CN-117569404-B - Control method of range-extended hybrid power backhoe loader

CN117569404BCN 117569404 BCN117569404 BCN 117569404BCN-117569404-B

Abstract

The invention provides a control method and a system for a range extender type hybrid power digger, which are based on a working mode, determine working conditions of a power battery according to the charge state of the power battery, control the power supply proportion of the range extender and the power battery for electric equipment of the whole machine or control the power supply proportion of the range extender for the power battery and the electric equipment of the whole machine by combining the relation between the optimal output electric power of the range extender and the operation required power of the whole machine, so that the output electric power of the range extender or the sum of the output electric power of the range extender and the output electric power of the power battery always meets the operation required power of the whole machine, and ensure that an engine of the range extender is always in a fuel economy interval. According to the invention, the output power of the range extender can be adaptively adjusted according to the charge state of the power battery and the power required by the whole machine, so that the range extender engine is in a fuel economy interval corresponding to different working condition requirements, and the power sufficiency of the excavating loader during operation is ensured.

Inventors

WANG YANAN
JIANG XINGBAO
ZHU JINCAN
XIE ZONGFA
Min Fanli
LIU KEZHI
PEI WENCAI
XU JIANBO

Assignees

山东大学
山东威猛工程机械有限公司

Dates

Publication Date: 20260505
Application Date: 20230926

Claims (11)

1. The control method of the extended-range hybrid power backhoe loader is characterized by comprising the following steps of: Determining a current working mode of the range-extending hybrid power excavating loader according to the states of the working motor and the running motor, wherein the specific process comprises that at least one of the working motor and the running motor is running, the range-extending hybrid power excavating loader adopts a working mode, otherwise, the working mode is a standby mode, and the range extender always keeps a power generation state in the working mode; Based on the working mode, determining the working condition of the power battery according to the state of charge of the power battery, controlling the power supply proportion of the range extender and the power battery to the electric equipment of the whole machine or controlling the power supply proportion of the range extender to the electric equipment of the whole machine by combining the relation between the optimal output electric power of the range extender and the operation required power of the whole machine, so that the output electric power of the range extender or the sum of the output electric power of the range extender and the output electric power of the power battery always meets the operation required power of the whole machine, and the engine of the range extender is always in a fuel economy interval; When the power battery adopts a battery to-be-charged working condition in the working mode, if the operation required power of the whole machine is higher than the optimal output electric power of the Yu Zengcheng device, the range extender is controlled to independently supply power to the electric equipment of the whole machine, and the output electric power of the range extender is enabled to be equal to the operation required power of the whole machine; If the running required power of the whole machine is lower than the optimal output electric power of the range extender, and the optimal output electric power of the range extender is lower than the sum of the running required power of the whole machine and the maximum input electric power of the power battery, the range extender is controlled to supply power to electric equipment and the power battery of the whole machine at the same time, and the output electric power of the range extender is enabled to be equal to the optimal output electric power of the range extender; If the sum of the whole machine operation required power and the maximum input electric power of the power battery is smaller than or equal to the optimal output electric power of the range extender, the range extender is controlled to supply power to the electric equipment of the whole machine and the power battery at the same time, and the output electric power of the range extender is enabled to be equal to the sum of the whole machine operation required power and the maximum input electric power of the power battery.
2. The control method of the extended-range hybrid excavator loader according to claim 1, wherein in the operation mode, if the state of charge of the power battery is smaller than or equal to the lowest limit value of the state of charge, the power battery is determined to be in a battery waiting condition, if the state of charge of the power battery is larger than or equal to the highest limit value of the state of charge, the power battery is determined to be in a battery waiting condition, otherwise, the battery condition at the previous moment is maintained, and if the operation mode does not have the previous moment, the power battery is determined to be in a battery waiting condition.
3. The control method of the range-extending hybrid power shovel loader according to claim 2, wherein in the working mode, when the power battery is in a battery to-be-discharged working condition, if the operation required power of the whole machine is greater than or equal to the sum of the optimal output electric power of the range extender and the maximum output electric power of the power battery, the power battery and the range extender are controlled to supply power to the whole machine electric equipment at the same time, the power battery is enabled to output at the maximum output electric power, and the output electric power of the range extender is enabled to be equal to the difference between the operation required power of the whole machine and the maximum output electric power of the power battery; if the running required power of the whole machine is between the optimal output electric power of the range extender and the sum of the optimal output electric power of the range extender and the maximum output electric power of the power battery, controlling the power battery and the range extender to supply power to the electric equipment of the whole machine at the same time, and enabling the output electric power of the range extender to be equal to the optimal output electric power of the range extender, wherein the output electric power of the power battery changes along with the running required power of the whole machine; And if the running required power of the whole machine is smaller than or equal to the optimal output electric power of the range extender, controlling the range extender to independently supply power to electric equipment of the whole machine, and enabling the output electric power of the range extender to be equal to the running required power of the whole machine.
4. The control method of the extended range hybrid excavator loader according to claim 1, wherein in the standby mode, if the state of charge of the power battery is smaller than or equal to the lowest limit value of the state of charge, the power battery is determined to be in a battery waiting condition, if the state of charge of the power battery is larger than or equal to the highest limit value of the state of charge, the power battery is determined to be in a battery waiting condition, otherwise, the battery condition at the previous moment is maintained, and if the standby mode does not have the previous moment, the power battery is determined to be in a battery waiting condition.
5. The control method of a range-extending hybrid power backhoe loader according to claim 4, wherein when the power battery is in a standby mode and the battery is in a standby state, if the operation required power of the whole machine is higher than the optimal output electric power of the Yu Zengcheng machine, the range-extending machine is controlled to independently supply power to the electric equipment of the whole machine, and the output electric power of the range-extending machine is equal to the operation required power of the whole machine; If the running required power of the whole machine is lower than the optimal output electric power of the range extender, and the optimal output electric power of the range extender is lower than the sum of the running required power of the whole machine and the maximum input electric power of the power battery, the range extender is controlled to supply power to electric equipment of the whole machine and the power battery at the same time, the output electric power of the range extender is enabled to be equal to the optimal output electric power of the range extender, and the input electric power of the power battery changes along with the running required power of the whole machine; And if the sum of the running required power of the whole machine and the maximum input electric power of the power battery is smaller than or equal to the optimal output electric power of the range extender, controlling the range extender to supply power to the electric equipment of the whole machine and the power battery at the same time, and enabling the output power of the range extender to be equal to the sum of the running required power of the whole machine and the maximum input electric power of the power battery.
6. The control method of a range-extending hybrid power shovel loader according to claim 4, wherein when the power battery is in a battery to-be-discharged working condition in a standby mode, if the total operation required power is greater than or equal to the sum of the optimal output electric power of the range extender and the maximum output electric power of the power battery, the power battery and the range extender are controlled to supply power to the electric equipment of the whole machine at the same time, the power battery is enabled to output at the maximum output electric power, and the output power of the range extender is enabled to be equal to the difference between the total operation required power and the maximum output electric power of the power battery; if the running required power of the whole machine is between the optimal output electric power of the range extender and the sum of the optimal output electric power of the range extender and the maximum output electric power of the power battery, controlling the power battery and the range extender to supply power to the electric equipment of the whole machine at the same time, and enabling the output electric power of the range extender to be equal to the optimal output electric power of the range extender, wherein the output electric power of the power battery changes along with the running required power of the whole machine; If the operation required power of the whole machine is smaller than or equal to the optimal output electric power of the range extender, the range extender is controlled to independently supply power to electric equipment of the whole machine, and the output electric power of the range extender is enabled to be equal to the operation required power of the whole machine; if the operation required power of the whole machine is smaller than or equal to the maximum output electric power of the power battery, the range extender is controlled to be closed, the power battery is controlled to independently supply power to electric equipment of the whole machine, and the whole machine works in a pure electric mode.
7. The control method of a range extender hybrid loader according to claim 1,3, 5 or 6, wherein the specific process of determining the range extender output electric power curve includes finding corresponding rotational speeds and torques according to a plurality of points on an engine fuel economy curve, respectively setting rotational speeds of the engine and electromagnetic resistance moments of the generator according to the rotational speeds and the torques, respectively, obtaining a plurality of range extender output electric power points at different rotational speeds, and connecting adjacent points to obtain the range extender output electric power curve.
8. The control method of a range extender hybrid shovel loader according to claim 1,3, 5, or 6, wherein the step of determining the optimal output electric power of the range extender comprises finding a rotational speed and a torque corresponding to a fuel-most economical point on a fuel-most economical curve of the engine, and then setting the rotational speed of the engine and the electromagnetic resistance torque of the generator according to the rotational speed and the torque, respectively.
9. The control method of a range extender hybrid shovel loader according to claim 1, 3, 5, or 6, wherein the step of controlling the range extender output power to be equal to the sum of the overall machine operation demand power and the power cell maximum input electric power comprises finding the range extender output electric power corresponding to the sum of the overall machine operation demand power and the power cell maximum input electric power on a range extender output electric power curve and a corresponding rotational speed thereof, finding a corresponding torque on an engine fuel economy curve according to the rotational speed, and setting the rotational speed of the engine and the electromagnetic resistance torque of the generator according to the rotational speed and the torque, respectively.
10. The control method of a range extender hybrid shovel loader according to claim 1, 3, 5, or 6, wherein the specific control process for controlling the range extender output electric power to be equal to the difference between the overall operation required power and the maximum output electric power of the power battery comprises finding the range extender output electric power corresponding to the difference between the overall operation required power and the maximum output electric power of the power battery on a range extender output electric power curve and a corresponding rotational speed thereof, finding a corresponding torque on an engine fuel economy curve according to the rotational speed, and setting the rotational speed of the engine and the electromagnetic resistance torque of the generator according to the rotational speed and the torque, respectively.
11. An extended-range hybrid shovel loader control system employing the method of claim 1, comprising: the working mode determining module is configured to determine the current working mode of the extended-range hybrid power digger according to the states of the working motor and the running motor; the battery working condition determining module is configured to determine the working condition of the power battery according to the state of charge of the power battery based on the working mode; The control module is configured to combine the relation between the optimal output electric power of the range extender and the operation required power of the whole machine, control the power supply proportion of the range extender and the power battery to the electric equipment of the whole machine or control the power supply proportion of the range extender to the power battery and the electric equipment of the whole machine, so that the output electric power of the range extender or the sum of the output electric power of the range extender and the output electric power of the power battery always meets the operation required power of the whole machine, and the range extender engine is always in a fuel economy interval.

Description

Control method of range-extended hybrid power backhoe loader Technical Field The invention belongs to the technical field of new energy engineering machinery control, and relates to a control method and a system for a range-extending hybrid power excavating loader. Background The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art. With the development of social economy, the demand for off-road mobile construction machines is also increasing. The traditional engineering machinery usually takes a fuel engine as a power source, and air pollutants generated during the operation of the fuel engine mainly comprise oxides such as carbon, nitrogen, sulfur and other harmful substances, and the discharge amount of the pollutants is positively related to the fuel consumption. Therefore, the development of new energy products capable of realizing energy conservation and emission reduction has become a serious issue in the field of engineering machinery. In the new energy engineering machinery, the pure electric engineering machinery can truly realize zero emission and zero pollution, but due to the limitations of battery energy density, external dimension, service life, manufacturing cost and other aspects, the single working time of the pure electric engineering machinery often cannot completely meet the use requirement. The extended-range hybrid power engineering machine solves the energy supply problem of the pure electric engineering machine. Meanwhile, compared with the traditional engineering machinery, the extended-range hybrid engineering machinery generally sets an engine to work in a fuel economy section, and can reduce the fluctuation of output power of the engine, so that the fuel economy of the engineering machinery is improved. At present, control strategies commonly adopted by the extended-range hybrid power engineering machinery mainly comprise a constant temperature control strategy, a multipoint control strategy, a power following control strategy and the like. The constant temperature control strategy can lead the power battery to be in an overcharging and discharging state frequently, which is not beneficial to prolonging the cycle life of the power battery, and meanwhile, as the engine is required to be independently powered when the state of charge SOC of the battery is lower, if the engine displacement is smaller, the engineering machinery can often face the risk of insufficient power, so that the engine with larger output power is required to be equipped. The multipoint control strategy and the power following control strategy reduce the fluctuation of the battery SOC, and can avoid the overcharge and discharge of the power battery, but the working interval of the engine is larger, and the energy utilization rate is not high in idle speed. For example, patent number CN115626069a discloses a range extender control method for a forklift, a range extender forklift and a storage medium, and the technology can obtain preset power meeting the charging requirement of a storage battery through average power of a driving mechanism in a real-time working cycle and historical power in a previous working cycle. The range extender can meet the power requirement of engineering machinery when working with constant power under the preset power, however, the power battery is often in an overcharging and discharging state, which is unfavorable for prolonging the service life of the battery, and the range extender engine is not necessarily in a fuel economy interval when running under the preset power, which leads to poor economy and emission. For another example, patent number CN116160875B discloses a control method and a control device for a range extender system, which determine whether to start the range extender according to current vehicle state information, and adjust the power generated by the range extender according to the driving intention of a driver, so that the power generated responds to the power required by the whole vehicle. Patent number CN113879132B discloses a power control method for an extended range system of an automobile, which can realize power following control of the extended range power system according to real-time operation parameters and input power system parameters. The two technologies can realize the power following control of the range extender, but the input power of the power battery is not changed along with the change of the required power, so that the range extender engine is not necessarily in a fuel economy interval, and the optimal economy and emission performance cannot be ensured. Disclosure of Invention In order to solve the problems, the invention provides a control method and a system of a range extender hybrid power backhoe loader, which can adaptively adjust the output power of the range extender according to the charge state of a power battery and the power required by