WO2012073266A1

WO2012073266A1 - Command system for the active and diagnostic control of a railway pantograph

Info

Publication number: WO2012073266A1
Application number: PCT/IT2011/000378
Authority: WO
Inventors: Gianfranco Borriello; Giorgio Diana; Andrea Collina
Original assignee: Contact S.R.L.
Priority date: 2010-11-30
Filing date: 2011-11-17
Publication date: 2012-06-07
Also published as: IT1402945B1; EP2646272A1; ITNA20100058A1

Abstract

Command system for the active and diagnostic control of a railway pantograph that continuously controls the pressure in the pneumatic actuator and, thus, the contact force on the catenary. The system also realizes the diagnostic and the maintenance under condition of the pantograph and of the contact line by using optical sensors.

Description

COMMAND SYSTEM FOR THE ACTIVE AND DIAGNOSTIC CONTROL OF A RAILWAY PANTOGRAPH.

The pantograph is the device that picks up in trains the current from the overhead feeder line.

For most of the vehicles in use, the thrust of the pantograph on the overhead supply line is determined by electropneumatic motor systems and by aerodynamic forces.

The users' demand for picking up systems more and more reliable and able to guarantee a suitable level in the quality of the picking up, in particular for high-speed trains, has brought about the necessity to develop a command system for the active and diagnostic control of railway pantographs.

The system, that constitutes the object of the present patent for industrial invention, allows the continuous control of the pantograph thrust as a function of the running parameters of the railway vehicle and realizes a diagnostic system able to detect and to prevent the faultiness of the pantograph and that of the contact line.

This continuous control of the pantograph thrust is carried out by operating on the pneumatic actuator which, in the case of a railway pantograph, consists of an air spring.

By continually controlling the pressure of the air spring it is possible to obtain, through the transfer function of the pantograph, the continuous control of its thrust.

Furthermore, it is possible to realize a diagnostic of the pantograph and of the contact line.

On the enclosed table a pantograph [1) is shown, with a diagram of the command system for the active and diagnostic control.

In particular, the active control of the pressure of the spring air (2) is realized by means of a proportional valve (4] that, under the command signal coming from the electronic control unit [3), governs, in a continous way, the outgoing pressure.

The command signal processed by the electronic control unit (3) is a function of the running parameters of the vehicle on which the pantograph is installed. These running parameters of the train are tranferred to the electronic control unit by the vehicle bus (MVB or ethernet or by wired signals.

The running parameters of the train transmitted to the electronic control unit [3) and necessary to realize the continuous control function of the thrust are:

• lifting and lowering control of the pantograph,

• supply voltage of the overhead contact line,

· train speed,

• train direction,

• single or multiple picking up,

• train localization.

Under these input signals the control unit (3) processes a command current signal (typical value 4÷20mA) for the proportional valve (4).

The values of the command signals of the proportional valve, as a function of the train speed, characterize therefore the overhead contact line, the train direction and the single or multiple picking up.

It is also possible to process the command signal of the proportional valve (4) as a function of the train localization.

The proportional valve (4), as a function of the command of the control unit (3), supplies a continuous outgoing pressure (typical value 0÷5 bar] controlled by a pressure sensor placed on the outgoing pneumatic pipe of the valve itself.

Finally, the system composed by the control unit (3) and the proportional valve (4) supplies, as a function of the running parameters, a continuous pressure which is controlled as input by the pantograph air spring that brings about a continuous and controlled thrust of the pantograph on the catenary. The standard configuration of the control unit (3) consists of the following boards: • Micro board (3.1) with electric/optic interface MVB or electric interface Ethernet (bus-vehicle dialogue) and connection with diagnostic board (5).

• Board with analogue interface (3.5) (proportional valve command). · Interface board digital input (3.3) (interface for digital input signals of the vehicle).

• Interface board digital output (3.4) (interface for digital output signals of the vehicle).

• Stabilized power supply (3.2).

The standard configuration of the proportional valve (4) consists of:

• a mechanic component to reduce the supply pressure to the outgoing pressure required by the control unit (3) for the selected pantograph;

• an electronic pilot system for the command and control of the mechanic component;

· a pressure sensor for the feedback on the outgoing pressure.

Apart from the continuous control of the thrust, the system includes a diagnostic (5) to register the failures of both the pantograph and the overhead contact line, bringing about their maintenance under condition. The picking up systems nowadays in use do not include diagnostic systems able to measure the acceleration of the pantograph slidings and the dynamic parameters of the board.

The absence of this kind of diagnostic system on traditional pantographs is due to the fact that the pantograph is in tension (l,5-3-15-25kV), so that the use of traditional sensors that are electrically supplied is particularly onerous in terms of electric safety and installation costs.

With the new technologies it has been possible to use sensors that are completely optical and directly connected to the pantograph. These sensors solve all the problems of galvanic insulation and safety.

In particular, by using sensors that are completely optical, without electric supply and directly connected to the pantograph, it is possible to process, in the domain of time and frequency, signals that are measured to evaluate the correct working of both the pantograph and the contact line.

The control unit (5), by processing the analogue signals coming from the optical sensors and interrelating them with the train speed and its geographic location, may transmit any information to the train diagnostic system, by means of a bus MVB/Ethernet, concerning possible faultiness of:

• picking up head,

• mobile frame,

• pantograph motor system (air spring],

· overhead supply line.

In its standard configuration, the diagnostic system measures and processes the acceleration signals of the pantograph single sliding bow.

The passband required for optical accelerometers is 0,5÷200 Hz and the sampling rate is equal to 2 Hz.

The processings required for the acceleration signals of each single sliding bow, interrelated to the train direction, location and speed are, for each km of line:

• total effective value,

• peak (max 10),

· effective value (typical) in 4 frequency bands (0,5÷4 Hz); (4÷20 Hz);

(20÷100 Hz); (55÷65 Hz).

Furthermore, regarding the acceleration values measured for each km of line, a statistical processing of the registered accelerations is carried out by calculating the:

· mean,

• root-mean-square deviation,

• skewness,

• kurtosis.

If the processed values overcome the limit values, the relative data, combined with the train speed and location, are transmitted to the train diagnostic through the bus vehicle.

The standard configuration of the diagnostic system consists of:

• optical sensors (6) with fibre optics and connectors (standard configuration optical accelerometers),

· board for the management of optical sensors (5.1) and the convertion in analogue electric signal (typical value lOOmV/g),

• board for the processing of analogue electric signal, data storage, connection to the central unit (5.2) and interface to the bus vehicle (option).

The main advantages of the command system for the active and diagnostic control are:

• improvement in the quality of the pantograph picking up, both in single and multiple picking up,

• lower wear of the slidings,

· lower aggression of the pantograph on the contact line,

• diagnostic aimed at the maintenance under condition of the pantograph and contact line.

Formal and structural changes may be made to the patent, without departing from the solution idea that is defined by the following claims.

Claims

C L A I M S

1) Active monitoring and diagnostics control system for railway pantograph characterized by the fact that it continuously monitors the pressure in the pneumatic actuator, and then, using the transfer function of the pantograph, the contact force on the catenary. This monitoring takes place through two sub-systems consisting of a special electronic control unit and proportional valve.

2) System, like the previous claim, characterized by the fact that it creates a device for detecting the pantograph and catenary defects thanks the use of optical sensors and special electronic diagnostic check control unit.

3) System, like the previous claims, characterized in that the electronic control units specified in claims 1) and 2] are the railway type and dialogue with the vehicle's BUS and each other.

4) System, like the previous claims, characterized in that the pantograph thrust monitoring control unit processes starting from the vehicle operation parameters such as speed, single or multi-tapping, the direction of train travel and a supply voltage of the contact line and location, the control signal to power the proportional valve continuously to regulate the pressure of the pneumatic actuator of the pantograph.

5) System, like the previous claims, characterized in that the diagnostic control unit sees to the processing from the optical sensors in the time and frequency domain.

On the basis of such signals, related to the location of the convoy, the diagnostic system reports any faults of the pantograph or contact line and provides information for the maintenance on the condition of the pantograph and contact line.