asymmetry coefficient of traction return current

Could anyone refer me to any sources where the problem of electromagnetic compatibility between railway electric traction and track circuits is researched? I am interested in asymmetry coefficient, namely how you estimate is it value. What kind of asymmetries which impact on railway equipment is to be assessed do you have in your documentations? And there is one another thing I want to know. Do you have any way to estimate the asymmetry coefficient value of traction return current that arises when a driver feeds the rail-wheel contact with sand to increase adhesion coefficient?

Thanks.

Hi Yurec,
this is a really specialised area, so I wish you all the best in your research. I have located an interesting paper by the IEEE here:http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=5557440&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D5557440

Some more considerations on the effects of asymmetric currents of track circuits are discussed here: http://www.google.co.uk/url?sa=t&rct=j&q=rail%20traction%20asymetric%20current&source=web&cd=9&ved=0CF8QFjAI&url=http%3A%2F%2Fwww.rgsonline.co.uk%2FRailway_Group_Standards%2FControl%2520Command%2520and%2520Signalling%2FCodes%2520of%2520Practice%2FGKRC0755%2520Iss%25202.pdf&ei=WZwoUJvDEqe80QWosYCgCg&usg=AFQjCNEG1_qJ1SBK_Sontmq8_p2zPUk49w

Another link to asymmetric considerations of pantograph arcing, which will have some similarities to considerations of the effect of sanding on the return current are here: http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=5713367&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D5713367

I can't find anything specific on the effects of sanding on the assymetric component of traction return current at the rail. However, an old friend of mine runs York EMC Services, who have a lot of expertise in EMC consultancy and measurments in the railway industry. See http://www.yorkemc.co.uk/industry/railway/

So I hope that these links will at least give you some pointers for help in your research. Good luck!!

I seem to have solved that problem. I’ve designed a mathematical model for that. I’ve already written the article, but I don’t know where to publish it. If somebody knows any science British journal post them here, please. Thank you.