Ways to improve the efficiency of automatic control systems of pressing current collectors for railway service of high speeds

One of the limiting factors in increasing train speeds on railway transport is the quality of current collection. With increasing operation speeds, the dynamic loads on the current collector from the rolling stock increase and the aerodynamic impact increases as well, which leads to an increase in the variation of the contact pressure, tearing off the current collector from the contact wire, arcing in contact and increased wear of the contact elements. A promising direction in addressing this issue is the use of automatic control systems, allowing to stabilize the amount of contact pressure. The article discusses the features of modern automatic control systems for pressing current collectors, its main disadvantages are indicated. Authors proposed new automatic control circuit for pressing a current collector, characterized by increased speed. A mathematical model of a current collector equipped with a high-speed automatic pressure control system is described. The results of the calculation of the parameters of the high-speed control system are presented, showing the possibility of its use in order to reduce the spread of the contact pressure of the current collector and improve the quality of the current collection at high speeds. Analysis of the characteristics of the transfer functions of the regulator shows that the application of the PI controller algorithm is effective for stabilizing the contact pressure. Since the rod length of the pneumatic cylinder is limited, the regulator is able to maintain pressure for a limited time, after which the rod must be returned to its original position. The speed of the rod is limited by the characteristics of the actuator (electric motor). These features cause a significant variation in system parameters, such as the time constant and the duration of maintaining a stable depression, depending on the values of the controller coefficients kp and ki, which should be set taking into account the parameters of the current collector, operating conditions and type of contact suspension. For the considered current collector model, the optimal values of the controller coefficients are kp = 1.5 and ki= 1.0. Results of the calculations showed that the use of a rapid regulator based on a pneumatic cylinder in the carriage design reduces the standard deviation of the contact pressure to 37 % at speeds of up to 260 km/h.

1. Etskov T. A., Popov P. V. Issledovanie aerodinamicheskikh kharakteristik skorostnogo tokopriemnika [Research of aerodynamic characteristics of rapid current collector]. Vestnik VELNII [Bulletin of VELNII], 2014, no. 1, pp. 28–37.

2. Vologin V. A., Gerasimov A. S. Dinamicheskie parametry sistemy kontaktnaya set' — tokopriemnik [Dynamic parameters of the system contact network — current collector]. Vestnik VNIIZhT [Vestnik of the Railway Research Institute], 2008, no. 2, pp. 19–23.

3. Tyurnin P. G., Tibilov A. T., Mironos N. V. Tokos"em: nadezhnost', ekonomichnost' i puti sovershenstvovaniya. Sb. tr. uchenykh OAO “VNIIZhT” [Current collection: reliability, efficiency and ways to improve. Proc. of works of scientists of the JSC “VNIIZhT”]. Moscow, VMG-Print Publ., 2015, 166 p.

4. Chater E., Ghani D., Giri F., Haloua M. Output feedback control of pantograph – catenary system with adaptive estimation of catenary parameters. Journal of Modern Transportation. 2015. Vol. 23, no. 4. pp. 252–261. URL: https://link.springer.com/article/10.1007/s40534-015-0085-z (retrieved on 10.01.2019).

5. Yamashita Y., Ikeda M., Masuda A. Advanced active control of a contact force between a pantograph and a catenary for a high speed train. Proceedings of 9th world congress of railway research. Lille, 2011, pp. 28–33. URL: https://www.jstage.jst.go.jp/article/rtriqr/53/1/53_1_28/_article (retrieved on 10.01.2019).

6. Etskov T. A., Popov P. V. Sistemy upravleniya tokopriemnikami [Control systems for current collectors]. Vestnik VELNII [Bulletin of the VELNII], 2015, no. 2, pp. 12–21.

7. Sidorov O. A., Smerdin A. N., Zhdanov V. A. Metodika otsenki funktsional'noy gotovnosti sistemy tokos"ema skorostnykh uchastkov magistral'nykh zheleznykh dorog [Methods for assessing the functional readiness of the current collection system of high-speed sections of main railways]. Vestnik VNIIZhT [Vestnik of the Railway Research Institute], 2012, no. 1, pp. 27–32.

8. Meshcheryakov V. A., Smerdin A. N., Golubkov A. S. Predposylki polucheniya statisticheski dostovernykh dannykh v khode imitatsionnogo modelirovaniya tokos"ema [Prerequisites for obtaining statistically reliable data during the simulation of current collection]. Vestnik VELNII, 2013, no. 2, pp. 104–121.

9. Makino T., Yoshida K., Seto S., Makino K. Running test on current collector with contact force controller for high-speed railways. JSME International Journal, Series C, 1997, Vol. 40, no. 4, pp. 671–680.

10. Pisano A., Usai E. Output-feedback regulation of the contact-force in high-speed train pantographs. Transactions of the ASME, 2004, Vol. 126, pp. 82–87.

11. Allotta B., Pisano A., Pugi L., Usai E. VSC of a servo-actuated ATR 90-type pantograph. Proceedings оf the 44th IEEE Conference on Decision, and Control and the European Control Conference (Siviglia, Desember 12–15, 2005), Siviglia, 2005, pp. 590–595.

12. Sidorov O. A., Goryunov V. N., Golubkov A. S. Improvement of automatic control system for high-speed current collectors. Journal of Physics: Conference Series, 2018, Vol. 944. URL: https://iopscience.iop.org/article/10.1088/1742-6596/944/1/012108 (retrieved on 10.01.2019)