifier 170 (AC / DC converter) and the second rectifier 172 (AC / DC converter) respectively, and then connected to the grid (entering the main road 120) after obtaining direct current. Each branch is provided with a control switch 150.

[0108] The main principle diagram of this embodiment is shown in FIG. Figure 14 As shown, the electric energy of the first generator set 166 passes through the first rectifier system 178 and is then connected to the DC grid. The electric energy of the second generator set 168 passes through the second rectifier system 180 and is then connected to the DC grid. The electric energy after the DC grid connection is passed through the first inverter unit 184 to control the first drive motor 182, and through the second inverter unit 188 to control the second drive motor 186. At the same time, the current main circuit after the grid connection is also connected to the braking resistor 164 through the chopper 190, and is connected to the battery pack 196 through the charger 194.

[0109] Among them, G1 represents the first generator set 166 composed of an engine and a generator, G2 represents the second generator set 168 composed of an engine and a generator, RET1 represents the first rectifier system 178, RET2 represents the second rectifier system 180, VVVF1 represents the first inverter unit 184, VVVF2 represents the second inverter unit 188, TM1 represents the first drive motor 182, TM2 represents the second drive motor 186, CH represents the chopper 190, BR represents the braking resistor 164, BC represents the charger 194, and BAT represents the battery pack.

[0110] The basic method of the hybrid electric wheel dump truck technology based on multiple engine modules is that the battery pack collects excess energy from the generator set when the vehicle 200 is idling and low power and when the vehicle is waiting, as well as the electrical energy generated when the vehicle 200 converts the drive motor into a generator for electric braking during downhill operation, and collects the energy for use in the vehicle 200 under high power demand conditions during heavy loading, thereby reducing the fuel consumption of the engine 112.

[0111] As shown in Table 1, at a given engine speed, the lower the output power, the greater the BSFC (engine specific fuel consumption) value, and the worse the economic performance. This embodiment selects several economic engine speeds to maximize engine output power within these conditions. Engine 112 drives generator 114, which generates electrical energy that is stored in the lithium battery pack for use when vehicle 200 is heavily loaded.

[0112] Table 1 Relationship between engine speed and BSFC value

[0113] Engine speed Engine power BSFC value 800rpm ≤30kW 300g / kWh 800rpm 100kW 205g / kWh 1400rpm ≤50kW 300g / kWh 1400rpm 150kW 205g / kWh 1400rpm 200kW 200g / kWh 1400rpm 220kW 195g / kWh 1800rpm 500kW 200g / kWh 1800rpm 565kW 200g / kWh

[0114] The following describes the implementation steps of the hybrid technology of this embodiment through the specific conditions of each stage of the operation of the electric wheel dump truck:

[0115] (1) Engine 112 Idle Battery 144 Charging Mode

[0116] From the fuel consumption curve (BSFC) of the engine 112 , it can be seen that when the engine 112 is at a certain speed and the load power is very low (only the auxiliary power of the engine 112 ), the fuel consumption rate is very high, which means that the efficiency of the engine 112 is very low.

[0117] Charging battery 144 via the DC / DC converter (third converter 142) increases the output power of engine 112, optimizing its BSFC. This effectively operates engine 112 at an optimal BSFC state. Excess energy is temporarily stored in battery 144 and consumed when vehicle 200 reaches maximum power output. Whether this mode is energy-efficient depends on the economical ratio of stored energy to increased fuel consumption while battery 144 is charging. The BSFC of engine 112 is calculated based on the energy stored in battery 144 and the increased fuel consumption. If the resulting BSFC is lower than the BSFC corresponding to full engine 112 power, energy savings are achieved.

[0118] (2) Dump truck coasting battery charging mode

[0119] When the dump truck releases the accelerator pedal and coasts, the engine 112 speed will drop from high speed to idle speed. Since no traction is output, the load power of the engine 112 is very low (only the auxiliary power of the engine), and the efficiency of the engine 112 is very low.

[0120] If when the dump truck is coasting, the battery 144 is charged, the output power of the engine 112 is increased, and the engine 112 is operated in a state of high efficiency, which also has an energy-saving effect. This working state is consistent with the battery 144 charging operation mode when the dump truck is parked and idling.

[0121] (3) Vehicle 200 acceleration mode

[0122] In order to have better acceleration performance, traditional electric wheel dump trucks are generally designed with low idle and high idle. Low idle is adopted when parking in the middle gear. When the gear position is forward or backward, the engine 112 is controlled to high idle, which can ensure that greater power can be output immediately during acceleration.

[0123] However, when the engine 112 is at high idle speed (typically 1300 rpm or 1400 rpm), the output power is low, and the fuel economy of the engine 112 is very poor. Therefore, in the traditional engine-only mode, when the dump truck is coasting before acceleration (output power < 100 kW), the efficiency of the engine 112 is very low, which is not conducive to energy saving.

[0124] In the hybrid drive mode, at low power output, the speed of the engine 112 is always controlled at a low value (800 rpm). During acceleration, the engine is always controlled according to the optimal power output mode corresponding to the speed. Although the speed of the engine 112 increases slowly, the battery 144 can be used to supplement power to ensure the acceleration performance of the vehicle 200.

[0125] In the hybrid drive control mode without high idle speed, it can ensure that the engine 112 always operates in the economic range, achieving energy-saving effects.

[0126] (4) Downhill electric braking mode

[0127] When the dump truck is going downhill, electric braking is applied to control the vehicle speed. At this time, the battery 144 is charged first through the DC / DC (third converter 142) to absorb and store feedback energy, and the remaining energy is consumed by the braking resistor.

[0128] According to the GBJ22 factory and mine road design specification for the third-level open-pit mine road, the corresponding distances of different slopes, the no-load downhill time of a 150-ton electric wheel dump truck and the electrical energy stored in the battery 144 are shown in Table 2.

[0129] Table 2 Downhill stored energy

[0130]

[0131] The actual power control method of the hybrid system on the generator 114 is:

[0132] To ensure optimal BSFC for engine 112, the electric drive system uses pedal depth as a given system power, and controls the corresponding engine speed to ensure that engine 112 always operates at high efficiency. When traction power is not required, such as during parking, coasting, or electric braking, the engine is controlled at 800 rpm and charges battery 144 at a constant power.

[0133] During the vehicle's uphill or dynamic acceleration process, the engine 112 is always controlled in the economic range of 1400 rpm-1800 rpm. When the accelerator pedal depth and the engine 112 speed do not match, the battery 144 can be used to supplement the power to meet the traction power demand, such as Figure 15 shown. Figure 15 In the figure, the horizontal axis represents the engine speed, the vertical axis represents the engine output torque, the solid line represents the fuel consumption value, and the dotted line represents the power value.

[0134] This embodiment effectively solves the problem of purchasing imported high-horsepower engines and high cost prices for electric wheel dump trucks for mining, and thus the manufacturing cost and selling price of electric wheel dump trucks for mining are significantly reduced.

[0135] When users of open-pit mines use electric wheel dump trucks for mining, fuel consumption usually accounts for more than 45% of the total cost of use. This embodiment can reduce fuel consumption by more than 10%, which has great economic benefits.

[0136] In summary, the beneficial effects of the embodiments of the present invention are:

[0137] 1. By using a combination of multiple engines 112 and multiple generators 114 to replace high-power engines and generators, the manufacturing cost and maintenance cost of the vehicle 200 are reduced without reducing the performance of the vehicle 200.

[0138] 2. By providing the third branch 140, electrical energy from the main road 120 is stored or released to the main road 120, thereby greatly reducing the fuel consumption of the engine and achieving the purpose of improving fuel utilization.

[0139] In the present invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "plurality" refers to two or more, unless expressly limited otherwise. Terms such as "installed," "connected," "connected," and "fixed" should be interpreted broadly. For example, "connected" can mean a fixed connection, a detachable connection, or an integral connection; "connected" can mean a direct connection or an indirect connection through an intermediary. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0140] In the description of the present invention, it should be understood that the directions or positional relationships indicated by terms such as "up", "down", "left", "right", "front" and "back" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0141] Throughout this specification, terms such as "one embodiment," "some embodiments," and "specific embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these 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 any one or more embodiments or examples.

[0142] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A vehicle driving device, characterized in that: The vehicle drive device is used for a mining electric wheel dump truck, comprising: Main road; At least one first branch, the first branch comprising an engine, a generator, and a first converter; the engine drives the generator to output alternating current, the first converter converts the alternating current into direct current, and outputs the direct current to the main road; at least one second branch connected to the main road, comprising a drive motor and a second converter, wherein the drive motor is used to drive the electric wheel dump truck for mining, and the second converter converts the direct current of the main road into alternating current and outputs the alternating current to the drive motor; a third branch road connected to the main road, comprising a battery and a third converter, wherein the battery is used to collect excess energy from the first branch road when the electric wheel dump truck for mining is in an unloaded and low-power state or when the electric wheel dump truck for mining is waiting, as well as electrical energy generated by the driving motor of the electric wheel dump truck during downhill operation converted into electrical energy generated by the generator during electric braking; the third converter converts the DC power of the main road into DC power suitable for the battery, and the battery stores the electrical energy; or the battery releases the electrical energy, and the electrical energy is output to the main road through the third converter; a fourth branch, connected to the main road, comprising a fourth converter and a braking resistor, wherein the fourth converter converts the DC power of the main road into DC power suitable for the braking resistor and outputs the DC power to the braking resistor; When the engine is idling and the output power is equal to the auxiliary power of the engine, increasing the output power of the engine and controlling the battery to collect excess electric energy; When the electric wheel dump truck for mining is in coasting and the accelerator pedal of the electric wheel dump truck for mining is lost, increasing the output power of the engine and controlling the battery to collect the excess electric energy; When the electric wheel dump truck for mining is accelerating, the electric wheel dump truck for mining controls the engine to output at a first speed before accelerating, and during acceleration, controls the engine according to an optimal power output mode corresponding to the speed, and controls the battery to output supplementary power to meet the acceleration requirement of the electric wheel dump truck for mining; When the electric wheel dump truck for mining is in downhill electric braking, the battery is controlled to collect the electric energy generated by the driving motor of the electric wheel dump truck for mining converted into the electric braking of the generator during the downhill process, and the remaining energy is consumed by the braking resistor.

2. The vehicle drive device according to claim 1, wherein: A ratio of the excess electric energy collected by the battery to the increased fuel consumption of the engine due to the increased output power is less than or equal to a BSFC value corresponding to the full power of the engine.

3. The vehicle driving device according to claim 1, wherein: The depth of the accelerator pedal of the electric wheel dump truck for mining is given as the system power of the engine.

4. The vehicle driving device according to claim 3, characterized in that: Also includes: When the electric wheel dump truck for mining does not need traction power, controlling the engine to run at the first speed and charging the battery at a constant power; When the mining electric wheel dump truck is in an uphill or dynamic acceleration process, the engine is controlled to be in the economic range of the second speed. When the accelerator pedal depth and the engine speed do not match, the battery is controlled to output supplementary power to meet the traction power demand.

5. The vehicle driving device according to claim 4, characterized in that: The first rotation speed is 800 rpm.

6. The vehicle drive device according to claim 4 or 5, characterized in that: The second rotation speed is in the range of 1400 rpm-1800 rpm.

7. The vehicle driving device according to claim 1, wherein: It also includes a charger and a discharger, which is connected to the battery.

8. The vehicle driving device according to claim 1, wherein: The first branch further includes a control switch for controlling the connection or disconnection of the first branch and the main line respectively.

9. The vehicle driving device according to claim 1, wherein: It also includes a chopper; the chopper is connected to the braking resistor.

10. A vehicle, characterized in that: The vehicle is a mining electric wheel dump truck, and the vehicle comprises: Vehicle body; The vehicle drive device according to any one of claims 1 to 9; Wherein, the vehicle driving device is arranged on the vehicle body.

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