A speed control method for AC transmission locomotive

Abstract

The present invention discloses a speed control method for an AC locomotive. The speed control method is used during the deceleration and stopping phases, the constant speed operation phase, and the acceleration phase of the AC locomotive. The speed control method includes the following steps: setting a target speed value; setting an acceleration target value; calculating a real-time acceleration feedback value, performing closed-loop control on the acceleration target value and the acceleration feedback value to obtain the required real-time motor torque of the AC locomotive; and obtaining a corresponding gear position based on the motor torque of the AC locomotive to control the AC locomotive. The speed control method for an AC locomotive of the present invention utilizes an acceleration closed-loop algorithm, which can be operated according to an acceleration-speed difference curve and a control algorithm to achieve regulation of output traction.

Description

Technical Field

[0001] The present invention relates to the technical field of AC transmission locomotive design, and in particular to a speed control method for an AC transmission locomotive. Background Art

[0002] Trains must stop at designated locations when entering stations to facilitate passenger boarding and alighting. Speed ​​control is required during operations in marshaling yards, and the positioning of rolling stock for factory and mining operations all require speed and position control. To ensure accurate and timely stops, the ability to quickly and precisely adjust both speed and acceleration is crucial.

[0003] Positioning parking, constant speed, deceleration control, and acceleration control are difficult and require high operator skills if they rely entirely on the driver. Implementing speed and position parking control will improve positioning accuracy and speed control precision, reducing the workload of drivers and passengers.

[0004] Many users require locomotives to operate in constant speed mode, placing high demands on speed accuracy and dynamic response. Most methods use the speed signal as a closed-loop control to adjust the motor current or torque. Effective adjustments to the motor current or traction force are only possible when there are significant deviations in speed or acceleration. Other methods detect acceleration and, when the speed deviation reaches a certain threshold, calculate the output traction force to meet a certain acceleration to achieve speed regulation control. This results in a wide speed fluctuation range. Some speed controls also require information such as the total mass of the train, the slope's oblique force, and the running resistance, making the calculations complex. Calculations are difficult to perform under varying loads.

[0005] In the existing technology, the sum of the current resistance of the train, the oblique force of the slope of the current line of the train, and the external forces acting on the train under different operating conditions is used as the reference value for constant speed control. The output force of the train's traction motor is calculated during constant speed control to keep the train's operating speed constant.

[0006] This method is actually an incremental control based on the deviation between the target speed and the actual speed. The expected acceleration requires the knowledge of the train mass and the calculation of the running resistance, slope resistance, etc. Many parameters are required to implement the function. The feedback acceleration is not directly involved in the control. The calculation is complex, and it is not suitable for application scenarios such as changing loads and unknown line conditions. This method also requires knowing parameters such as the train load m, and the accuracy is greatly affected by changing loads. Constant speed mode can only be entered when the actual speed is close to the target speed. This is a supplementary method for constant speed control, which is slow to adjust and has a static speed error. Its control is a control with a static speed error. It is adjusted through speed feedback and cannot be stabilized at the set point. The traction output will only be corrected when the load change causes a large change in speed deviation.

[0007] The existing technology also uses a speed closed loop and a current closed loop to control the main generator excitation current and adjust the traction motor current. The disadvantage is that the current closed loop and the speed closed loop are used, the speed fluctuation range is relatively large, and the adjustment response is slow. The adhesion control effect is also poor. The response to idling is slow. There are related issues such as speed overshoot, starting time, and speed fluctuation range when the load changes. There is a contradiction between response time and overshoot. The lower the loading rate, the smaller the overshoot, but the response time will be longer. Especially in the case of sudden load changes, the speed step decreases. If the loading rate is low, the response time will be longer. In addition, the idling situation is not taken into consideration. When the track surface condition is poor, it affects the application.

[0008] Based on this, the existing technology still needs to be improved. Summary of the Invention

[0009] To solve the above technical problems, an embodiment of the present invention provides a speed control method for an AC transmission locomotive.

[0010] An embodiment of the present invention discloses a speed control method for an AC transmission locomotive. The speed control method is used in the deceleration and parking phase, the constant speed operation phase, and the acceleration operation phase of the AC transmission locomotive. The speed control method includes the following steps:

[0011] Set the speed target value;

[0012] Set the acceleration target value;

[0013] Calculate the real-time acceleration feedback value, perform closed-loop control on the acceleration target value and the acceleration feedback value, and obtain the real-time required motor torque of the AC transmission locomotive;

[0014] According to the motor torque of the AC transmission locomotive, the corresponding gear position is obtained and the AC transmission locomotive is controlled.

[0015] Furthermore, the deceleration and parking phase of the AC transmission locomotive is when the AC transmission locomotive is running in a parking interval, wherein the parking interval is a certain distance from the parking location and the AC transmission locomotive changes from constant speed operation to deceleration operation; the speed control method comprises the following steps:

[0016] Set the speed target value;

[0017] Set the acceleration target value;

[0018] Calculate the real-time acceleration feedback value, perform closed-loop control on the acceleration target value and the acceleration feedback value, and obtain the real-time required motor torque of the AC transmission locomotive;

[0019] According to the motor torque of the AC transmission locomotive, the corresponding gear is obtained and the braking control of the AC transmission locomotive is performed;

[0020] Determine the displacement deviation between the AC transmission locomotive and the parking location, and apply air brakes to stop the vehicle when the displacement deviation approaches zero.

[0021] Furthermore, “setting the acceleration target value” includes:

[0022] Obtain the actual speed value and the estimated running distance of the AC transmission locomotive;

[0023] Calculate the target acceleration based on the actual speed and the expected running distance.

[0024] Furthermore, “calculating the target acceleration according to the actual speed value and the actual speed value” includes:

[0025] According to the actual speed value, calculate the average speed v avg =v0 / 2

[0026] According to the average speed and the expected running distance, the running time t=s / v is calculated avg =2s / v0, calculate the target acceleration

[0027] Among them, v0 is the actual speed value and s is the expected running distance.

[0028] Furthermore, the "calculation of real-time acceleration feedback value" is iteratively calculated using the following formula:

[0029] a(n)=b1*a(n-5)-b2*a(n-4)+b3*a(n-2)+b4*[c(n)+c(n-2)-c(n-4)-c(n-5)]

[0030] Where a(n) is the acceleration frequency acceleration feedback value of the current cycle,

[0031] c(n) is the angular velocity frequency corresponding to the current velocity,

[0032] b1, b2, b3, b4 are constants at a certain sampling time.

[0033] n is the current cycle, n-2 is the two cycles before the current cycle, n-4 is the four cycles before the current cycle, and n-5 is the five cycles before the current cycle.

[0034] Furthermore, the constant speed operation phase of the AC transmission locomotive is when the AC transmission locomotive operates at a constant speed; the speed control method comprises the following steps:

[0035] Set the speed target value;

[0036] Obtain the actual speed value. If the actual speed value is not equal to the target speed value, set the acceleration target value and calculate the real-time acceleration feedback value. Perform closed-loop control on the acceleration target value and the acceleration feedback value to obtain the real-time required motor torque of the AC transmission locomotive.

[0037] According to the motor torque of the AC transmission locomotive, the corresponding gear is obtained to control the acceleration or deceleration of the AC transmission locomotive.

[0038] Furthermore, the acceleration target value is zero.

[0039] Furthermore, when the speed target value and the actual speed value have a positive deviation, the acceleration target value is positive; when the speed target value and the actual speed value have a negative deviation, the acceleration target value is negative. The acceleration target value is set according to the magnitude of the speed deviation.

[0040] Furthermore, the speed target value is a constant operating speed value.

[0041] An AC transmission locomotive disclosed in an embodiment of the present invention includes: using the above-mentioned speed control method to perform precise parking and constant speed operation.

[0042] By adopting the above technical solution, the present invention has at least the following beneficial effects:

[0043] 1) Typically, locomotive parking requires position information and is controlled according to the speed-displacement curve. Speed ​​control can result in overshoot, long adjustment times, and large static speed errors. Acceleration control provides a faster response, adjusting the speed according to the set acceleration, and fully controllable overshoot.

[0044] 2) Existing control methods require input of train mass to calculate train resistance, slope resistance, etc. In practice, loads vary and line conditions are complex, resulting in a large amount of data input and low accuracy. The control method of the present invention uses acceleration closed-loop control, eliminating the need for inputting extensive information. Load changes and line effects can be expressed in the feedback acceleration to execute the control algorithm.

[0045] 3) The existing control method requires that the actual speed be close to the set speed before entering the constant speed mode. The control method of the present invention uses an acceleration closed-loop algorithm, which can operate according to the acceleration-speed difference curve and the control algorithm to achieve the adjustment of the output traction force.

[0046] 4) While existing control methods incorporate acceleration control, using speed and acceleration as criteria, they employ complex logic for control, requiring consideration of various operating conditions. This lacks versatility and requires repeated debugging. The precise locomotive acceleration values ​​required to execute a particular action at different speeds require on-site debugging, and each data point must be repeatedly debugged to meet the requirements. This consumes considerable debugging time. The control method of the present invention utilizes a universal acceleration closed-loop algorithm, enabling effective control in different application scenarios by simply modifying the locomotive's characteristic parameters.

[0047] 5) In the prior art control process, acceleration is used as a criterion, not a parameter. When acceleration exceeds a threshold, traction is increased or decreased, adjusted based on an estimated value rather than the output of a control function. The acceleration control algorithm in the control method of the present invention uses acceleration as a reference and feedback parameter, employing a mature algorithm to achieve optimized performance.

[0048] 6) Existing control methods do not consider adhesion control, and under complex operating conditions, the desired acceleration cannot be output normally. The control method of the present invention uses an acceleration control algorithm, which can quickly respond to idling / coasting and quickly restore adhesion.

[0049] 7) Due to the large speed threshold of acceleration detection, acceleration detection is not accurate enough, resulting in static speed error in locomotive operation control. The acceleration control algorithm adopted by the control method of the present invention uses an advanced acceleration algorithm and combines the current speed, historical speed, historical acceleration, etc. to calculate the acceleration. The acceleration calculation result is stable and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0051] Figure 1 A flow chart of a speed control method for an AC transmission locomotive according to an embodiment of the present invention;

[0052] Figure 2 A schematic diagram of a control system with added displacement, velocity and acceleration functions according to an embodiment of the present invention;

[0053] Figure 3 A traction and braking force curve diagram of a locomotive according to an embodiment of the present invention;

[0054] Figure 4 FIG. 4 is a flow chart of various speed mode conversions according to an embodiment of the present invention. DETAILED DESCRIPTION

[0055] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0056] Most methods for calculating acceleration use acceleration, speed, and other factors as criteria, distinguishing between various situations and adjusting the motor's output torque or current. These adjustments typically rely on a fixed acceleration expectation value for control. This is actually a speed difference comparison, where the output traction force is corrected by setting certain parameters, rather than directly controlling acceleration. Acceleration feedback does not directly participate in control, but rather serves as a control condition. Adjustments are made through speed deviation, or acceleration or traction is set based on speed deviation. Alternatively, a simple speed difference is used to determine the loading and unloading state, and a more complex calculation is used to determine the output traction force.

[0057] The accuracy, response time, overshoot and other indicators of existing speed control are all affected. Especially when there is a large disturbance in the load, the speed fluctuation will be relatively large.

[0058] In addition, in bad weather, when the traction braking force is relatively large, adhesion control is more difficult and idling and other problems are prone to occur. These problems need to be solved.

[0059] For deceleration, it would be ideal to achieve it through electric braking, which can recover energy and be assisted by air braking.

[0060] like Figure 1 As shown, some embodiments of the present invention disclose a speed control method for an AC transmission locomotive. The speed control method is used in the deceleration and parking phase, the constant speed operation phase, and the acceleration operation phase of the AC transmission locomotive. The speed control method includes the following steps:

[0061] S100 sets the speed target value;

[0062] S200 sets the acceleration target value;

[0063] S300 calculates the real-time acceleration feedback value, performs closed-loop control on the acceleration target value and the acceleration feedback value, and obtains the real-time required motor torque of the AC transmission locomotive;

[0064] S400 obtains the corresponding gear position according to the motor torque of the AC transmission locomotive and controls the AC transmission locomotive.

[0065] In some preferred embodiments of the present invention, the deceleration and parking phase of the AC transmission locomotive is when the AC transmission locomotive is running in a parking interval, which is a certain distance from the parking location and when the AC transmission locomotive changes from constant speed operation to decelerated operation; the speed control method includes the following steps:

[0066] Set the speed target value;

[0067] Set the acceleration target value;

[0068] Calculate the real-time acceleration feedback value, perform closed-loop control on the acceleration target value and the acceleration feedback value, and obtain the real-time required motor torque of the AC transmission locomotive;

[0069] According to the motor torque of the AC transmission locomotive, the corresponding gear is obtained and the braking control of the AC transmission locomotive is performed;

[0070] The distance between the AC locomotive and the parking spot is determined using ground beacons, position detection radar, and speed-time calculations. When the distance approaches zero, air braking is applied to stop the vehicle. The traction braking mode and gear are determined based on the torque value, enabling motor torque control and controlling the locomotive speed. Furthermore, when the distance to the target is within the error range and the speed is within the zero speed error range, air braking is applied to stop the vehicle.

[0071] In some preferred embodiments of the present invention, “setting an acceleration target value” includes:

[0072] Obtain the actual speed value and the estimated running distance of the AC transmission locomotive;

[0073] Calculate the target acceleration based on the actual speed and the expected running distance.

[0074] In some preferred embodiments of the present invention, “calculating the target acceleration according to the actual speed value and the actual speed value” includes:

[0075] According to the actual speed value, calculate the average speed v vag =0 / 2

[0076] According to the average speed and the expected running distance, the running time t=s / a is calculated avg =2s / v0, calculate the target acceleration

[0077] Among them, v0 is the actual speed value, s is the expected running distance;

[0078] The above calculation method can correct the target acceleration in real time according to the actual speed value at a certain moment and the current expected running distance.

[0079] In some preferred embodiments of the present invention, “calculating the real-time acceleration feedback value” is performed iteratively using the following formula:

[0080] a(n)=b1*a(n-5)-b2*a(n-4)+b3*a(n-2)+b4*[c(n)+c(n-2)-c(n-4)-c(n-5)]

[0081] Where a(n) is the acceleration feedback value of the current cycle,

[0082] c(n) is the angular velocity frequency corresponding to the current velocity,

[0083] b1, b2, b3, and b4 are constants at a certain sampling time. For example, when the controller samples at 0.5 ms, b1 = 0.98494555, b2 = 2.96979666, b3 = 2.98485088, and b4 = 0.00012309.

[0084] n is the current cycle, n-2 is the two cycles before the current cycle, n-4 is the four cycles before the current cycle, and n-5 is the five cycles before the current cycle.

[0085] In some preferred embodiments of the present invention, the constant speed operation phase of the AC transmission locomotive is when the AC transmission locomotive operates at a constant speed; the speed control method comprises the following steps:

[0086] Set the speed target value;

[0087] Obtain the actual speed value. If the actual speed value is not equal to the target speed value, set the acceleration target value and calculate the real-time acceleration feedback value. Perform closed-loop control on the acceleration target value and the acceleration feedback value to obtain the real-time required motor torque of the AC transmission locomotive.

[0088] According to the motor torque of the AC transmission locomotive, the corresponding gear is obtained to control the acceleration or deceleration of the AC transmission locomotive.

[0089] In some preferred embodiments of the present invention, the acceleration target value is zero.

[0090] In some preferred embodiments of the present invention, when the speed target value and the actual speed value have a positive deviation, the acceleration target value is positive; when the speed target value and the actual speed value have a negative deviation, the acceleration target value is negative. The acceleration target value is set based on the magnitude of the speed deviation.

[0091] In some preferred embodiments of the present invention, the speed target value is a constant operating speed value.

[0092] The AC transmission locomotive according to the embodiment of the present invention uses the above speed control method to perform precise parking and constant speed operation.

[0093] Preferably, during the deceleration and parking phase, the target speed value is set as the speed target value for each time period during the process of the vehicle moving from the initial running speed to zero speed, for example, according to different time intervals. The target speed can be set according to a speed-displacement curve.

[0094] Preferably, during the constant speed operation phase, the target speed can be set according to the speed-displacement curve, or through a display screen, a controller handle, or the like.

[0095] Preferably, the acceleration target value should not exceed the acceleration limit value, and the acceleration limit should be performed, otherwise the riding experience and comfort will be affected.

[0096] Preferably, the motor torque or motor current is calculated to be equivalent to the locomotive traction force or braking force.

[0097] Preferably, the motor torque is calculated and the relevant gear is determined based on the torque-speed curve of each gear, thereby obtaining the current appropriate traction line or braking line to ensure torque output capacity. However, it is still limited by the maximum traction torque and maximum braking torque envelope.

[0098] like Figure 2 As shown, the positioning stop function is achieved through three closed-loop control systems. The outer loop is the distance closed-loop, which sets the target speed value based on the target distance and the calculated distance. The middle loop is the speed closed-loop, which sets the target acceleration based on the target speed and the feedback speed. The inner loop is the acceleration closed-loop, which performs acceleration closed-loop control based on the set acceleration and the calculated acceleration value, outputting the control torque value. This achieves a linear relationship between torque and acceleration. Positioning stop can be achieved through acceleration closed-loop control based on the acceleration-time curve. Acceleration control also involves comfort control. Jerk control limits reaction shock, and response time is controllable.

[0099] like Figure 3 The figure shows the traction-braking force curve for one locomotive direction. The traction-braking force curve for the other direction is symmetrical. The gear curves in the figure are for reference only and may vary depending on the traction characteristics of the locomotive. During traction, the appropriate traction gear is selected by comparing the calculated torque (or traction force) with the traction gear curve.

[0100] By detecting the target distance, running speed, running time limit, etc., the speed-displacement curve is planned, and the acceleration-displacement curve is further planned.

[0101] Acceleration control: The acceleration closed-loop achieves smooth speed control. When the setpoint changes, the torque increases according to the set acceleration, then quickly recovers and stabilizes at a lower torque value, maintaining constant speed operation. As a PI application, acceleration closed-loop control can adjust PI control parameters to achieve stable control and reduce acceleration overshoot. Furthermore, during constant speed control, to reduce speed fluctuations, the target acceleration is reduced to zero as the target speed approaches.

[0102] During constant speed operation, when the initial speed is high, it can automatically enter the electric braking mode (output torque is negative) to achieve locomotive deceleration control.

[0103] At the same time, it meets the limit requirements of the adhesion control acceleration threshold, reduces impact and improves operating comfort.

[0104] The acceleration target value can also be reasonably adjusted according to the set target speed. For example, when the locomotive running speed is high and the output torque is low, the acceleration set value can be lowered to make the output torque more accurate and the speed adjustment smoother.

[0105] "Calculating real-time acceleration feedback" can use a second-order forward difference quotient algorithm or a higher-order algorithm to calculate acceleration based on current speed, historical speed, and historical acceleration. This makes acceleration calculation more stable and better reflects actual operating conditions. For multi-axle locomotives, the maximum or minimum acceleration is selected as the feedback acceleration based on the traction and braking mode.

[0106] The target speed is filtered and controlled to obtain a reference speed value, making the speed setting smooth. Constant speed mode can be entered or exited at any speed. Actual speed can be obtained at any time.

[0107] Closed-loop control is performed on the acceleration reference and acceleration feedback values ​​to calculate motor torque and current. Acceleration closed-loop control can reduce torque shock and peak torque ripple. It also facilitates adhesion control and ensures smooth locomotive operation.

[0108] According to the calculated output torque or current, the working condition is converted through hysteresis control, which can achieve constant speed traction or constant speed electric braking, ensuring the realization of the set speed target under different load conditions.

[0109] The locomotive's traction and braking capacity is limited. The controller calculates the locomotive motor torque based on the torque-speed curve for each gear. Through hysteresis control, it obtains the relevant gear and determines the current appropriate traction line / brake line to ensure torque output capacity. However, it is still limited by the maximum traction torque and maximum braking torque envelope.

[0110] The target speed setting for locomotive adhesion control is achieved. The acceleration reference can be used as the basis for adhesion control, and the locomotive torque is controlled according to the preset acceleration. The output torque is automatically adjusted according to the acceleration feedback.

[0111] At the same time, creep control is implemented, setting a creep speed limit based on the speed reference. When the limit is exceeded, output torque is rapidly adjusted. The creep speed limit is also determined by the operating direction and traction braking conditions.

[0112] The control method of the present invention can be used when multiple controllers are put into use. One controller can be set as the main controller and the rest can be set as slave controllers in sequence. The main controller calculates the traction electric braking condition, torque, gear position, etc. through the control algorithm and sends them to the slave controllers to achieve synchronous operation of multiple controllers.

[0113] PID control algorithms or equivalent algorithms can be used for acceleration, and the output signals, torque, current, etc. are all equivalent to traction force. Reference data includes: traction characteristic curve envelope, traction torque-speed curves for each gear, braking torque-speed curves for each gear, as well as planned speed-displacement curves, planned acceleration-displacement curves, speed-time curves, acceleration-time curves, etc.

[0114] When the deviation between the reference speed and the actual speed is small and the acceleration feedback is very small, the target acceleration can be set to zero to lock the output torque. When the load changes, causing a large deviation between the reference speed and the actual speed, the target acceleration is set according to the acceleration-speed deviation curve, filtered to obtain the reference acceleration, and then adjusted according to the acceleration closed loop with reference to the acceleration limit.

[0115] Adjustments can be made based on reference acceleration, or adhesion control can be performed. Adhesion control is used when hauling heavy loads, enabling rapid response to idling. Adhesion control with creep rate improves adhesion utilization. Based on the locomotive's direction command, actual operating conditions, and reference speed, the creep rate determines the creep limit speed. If the creep limit is exceeded, output torque reduction is applied.

[0116] In traction mode, if the creep limit speed is exceeded, the output torque will be reduced.

[0117] In braking mode, if the speed is lower than the creep limit, the output torque will be reduced.

[0118] When positioning the vehicle for parking, the acceleration-distance curve, speed-time curve, acceleration-time curve, etc. can be planned and corrected based on the target distance, current speed, etc. This is used for speed control.

[0119] Figure 4The flow chart of various speed mode conversions is shown. After the control system is initialized, it enters the judgment of whether to perform positioning parking:

[0120] If a positioning stop is performed, the speed target value and the acceleration target value are set; the real-time acceleration feedback value is calculated, and the acceleration target value and the acceleration feedback value are closed-loop controlled to obtain the real-time required motor torque of the AC transmission locomotive; according to the motor torque of the AC transmission locomotive, the corresponding gear is obtained and the AC transmission locomotive is braked; the displacement deviation between the AC transmission locomotive and the parking position is determined, and when the displacement deviation is close to zero, the air brake is applied to stop the vehicle; when the displacement deviation is not close to zero, the previous steps are continued.

[0121] If positioning parking is not performed, constant speed operation control is entered to obtain the actual speed value. If the actual speed value is not equal to the speed target value, the acceleration target value is set and the real-time acceleration feedback value is calculated. The acceleration target value and the acceleration feedback value are closed-loop controlled to obtain the real-time required motor torque of the AC transmission locomotive; according to the motor torque of the AC transmission locomotive, the corresponding gear is obtained to control the acceleration or deceleration of the AC transmission locomotive.

[0122] Acceleration control makes the response faster, and the speed is adjusted according to the set acceleration. The overshoot is fully controllable. The overshoot is small, the response is fast, the operation is smooth, and the impact is small.

[0123] Acceleration closed-loop control eliminates the need for extensive data input. Load changes and line effects are reflected in the feedback acceleration, allowing the control algorithm to run. Precise control is achieved without requiring information about train mass or slope.

[0124] By adopting the acceleration closed-loop algorithm, the output traction force can be adjusted according to the acceleration-speed difference curve and the control algorithm.

[0125] It realizes automatic conversion of working conditions and can work in electric braking mode to achieve smooth operation, which is beneficial to energy recovery.

[0126] The acceleration closed-loop algorithm is universal and can achieve good control effects in different application scenarios by simply modifying characteristic parameters such as the locomotive.

[0127] The acceleration control algorithm uses acceleration as a reference and feedback parameter, employing a mature algorithm to optimize performance. Closed-loop acceleration control is implemented using a mature control algorithm. Parameter configuration allows for adjustment of response time, overshoot, and other parameters. This results in fast response, minimal overshoot, and simple control without the need for complex logic processing.

[0128] The acceleration control algorithm can quickly respond to idling / coasting and quickly restore adhesion. It implements acceleration adhesion control to meet adhesion control requirements in harsh environments. It also implements creep rate adhesion control to protect against low acceleration and high speed conditions, allowing for rapid adhesion recovery.

[0129] The acceleration control algorithm uses advanced acceleration calculation methods, combining current speed, historical speed, historical acceleration, etc. to calculate the acceleration. The calculation results are stable and reliable.

[0130] The target speed is set using a velocity-target displacement curve. This speed-time curve is converted into an acceleration-time curve for speed tracking and acceleration closed-loop control. The target speed can also be set using other methods, such as the display or the controller's gear position. The target acceleration is set using a speed deviation for both speed and acceleration control.

[0131] Gear limit, acceleration shock, and PI regulation are controlled based on acceleration.

[0132] In the case of multiple controllers, the master controller can perform calculations and send the working conditions, gear limits, torque, etc. to the slave controllers to achieve coordinated work.

[0133] The control method of the present invention is not only applicable to AC transmission diesel locomotives, electric locomotives and hybrid locomotives, but also suitable for positioning parking, speed control, acceleration control, etc. of other rail vehicles, all of which are within the protection scope of the present invention.

[0134] The output control variable can be motor torque, motor current, or traction / braking force. The target acceleration for closed-loop speed and acceleration control is merely an example and does not limit the present invention in any way. Simple modifications, equivalent variations, modifications, and adaptations through other means are also intended to fall within the scope of protection of the present invention.

[0135] Reference acceleration setting, adjustment by other means, simple processing and modification, etc. should all fall within the scope of protection of the technical solution of the present invention.

[0136] The calculation of the feedback acceleration is not limited to the method of the present invention, and other methods may also be used, all of which should fall within the scope of protection of the technical solution of the present invention.

[0137] The speed and acceleration are closed-loop controlled to achieve the target acceleration.

[0138] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any form. Any simple modifications, equivalent changes, modifications, and adaptations to the above embodiments made in accordance with the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

[0139] It should be pointed out in particular that the various components or steps in the above-mentioned embodiments can be cross-linked, replaced, added, or deleted with each other. Therefore, the combinations formed by these reasonable permutations and combinations should also fall within the scope of protection of the present invention, and the scope of protection of the present invention should not be limited to the embodiments.

[0140] The above are exemplary embodiments disclosed in the present invention. The order in which the above embodiments of the present invention are disclosed is for description only and does not represent the pros and cons of the embodiments. However, it should be noted that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope disclosed in the embodiments of the present invention (including the claims) is limited to these examples. Various changes and modifications may be made without departing from the scope defined in the claims. The functions, steps and / or actions of the method claims according to the disclosed embodiments described herein do not need to be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or required in individual form, they may also be understood as multiple unless expressly limited to the singular.

[0141] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples. Within the spirit of the embodiments of the present invention, the technical features of the above embodiments or different embodiments may be combined, and there are many other variations of the different aspects of the embodiments of the present invention described above, which are not provided in detail for the sake of clarity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included within the scope of protection of the embodiments of the present invention.

Claims

1. A speed control method for an AC transmission locomotive, characterized in that: The speed control method is used in the deceleration and parking stage, constant speed operation stage and acceleration operation stage of the AC transmission locomotive; the speed control method is applicable to the entire process of deceleration, constant speed and acceleration operation stages; The speed control method in the deceleration and parking stage includes the following steps: Set the speed target value; Get the actual speed value; Set the acceleration target value; the acceleration target value is a continuous function of the speed difference; when the speed difference is positive, the acceleration target value is positive; when the speed difference is zero, the acceleration target value is zero; when the speed difference is negative, the acceleration target value is negative; Calculate the real-time acceleration feedback value, perform acceleration PID closed-loop control on the acceleration target value and acceleration feedback value, obtain the real-time required motor torque of the AC transmission locomotive, and implement acceleration PID closed-loop control; According to the motor torque of the AC transmission locomotive, the corresponding gear is obtained and the braking control of the AC transmission locomotive is performed; Determine the displacement deviation between the AC transmission locomotive and the parking location, and apply air brakes to stop the vehicle when the displacement deviation approaches zero; The speed control method in the constant speed operation stage and the accelerated operation stage includes the following steps: Set the speed target value; Get the actual speed value; Set the acceleration target value; the acceleration target value is a continuous function of the speed difference; when the speed difference is positive, the acceleration target value is positive; when the speed difference is zero, the acceleration target value is zero; when the speed difference is negative, the acceleration target value is negative; Calculate real-time acceleration feedback value; The acceleration target value and the acceleration feedback value are subjected to acceleration PID closed-loop control to obtain the motor torque required by the AC transmission locomotive in real time; According to the motor torque of the AC transmission locomotive, the corresponding gear is obtained to control the acceleration or deceleration of the AC transmission locomotive; The "calculation of real-time acceleration feedback value" in the speed control method during the deceleration and stop phase, the constant speed operation phase, and the acceleration phase is iteratively calculated using the following formula: a(n)=b1×a(n-5)-b2×a(n-4)+b3×a(n-2)+b4×[c(n)+c(n-2)-c(n-4)-c(n-5)] Where a(n) is the angular velocity frequency acceleration feedback value of the current cycle, c(n) is the angular velocity frequency corresponding to the current velocity, b1, b2, b3, b4 are constants at a certain sampling time. n is the current cycle, n-2 is the two cycles before the current cycle, n-4 is the four cycles before the current cycle, and n-5 is the five cycles before the current cycle.

2. The speed control method for an AC transmission locomotive according to claim 1, characterized in that: The deceleration and parking stage of the AC transmission locomotive is when the AC transmission locomotive is running in a parking section, which is a certain distance from the parking location and when the AC transmission locomotive changes from constant speed operation to deceleration operation.

3. The speed control method for an AC transmission locomotive according to claim 2, characterized in that: The "setting of the acceleration target value" in the speed control method during the deceleration and parking phase includes: Obtain the actual speed value and the estimated running distance of the AC transmission locomotive; Calculate the target acceleration based on the actual speed and the expected running distance.

4. The speed control method for an AC transmission locomotive according to claim 3, wherein: "Calculate target acceleration based on actual speed value and speed actual value" includes: Calculate the average speed based on the actual speed value Calculate the running time based on the average speed and the expected running distance , Calculating target acceleration Among them, v0 is the actual speed value and s is the expected running distance.

5. The speed control method for an AC transmission locomotive according to claim 1, characterized in that: The constant speed operation stage of the AC transmission locomotive is when the AC transmission locomotive operates at a constant speed.

6. The speed control method for an AC transmission locomotive according to claim 5, characterized in that: In the speed control method in the constant speed operation stage, when the speed target value is equal to the actual speed value, the acceleration target value is zero.

7. The speed control method for an AC transmission locomotive according to claim 5, characterized in that: The speed target value in the speed control method in the constant speed operation stage is a constant operating speed value.

8. An AC transmission locomotive, characterized in that: include: The speed control method according to any one of claims 1 to 7 is used to perform precise parking, constant speed operation and accelerated operation.

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