Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B61—RAILWAYS
  • B61C—LOCOMOTIVES; MOTOR RAILCARS
  • B61C15/00—Maintaining or augmenting the starting or braking power by auxiliary devices and measures; Preventing wheel slippage; Controlling distribution of tractive effort between driving wheels
  • B61C15/08—Preventing wheel slippage
  • B61C15/12—Preventing wheel slippage by reducing the driving power
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L3/00—Electric devices on electrically-propelled vehicles for safety purposes; Monitoring operating variables, e.g. speed, deceleration or energy consumption
  • B60L3/10—Indicating wheel slip ; Correction of wheel slip
  • B60L3/106—Indicating wheel slip ; Correction of wheel slip for maintaining or recovering the adhesion of the drive wheels
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
  • B60W10/04—Conjoint control of vehicle sub-units of different type or different function including control of propulsion units
  • B60W10/08—Conjoint control of vehicle sub-units of different type or different function including control of propulsion units including control of electric propulsion units, e.g. motors or generators
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W30/00—Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units
  • B60W30/18—Propelling the vehicle
  • B60W30/18172—Preventing, or responsive to skidding of wheels
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L2240/00—Control parameters of input or output; Target parameters
  • B60L2240/40—Drive Train control parameters
  • B60L2240/42—Drive Train control parameters related to electric machines
  • B60L2240/423—Torque
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L2240/00—Control parameters of input or output; Target parameters
  • B60L2240/40—Drive Train control parameters
  • B60L2240/46—Drive Train control parameters related to wheels
  • B60L2240/463—Torque
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L2240/00—Control parameters of input or output; Target parameters
  • B60L2240/40—Drive Train control parameters
  • B60L2240/46—Drive Train control parameters related to wheels
  • B60L2240/465—Slip
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W2520/00—Input parameters relating to overall vehicle dynamics
  • B60W2520/26—Wheel slip
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W2710/00—Output or target parameters relating to a particular sub-units
  • B60W2710/08—Electric propulsion units
  • B60W2710/083—Torque
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/60—Other road transportation technologies with climate change mitigation effect
  • Y02T10/64—Electric machine technologies in electromobility

Definitions

• the present invention relates to the methods and procedures used in electric traction vehicles to avoid, or reduce, the skating or sliding that occurs between the wheels of the vehicles and the raceway through which they travel.
• the electric traction control systems of railway vehicles ensure that the electric traction motors under their control provide a traction torque, or a braking torque, equal to a reference torque value demanded by the driver of the railway vehicle, or by the control system itself.
• the control system increases the revolutions of electric traction motors to transmit respective turning movements to drive axles to which the wheels of the railway vehicle are associated.
• the relative speed between the wheel and the rails should be understood, that is, the difference between the linear speed of the wheel and the speed of the vehicle.
• the wheel tends to suffer a skating when it is split, or tends to block when braking, this produces vibrations that decrease the comfort of the users of the railway vehicle and produces degradations of the material that constitutes the wheels, being able to produce defects that cause a malfunction of the wheels, or even their destruction, such as planes, cracks, coke, exfoliations, etc.
• the maximum tensile stress that can be transmitted that is, the maximum torque that the electric traction motor can transmit to the drive axle depends on the adhesion between the wheel and the rail.
• the tensile stress to be transmitted can be improved by increasing the adhesion, a conventional solution to increase the adhesion consists of throwing sand on the rail, thus, in the driver's cabin there is a light that warns at the time of skating or sliding , so that at that moment the driver drops sand on the rail to increase adhesion.
• Another solution to improve adhesion and optimize traction effort is to associate each electric traction motor that has the rail vehicle to a greater number of axles drives, so that the tensile stress that must be transmitted to each drive axle is reduced.
• By having a greater number of axles the total weight of the vehicle is increased, which improves the grip between wheel and rail, however, this increase in weight implies a higher energy consumption by electric traction motors, in addition to result in a complex and expensive assembly.
• a conventional solution to act on the skating, or sliding, of the wheels of a railway vehicle is that the driver of the vehicle manually reduce the speed of the vehicle, however, this reduction is not fast or precise enough to maximize the tensile stress that is transmitted to the drive axles.
• a method of controlling the skating of the wheels of electric traction vehicles is proposed, mainly railway traction vehicles, such as trains, trams or meters, which is based on acting on the traction torque of the electric motor controlling its revolutions, so that when a wheel slip on the rail is detected, the traction torque is acted upon by a reduction according to an exponential expression.
• the method object of the invention allows a maximum tensile or braking effort to be applied with respect to the conditions of adherence of the road through which the vehicle is traveling.
• vibrations are minimized at the box level of the vehicle, that is, the cars where users travel.
• the reduction of the traction torque exponentially prevents the torque variations from being too strong, reducing the stress of the mechanical system and improving comfort at the box level.
• greater stability of control of the vehicle in different operating conditions is achieved, such as road defects, winding curves, etc.
• a method of very advantageous characteristics is thus obtained, acquiring its own life and preferential character for the application function to which it is intended in relation to the control of the skating of the wheels of a railway vehicle on the raceways through which it circulates.
• Figure 1 shows a graph that relates the evolution of the traction torque of an electric traction motor of a railway vehicle over time.
• Rail vehicles usually have rolling structures, called bogies, on which rest the cars in which the users of the vehicle travel.
• a bogie consists of a platform where some axes are arranged, which have at their ends the corresponding wheels to travel on some traffic lanes, in the case of a tractor bogie, these axes are driving axes which are associated with an electric traction motor that transmits a traction torque to said drive axles. It may also be the case that each bogie wheel has an independent electric drive motor.
• the invention proposes a method of controlling the roller skating of electric traction vehicles based on a real-time control of the traction torque transmitted to the drive axles, or if applicable to the drive wheels.
• the method is based on acting on the traction torque of the electric motor by controlling its revolutions, so that when a wheel slip on the rail is detected, the traction torque is acted on according to two consecutive phases:
• the method object of the invention is composed entirely in the following three stages:
• a first stage where a series of rail vehicle variables are assigned and monitored in real time.
• a second stage where it is detected if there has been a skating, or sliding, of the wheel on the rail, by comparing the variables monitored in the previous stage with preset values.
• a third stage that occurs if a skating or sliding is detected in the previous stage, and in which the traction torque is acted upon by a reduction thereof.
• a reference torque value (T_ref) is assigned for the traction motor, corresponding to the torque demanded by the driver of the railway vehicle.
• the variables of the railway vehicle monitored in the previous stage are compared in real time with a series of preset values for the detection of a sliding, or skating, of the wheel on the rail.
• the detection of a slip, or skating occurs if any of the following conditions are met:
• the linear acceleration threshold can take different values.
• the linear acceleration threshold value can be between 2 m / s 2 and 6 m / s 2 .
• the linear acceleration threshold value is between -2 m / s 2 and -6 m / s 2 .
• the linear speed threshold may be variable with the vehicle speed to obtain optimum operation at different vehicle speeds.
• the linear velocity threshold value can be between 0.5 m / s and 2 m / s.
• This stage of the method occurs when a slip is detected in the previous stage. If no slippage is detected, the railway vehicle is maintained in a normal state where the required traction torque (T ref) is maintained.
• the electric motor drive torque is activated according to two consecutive phases:
• T_fin the value of the tensile torque in the exponential reduction
• J eq the equivalent inertia that relates the tensile torque expressed in rotation of the electric motor with the linear acceleration of the wheel
• a max is the angular acceleration of the drive shaft
• T_ini the initial value of the traction torque.
• the initial value of the traction torque (T_ini) is calculated according to the expression:
• T ini T ref C
• T_ref the required torque to the electric traction motor
• C is a constant in the range [0.85 - 0.95].
• the initial value of the traction torque (T_ini) is between 5% and 15% lower than the required traction torque (T_ref).
• the reduction time (t_red) is a predefined value that is calculated in a parameterization test of the route through which the railway vehicle circulates.
• the reduction time (t_red) takes values in the time interval between 0.05 seconds and 0.5 seconds.
• B. Linear recovery of traction torque until reaching the required traction torque (T_ref) or the detection of a new slip.
• this linear recovery of the traction torque is performed along a straight line whose slope is between 100 Nm / s and 500 Nm / s.
• Steps 1 and 2 of the method, variable assignment and slip detection are carried out continuously and in real time during the entire time the vehicle is in operation, while stage 3 of acting on the traction torque is only Performs when a slip is detected.
• Figure 1 shows a graph of the evolution of the traction torque, where the detection of a slip occurs at a point designated as (D), observing how an exponential reduction occurs during a reduction time (t_red) from an initial value of the traction torque (T_ini) until a final value of traction torque (T_fin) is reached, from this exponential reduction a linear recovery of the traction torque occurs until reaching the required traction torque (T_ref).
• the method object of the invention is applicable to limit the skating, or sliding, of the wheels of a railway vehicle on the traffic lane, both in traction conditions and in braking conditions in which wheel locks occur.

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• Engineering & Computer Science (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Automation & Control Theory (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Power Engineering (AREA)
• Electric Propulsion And Braking For Vehicles (AREA)

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• 2010
  • 2010-08-02 ES ES201001002A patent/ES2374232B1/es active Active
• 2011
  • 2011-04-14 WO PCT/ES2011/000118 patent/WO2012017101A1/es active Application Filing
  • 2011-04-14 CN CN201180037843.3A patent/CN103052552B/zh not_active Expired - Fee Related

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