Locomotive idling detection method and device

Abstract

The invention provides a locomotive idling detection method and device, and the method comprises the steps: calculating the rotating speed of a traction motor through obtaining the physical quantity during the operation of a locomotive; and detecting the change rate of the rotating speed of the motor in real time according to the rotating speed of the motor, and judging whether idling occurs through a preset idling judgment method according to the change rate of the rotating speed. According to the technical scheme, the physical quantity of the locomotive is collected, the magnetic flux is calculated through the magnetization curve function stored in the locomotive, and then the rotating speed of the traction motor is calculated. The defect that the wheel set idling monitoring mode is delayed in response due to the large rotational inertia of the locomotive wheel set is overcome, and the idling recognition method has the advantages of being fast and free of blind areas.

Description

Technical Field

[0001] This document relates to the technical field of locomotive idling detection, and in particular to a locomotive idling detection method and device. Background Art

[0002] When the locomotive is pulling a train, it is necessary to increase the traction force when starting, accelerating and climbing. On long downhill slopes, resistance braking or regenerative braking is required to increase the braking force of the locomotive to prevent the train from overspeeding. In bad weather, when there is frost, snow, ice, or water on the rails, or when there is oil stains on the rails, rail damage, the locomotive wheel tread is out of round, or when passing through a small curve radius, the adhesion coefficient between the wheel and the rail will decrease, and the wheels are prone to idling and slipping. The traction force of the idling wheel axle drops sharply, which in turn affects the traction of the entire locomotive. Severe idling can also cause wear on the rail surface and the locomotive wheel tread, sometimes causing the train to stop on the way, and even causing permanent damage to the traction motor. Therefore, it is particularly important to detect the idling of the wheelset in time during locomotive operation and take measures such as reducing power and spreading sand in time to quickly eliminate idling to restore the normal operation of the locomotive.

[0003] The existing locomotive idling detection method has the following disadvantages:

[0004] 1. The idling signal detection sensitivity of the traction motor voltage identification and comparison detection method is not enough, and there is a detection blind area;

[0005] 2. The disadvantages of the idling detection mode for measuring wheelset speed are that the system has a large amount of equipment and a high failure rate. In addition, the large rotational inertia of the locomotive wheels causes the change in wheelset speed to lag behind the change in the electrical parameters of the traction motor, making the system idling protection that uses wheelset speed as an idling sampling measurement signal not fast enough.

[0006] In order to reduce the harm of idling, it is very necessary to adopt idling detection and protection methods with more sensitive detection and more reliable performance. Summary of the invention

[0007] The present invention provides a locomotive idling detection method and device, aiming to solve the above-mentioned problem.

[0008] The present invention provides a locomotive idling detection method, comprising:

[0009] S1. Calculate the rotation speed of the traction motor by obtaining the physical quantity of the locomotive during operation;

[0010] S2. According to the rotation speed of the motor, detecting the rate of change of the rotation speed of the motor in real time, and judging whether idling occurs by a preset idling judgment method according to the rate of change of the rotation speed;

[0011] The physical quantities include: traction motor terminal voltage U, armature current Ia, traction motor structural constant, traction motor branch total resistance R 支 And the main pole flux Φ of the traction motor.

[0012] The present invention provides a locomotive idling detection device, comprising:

[0013] Data acquisition module, used to obtain physical quantities when the locomotive is running;

[0014] The upper central processing unit calculates the rotation speed of the traction motor according to the physical quantity of the locomotive during operation, detects the rate of change of the rotation speed of the motor in real time according to the rotation speed of the motor, and determines whether idling occurs according to the rate of change of the rotation speed by a preset idling determination method;

[0015] The physical quantities include: traction motor terminal voltage U, armature current Ia, traction motor structural constant, traction motor branch total resistance R 支 And the main pole flux Φ of the traction motor.

[0016] The present application collects physical quantities such as current, voltage, and magnetic field weakening coefficient of the locomotive traction motor, calculates the magnetic flux through the built-in stored magnetization curve function, and then calculates the speed of the traction motor. The defect of the sluggish response of the wheel set idling monitoring method caused by the large rotational inertia of the locomotive wheel set is overcome, and the idling identification method has the characteristics of fast and no blind spots. The present application has the functions of monitoring and protecting the branch current overload of the locomotive traction motor. The device provided by the present application has the characteristics of simple structure, reliable performance, and stable quality. The device detects the voltage, current and other parameters of each traction motor of the locomotive in real time, performs intelligent analysis on the detection data, identifies the effective idling signal and makes corresponding control and protection, ensures the operation efficiency of the locomotive, and has obvious economic benefits. The present application can quickly realize the identification of locomotive idling / slipping, and opens up space for the optimization of the adhesion coefficient; this idling detection method does not require the installation of a speed sensor on each wheel axle, reduces the amount of equipment in the idling monitoring system, and improves the reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate one or more embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 is a flow chart of a locomotive idling detection method according to an embodiment of the present invention;

[0019] Figure 2 A schematic diagram of a locomotive idling detection device according to an embodiment of the present invention;

[0020] Figure 3 A data processing flow chart of a locomotive idling detection method according to an embodiment of the present invention;

[0021] Figure 4 A connection diagram of a locomotive idling detection device according to an embodiment of the present invention;

[0022] Figure 5 This is a locomotive circuit diagram of a traction motor voltage identification and comparison method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the technical solutions in one or more embodiments of this specification, the technical solutions in one or more embodiments of this specification will be clearly and completely described below in conjunction with the drawings in one or more embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of them. Based on one or more embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this document.

[0024] Existing idling detection principles include: a traction motor voltage identification and comparison method and an idling detection mode for measuring the wheelset rotation speed.

[0025] The principle of the traction motor voltage identification and comparison method is:

[0026] When a wheelset is idling, the speed of the traction motor will increase sharply and its branch current will decrease accordingly; at this time, the potential difference between points a and b at the high potential of the main magnetic poles of the two motors becomes larger, when Uab=ΔI×R≥2 volts (ΔI: the current difference of the armature of the traction motor at both ends of the idling relay KJ, R: the equivalent value of the excitation winding RL and the magnetic field weakening resistors R1 and R2 in parallel); the coil of the idling relay KJ is energized, and its normally open interlocking contact turns on the idling indicator light on the operator's cab, prompting the crew that the locomotive is idling.

[0027] Figure 5 This is a locomotive circuit diagram of a traction motor voltage identification and comparison method according to an embodiment of the present invention, and is specifically described by taking a type A freight locomotive and a type B traction motor as an example:

[0028] The speed of the traction motor can be calculated using the formula (Unit: rpm) indicates,

[0029] Where U is the terminal voltage of the traction motor, in volts; Ia is the current flowing through the armature, in amperes; R支 : Total resistance of the traction motor branch, in ohms;

[0030] R 支 The calculation method is: armature winding resistance Ra = 0.0103Ω + commutation pole winding resistance Rh = 0.00566Ω + equivalent resistance R after the main magnetic pole and the field weakening resistance are connected in parallel (all resistance values ​​are when the ambient temperature is 15°C).

[0031] In the formula: Motor structure constant

[0032] Φ: Main pole magnetic flux of traction motor, in Weber.

[0033] There are two ways to adjust the speed of the DC traction motor: the first is to adjust the output voltage U of the main generator;

[0034] The second is to adjust the excitation flux Φ of the traction motor. The method of adjusting the excitation flux Φ of the locomotive traction motor is to adjust the excitation flux Φ of the traction motor main magnetic pole coil R L A resistor R1 is connected in parallel (primary magnetic field weakening) or two resistors R1 and R2 are connected in parallel (secondary magnetic field weakening).

[0035] When the magnetic field is full, β = 1 (no magnetic field weakening): R = main magnetic pole coil R L Resistance = 0.0077Ω,

[0036] When the primary magnetic field is weakened: β = 0.6, the equivalent resistance of the main pole coil and the primary magnetic field weakening resistor in parallel

[0037] R=β×R L =0.6×0.0077=0.00462Ω,

[0038] When the secondary magnetic field is weakened: β = 0.43, the equivalent resistance of the main pole coil and the two-stage magnetic field weakening resistor in parallel

[0039] R=β×R L =0.43×0.0077=0.00331Ω.

[0040] In the formula, β=I L / I a is the magnetic field weakening coefficient, which means the current flowing through the excitation coil accounts for the total current I flowing through the branch a proportion.

[0041] Calculate the current difference ΔI=U between the two traction motors when the idling relay KJ reaches the action value (2 volts) ab / R.

[0042] In full magnetic field: ΔI = 2 / 0.0077 = 259.74A;

[0043] When the primary magnetic field is weakened: ΔI = 2 / 0.00462 = 432.90A;

[0044] When the secondary magnetic field weakens: ΔI = 2 / 0.00331 = 604.23A.

[0045] During the locomotive operation, after the starting phase reaches a stable operating speed, the armature current I a It is usually less than 600A, which means that when the locomotive idles in the secondary magnetic field weakening state at a high operating speed, even if the current in the faulty traction motor branch drops close to zero, it cannot reach the action value of the idling relay KJ, that is, the idling signal detection sensitivity of the traction motor voltage identification method is not enough and there is a blind spot.

[0046] The detection principle of the idling detection mode for measuring the wheelset speed is:

[0047] A speed sensor is installed on each wheel set, and idling is determined by measuring the speed of each wheel set and calculating its speed change rate. The advantage of this method is that the speed signal sampling is direct and accurate, but its disadvantages are that the system equipment is large, the failure rate is high, and the large rotational inertia of the locomotive wheel set causes the wheel set speed change to lag behind the change of the traction motor electrical parameters, making the system idling protection that uses the wheel set speed as the idling sampling measurement signal not fast enough.

[0048] Method Embodiment

[0049] According to an embodiment of the present invention, a locomotive idling detection method is provided. Figure 1 is a flow chart of a locomotive idling detection method according to an embodiment of the present invention, Figure 3 is a data processing flow chart of the locomotive idling detection method according to an embodiment of the present invention. Figure 1 and Figure 3 As shown, the locomotive idling detection method of the embodiment of the present invention specifically includes:

[0050] S1. Calculate the rotation speed of the traction motor by obtaining the physical quantity of the locomotive during operation;

[0051] The speed of the motor is obtained by formula 1:

[0052]

[0053] Among them, U is the terminal voltage of the traction motor, Ia is the armature current, R 支 is the total resistance of the traction motor branch, Ce is the structural constant of the traction motor, and Φ is the main pole flux of the traction motor.

[0054] The methods for determining each physical quantity in formula 1 are as follows:

[0055] The original locomotive design is equipped with sensors for the traction motor terminal voltage U and armature current Ia, which can be collected while the locomotive is running;

[0056] Traction motor structural constant Ce = 6.667;

[0057] R 支 Determination of:

[0058] When β=1:R 支 =0.0103+0.00566+0.0077=0.02366Ω;

[0059] When β=0.6:R 支 =0.0103+0.00566+0.00462=0.02058Ω;

[0060] When β=0.43:R 支 =0.0103+0.00566+0.00331=0.01927Ω;

[0061] Determination of the main pole flux Φ value of the traction motor:

[0062] A series of motor terminal voltage U, speed n, excitation current I are measured by the traction motor test bench. L The values ​​of Ce and R 支 Substituting the values ​​into the formula, we can calculate the value corresponding to each I L The Φ value is then used to obtain the Φ value and the excitation current I L The relationship function is stored in the detection device so that it can be called at any time.

[0063] According to the speed of the traction motor The formula (unit: rpm) is used to detect whether idling occurs by monitoring the rate of change of the speed of each motor dn / dt in real time.

[0064] Locomotive speed V = 60πDn / 1000μ (V unit: km / h; wheel diameter D = 1.05 m; μ: transmission ratio, traction motor μ = 63 / 14 = 4.5; n is the traction motor speed, unit: rpm) Substitute the data and get: n = 22.74V. According to actual tests, the maximum acceleration of the locomotive is no more than 1 km / h per second, that is, the maximum acceleration of the traction motor speed n is no more than 22.74 rpm per second, that is, dn / dt≤22.74. If this value is exceeded, it is idling. The idling monitoring rate is set to 100 milliseconds / time.

[0065] By monitoring the speed of each traction motor in real time, its acceleration change is calculated respectively. If the acceleration is greater than 22.74 rpm for 300 milliseconds (which can be set as appropriate), the traction motor is judged to be idling. This avoids the limitation of absolute sampling accuracy.

[0066] When any traction motor idles irreversibly and the speed reaches its maximum design value, that is, n ≥ 2365, the protection device will operate and connect the corresponding circuit to control the locomotive to unload.

[0067] When the current in any branch of the traction motor is ≥1080 amperes, the protection device will operate and the locomotive will be unloaded.

[0068] S2. According to the rotation speed of the motor, detecting the rate of change of the rotation speed of the motor in real time, and judging whether idling occurs by a preset idling judgment method according to the rate of change of the rotation speed;

[0069] The physical quantities include: traction motor terminal voltage U, armature current Ia, traction motor structural constant, traction motor branch total resistance R 支 And the main magnetic pole magnetic flux Φ of the traction motor. The S2 specifically includes:

[0070] Acquire the rate of change of the motor speed according to the motor speed;

[0071] If the rate of change of the motor speed is greater than a preset monitoring rate, it is determined that the locomotive is idling;

[0072] If the idling phenomenon lasts longer than the preset time, it is determined that the traction motor is idling.

[0073] The locomotive idling detection method further comprises:

[0074] If the rotation speed of the traction motor is greater than the first preset rotation speed value, a protection action is executed and a corresponding circuit is connected to control the locomotive to unload.

[0075] The locomotive idling detection method further comprises:

[0076] The branch current of the traction motor is monitored in real time. When the branch current is greater than a first preset current value, a protection action is executed and a corresponding circuit is connected to control the locomotive to unload.

[0077] The following beneficial effects are achieved by adopting the embodiments of the present invention:

[0078] The present application collects physical quantities such as current, voltage, and magnetic field weakening coefficient of the locomotive traction motor, calculates the magnetic flux through the built-in stored magnetization curve function, and then calculates the speed of the traction motor. The defect of the sluggish response of the wheel set idling monitoring method caused by the large rotational inertia of the locomotive wheel set is overcome, and the idling identification method has the characteristics of fast and no blind spots. The present application has the functions of monitoring and protecting the branch current overload of the locomotive traction motor. The device provided by the present application has the characteristics of simple structure, reliable performance, and stable quality. The device detects the voltage, current and other parameters of each traction motor of the locomotive in real time, performs intelligent analysis on the detection data, identifies the effective idling signal and makes corresponding control and protection, ensures the operation efficiency of the locomotive, and has obvious economic benefits. The present application can quickly realize the identification of locomotive idling / slipping, and opens up space for the optimization of the adhesion coefficient; this idling detection method does not require the installation of a speed sensor on each wheel axle, reduces the amount of equipment in the idling monitoring system, and improves the reliability of the system.

[0079] Device Embodiment

[0080] According to an embodiment of the present invention, a locomotive idling detection device is provided. Figure 2 Schematic diagram of a locomotive idling detection device according to an embodiment of the present invention. Figure 2 As shown, the locomotive idling detection device of the embodiment of the present invention specifically includes:

[0081] The data acquisition module 20 is used to obtain the physical quantities of the locomotive during operation;

[0082] The upper central processing unit 22 calculates the rotation speed of the traction motor according to the physical quantity of the locomotive during operation, detects the rate of change of the motor rotation speed in real time according to the motor rotation speed, and determines whether idling occurs according to the speed change rate by a preset idling determination method;

[0083] The physical quantities include: traction motor terminal voltage U, armature current Ia, traction motor structural constant, traction motor branch total resistance R 支 And the main pole flux Φ of the traction motor.

[0084] The data acquisition module 20 specifically includes:

[0085] The front-end data acquisition machine consists of a single-chip microcomputer, a multi-channel isolation operational amplifier, an analog / digital conversion device, a communication level conversion interface, etc.

[0086] The upper central processing unit specifically includes:

[0087] Industrial control host, LCD display and memory;

[0088] The industrial control host is specifically used to calculate the speed of the motor according to Formula 1 through the physical quantity of the locomotive when it is running;

[0089]

[0090] Among them, U is the terminal voltage of the traction motor, Ia is the armature current, R 支 is the total resistance of the traction motor branch, Ce is the structural constant of the traction motor, and is the main pole flux of the traction motor;

[0091] acquiring a rate of change of the rotation speed of the traction motor according to the rotation speed of the traction motor;

[0092] If the rate of change of the rotation speed of the traction motor is greater than a preset monitoring rate, it is determined that the locomotive is idling;

[0093] If the idling phenomenon lasts longer than the preset time, it is judged that the traction motor is idling;

[0094] The liquid crystal display screen is used to display the physical quantity and the rotation speed of the traction motor in the form of a table and a curve;

[0095] The memory is used to store the physical quantity and the rotation speed of the traction motor.

[0096] The locomotive idling detection device further comprises:

[0097] The alarm module determines that if the rotation speed of the traction motor is greater than the first preset rotation speed value, a protection action is executed and the corresponding circuit is connected to control the locomotive to unload; if the branch current is greater than the first preset current value, a protection action is executed and the corresponding circuit is connected to control the locomotive to unload.

[0098] The upper central processing unit is connected to the data acquisition module via an RS-232 communication interface.

[0099] like Figure 4 A specific connection diagram of an embodiment of the present invention is shown:

[0100] The locomotive idling detection device of the embodiment of the present invention is composed of two parts: a front-end data acquisition machine (hereinafter referred to as the front-end machine) and a host central processing machine (hereinafter referred to as the host machine). The front-end machine is composed of a single-chip microcomputer and corresponding peripheral devices, and completes the collection and upload of input signals such as the armature current, terminal voltage and magnetic field weakening state of each axis traction motor; the host machine is composed of an industrial control microcomputer, which receives the collected data sent by the front-end machine and completes the subsequent tasks of speed calculation, data analysis, record storage, and alarm control.

[0101] The front-end data acquisition machine consists of a single-chip microcomputer, a multi-channel isolation operational amplifier, an analog / digital conversion device, a communication level conversion interface, etc.

[0102] The current signal input to this device is taken from the traction motor ammeter, whose output voltage is only 75 millivolts at 1000 amperes, which cannot meet the 5-volt conversion level requirement of the A / D device, and each signal must be amplified. Because the input signal is a weak DC voltage and there is no common point between the shunts, a multi-channel isolation amplifier must be used; because the input current signal is a pulsating DC and the sparks generated by the carbon brushes of the traction motor make the measured signal full of various peak interferences and high-order harmonics, a low-pass filter must be used to filter them out to ensure the accuracy of the A / D conversion.

[0103] The upper central processing unit consists of an industrial control host, a liquid crystal display with a touch panel, a large-capacity disk storage device, etc., and completes the following functions:

[0104] The data information collected by the front-end machine is received through the RS-232 communication interface, and the current locomotive main generator voltage and the working current of each traction motor are obtained through decoding and calculation.

[0105] The speed of each traction motor is calculated based on the mathematical model, and various data such as voltage, current, magnetic field weakening state, speed, etc. are displayed on the LCD screen in the form of intuitive tables and graphs.

[0106] Alarm and control: According to the predetermined control strategy, after obtaining the exact information of a traction motor idling, it will issue an audible and visual alarm or unloading instruction in time according to the degree of idling, and record and store this event for future reference. When it is detected that the current of a traction motor is too large, exceeding the rated value (1080A) or the speed of the traction motor is greater than the design limit value (2365 rpm), a control command will also be issued.

[0107] Storage records: The voltage, current and other data parameters collected by the front-end are recorded in real time so that the relevant departments can analyze and query through the chart interface provided by this system when analyzing and judging faults or accidents.

[0108] Other functions: Through data analysis, some other fault phenomena or signs of accidents can also be analyzed according to the recorded voltage and current curve waveforms, such as parameter changes caused by pole winding breakage, carbon brushes, and loose connection of connecting lines in the traction motor circuit, and records and alarms can be made to facilitate the safe operation of the locomotive.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements 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 locomotive idling detection method, characterized in that include: S1. Calculate the rotation speed of the traction motor by obtaining the physical quantity of the locomotive during operation; S2. According to the rotation speed of the motor, detecting the rate of change of the rotation speed of the motor in real time, and judging whether idling occurs by a preset idling judgment method according to the rate of change of the rotation speed; The physical quantities include: traction motor terminal voltage U, armature current Ia, traction motor structural constant, traction motor branch total resistance R 支 And the main pole flux Φ of the traction motor.

2. The method according to claim 1, characterized in that The speed of the motor is obtained by formula 1: Among them, U is the terminal voltage of the traction motor, Ia is the armature current, R 支 is the total resistance of the traction motor branch, Ce is the structural constant of the traction motor, and Φ is the main pole flux of the traction motor.

3. The method according to claim 1, characterized in that: The S2 specifically includes: Acquire the rate of change of the motor speed according to the motor speed; If the rate of change of the motor speed is greater than a preset monitoring rate, it is determined that the locomotive is idling; If the idling phenomenon lasts longer than the preset time, it is determined that the traction motor is idling.

4. The method according to claim 1, characterized in that: The locomotive idling detection method further comprises: If the motor speed is greater than the first preset speed value, a protection action is executed and a corresponding circuit is connected to control the locomotive to unload.

5. The method according to claim 1, characterized in that The locomotive idling detection method further comprises: The branch current of the traction motor is monitored in real time. When the branch current is greater than a first preset current value, a protection action is executed and a corresponding circuit is connected to control the locomotive to unload.

6. A locomotive idling detection device, characterized in that: include: Data acquisition module, used to obtain physical quantities when the locomotive is running; The upper central processing unit calculates the rotation speed of the traction motor according to the physical quantity of the locomotive during operation, detects the rate of change of the rotation speed of the motor in real time according to the rotation speed of the motor, and determines whether idling occurs according to the rate of change of the rotation speed by a preset idling determination method; The physical quantities include: traction motor terminal voltage U, armature current Ia, traction motor structural constant, traction motor branch total resistance R 支 And the main pole flux Φ of the traction motor.

7. The device according to claim 6, characterized in that The data acquisition module specifically includes: The front-end data acquisition machine consists of a single-chip microcomputer, a multi-channel isolation operational amplifier, an analog / digital conversion device, a communication level conversion interface, etc.

8. The device according to claim 6, characterized in that The upper central processing unit specifically includes: Industrial control host, LCD display and memory; The industrial control host is specifically used to calculate the speed of the motor according to Formula 1 through the physical quantity of the locomotive when it is running; Among them, U is the terminal voltage of the traction motor, Ia is the armature current, R 支 is the total resistance of the traction motor branch, Ce is the structural constant of the traction motor, and is the main pole flux of the traction motor; Acquire the rate of change of the motor speed according to the motor speed; If the rate of change of the motor speed is greater than a preset monitoring rate, it is determined that the locomotive is idling; If the idling phenomenon lasts longer than the preset time, it is judged that the traction motor is idling; The liquid crystal display screen is used to display the physical quantity and the rotation speed of the motor in the form of a table and a curve; The memory is used to store the physical quantity and the motor speed.

9. The device according to claim 6, characterized in that The locomotive idling detection device further comprises: The alarm module determines that if the motor speed is greater than the first preset speed value, a protection action is executed and the corresponding circuit is connected to control the locomotive to unload; if the branch current is greater than the first preset current value, a protection action is executed and the corresponding circuit is connected to control the locomotive to unload.

10. The device according to claim 6, characterized in that The upper central processing unit is connected to the data acquisition module via an RS-232 communication interface.

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