What is hard point of contact?

During the operation of electric locomotive, the change of contact force between pantograph contact wire is very recorded. Generally speaking, we call the place that causes the sudden change of contact force between pantograph contact wire as contact hard point, which is generally called hard point. The ground point that causes the contact force pinch change on contact wire is contact hard point. The railway track equipment company said that it can be said that the hard point can cause mechanical damage to pantograph contact network. If the damage is caused, it is called the point of touching the pantograph (the more serious point is called the point of striking scraping the pantograph)

Hazard of contact with hard point

Contact hard point is one of the important reasons for locomotive pantograph off-line. Locomotive pantograph off-line is harmful to locomotive traction motor, electric appliance, pantograph, catenary, traction transformer power supply system. Due to the existence of hard points on the conductor, when the impact acceleration (currently the parameter to detect the size of hard points) is small, it will cause poor back contact of pantograph catenary. When the impact acceleration is large, it will cause off-line, off-line generation of high-temperature arc, to a certain extent, it will cause mechanical damage to the catenary pantograph. Locally speaking, when the high-temperature arc is serious, it may burn the contact pantograph, A lot of pitting corrosion occurs on the contact surface of contact wire pantograph, resulting in insufficient cross-sectional area of contact wire, deterioration of electric energy transmission of contact wire pantograph, long-term operation, even wire breaking accident: in terms of electrical principle, the resistance of air is non-linear when off-line, resulting in the sudden current of locomotive vehicle, resulting in impact current instantaneous over-high voltage, high-order harmonic, affecting the traction of locomotive The power quality of the locomotive, traction transformer power supply system, especially the original hard point, makes the locomotive's power receiving number seriously offline. The secondary tertiary contact impact hard points generated after the pantograph bounces, because of its small off-line auxiliary degree short time, the burn of the arc butt contact line pantograph is more obvious.