A method for slope auxiliary starting of electric locomotive based on active disturbance rejection control technology

Abstract

The application provides a power locomotive slope auxiliary starting method based on a self-disturbance control technology, which comprises the following steps: judging whether the power locomotive is in a slope parking state; after the power locomotive enters the slope parking state, judging whether the power locomotive enters a slope coasting state; after the power locomotive enters the slope coasting state, adopting a self-disturbance control method based on a speed given error to realize the power locomotive slope parking function through a zero-speed closed loop. The application prevents the slope starting coasting through the zero-speed closed loop, makes the heavy load slope starting operation more convenient and easy, automatically identifies the slope coasting working condition, realizes the slope parking and slope starting auxiliary functions through the electric braking force of the traction motor, simplifies the driver operation, and makes the traction transmission system more safe and reliable. The technical scheme of the application solves the problems of the slope coasting, sticking misjudgment and starting failure caused by the traction motor overcurrent of the existing technology for the heavy load slope starting working condition of the high-power AC transmission power locomotive.

Description

Technical Field

[0001] This invention relates to the field of electric locomotive technology, and more particularly to a method for assisting electric locomotive starting on a slope based on active disturbance rejection control technology. Background Technology

[0002] In recent years, my country's rail transit construction has developed rapidly, driving the prosperity of related industrial chains, optimizing the economic and social layout, and improving people's living standards. High-speed trains and high-power heavy-haul freight electric locomotives are two important directions in railway vehicle research and development, and it is essential to improve the stability, safety, and reliability of their core control equipment.

[0003] High-power AC drive electric locomotives are currently the mainstay of heavy-haul freight railway transportation in my country, with the HXD2 eight-axle electric locomotive being a typical example. Its traction drive and network control system have been completely domestically produced. It is necessary to conduct relevant technical research and development on the HXD2 eight-axle electric locomotive to address the specific needs of coal cars and oil tankers in field operations, particularly regarding slope starting and low-speed operation.

[0004] Currently, starting electric locomotives on slopes generally relies on the driver's manual coordination of releasing mechanical brakes and applying traction. When the locomotive is heavily loaded, this becomes difficult, and the locomotive is prone to slipping or misjudging adhesion, leading to starting failure. Existing electric locomotives achieve slope starting through manual control of traction and mechanical braking by the driver. The locomotive's transmission system structure is as follows: Figure 1 As shown. When a heavy-haul electric locomotive needs to be restarted after stopping on a slope, the parking brake is first released, then the mechanical brake lever is slowly released, while the traction lever is pushed to gradually apply traction. The locomotive starts moving through the coordination of traction and braking forces. When the locomotive reaches a certain speed, the mechanical brake lever is completely released, and the locomotive enters normal operating condition. However, this existing technology has the following drawbacks:

[0005] Under heavy-load slope starting conditions, the coordinated operation of traction and braking is more difficult, placing considerable pressure on the driver and easily leading to problems such as slope slippage, misjudgment of adhesion, or traction motor overcurrent, resulting in slope start failure. Applying mechanical braking and traction force simultaneously during locomotive start-up increases wear on the mechanical braking system, reducing equipment lifespan. Furthermore, the equipment's automation level is low, failing to fully utilize and leverage the technological advantages of the electric drive system. Summary of the Invention

[0006] To address the aforementioned problems of track slippage, adhesion misjudgment, and starting failure due to traction motor overcurrent in high-power AC drive electric locomotives under heavy-load slope starting conditions, this invention provides an electric locomotive slope-assisted starting method based on active disturbance rejection control technology. This invention prevents track slippage during slope starting through a zero-speed closed-loop system, making heavy-load slope starting operations more convenient and easier. The system automatically identifies track slippage conditions and applies electric braking force to the traction motor to achieve slope stopping and slope starting assistance functions, simplifying driver operation and making the traction drive system safer and more reliable.

[0007] The technical means employed in this invention are as follows:

[0008] A method for assisted starting of an electric locomotive on a slope based on active disturbance rejection control technology includes:

[0009] Determine if the electric locomotive is stopped on a slope;

[0010] After an electric locomotive enters a parking state on a slope, it is determined whether the electric locomotive has entered a state of rolling back on the slope.

[0011] After the electric locomotive enters the slope slippage state, the active disturbance rejection control method based on the speed setpoint error is adopted to realize the electric locomotive slope stopping function through zero-speed closed loop.

[0012] Furthermore, determining whether the electric locomotive is in a slope-stopped state includes:

[0013] When the average speed of the motor is less than the set threshold for a certain period of time, the traction handle travel is zero, the parking brake is applied, and the system enters the slope parking state.

[0014] If the motor speed exceeds the set threshold for a certain period of time, the hill start stop will be exited.

[0015] Furthermore, after the electric locomotive enters the ramp parking state, determining whether the electric locomotive has entered the ramp rollaway state includes:

[0016] After the electric locomotive enters the parking state on the slope, if it needs to start on the slope, the mechanical brake handle begins to release when the throttle handle is in the free state. If the motor speed exceeds the set threshold for a certain period of time, the locomotive enters the slope slippage state. The acceleration value of the electric locomotive at this time is calculated and recorded through data processing, and the uphill and downhill information is obtained through the direction of motor rotation.

[0017] Furthermore, after the electric locomotive enters the slope runaway state, an active disturbance rejection control method based on the speed setpoint error is adopted to realize the electric locomotive slope stopping function through zero-speed closed loop, including:

[0018] The recorded acceleration is converted into corresponding traction braking force as feedforward to reduce the dynamic adjustment time of the system. When the electric locomotive's mechanical braking is completely released and it stops stably on the slope, the electromagnetic torque of the motor is recorded at this time.

[0019] The zero-speed closed loop is implemented using an active disturbance rejection control method. The output is the motor torque setpoint. The speed closed loop is set with a minimum speed threshold. When the actual motor speed is less than this threshold, the speed loop adjustment stops to prevent the locomotive from shaking at low speed.

[0020] When starting on a slope, if the electric locomotive is operating in constant speed mode, it can be controlled directly according to the set speed value, which is seamlessly connected with the zero speed closed loop on the slope.

[0021] If the electric locomotive is operating in torque mode, when the slope is determined to be downhill, the electric braking force for stopping on the slope is first reduced to zero at a certain slope, and then switched to normal driving mode. If the slope is determined to be uphill, the torque corresponding to the traction handle stroke needs to be greater than the slope stopping torque before switching to normal driving mode, thus realizing the function of automatically preventing the locomotive from rolling back on the slope.

[0022] Furthermore, the zero-speed closed loop is implemented using an active disturbance rejection control method, including:

[0023] Constructing a first-order model, the relationship between the electromagnetic torque and speed of the electric motor is as follows:

[0024]

[0025] Where v is the motor speed, K is the unit transformation constant, and T e is the electromagnetic torque setpoint of the motor, f(v) is the equivalent load torque, and m is the vehicle mass;

[0026] Let the motor speed v be denoted as the output y, and the motor electromagnetic torque T be... e Let u be the control input, f be the total disturbance, and r be the given rotational speed. Then the system can be represented as:

[0027]

[0028] Where b is the controller gain;

[0029] Construct a second-order linear extended state observer (ESO) that combines the rotational speed deviation e = ry with a function containing the total disturbance. As state variables x1 and x2 respectively, we get:

[0030]

[0031] The constructed second-order linear ESO is as follows:

[0032]

[0033] Where β1 and β2 are the observation coefficients of the extended state observer, z1 is the error observation value, and z2 is the total disturbance observation value;

[0034] Proportional-integral control error feedback is used as follows:

[0035] u0 = k p e+k i ∫edt

[0036] This leads to the overall control law, as follows:

[0037]

[0038] Among them, u0 is error feedback control; u1 is feedforward compensation control, which is obtained by calculating the locomotive acceleration at the moment of the car slipping on the slope. Adding u1 can reduce the adjustment burden of the controller and make the output converge to the target value quickly; z2 / b0 is disturbance compensation, which can track the influence of total internal and external disturbances on the system.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] 1. The electric locomotive ramp-assisted starting method based on active disturbance rejection control technology provided by the present invention can prevent the electric locomotive from failing to start under heavy load by applying ramp-assisted starting control algorithm, making the driver's operation more convenient and easier, and improving the adaptability of the traction transmission system to different working conditions on site.

[0041] 2. The electric locomotive ramp-assisted starting method based on active disturbance rejection control technology provided by the present invention uses error-based active disturbance rejection control technology to realize closed-loop control of locomotive zero speed, which can increase the motor speed tracking speed and improve system stability.

[0042] 3. The electric locomotive slope-assisted starting method based on active disturbance rejection control technology provided by this invention can automatically identify the slope slippage state and apply corresponding electric braking force without adding an tilt angle sensor. The control algorithm can be embedded in the original vehicle traction control software without adding additional equipment, and can be directly implemented on existing electric locomotives, saving costs.

[0043] Based on the above reasons, this invention can be widely promoted in fields such as electric locomotives. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of the existing locomotive transmission system.

[0046] Figure 2 This is a block diagram of the error-based active disturbance rejection control of the present invention.

[0047] Figure 3 This is a flowchart of the auxiliary control process for hill parking and hill start in this invention.

[0048] Figure 4 This is the zero-speed closed-loop control diagram of the present invention. Detailed Implementation

[0049] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] 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, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. 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.

[0052] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0053] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0054] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0055] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0056] This invention provides a method for assisted starting of an electric locomotive on a slope based on active disturbance rejection control technology, comprising:

[0057] S1. Determine whether the electric locomotive is stopped on a slope.

[0058] S2. After the electric locomotive enters the slope parking state, determine whether the electric locomotive has entered the slope rolling state.

[0059] S3. After the electric locomotive enters the slope slippage state, the active disturbance rejection control method based on the speed setpoint error is adopted to realize the electric locomotive slope stopping function through zero-speed closed loop.

[0060] In specific implementation, as a preferred embodiment of the present invention, such as Figure 3 As shown, in step S1, determining whether the electric locomotive is in a slope-stopped state includes:

[0061] When the average speed of the motor is less than a set threshold for a certain period of time, the traction handle travel is zero, the parking brake is applied, and the system enters the slope parking state. If the motor speed remains greater than the set threshold for a certain period of time, the system exits the slope parking state. In this embodiment, determining this state is to prepare for the next step of determining whether the vehicle is rolling back on the slope, and it cannot determine whether the vehicle is stopped on a straight track or on a slope.

[0062] In specific implementation, as a preferred embodiment of the present invention, please refer to [reference needed]. Figure 3 In step S2, after the electric locomotive enters the ramp parking state, determining whether the electric locomotive has entered the ramp rollaway state includes:

[0063] After the electric locomotive enters the parking state on the slope, if it needs to start on the slope, the mechanical brake handle begins to release when the throttle handle is in the free state. If the motor speed exceeds the set threshold for a certain period of time, the locomotive enters the slope slippage state. The acceleration value of the electric locomotive at this time is calculated and recorded through data processing, and the uphill and downhill information is obtained through the direction of motor rotation.

[0064] In specific implementation, as a preferred embodiment of the present invention, such as Figure 4 As shown, in step S3, after the electric locomotive enters the ramp slippage state, an active disturbance rejection control method based on the speed setpoint error is adopted to realize the electric locomotive ramp stopping function through zero-speed closed loop, including:

[0065] The recorded acceleration is converted into corresponding traction braking force as feedforward to reduce the dynamic adjustment time of the system. When the electric locomotive's mechanical braking is completely released and it stops stably on the slope, the electromagnetic torque of the motor is recorded at this time.

[0066] The zero-speed closed loop is implemented using an active disturbance rejection control method. The output is the motor torque setpoint. The speed closed loop is set with a minimum speed threshold. When the actual motor speed is less than this threshold, the speed loop adjustment stops to prevent the locomotive from shaking at low speed.

[0067] When starting on a slope, if the electric locomotive is operating in constant speed mode, it can be controlled directly according to the set speed value, which is seamlessly connected with the zero speed closed loop on the slope.

[0068] If the electric locomotive is operating in torque mode, when the slope is determined to be downhill, the electric braking force for stopping on the slope is first reduced to zero at a certain slope, and then switched to normal driving mode. If the slope is determined to be uphill, the torque corresponding to the traction handle stroke needs to be greater than the slope stopping torque before switching to normal driving mode, thus realizing the function of automatically preventing the locomotive from rolling back on the slope.

[0069] In specific implementation, as a preferred embodiment of the present invention, such as Figure 2 As shown, the zero-speed closed loop is implemented using an active disturbance rejection control method, including:

[0070] Constructing a first-order model, the relationship between the electromagnetic torque and speed of the electric motor is as follows:

[0071]

[0072] Where v is the motor speed, K is the unit transformation constant, and T e is the electromagnetic torque setpoint of the motor, f(v) is the equivalent load torque, and m is the vehicle mass;

[0073] Let the motor speed v be denoted as the output y, and the motor electromagnetic torque T be... e Let u be the control input, f be the total disturbance, and r be the given rotational speed. Then the system can be represented as:

[0074]

[0075] Where b is the controller gain;

[0076] Construct a second-order linear extended state observer (ESO) that combines the rotational speed deviation e = ry with a function containing the total disturbance. As state variables x1 and x2 respectively, we get:

[0077]

[0078] The constructed second-order linear ESO is as follows:

[0079]

[0080] Where β1 and β2 are the observation coefficients of the extended state observer, z1 is the error observation value, and z2 is the total disturbance observation value;

[0081] Proportional-integral control error feedback is used as follows:

[0082]

[0083] This leads to the overall control law, as follows:

[0084]

[0085] Among them, u0 is error feedback control; u1 is feedforward compensation control, which is obtained by calculating the locomotive acceleration at the moment of the car slipping on the slope. Adding u1 can reduce the adjustment burden of the controller and make the output converge to the target value quickly; z2 / b0 is disturbance compensation, which can track the influence of total internal and external disturbances on the system.

[0086] In this embodiment, the transient response time (TD) can be arranged in a linear mode. That is, when the locomotive's given speed suddenly increases or decreases by a certain value, the TD output tracks the given speed according to a fixed slope. The specific value of the slope is selected based on the actual speed tracking response speed required by the system. The observer and controller parameters that need to be tuned are β1, β2, b0, and k. p and k i β1 and β2 are tuned according to the concept of the bandwidth of a linear active disturbance rejection controller, with β1 = 2ω0. Where ω0 is the designed observer bandwidth, its value is selected based on the actual system control delay and control requirements. b0 is the ratio coefficient of the motor's electromagnetic torque and acceleration, reflecting the vehicle's equivalent moment of inertia to the motor, which can be calculated according to the locomotive's actual parameters. k p and k i It is the proportional-integral coefficient, which can be adjusted using the classic PID parameter tuning method, following a pattern from small to large, to accelerate the speed error adjustment speed without system oscillation.

[0087] In summary, in order to achieve rapid tracking of a given speed and reduce the rolling distance of the locomotive when parking on a slope, a high-performance speed closed-loop control algorithm is required. This invention adopts active disturbance rejection control technology based on speed setpoint error, and realizes the slope parking function of electric locomotive through zero-speed closed-loop control.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for assisted starting of an electric locomotive on a slope based on active disturbance rejection control technology, characterized in that, include: Determine if the electric locomotive is stopped on a slope; After an electric locomotive enters a parking state on a slope, it is determined whether the electric locomotive has entered a state of rolling back on the slope. After the electric locomotive enters the gradient runaway state, an active disturbance rejection control method based on the speed setpoint error is adopted to realize the electric locomotive gradient stopping function through zero-speed closed loop, including: The recorded acceleration is converted into corresponding traction braking force as feedforward to reduce the dynamic adjustment time of the system. When the electric locomotive's mechanical braking is completely released and it stops stably on the slope, the electromagnetic torque of the motor is recorded at this time. The zero-speed closed loop is implemented using an active disturbance rejection control method. The output is the motor torque setpoint. The speed closed loop is set with a minimum speed threshold. When the actual speed of the motor is less than this threshold, the speed loop adjustment stops to prevent the locomotive from shaking at low speed. When starting on a slope, if the electric locomotive is operating in constant speed mode, it can be controlled directly according to the set speed value, which is seamlessly connected with the zero speed closed loop on the slope. If the electric locomotive is operating in torque mode, when the slope is determined to be downhill, the electric braking force for stopping on the slope is first reduced to zero at a certain slope, and then switched to normal driving mode. If the slope is determined to be uphill, the torque corresponding to the traction handle stroke needs to be greater than the slope stopping torque before switching to normal driving mode, thus realizing the function of automatically preventing the locomotive from rolling back on the slope. The zero-speed closed loop is implemented using an active disturbance rejection control method, including: Constructing a first-order model, the relationship between the electromagnetic torque and speed of the electric motor is as follows: in, This refers to the motor speed. It is the unit transformation constant. It is the electromagnetic torque setpoint of the electric motor. It is the equivalent load torque. It refers to the overall vehicle quality; Motor speed denoted as output Electromagnetic torque of the electric motor Recorded as control input , For the total disturbance, For a given rotational speed, the system can be represented as: in, b For controller gain; Construct a second-order linear extended state observer (ESO) to measure the rotational speed deviation. and functions containing total disturbances As state variables respectively and ,get: The constructed second-order linear ESO is as follows: in, and These are the observation coefficients of the extended state observer. These are error observations. This is the total disturbance observation; Proportional-integral control error feedback is used as follows: This leads to the overall control law, as follows: in, For error feedback control; It is feedforward compensation control. The acceleration of the locomotive at the instant of the car sliding down the slope was calculated, and then... This can reduce the adjustment burden on the controller and allow the output to converge quickly to the target value; To compensate for disturbances, the system can track the impact of total internal and external disturbances on the system; to prevent slippage during ramp starts through a zero-speed closed loop, the system automatically identifies the slippage condition on ramps and applies electric braking force through the traction motor to achieve ramp parking and ramp start assistance functions.

2. The method for assisting electric locomotive starting on a slope based on active disturbance rejection control technology according to claim 1, characterized in that, The determination of whether the electric locomotive is stopped on a slope includes: When the average speed of the motor is less than the set threshold for a certain period of time, the traction handle travel is zero, the parking brake is applied, and the system enters the slope parking state. If the motor speed exceeds the set threshold for a certain period of time, the hill start stop will be exited.

3. The method for assisting electric locomotive starting on a slope based on active disturbance rejection control technology according to claim 1, characterized in that, After the electric locomotive enters the ramp parking state, determining whether the electric locomotive has entered the ramp rollaway state includes: After the electric locomotive enters the parking state on the slope, if it needs to start on the slope, the mechanical brake handle begins to release beyond the set threshold while the throttle handle is in the free state. If the motor speed continues to exceed the set threshold for a certain period of time, the locomotive enters the slope slippage state. The acceleration value of the electric locomotive at this time is calculated and recorded through data processing, and the uphill and downhill information is obtained through the rotation direction of the motor.

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