WO2019109702A1

WO2019109702A1 - Electrical transmission method and system for off-road vehicle

Info

Publication number: WO2019109702A1
Application number: PCT/CN2018/105439
Authority: WO
Inventors: 梁金成; 胡家喜; 蓝德劭; 刘辉荣; 何亚屏; 张文进; 刘猛; 胡仙; 唐勋路; 郜永涛
Original assignee: 株洲中车时代电气股份有限公司
Priority date: 2017-12-06
Filing date: 2018-09-13
Publication date: 2019-06-13
Also published as: CN109878338A; CN109878338B; AU2018379888A1

Abstract

An electrical transmission system (100) for an off-road vehicle comprises: a main power supply device (101) comprising an overhead line power supply module (1011) and an electric energy storage and supply module (1012) which supply power to multiple traction motors (1, 2) of an off-road vehicle at different times; and an auxiliary power supply device (102) for supplying power to an auxiliary load of the off-road vehicle. Power is independently supplied to the main transmission system (100) and the auxiliary load, thereby increasing reliability of the vehicle. The electric energy storage and supply module (1012) can store braking energy. Moreover, the invention adopts two power supply modes to alternately supply power according to an operating state of an off-road vehicle.

Description

Off-road vehicle electric drive method and system

The present application claims priority to Chinese Patent Application No. CN201711277435.0, filed on Dec. 6, s.

Technical field

The present invention relates to the field of vehicle control, and in particular to a method and system for electric drive of off-highway vehicles.

Background technique

The characteristics of off-highway vehicles are: the shape is huge, some vehicles have a tire diameter of more than 5 meters; the tonnage is large, generally 100 to 500 tons; the power is strong, the off-highway vehicles are equipped with large diesel engines, and the displacement is even over 100 liters. The total power exceeds 3,700 horsepower; the operating conditions are harsh, the environment is harsh, and the road conditions are complex and changeable. Due to the above characteristics, these vehicles cannot run on standard roads and can only run on dedicated roads, so they are called off-highway vehicles. Off-highway vehicles are widely used in mines, large-scale construction projects, hydropower dam projects, iron powder or coal yards where large-scale transportation is required.

Most of the off-highway vehicles use an electric drive system. Similar to the diesel locomotive, the diesel engine on the vehicle drives the generator. The generator generates electricity through a traction converter and converts it into a variable voltage variable frequency (VVVF) power supply to drive the traction motor. The electric drive traction system is the core component of off-highway vehicles. The traditional electric drive system is mainly composed of diesel engine, generator, converter, braking resistor and hub motor.

At present, there is a pure electric dump truck drive system using a power battery pack, and auxiliary motors such as a traction motor and a lift pump motor are powered by a power battery pack. However, for off-highway vehicles with hundreds of tons of load, the solution requires a large amount of power battery and a very high cost; and in the case of no breakthrough in high-power fast charging technology, the charging time is much longer than the running time of the vehicle. It is very difficult to implement.

Therefore, there is an urgent need for a more efficient off-road vehicle electric drive method and system.

Summary of the invention

One of the technical problems to be solved by the present invention is to provide a more efficient off-road vehicle electric drive method and system.

1) In order to solve the above technical problem, the present invention provides an off-highway electric drive system, comprising: a main power supply device comprising a contact network power supply module and a savings power supply module, the contact network power supply module and the saved power The power supply module is connected, and the two supply power to the plurality of traction motors of the off-highway vehicle by means of time-sharing power supply, wherein the stored power supply module absorbs braking energy when the off-highway vehicle is in a braking state; A power supply device for supplying power to an auxiliary load of the off-highway vehicle.

2) In a preferred embodiment of the first aspect of the present invention, the contact network power supply module supplies power to the plurality of traction motors and the power storage power supply module via a contact network, the contact network power supply module comprising:

a pantograph for receiving input power transmitted by the contact net when raised, and isolating the contact net when lowered;

a power receiving unit connected to the pantograph, comprising a DC circuit breaker, a charging subunit, and a filtering subunit, wherein the charging subunit is configured to delay input time of the input electric energy, the filtering subunit For filtering the input electrical energy;

The main inverter has a DC side connected to the power receiving unit for driving the plurality of traction motors, wherein the number of the main inverters is a positive integer.

3) In a preferred embodiment of the first or second aspect of the present invention, the power storage power supply module is a power battery pack, a super capacitor, a fuel cell, and a lithium battery, and is connected to the power receiving unit And between the main inverters for supplying power to the plurality of traction motors when the off-highway vehicle is disengaged from the contact net.

4) In a preferred embodiment of any one of the items 1) to 3), the auxiliary power supply device comprises:

a diesel engine for providing drive energy;

An auxiliary generator connected to the diesel engine by coaxial connection for receiving the driving energy provided by the diesel engine and generating electric energy;

An auxiliary rectifier connected to the auxiliary generator for receiving the electrical energy and rectifying the electrical energy to obtain rectified processed rectified electrical energy;

An auxiliary inverter having a DC side connected to the auxiliary rectifier for receiving the rectified electric energy and driving the auxiliary load by the rectified electric energy, wherein the number of the auxiliary inverters is a positive integer, wherein The auxiliary load includes a main fan, a resistance cabinet fan, and a hydraulic pump motor.

5) In a preferred embodiment of any one of the items 1) to 4), further comprising a DC conversion device between the power receiving unit and the main inverter, The main inverter common DC bus is configured to control the DC side to charge the saving power supply module when the saving power supply module is charged, and to control the saving power supply module when the saving power supply module is discharged Discharging to the DC side, and automatically matching the voltage between the two when the voltage of the stored power supply module does not match the voltage of the DC side.

6) In a preferred embodiment of any one of the items 1) to 5), the brake receiving device is further included between the power receiving unit and the main inverter, Braking energy exceeding the set threshold is consumed when the braking energy exceeds a set threshold.

7) In a preferred embodiment of any one of the items 1), wherein the system further comprises a charging interface connected to the saving power supply module for receiving an external Charging a power source to power the stored power supply module, wherein the charging interface includes a circuit breaker that interlocks with the DC circuit breaker.

8) In a preferred embodiment of any one of the items 1), wherein the system further comprises a power management module coupled to the saving power supply module for managing The voltage, temperature rise, fault, power consumption, and power flow direction of the saving power supply module.

9) In a preferred embodiment of the first item to the eighth item of the present invention, the system further includes a grounding detecting device for detecting a grounding state of the portion of the DC busbar to be tested, which includes the saving power supply module Grounding detection device, main inverter grounding detection device, and auxiliary inverter grounding detection device.

10) According to another aspect of the present invention, there is also provided an off-highway electric drive method comprising: supplying power to a plurality of traction motors of the off-highway vehicle by a main power supply device, the main power supply device comprising a contact network power supply a module and a saving power supply module, both of which supply power to a plurality of traction motors of the off-highway vehicle in a time-sharing manner, wherein the stored power supply module absorbs braking when the off-highway vehicle is in a braking state Energy; power is supplied to the auxiliary load of the off-highway vehicle by an auxiliary power supply device.

One or more embodiments of the present invention may have the following advantages over the prior art:

In the present invention, the DC contact network and the power storage power supply module are jointly supplied with power to the main drive system to assist the diesel generator set to supply power to the auxiliary load. The main drive system and the auxiliary load are independent of each other, which improves the reliability of the whole vehicle. Among them, the saving power supply module can store the braking energy, and can also be charged by the external power source when the power is insufficient. Moreover, the saving power supply module can increase or decrease the amount of energy storage medium according to the actual demand of the vehicle. In addition, the present invention is also capable of alternately supplying power in two power supply modes depending on the operating state of the off-highway vehicle.

Other features and advantages of the invention will be set forth in the description which follows, The objectives and other advantages of the invention may be realized and obtained by means of the structure particularly pointed in the appended claims.

DRAWINGS

The drawings are intended to provide a further understanding of the invention, and are intended to be a part of the description of the invention. In the drawing:

1 is a block diagram showing the structure of an off-highway electric drive system according to an embodiment of the present invention;

2 is a block diagram showing the structure of a main power supply device for an off-highway electric drive system according to an embodiment of the present invention;

3 is a block diagram showing the structure of an auxiliary power supply device for an off-highway electric drive system according to an embodiment of the present invention;

4 is a circuit diagram of a brake consuming device for an off-highway electric drive system in accordance with an embodiment of the present invention;

Figure 5 is a circuit diagram showing a grounding monitoring device for an off-highway electric drive system in accordance with one embodiment of the present invention;

6 is a circuit diagram of a brake consuming device for an off-highway electric drive system in accordance with another embodiment of the present invention;

Figure 7 is a flow chart showing the time sharing power supply mode of the off-highway vehicle electric drive method in accordance with one embodiment of the present invention.

Detailed ways

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail below with reference to the accompanying drawings.

1 is a block diagram showing the structure of an off-highway electric drive system in accordance with one embodiment of the present invention. As shown in FIG. 1, the electric drive system 100 includes a main power supply device 101 and an auxiliary power supply device 102. The main power supply device 101 includes a contact network power supply module 1011 and a power storage power supply module 1012.

In the system provided by the present invention, the main power supply device 101 includes a contact network power supply module 1011 and a power storage power supply module 1012. The contact network power supply module 1011 is connected to the power storage power supply module 1012, and the two are connected to the off-highway vehicle by means of time-sharing power supply. The plurality of traction motors are powered, wherein the savings power supply module 1012 absorbs braking energy when the off-highway vehicle is in a braking state. The auxiliary power supply device 102 is used to supply power to an auxiliary load of the off-highway vehicle.

According to one embodiment of the invention, the catenary is a power line that is erected over the road of the off-highway vehicle for the pantograph to take. The catenary consists of contact suspensions, support devices, positioning devices, and pillars and foundations.

Among them, the contact suspension includes contact wires, suspension strings, load cables, and connecting parts and insulators. The contact suspension is erected on the support by means of a support device, the function of which is to transfer electrical energy obtained from the traction substation to the off-highway vehicle.

The support device is used to support the contact suspension and transfer its load to the strut or other building. The support device differs depending on the environment surrounding the hypothetical area of the contact network. Supporting devices include wrist arms, horizontal tie rods, suspension insulator strings, rod insulators and special support equipment for other buildings.

The positioning device comprises a positioning tube and a positioner, and the function thereof is to fix the position of the contact line, so that the contact line is within the range of the track of the pantograph slide, ensuring that the contact line and the pantograph are not separated, and the horizontal load of the contact line is transmitted to the contact line. pillar.

The struts and foundations are used to withstand the full load of the contact suspension, the support device, and the positioning device, and secure the contact suspension at a prescribed position and height. At present, the prestressed reinforced concrete pillars and steel columns are used in the contact net. The foundation is for the steel pillars, that is, the steel pillars are fixed on the basis of the reinforced concrete below, and the entire load transmitted by the foundation bears the pillars. And to ensure the stability of the pillars. The prestressed reinforced concrete struts are made in one piece with the foundation and the lower end is directly buried in the ground.

The invention adopts the contact net and the saving electric energy power supply module to jointly supply the traction motor of the main transmission system, and can recover, store and reuse the braking energy, and has low running cost and high reliability. The saving electric power supply module only needs to provide the driving energy between the contact net and the loading point, the contact net and the unloading point of the off-highway vehicle, so the quantity and cost of saving electric energy can be controlled. Auxiliary power supply to power the auxiliary load. The invention adopts the way of separating the power supply between the main transmission system and the auxiliary load system, thereby improving the reliability of the whole vehicle.

2 is a block diagram showing the structure of a main power supply device for an off-highway electric drive system according to an embodiment of the present invention. As shown in FIG. 2, the main power supply device includes a pantograph 1011A, a power receiving unit 1011B, a main inverter 1011C, a saving power supply module 1012, a DC converter 201, a brake consuming device 202, a charging interface 203, and a power management module. 204. A saving power supply module grounding monitoring device 2051 and a main inverter grounding monitoring device 2052.

In one embodiment of the invention, the pantograph 1011A includes a positive pantograph P and a negative pantograph N. When the electric drive system is powered by the contact network, the pantograph P and the negative pantograph N are simultaneously raised and connected to the contact net. The traction motor of the main drive system is powered by the contact net, and the contact net power is directly input to the DC side. When the electric drive system is disengaged from the contact net, the positive pantograph P and the negative pantograph N are simultaneously lowered, and the traction motor of the main drive system is powered by the saving electric power supply module 1012.

In an embodiment of the invention, the power receiving unit 1011B includes a DC circuit breaker, a charging subunit, and a filtering subunit. The DC circuit breaker is interlocked with the DC circuit breaker of the charging interface 203. The charging sub-unit can make the voltage on the DC side rise slowly, and prevent the contact network power supply from being input to the DC side too quickly. The filtering sub-unit functions to filter the contact network power supply and avoid mutual influence between the contact network and the DC side.

The power receiving unit 1011B in the present invention supplies the contact network power to the DC side. The DC side is the common DC side of the main inverter 1011C and the DC converter 201.

Preferably, the two main inverters 1011C in the present invention drive the traction motor 1 and the traction motor 2, respectively. The main inverter 1011C adopts a voltage source type three-phase inverter structure, including a heat sink, an IGBT, and a supporting capacitor. The main inverter 1011C adopts a common DC bus working mode. According to the number of traction motors designed for the off-highway vehicle, the present invention can conveniently expand the number of the main inverter and the traction motor, and the expansion mode is as shown in FIG. 2 . The inverter is connected in the same way as the traction motor.

According to an embodiment of the present invention, the brake consuming device 202 can consume a portion of the braking energy when the braking energy is excessive, wherein the braking consuming device 202 includes the chopper 2021 and the braking resistor 2022, and the chopper 2021 The passage of braking energy to the braking resistor 2022 can be controlled and the amount of energy flowing to the braking resistor 2022 can be controlled.

One implementation of chopper 2021 and braking resistor 2022 is shown in FIG. 4, which shows a circuit diagram of a brake consumer of an off-highway electric drive system in accordance with one embodiment of the present invention. As shown in FIG. 4, the chopper 2021 includes an insulated gate bipolar transistor 401, a diode 402, and a diode 403. In FIG. 4, an insulated gate bipolar transistor 401 is used as a control switch, and a braking resistor 2022 is connected in parallel with the diode 403. Insulated Gate Bipolar Transistor (IGBT) is a composite fully-regulated voltage-driven power semiconductor device composed of BJT (bipolar transistor) and MOS (insulated gate field effect transistor), which has both MOSFETs. That is, the high input impedance of the metal-oxide semiconductor field effect transistor and the low on-voltage drop of the GTR power transistor. The GTR saturation voltage is reduced, the current carrying density is large, but the driving current is large; the MOSFET driving power is small, the switching speed is fast, but the conduction voltage drop is large, and the current carrying density is small. The IGBT combines the advantages of the above two devices, with low driving power and reduced saturation voltage.

Therefore, in one embodiment of the present invention, an IGBT can be employed as the control switch, which satisfies the need to consume a portion of the braking energy when the braking energy is excessive.

Additionally, the present invention also provides an embodiment of a brake consuming device 202. 6 is a circuit diagram of a brake consuming device for an off-highway electric drive system in accordance with another embodiment of the present invention. As shown in FIG. 6, the brake consuming device 202 includes a three-phase inverter 601, a chopper 602, and a braking resistor 2022. By integrating the chopper 602 with the three-phase inverter 601, instead of the previous chopper 2021, it is also possible to absorb a portion of the braking energy when the braking energy is excessive.

In the present invention, the DC converter 201 functions to control the DC side to stably charge the stored power supply module 1012 while the power storage module 1012 is being charged. When the saving power supply module 1012 is discharged, the control saving power supply module 1012 is stably discharged to the DC side. When the voltage of the saving power supply module 1012 does not match the voltage of the DC side, the voltage is automatically changed.

According to another embodiment of the present invention, the DC converter 201 can also be designed to design the power storage module 1012 to a voltage level and a voltage fluctuation range that match the contact network voltage, thereby eliminating the DC converter 201. The power supply module 1012 is directly powered by the contact network.

In addition, on the basis of the above solution, a DC step-down converter can be added to the back end of the saving power supply module 1012, and charged by an external low-voltage power source. Finally, other devices or links that improve functions and auxiliary properties such as isolation and transformation can be added between the DC side, the saving power supply module 1012, and the charging interface 203. Other DC conversion device solutions capable of supporting the present invention can also be applied to the embodiments of the present invention, and the present invention is not limited thereto.

In addition, the saving power supply module 1012 is formed by connecting a plurality of power battery cells in series and in parallel, and absorbs braking energy when the off-highway vehicle brakes; and supplies power to the main inverter when the off-highway vehicle is out of the contact network. Braking energy refers to when the off-highway vehicle is decelerating or braking, the traction motor is in the generator state, and the electric energy is fed back to the DC side. The saving power supply module 1012 adopts a modular design, and can be easily expanded according to the distance between the contact net and the loading point, the distance between the contact net and the unloading point, and converted into the number of batteries that need to be increased.

In the present invention, the charging power supply module 1012 charging scheme is: when the off-highway vehicle is connected to the contact network, the charging network charges the saving power supply module 1012; when the off-highway vehicle goes downhill, the saving energy is stored by the saving power supply module 1012. To charge; the off-highway vehicle can use the external power supply to supply power to the saving power supply module 1012 during the waiting time of the loading and unloading points. The charging scheme avoids the disadvantage that the saving power supply module 1012 is charged for too long, thereby affecting the running time.

According to another embodiment of the present invention, the saving power supply module 1012 may be an energy storage device such as a super capacitor, a fuel cell, a lithium battery, etc., and the saving power supply module 1012 may be based on the tonnage of the off-highway vehicle, the running speed, and the gradient. Calculate the energy storage capacity required in different situations. It is also possible to expand the capacity by using a combination of series or parallel depending on the capacity of a single energy storage device.

In an embodiment of the present invention, the DC converter 201 and the chopper 2021 cooperate with each other. The power management module 204 detects the speed and the rise of the DC voltage, and allocates the stored energy to the power supply module 1012. 2022 consumes much energy and stores most of the energy in the savings power supply module 1012. In addition, the power management module 204 is configured to manage the saving power supply module 1012 online, and automatically detect the voltage condition, temperature rise, fault, power consumption, and power flow direction of the battery.

In summary, when power is supplied to the traction motor of the main drive system, the pantograph 1011A is controlled to be connected and separated from the contact network, and the contact network power is supplied to the DC side via the power receiving unit 1011B. The two main inverters 1011C drive the traction motor 1 and the traction motor 2, respectively, and the two main inverters 1011C share a common DC bus. The brake consuming device 202 consumes part of the braking energy in the event of excessive braking energy and protects the DC side, wherein the brake consuming device 202 includes a chopper 2021 and a braking resistor 2022.

In addition, the DC converter 201 controls the DC side to stably charge the power storage power supply module 1012, and can also control the power storage power supply module 1012 to stably discharge to the DC side. When the voltage of the power storage power supply module 1012 does not match the DC voltage, The voltage is automatically converted. The power management module 204 is configured to manage the saving power supply module 1012 online, and automatically detect the voltage condition, temperature rise, fault, and the like of the saving power supply module 1012. The charging interface 203 is configured to receive an external charging power source, including a circuit breaker, and interlock with the circuit breaker of the power receiving unit 1011B.

It should be noted that the present invention can increase the number of main inverters or the number of auxiliary inverters. In addition, other types of inverters can be used, and other methods of grounding detection devices can be used, or those skilled in the art can adopt The generally understood power receiving unit and charging interface, and even the addition of fuses and voltage current sensors to optimize or perfect the components or devices of the nature, the invention is not limited thereto.

3 is a block diagram showing the structure of an auxiliary power supply device for an off-highway electric drive system according to an embodiment of the present invention. As shown in FIG. 3, the auxiliary power supply device 102 includes a diesel engine 1012A, an auxiliary generator 1012B, an auxiliary rectifier 1021C, an auxiliary inverter grounding detecting device 2053, and three auxiliary inverters 1012D. The auxiliary power supply device 102 supplies power to the main fan 301, the resistance fan 302, and the oil pump fan 303.

In the auxiliary power supply device 102 provided by the present invention, the diesel engine 1012A and the auxiliary generator 1012B are coaxially connected via a coupling. The diesel engine 1012A and the auxiliary generator 1012B constitute an auxiliary generator set. The capacity of the auxiliary generator set only needs to meet the driving capacity of the auxiliary load, so from the environmental protection point of view, the environmental pollution caused by the diesel engine emission is greatly reduced.

The auxiliary generator 1012B supplies power to the auxiliary rectifier 1012C. The first auxiliary inverter 1012D drives the main fan 301, which provides cooling to all of the main inverters 1011C, all of the auxiliary inverters 1012D and the auxiliary rectifiers 1012C, and all of the traction motors. The second auxiliary inverter 1012D drives a resistive fan 302 that provides cooling to the braking resistor 2022. The third auxiliary inverter 1012D oil pump motor 303, the oil pump motor 303 drives the hydraulic pump, and the hydraulic pump drives the hydraulic lifting system to control the lifting and landing of the cargo box. The three auxiliary inverters 1012D are in a common DC bus operation mode.

In addition, the auxiliary inverter 1012D and the auxiliary load motor are in one-to-one correspondence, and an auxiliary inverter can also be used to drive a plurality of auxiliary load motors of the same nature. The number of auxiliary inverters and auxiliary load motors can be expanded according to the number of traction motors designed for off-highway vehicles. The expansion mode is the same as that of the auxiliary inverters and auxiliary motors of FIG.

The grounding detecting devices 2051, 2052, and 2053 detect the grounding conditions of the DC busbars of each segment. Figure 5 shows a circuit diagram of an off-road vehicle electric drive system ground monitoring device in accordance with one embodiment of the present invention. As shown in Fig. 5, 501 is a fixed discharge resistor for discharging when the vehicle is stopped, and the DC voltage is reduced to within a safe range within a prescribed time range. The full voltage across the fixed discharge resistor 501 is collected by voltage sensor 504. 502 and 503 are half-voltage resistors, and the half voltage across the half-voltage 502 is collected by the voltage sensor 505, and the grounding condition is obtained by comparison of the half voltage and the full voltage.

In summary, in the auxiliary power supply device provided by the present invention, the diesel engine 1012A and the auxiliary generator 1012B are coaxially connected via a coupling. The auxiliary generator 1012B supplies power to the auxiliary rectifier 1012C. The first auxiliary inverter 1012D drives the main fan 301, the second auxiliary inverter 1012D drives the resistance fan 302, the third auxiliary inverter 1012D drives the oil pump motor 303, and the common auxiliary bus between the three auxiliary inverters The auxiliary inverter is in one-to-one correspondence with the auxiliary load motor, but an auxiliary inverter with multiple auxiliary load motors can also be used. The grounding detecting devices 2051, 2052, and 2053 detect the grounding conditions of the respective DC bus bars.

Additionally, in one embodiment of the invention, there is an alternative to the oil pump motor. Instead of using a motor-driven method, the oil pump can be driven coaxially by a diesel engine. The oil pump drives a hydraulic lift system to control the lifting and lowering of the cargo box. Other solutions that can replace the oil pump motor can also be applied to the present invention, and the present invention is not limited thereto.

As shown in FIG. 7, in step S701, it is determined whether there is a contact net, that is, whether there is a contact net on the current road of the off-highway vehicle, and if there is a contact net and the contact net can supply power to the off-highway vehicle, then step S702 is entered. The pantograph rises and receives input power transmitted by the contact network. Next, in step S703, power is supplied to the plurality of traction motors by the contact net. As the off-highway vehicle travels, it is determined in step S704 whether or not there is a catenary. If the result of the determination is YES, the process returns to step S703 to supply power to the plurality of traction motors from the catenary. If the result of the determination is no, then in step S705, the pantograph is lowered, and the process proceeds to step S708, where the power is supplied to the plurality of traction motors.

In step S701, if the result of the determination is no, the process proceeds to step S706, and it is determined whether the off-highway vehicle is between the catenary and the loading point. If the result of the determination is yes, the process proceeds to step S708, and the plurality of traction motors are powered by the saving power supply module. If the result of the determination in step S706 is no, the process goes to step S707 to determine whether the off-highway vehicle is between the contact network and the unloading point. If the result of the determination in step S707 is YES, the process proceeds to step S708, and the plurality of tractions are performed by the saving power supply module. The motor is powered.

In summary, the off-road vehicle electric drive method and system provided by the present invention jointly supplies power to the main drive system by the DC contact net and the saved electric energy supply module, and assists the diesel generator set to supply power to the auxiliary load. The main drive system and the auxiliary load are independent of each other, which improves the reliability of the whole vehicle. Among them, the saving power supply module can store the braking energy, and can also be charged by the external power source when the power is insufficient. Moreover, the saving power supply module can increase or decrease the amount of energy storage medium according to the actual demand of the vehicle. In addition, the present invention is also capable of alternately supplying power by two power supply modes according to the operating state of the off-highway vehicle.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope of the present invention. All should be covered by the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

An off-highway electric drive system includes:

a main power supply device, comprising a contact network power supply module and a power storage power supply module, wherein the catenary power supply module is connected to the power storage power supply module, and the two are connected to the traction motor of the off-highway vehicle by means of time-sharing power supply Power supply, wherein the saving power supply module absorbs braking energy when the off-highway vehicle is in a braking state;

An auxiliary power supply device for supplying power to an auxiliary load of the off-highway vehicle.
The system of claim 1 wherein said catenary power supply module supplies power to said plurality of traction motors and said stored energy power supply module via a contact network, said catenary power supply module comprising:

a pantograph for receiving input power transmitted by the contact net when raised, and isolating the contact net when lowered;

a power receiving unit connected to the pantograph, comprising a DC circuit breaker, a charging subunit, and a filtering subunit, wherein the charging subunit is configured to delay input time of the input electric energy, the filtering subunit For filtering the input electrical energy;

The main inverter has a DC side connected to the power receiving unit for driving the plurality of traction motors, wherein the number of the main inverters is a positive integer.
The system of claim 2 wherein

The saving power supply module is a power battery pack, a super capacitor, a fuel cell, and a lithium battery connected between the power receiving unit and the main inverter for disengaging the contact network from the off-highway vehicle The plurality of traction motors are powered.
The system of claim 1 wherein said auxiliary power supply means comprises:

a diesel engine for providing drive energy;

An auxiliary generator connected to the diesel engine by coaxial connection for receiving the driving energy provided by the diesel engine and generating electric energy;

An auxiliary rectifier connected to the auxiliary generator for receiving the electrical energy and rectifying the electrical energy to obtain rectified processed rectified electrical energy;

An auxiliary inverter having a DC side connected to the auxiliary rectifier for receiving the rectified electric energy and driving the auxiliary load by the rectified electric energy, wherein the number of the auxiliary inverters is a positive integer, wherein The auxiliary load includes a main fan, a resistance cabinet fan, and a hydraulic pump motor.
The system of claim 2 wherein

Further comprising a DC conversion device between the power receiving unit and the main inverter, and a common DC bus line with the main inverter, configured to control the DC lateral direction when the saving power supply module is charged Charging the power supply module to charge and control the stored power supply module to discharge to the DC side when the stored power supply module is discharged, and the voltage of the stored power supply module does not match the voltage of the DC side When it is, it automatically matches the voltage between the two.
The system of claim 2 wherein

A brake consuming device is further included between the power receiving unit and the main inverter for consuming braking energy exceeding the set threshold when the braking energy exceeds a set threshold.
The system of claim 2 wherein

The system further includes a charging interface coupled to the saving power supply module for receiving an external charging power source to supply power to the saving power supply module, wherein the charging interface includes a circuit breaker, The DC circuit breakers are interlocked.
The system of claim 1 wherein

The system further includes a power management module coupled to the power storage power supply module for managing voltage, temperature rise, fault, power consumption, and power flow direction of the power storage power supply module.
The system of claim 1 wherein

The system further includes a grounding detecting device for detecting a grounding state of a portion of the DC busbar to be tested, which includes a saving power supply module grounding detecting device, a main inverter grounding detecting device, and an auxiliary inverter grounding detecting device.
An off-road vehicle electric drive method, comprising:

Supplying power to a plurality of traction motors of the off-highway vehicle by a main power supply device, the main power supply device comprising a contact network power supply module and a power storage power supply module, the two of which are provided to the off-highway vehicle by means of time-sharing power supply Trapping motor power supply, wherein the saving power supply module absorbs braking energy when the off-highway vehicle is in a braking state;

The auxiliary load of the off-highway vehicle is powered by the auxiliary power supply.