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KPVA Operations

Technical sheet

Summary

The objective of the KPVA Beacon is to ensure control in the case of an overspeed of railway rolling stock that is manually driven.

In an overspeed scenario, it must emit a magnetic field for the onboard sensor (KFS or RPS) on trains, which commands the emergency braking of the AeAu system.

The KPVA is composed of two treatment chains:

  • An initial chain that measures the train’s speed, compares it with a system setting programmed beforehand, and transmits the fields and frequencies in the case of a potential overspeed situation
  • A secondary chain that remedies a defect in the principal chain.  Overspeed is no longer a measured speed, but one that is calculated and represents the train’s travel time over the KPVA Beacon located between the front of the train and the onboard AeAu system sensor.

General inside view

Inside view with the patented frequency frame (green plate)

The principal chain :

A 24 GHz Doppler effect microwave radar detects the train and measures its speed. After comparing the speed with the programmed setting, an electromagnet is fed and an F1 frequency is generated.

If the speed radar does not detect overspeed:

  • The electro-magnet is activated and emits amagnetic field.
  • The frequency frame emits an F1 frequency.
  • The onboard KFS sensor receives the signals which, if they are transmitted together, indicate that train passage is authorized.


Electromagnet

If the speed radar detects overspeed:

  • The electromagnet is activated and emits amagnetic field.
  • The frequency frame does not emit a frequency.
  • The onboard KFS sensor receives this signal which, if it is emitted alone, indicates that train passage is not authorized.


Frequency frame (green plate)

The secondary chain :

Overspeed is not a measured speed, but a calculated speed; it represents the train’s travel time over the KPVA Beacon located between the front of the train and the onboard AUAE system sensor.

The speed setting is timed and is adjustable.

When the front of the train is detected by the presence radar, the electromagnet is activated and maintained for the time corresponding to the speed setting.

If the electromagnet is still active when the onboard system sensor travels over the Beacon, the train is running in excess of the setting's speed, creating an overspeed situation.

An electromagnetic field emitted by the KPVA is detected by the onboard sensor that stops the train.

If the electromagnet is no longer active when the onboard system travels over the Beacon, the train’s speed is inferior to the speed setting.

The KPVA does not generate a field, and train passage is therefore authorized.

General Operations

Once the KPVA is activated, the two chains are enabled.

The principal chain is preponderant when the KPVA works normally.

Should an anomaly occur on the principal chain, the secondary chain becomes the principal chain, and the KPVA notifies this anomaly and works in fail-soft mode.

Should an anomaly occur on the secondary chain, the principal chain is preponderant, however the KPVA notifies this anomaly and works in fail-soft mode.

One can dialogue with the KPVA and configure its parameters with an RS422 link.

In addition to the main function of stopping the train in an overspeed situation, the KPVA:

  • Informs and diagnoses potential breakdowns,
  • If possible, reconfigures the system in the case of multiple breakdowns,
  • Inhibits the system in the case of critical breakdowns (stops trains that are not in an overspeed situation),
  • Informs of overspeed situations, memorizes prior overspeeds and passages,
  • Remotely indicates the speeds of train passages (to the operator).

Finally, the KPVA has external outlets to connect sensors or a signal link.  For example, the KPVA can be programmed so that 2 or 3 speed settings can be selected in real time depending on the state of the signals.

Contact us : Tel : 04 42 37 12 70 - Fax : 04 42 37 12 71 - contact@fersil.fr