A kind of engineering machinery distributed hybrid power system and high voltage power-on control method

Abstract

The application discloses an engineering machine distributed hybrid power system and a high-voltage power-on control method, comprising: a first kinetic energy system, a second kinetic energy system, a first power system and a second power system, the first kinetic energy system and the second kinetic energy system can independently supply energy or coupled energy to the whole machine, and the first power system and the second power system can independently drive or coupled drive to realize four-wheel independent drive. The problems that the existing hybrid system scheme has single energy and power transmission and cannot meet the basic driving demand in a fault state are solved.

Description

Technical Field

[0001] This invention belongs to the field of engineering machinery technology, specifically relating to a distributed hybrid power system for engineering machinery and a high-voltage power-on control method. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Large-tonnage construction machinery products are widely used in large-scale mines, and the key component technologies have long been monopolized by developed Western countries. With the innovative development of new energy construction machinery technologies in China, the use of hybrid and four-wheel drive technologies has not only broken through technological barriers but also achieved the goals of reducing energy consumption and improving energy utilization efficiency.

[0004] Large-tonnage construction machinery, such as hybrid loaders and bulldozers, operates long-term in large mining areas. The harsh environment and complex working conditions place extremely high demands on equipment reliability. Irregular equipment use and prolonged periods of inactivity or malfunctions can lead to a series of problems, including battery depletion and difficulty starting the engine. Even during normal use, various system components may fail. Existing hybrid systems rely on a single energy and power transmission method. When a large-tonnage construction machine experiences a power failure, the vehicle cannot move. Moving the vehicle and performing repairs require heavy equipment, resulting in high maintenance costs and significant inconvenience. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a distributed hybrid power system for engineering machinery and a high-voltage power-on control method, which solves the problem that existing hybrid system solutions have a single energy and power transmission method and cannot meet basic driving needs under fault conditions.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, the present invention provides a distributed hybrid power system for engineering machinery, comprising: The first power system includes an engine, a transfer case, a first generator, a second generator, a first generator controller, and a second generator controller; the engine drives the first generator, the second generator, and multiple hydraulic pumps simultaneously through the transfer case; the generator controller is used to convert electrical energy into direct current. The second power system includes a power battery system and a high-voltage distribution box. The first power system includes a left front travel motor control system, a right front travel motor control system, and a first braking resistor grid. The second power system includes a left rear travel motor control system, a right rear travel motor control system, and a second braking resistor grid. The first kinetic energy system and the second kinetic energy system can independently supply power to the whole machine or coupled power it, and the first power system and the second power system can independently drive or coupled drive to achieve four-wheel independent drive.

[0007] As a further implementation, the engine in the first kinetic energy system provides electrical energy to the second kinetic energy system, the first power system, and the second power system by driving the first generator and the second generator; The transfer case is connected in series with the engine and to multiple hydraulic pumps to provide hydraulic energy for the working, steering and braking hydraulic systems; When the second kinetic energy system fails to supply power, the first kinetic energy system supplies power to the entire machine.

[0008] As a further implementation, the high-voltage distribution box in the second kinetic energy system supplies power to the high-voltage auxiliary circuit system, which includes a high-voltage oil pump, a battery thermal management system, a high-voltage heat dissipation system, and a high-voltage water cooling system. The high-pressure oil pump is used to provide hydraulic energy to the braking system and steering system; When the first kinetic energy system is unable to provide power, the power battery system independently supplies power to the whole machine through the high-voltage auxiliary circuit system, the first power system, and the second power system.

[0009] As a further implementation, energy consumption loops are provided in both the first power system and the second power system; During long downhill driving or emergency electric braking, when the power battery charge exceeds a preset threshold or the instantaneous power generation current exceeds the battery's recovery capacity, the first braking resistor grid and / or the second braking resistor grid will convert the excess electrical energy into heat energy.

[0010] Secondly, the present invention also provides a high-voltage control strategy, including a normal power-on strategy, wherein the normal power-on strategy includes the following steps: The vehicle controller sends a high-voltage command to the power battery system; After the power battery completes its self-test, it executes the high-voltage command to complete the high-voltage connection of the power battery system and the auxiliary circuit system. The high-voltage distribution box provides high voltage to the generator system through a pre-charge function; Generator reverse-drive engine start; The engine and generator controllers feed back to the high-voltage power generation system. The high-voltage distribution box applies high voltage to the first power system through the pre-charge circuit and provides feedback on its status. The high-voltage distribution box applies high voltage to the second power system through the pre-charge circuit and provides feedback on the status.

[0011] As a further implementation, a first abnormal power-on strategy is also included, which is executed when an abnormality occurs in the high voltage of the power battery system. The vehicle controller sends an engine start command, and the engine controller controls the starter motor to start the engine and drive the generator to rotate. After the generator controller completes its self-test, the vehicle controller controls the generator controller to gradually increase the bus voltage, thus completing the high-voltage connection of the generator system. The vehicle controller controls the pre-charge circuit in the high-voltage distribution box to pre-charge the battery system in reverse, so as to complete the high voltage connection of the power battery system and the auxiliary road system.

[0012] As a further implementation, in the first abnormal power-on strategy, when the power battery is faulty and cannot be powered on, the auxiliary circuit system is controlled to be powered on at high voltage through reverse pre-charging in order to complete the high voltage power-on of the kinetic energy system.

[0013] As a further implementation, a second abnormal power-on strategy is also included, which is executed when the generator system or engine system experiences a power-on abnormality. After the power battery system is powered on, if any part of the normal power-on strategy malfunctions, the vehicle controller will control the malfunctioning system to stop applying high voltage and maintain the high voltage power-on state of the completed power system.

[0014] As a further implementation, the high-voltage control of the kinetic energy system specifically includes: The vehicle controller controls the high-voltage distribution box to apply high voltage to the first power system through the first kinetic energy pre-charge circuit; The vehicle controller controls the high-voltage distribution box to apply high voltage to the second power system through the second kinetic energy pre-charge circuit; When the high voltage of the first power system is abnormal or there is a system fault, the vehicle controller still executes the high voltage of the second power system to achieve independent power supply of the power system.

[0015] As a further implementation, the vehicle controller sends enable signals to the powered components and systems based on the power-on status of the kinetic energy system and the power system, executes corresponding functional control strategies according to different power-on statuses, and issues fault information for systems with abnormalities.

[0016] Compared with the prior art, the advantages and positive effects of this invention are: This invention presents a hybrid power system that operates independently and in combination with two kinetic energy systems and two power systems. In the first kinetic energy system, the engine simultaneously drives the first and second generators and multiple hydraulic pumps via a transfer case. The generator controller converts the generated AC power into DC power to power the walking system or accessory hydraulic systems. Simultaneously, the second kinetic energy system, equipped with a high-voltage distribution box via a power battery system, can function as an independent power source or be coupled with the first kinetic energy system to achieve hybrid power supply. The first and second power systems can either drive their respective wheels independently or work together to form a four-wheel independent drive. A braking resistor grid is used to dissipate excess energy during braking or downhill driving, protecting the system voltage stability. Furthermore, the two kinetic energy systems and two power systems serve as backups for each other; if one system fails, the other can still maintain basic operation of the entire machine, preventing complete machine failure. This solves the problem of single energy and power transmission in hybrid system designs, ensuring the basic driving function of large-tonnage functional machinery in fault conditions. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0018] Figure 1 This is a diagram of the distributed hybrid power system for engineering machinery of the present invention; Figure 2 This is a diagram of the high-voltage control strategy of the present invention. Detailed Implementation

[0019] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0020] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. Example 1 This embodiment discloses a distributed hybrid power system for engineering machinery, such as Figure 1As shown, the hybrid power system consists of a dual-energy system and a dual-power system, primarily improving the applicability of large-tonnage construction machinery under different environments and working conditions. The independent and coupled control of the dual-energy and dual-power systems enables multiple starting modes of the power system, solving the problem of system failure to start due to local faults in a single mode.

[0021] This embodiment proposes a distributed hybrid power system for engineering machinery, such as... Figure 1 As shown, it includes: The first power system includes an engine, a transfer case, a first generator, a second generator, a first generator controller, and a second generator controller; the engine drives the first generator, the second generator, and multiple hydraulic pumps simultaneously through the transfer case; the generator controller is used to convert electrical energy into direct current. The second power system includes a power battery system and a high-voltage distribution box. The first power system includes a left front travel motor control system, a right front travel motor control system, and a first braking resistor grid. The second power system includes a left rear travel motor control system, a right rear travel motor control system, and a second braking resistor grid. The first kinetic energy system and the second kinetic energy system can independently supply power to the whole machine or coupled power it, and the first power system and the second power system can independently drive or coupled drive to achieve four-wheel independent drive.

[0022] It is understood that the distributed hybrid power system proposed in this embodiment is a hybrid power system that operates independently and coupled with a dual kinetic energy system and a dual power system. In the first kinetic energy system, the engine simultaneously drives the first and second generators and multiple hydraulic pumps through a transfer case. The generator controller converts the generated AC power into DC power to power the walking system or accessory hydraulic system. Simultaneously, the second kinetic energy system, through a power battery system equipped with a high-voltage distribution box, can function as an independent power source or be coupled with the first kinetic energy system to achieve hybrid power supply. The first power system (i.e., the left front and right front walking motors + the first braking resistor grid) and the second power system (i.e., the left rear and right rear walking motors + the second braking resistor grid) can either drive their respective wheels independently or work together to form four-wheel independent drive. The braking resistor grid is used to dissipate excess energy during braking or downhill driving, protecting the system voltage stability.

[0023] The distributed hybrid power system features two kinetic energy systems and two power systems that serve as backups for each other. If one system fails, the other can still maintain basic operation of the entire system, preventing complete system failure. Excess electrical energy can charge the power battery; the braking resistor grid safely dissipates energy when the battery cannot absorb it, preventing overvoltage.

[0024] In addition, based on the composition of the distributed hybrid power system, the construction machinery can support multiple operating modes such as pure electric drive, pure engine power generation drive, and hybrid drive, and can dynamically switch according to load and working conditions to reduce fuel consumption and emissions.

[0025] The engine in the first kinetic energy system provides electrical energy to the second kinetic energy system, the first power system, and the second power system by driving the first generator and the second generator; the transfer case is connected in series with the engine and connected to multiple hydraulic pumps to provide hydraulic energy to the working, steering, and braking hydraulic systems; when the second kinetic energy system cannot supply power, the first kinetic energy system supplies electrical energy to the whole machine.

[0026] The engine in the first kinetic energy system serves as a power source, simultaneously driving the first and second generators to convert mechanical energy into electrical energy, which is then supplied to the second kinetic energy system, the first power system, and the second power system, ensuring that the overall power demand of the machine is met. By simultaneously driving the generator and hydraulic system with the engine, coordinated supply of electric and hydraulic power is achieved, reducing the number of independent power sources and lowering the overall weight and energy consumption. Furthermore, the engine and transfer case are arranged in series, with the transfer case connected to multiple hydraulic pumps. This transfer case diverts a portion of the engine's power and converts it into hydraulic drive for the hydraulic actuators of the working device, steering system, and braking system, providing them with a stable and independent hydraulic power source.

[0027] In the event that the secondary power system fails to supply power, the primary power system can automatically switch to become the main power supply for the entire machine, undertaking all power output tasks. Even if the secondary power system fails, the primary power system can still maintain the power supply for the entire machine, enhancing the fault tolerance and operational continuity of the machine, making it particularly suitable for engineering machinery or special vehicles with high reliability requirements.

[0028] The high-voltage distribution box in the second kinetic energy system supplies power to the high-voltage auxiliary circuit system, which includes a high-voltage oil pump, a battery thermal management system, a high-voltage heat dissipation system, and a high-voltage water cooling system. The high-voltage oil pump is used to provide hydraulic energy to the braking system and the steering system. When the first kinetic energy system cannot supply power, the power battery system independently supplies power to the whole machine through the high-voltage auxiliary circuit system, the first power system, and the second power system.

[0029] Understandably, the high-voltage distribution box in the second power system serves as an energy distribution node, supplying power to the high-voltage auxiliary system. This auxiliary system integrates a high-voltage oil pump, a battery thermal management system, a high-voltage heat dissipation system, and a high-voltage water cooling system. The high-voltage oil pump converts electrical energy into hydraulic energy to drive the braking and steering systems. When the first power system fails to supply power, the battery system can independently provide energy to the entire machine through the high-voltage auxiliary system, coordinating with both the first and second power systems to ensure continuous operation of the braking and steering systems, forming a redundant power supply and hydraulic backup mechanism. Even in the event of a failure in the first power system, the hydraulic energy supply to the braking and steering systems is still guaranteed, avoiding safety risks caused by power interruption. Simultaneously, the independent power supply capabilities of the battery thermal management, heat dissipation, and water cooling systems prevent high-voltage components from being damaged due to overheating.

[0030] The first power system and the second power system are equipped with energy consumption circuits; during long downhill driving or emergency electric braking, when the power battery charge is higher than a preset threshold or the instantaneous power generation current exceeds the battery recovery capacity, the first braking resistor grid and / or the second braking resistor grid will convert the excess electrical energy into heat energy.

[0031] Specifically, braking resistor grids are integrated into the first and second power systems to form an energy consumption loop. When the vehicle is on a long downhill slope or in emergency electric braking mode, the drive motor will switch to generator mode to produce regenerative energy. If the power battery charge is already higher than a preset safety threshold, or the instantaneous generator current exceeds the battery's maximum allowable charging current, the system cannot safely recharge all the energy back to the battery. In this case, the control circuit will actively guide the excess energy to the first and / or second braking resistor grids, using the heating effect of the resistors to convert the electrical energy into heat energy and dissipate it, thereby preventing battery overcharging or damage from current surges.

[0032] Example 2 This embodiment discloses a high-voltage control strategy that, through a hybrid power system power-on strategy, enables the entire machine to normally connect to high voltage even under a single system failure mode. This solves the problem of power paralysis caused by failures in large construction machinery, avoids construction interruptions that may be caused by blocking critical roads, and also solves the problem of maintenance difficulties caused by the lack of large maintenance equipment at the construction site.

[0033] like Figure 2 As shown, the high-voltage control strategy in this embodiment includes a normal power-on strategy, which includes the following steps: The vehicle controller sends a high-voltage command to the power battery system; After the power battery completes its self-test, it executes the high-voltage command to complete the high-voltage connection of the power battery system and the auxiliary circuit system. The high-voltage distribution box provides high voltage to the generator system through a pre-charge function; Generator reverse-drive engine start; The engine and generator controllers feed back to the high-voltage power generation system. The high-voltage distribution box applies high voltage to the first power system through the pre-charge circuit and provides feedback on its status. The high-voltage distribution box applies high voltage to the second power system through the pre-charge circuit and provides feedback on the status.

[0034] Understandably, the phased power-on and pre-charge circuit design effectively avoids the large current surge during high-voltage system power-on, protecting components such as the high-voltage distribution box and motor controller, and extending system lifespan. Simultaneously, powering the generator system first and reverse-drafting the engine before sequentially powering the two power systems facilitates the rational distribution of high-voltage energy, ensuring that engine starting and power system power-on do not interfere with each other, thus improving the reliability and stability of the vehicle's high-voltage power-on.

[0035] The high-voltage control strategy in this embodiment also includes a first abnormal power-on strategy, which is executed when an abnormality occurs in the high-voltage connection of the power battery system. The vehicle controller sends an engine start command, and the engine controller controls the starter motor to start the engine and drive the generator to rotate. After the generator controller completes its self-test, the vehicle controller controls the generator controller to gradually increase the bus voltage, thus completing the high-voltage connection of the generator system. This can solve the problem of high-voltage power-on of the battery under severe battery depletion and fault conditions. The vehicle controller controls the pre-charge circuit in the high-voltage distribution box to pre-charge the battery system in reverse, thereby completing the high-voltage connection of the power battery system and the auxiliary circuit system.

[0036] In the first abnormal power-on strategy, when the power battery is faulty and cannot be powered on, the auxiliary circuit system is controlled to be powered on at high voltage through reverse pre-charging in order to complete the high voltage power-on of the kinetic energy system.

[0037] The high-voltage control strategy in this embodiment also includes a second abnormal power-on strategy, which is executed when the generator system or engine system experiences an abnormal power-on. After the power battery system is powered on, if any part of the normal power-on strategy is abnormal, the vehicle controller controls the abnormal system to stop the high-voltage power-on and maintains the completed high-voltage power-on state of the kinetic energy system.

[0038] The high-voltage control of the kinetic energy system specifically includes: The vehicle controller controls the high-voltage distribution box to apply high voltage to the first power system through the first kinetic energy pre-charge circuit; the vehicle controller controls the high-voltage distribution box to apply high voltage to the second power system through the second kinetic energy pre-charge circuit; wherein, when the high voltage application of the first power system is abnormal or there is a system fault, the vehicle controller still executes the high voltage application of the second power system to achieve independent power supply of the power system.

[0039] The vehicle controller sends enable signals to the powered components and systems based on the power-on status of the kinetic energy system and the power system, executes corresponding functional control strategies according to different power-on statuses, and issues fault information for systems with abnormalities.

[0040] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A distributed hybrid power system for engineering machinery, characterized in that, include: The first power system includes an engine, a transfer case, a first generator, a second generator, a first generator controller, and a second generator controller; the engine drives the first generator, the second generator, and multiple hydraulic pumps simultaneously through the transfer case; the generator controller is used to convert electrical energy into direct current. The second power system includes a power battery system and a high-voltage distribution box. The first power system includes a left front travel motor control system, a right front travel motor control system, and a first braking resistor grid. The second power system includes a left rear travel motor control system, a right rear travel motor control system, and a second braking resistor grid. The first kinetic energy system and the second kinetic energy system can independently supply power to the whole machine or coupled power it, and the first power system and the second power system can independently drive or coupled drive to achieve four-wheel independent drive.

2. The distributed hybrid power system for engineering machinery as described in claim 1, characterized in that, The engine in the first kinetic energy system provides electrical energy to the second kinetic energy system, the first power system, and the second power system by driving the first generator and the second generator. The transfer case is connected in series with the engine and to multiple hydraulic pumps, which provide hydraulic energy for the working, steering and braking hydraulic systems. When the second kinetic energy system fails to supply power, the first kinetic energy system supplies power to the entire machine.

3. The distributed hybrid power system for engineering machinery as described in claim 1, characterized in that, The high-voltage distribution box in the second kinetic energy system supplies power to the high-voltage auxiliary circuit system, which includes a high-voltage oil pump, a battery thermal management system, a high-voltage heat dissipation system, and a high-voltage water cooling system. The high-pressure oil pump provides hydraulic energy to the braking and steering systems; When the first kinetic energy system is unable to provide power, the power battery system independently supplies power to the whole machine through the high-voltage auxiliary circuit system, the first power system, and the second power system.

4. The distributed hybrid power system for engineering machinery as described in claim 1, characterized in that, Both the first power system and the second power system are equipped with energy consumption loops; The first braking resistor grid and / or the second braking resistor grid convert excess electrical energy into heat energy.

5. A high-voltage control strategy based on the system according to any one of claims 1 to 4, characterized in that, This includes a normal power-on strategy, which comprises the following steps: The vehicle controller sends a high-voltage command to the power battery system; After the power battery completes its self-test, it executes the high-voltage command to complete the high-voltage connection of the power battery system and the auxiliary circuit system. The high-voltage distribution box provides high voltage to the generator system through a pre-charge function; Generator reverse-drive engine start; The engine and generator controllers feed back to the high-voltage power generation system. The high-voltage distribution box applies high voltage to the first power system through the pre-charge circuit and provides feedback on its status. The high-voltage distribution box applies high voltage to the second power system through the pre-charge circuit and provides feedback on the status.

6. The high-voltage control strategy as described in claim 5, characterized in that, It also includes a first abnormal power-on strategy, which is executed when an abnormality occurs at the high voltage of the power battery system. The vehicle controller sends an engine start command, and the engine controller controls the starter motor to start the engine and drive the generator to rotate. After the generator controller completes its self-test, the vehicle controller controls the generator controller to gradually increase the bus voltage, thus completing the high-voltage connection of the generator system. The vehicle controller controls the pre-charge circuit in the high-voltage distribution box to pre-charge the battery system in reverse, so as to complete the high voltage connection of the power battery system and the auxiliary road system.

7. The high-voltage control strategy as described in claim 6, characterized in that, In the first abnormal power-on strategy, when the power battery is faulty and cannot be powered on, the auxiliary circuit system is controlled to be powered on by reverse pre-charging to complete the high-voltage power-on of the kinetic energy system.

8. The high-voltage control strategy as described in claim 5, characterized in that, It also includes a second abnormal power-on strategy, which is executed when the generator system or engine system experiences a power-on abnormality. After the power battery system is powered on, if any part of the normal power-on strategy malfunctions, the vehicle controller will control the malfunctioning system to stop applying high voltage and maintain the high voltage power-on state of the completed power system.

9. The high-voltage control strategy as described in claim 5, characterized in that, The high-voltage control of the kinetic energy system specifically includes: The vehicle controller controls the high-voltage distribution box to apply high voltage to the first power system through the first kinetic energy pre-charge circuit; The vehicle controller controls the high-voltage distribution box to apply high voltage to the second power system through the second kinetic energy pre-charge circuit; When the high voltage of the first power system is abnormal or there is a system fault, the vehicle controller still executes the high voltage of the second power system to achieve independent power supply of the power system.

10. The high-voltage control strategy as described in claim 5, characterized in that, The vehicle controller sends enable signals to the powered components and systems based on the power-on status of the kinetic energy system and the power system, executes corresponding functional control strategies according to different power-on statuses, and issues fault information for systems with abnormalities.

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