New control approaches to improve contact quality in the conventional spans and overlap section in a high-speed catenary system

Continuous and quality contact between the pantograph and the catenary system is one of the major challenges for increasing the speed of electric trains. Compared to other studies, this paper has considered the catenary system as the main system and has assumed the pantograph as an excitation factor. Based on this, a controller has been applied on the contact wire, once at the last span and another time near the contact point of the pantograph. Results were compared with the conventional controllers that exert control force on a collector's head. Based on this, two different objectives were considered for the controller including ‘improvement of contact quality’ and ‘minimisation of the vertical velocity of the overlap point’. For this purpose, a full analytical model of the catenary system was presented and was verified using the relevant standards, and then three types of linear quadratic optimal controllers were added to the model with the two objectives mentioned above. The results of the study show that if the model aims to reduce the overlap point vertical velocity, contact quality will be improved. However, in case it aims to enhance contact quality, the velocity of the overlap point will not necessarily be reduced. Moreover, the contact point controller aiming at reducing the overlap point velocity outperforms other controllers and makes 71% improvement in contact quality in comparison with the no-controller case.