Problems of electromagnetic compatibility control command devices and rolling stock

UDC 656.259.1 ANDRZEJ BIAŁOŃ (RAILWAY INSTITUTE, POLAND) PROBLEMS OF ELECTROMAGNETIC COMPATIBILITY CONTROL COMMAND DEVICES AND ROLLING STOCK Представив д.ф.-м.н., професор Гаврилюк В.І. 1. Introduction A prospect of opening of passenger rail market and introduction into the PKP network high-speed trains (over 160 km/h) is inextricably related with the use of modern rolling stock. From the electromagnetic compatibility point of view this rolling stock significantly differs from the traditional one (higher power, numerous presence of various systems and power processing and feeding devices). As a result, the issue of improvement of compatibility of the rolling stock with systems and devices of railways technical equipment, their complexity and direct influence on railway traffic safety should be treated thouroughly and as a high priority. Moreover, new measurement techniqes and technologies and new areas of knowledge concerning compatibility of device operation should be sanctioned in regulations in force. There should be specified railway traffic control systems and devices sensitive to disruptions, and elaborated requirements conerning broadly defined rolling stock electromagnetic compatibility with railway traffic control devices (rtc). These requirements legitimised in regulations in force. It will allow the infrastructur owner to achieve several objectives, such as:  Limiting cases of rtc devices disrupted operation,  Elimintating of financial losses due to cases of durable breakdown of rtc devices or their elements cused by disruptions,  Elimintating of financial losses due to rtc devices disrupted operation,  Eliminating of risks caused by rtc devices disrupted operation,  Improvement of railway traffic safety,  Eliminating of work interference related to rtc devices disrupted operation. Operation frequency analysis of railway traffic control devices Research data published in litereature and gathered experiences indicate that track circuits and train sensors operating as track circuits are the most sensitive to disruptions. Experiences gathered in the last few years (in different railway board) show that also axle counters are sensitive to disruptions, in particular caused by high-power locomotives. Table 1 presents operation frequencies of track circuits, train sensors and axle counters applied in the network of Polish infrastructure owner PKP PLK S.A. Table 1 List of operation frequences for rtc devices Track circuit type Classic Jointless linear and station track Jointless point track Operation frequency [kHz] 0,05 1.58; 1.86; 2.17; 2.47; 2.8 7; 8; 10; 12.15; 14.6; 16.8 10; 14.6; 19.0; 20.8; 23.4; 26.1; Train sensors 28.7; 31.5; 34.6; 38.2 Axle counter 27; 42; 46; 48; 250; 1000; 1228 The frequencies listed above, or to be more precise, frequency bands will be conisdered further. The PKP PLK S.A. network uses, above traction substations with 6 and 12 halfway rectifiers. Theoretically, at the traction substation output only harmonics resulting from rectifiers operation should appear, that is 300, 600 Hz (and harmonics of these frequencies). However, for various reasons (i.e. transformers or rectifiers nonsymmetry) at the substation outlet appear harmonics of 50 and 100 Hz, all their harmonics, and harmonics resulting from super-positioning of basic substations harmonics and harmonics of 50 © Електрифікація транспорту, № 1. – 2011. 15 1.1 Operation Frequency Analysis Traction Substations and Traction Stock of and 100 Hz. The 50 and 100 Hz harmonics levels depend on the quality of substation elements (transformers, rectifiers). Filters (smoothing devices) used in traction substations are quite a different issue. This refers both to a filter type and their operation or nonoperation. In the aspect of disruptions, two conditions of filter operation should be assumed that is: switched filters and disabled filters. In both cases the proportions between specific harmonics are different and depend on parameters of traction substation elements. Moreover, theoretical studies and research results until now gathered indicate that substations working with resonance filters, in comparison with substations equipped with gamma filters, are less stable in terms of operation disruption. There are several reasons for it. They are, among others derangement of resonance filters and non-suppression by these filters of 50 and 100 Hz frequencies. Traction stock generates, above all, harmonic resulting from the converters operation. Converters of locomotives and electrical multiple units produced nowadays, work on frequency band from 30 to 300 Hz. Older type locomotives work with choppers on 33 1/3 Hz, 100 Hz and 300 Hz frequencies. Static converters usually work on frequencies of a few kHz. In practice, every traction vehicle generates specific harmonics. Their repeatability appears only in some vehicle series using the same converter type. Modern traction stock (traction vehicles, static converters, etc.) are usually equipped with filters that sufficiently suppress products of energy transformation in the stock. It is important to emphasise, that not all filters in the traction stock sufficiently suppress harmonics generated by converters. This refers, above all to static converters. Another issue is a manner of mass and earthing leading on the vehicle. Their inappropriate performance is often a cause of increase in disruption level, resulting from, among others entering of disruptions to traction networks (above all return network) beyond the installed filters. In some cases of the use of high-power traction vehicles, an influence on sensors applied in axle 16 counters appeared. A probable reason for this (European railways will conduct a research to explain this issue next year) are electromagnetic fields generated by rolling stock elements (traction engines, filter traction elements, etc.) or resonance in the return traction network. 2. Research Methodology In order to provide electromagnetic compatibility between the rolling stock and railway traffic control devices, acceptable disruption parameters influencing rtc devices should be defined. In order to define acceptable disruption levels and a choice of assessment criteria for receivers of rtc devices, their features of sensibility to disruptions should be specified. The first one is defined on the basis of calculation of signal threshold values at which the receiver operates correctly. These parameters encompass: amplitude, frequency, impulse duration and impulse process time. Features of the rtc devices receiver’s sensibility to disruptions are defined on the basis of disrupting signal parameters, similarly as in the case of defining sensibility and disruption parameters that may lead to improper operation of the receiver or its damage. The issue of electromagnetic interferences may be omitted in the measurements, as the experience shows, that this type of disruptions have a negative influence at higher ampl (...truncated)