European Railway Agency. Electromagnetic Compatibility Requirements. Italy

Transcription

1 European Railway Agency Electromagnetic Compatibility Requirements Italy Extract of the study on EMC Requirements Lloyd s Register - November 2010

2 European Railway Agency: Extract of the study on EMC Requirements Lloyd s Register Nov Italy belongs to a group of countries who have certain common requirements for international inter-operation. These are documented in the International Requirements List available from giving details requirements agreed between the five member countries of the working group. The Italian approach to compatibility demonstration uses a different approach to that used in other countries due to the strict requirements imposed by the Italian legal system on risk. The Italian assessments are based on probabilistic methods with adherence to specific test thresholds being only one part of the evaluation. Other factors used include risk assessments from the (local) infrastructure e.g. the probability of broken rails, number of trains permitted in section etc. The Italian representatives were insistent that this approach should be borne in mind when comparing the methodologies across Europe. 1. Processes National Safety Authority is the Agenzia Nazionale per la Sicurezza delle Ferrovie (ANSF) a part of the Italian department of transport. The safety assessment is established in Legislative Decree The process follows a similar pattern to others whereby a safety certificate is issued on the basis of demonstration of a safety management system and safety reporting targets/procedures. The ANSF is now the primary contact for any Railway Undertaking which supersedes the original requirement which referred compatibility assessment to Rete Ferroviaria Italiana (RFI: Infrastructure manager) although RFI still has a technical role in the process and must agree the technical verification. As far as electromagnetic compatibility assurance is concerned feedback from the convocation interviews summarised the organisational process in a diagram (Figure 1): RU/Supplier NSA Homologisation ISA/NOBO IM Figure 1 Organisational Process from Convocation Data Evidence of compatibility is supplied from testing and technical analysis. Concern was expressed at the convocation that any envisaged changes to the process, requirements or standards at European level should not affect current projects in progress. 2. Train Detection Network Access The Railway undertaking and Manufacturer are responsible for supplying evidence for compatibility with train detection. The evidence presented is from measurements undertaken by an approved test laboratory. Evidence is to European standard EN and to local rules FS. The evidence consists of a comparison with the limits in a probabilistic fashion given in the 2

3 Permissible Current Amps European Railway Agency: Extract of the study on EMC Requirements Lloyd s Register Nov standards and is supported by a detailed technical report. Compatibility with conventional track circuits, high frequency track circuits and Digicode circuits are to limits provided in FS96 (Under revision: FS 2007 not yet published). Digicode circuits have a susceptibility across a wide range of frequencies with a wide bandwidth (400Hz) and these are shown in Figure 2. These are stated to be under revision although no further information is available at the time of writing. Susceptibility of Digicode track circuit Frequency Hz Figure 2 - ALSTOM Digicode Circuits For the DC infrastructure both 50 Hz and 83Hz track circuits are used however, the susceptibility is defined differently. The levels for four train units are shown in Figure. The basic allowance for each track circuit type is 1.6A defined over -4Hz to +15Hz (+12Hz) about the centre frequency. Outside this frequency range higher and lower limits are defined according to the curves shown in Figure 3 which have a common structure outside the basic susceptibility. 3

4 Permitted Interference Current 4 trains ma European Railway Agency: Extract of the study on EMC Requirements Lloyd s Register Nov Gabarits for 50 and 83Hz on the Italian Railway Frequency Hz 50 Hz 83 Hz Figure 3 50Hz and 83Hz on Italian Railway The limits are defined for four trains in section and the basic susceptibility per train is the limit/4 i.e. 400mA at 50Hz or 83Hz (FFT; spectral resolution 1Hz 50% overlap). However, each train is permitted to exceed the basic limit during testing as long as the exceedance occurs with less than a certain probability. The permissible probabilities for the per train limit scaled by a factor k is given in Figure 4. k Permissible Probability <=1 - >1,<= E-02 >1.5,< E-03 >1.75,< E-05 >2.5,< E-11 Figure 4 - Permissible Probabilities As an example, during testing a train may create a harmonic at 50Hz of 730mA for a certain amount of time. This exceeds the basic limit of 400mA by a factor of 730/400= From Figure, a factor of would lie within the range >1.75, <2.5 and hence would be permitted and be compatible as long as its probability of occurrence is less than The actual calculation of the normalised probability from a series of measurements is a complex process depending upon the band of frequencies measured, the number of measurements containing an exceedance of the basic limit and the total number of measurements within the test period. There is also a requirement (on 3kV DC) for a device which open circuits the main contactor if a current of more than 1A at 50Hz continues for more than 3 seconds. The FS network uses the BACC in-cab signalling system. This system utilises conventional coded track circuits at 50Hz and 75Hz and uses inductive coils above the rails for pickup. 4

5 European Railway Agency: Extract of the study on EMC Requirements Lloyd s Register Nov Lineside Systems compatibility with lineside systems. No specific limits are given. Information from the convocation stated that compatibility is achieved by means of specifying the signal to noise ratio of systems with respect to the train. No psophometric disturbance limit was mentioned. 4. Energy Supply compatibility with the Energy supply system. No specific limits were given. The documentation in the RTI states that at frequencies above 32Hz the input impedance of the system should be inductive. 5. Radio Frequency Systems compatibility with radio frequency systems. Evidence is stated to be to European standard EN The evidence consists of a comparison with the limits in the standards supported by a detailed technical report. FS uses the services of the public operator on the analogue (ETACS) and the digital (GSM). Details of these systems may found in the TSI CCS Annexe B. 6. Other systems No details were given of whether compatibility with human exposure to EMF effects was evaluated. 7. EN Italy does use the technical documentation in appendix TR5057 of EN in its assessment. 5