Author: Jiao Yehong, lawyer and patent teacher of Guangdong Guanghe Law Firm.
China's high-speed rail is known for its environmental protection, high speed, safety and punctuality, and it is at the peak of the Spring Festival in winter.
The pantograph and catenary system of high-speed rail (referred to as pantograph system) provide traction power for the stable operation of electric locomotives through sliding contact. In the case of rain and snow in winter, due to the combined action of temperature, humidity, cold and warm air convection, circulation and other factors, the catenary will be covered with ice, and the icing of the catenary will easily lead to poor flow of the pantograph from the catenary, arc burn power supply equipment, and even lead to catenary disconnection and interruption of railway traffic accidents.
The traditional methods of de-icing are as follows:
1. Hot skating and ice melting, install an ordinary carbon aluminum skateboard on the pantograph of the no-load EMU, and when the no-load EMU travels, the ice on the catenary will be melted through friction and heating. This method is suitable for operation when the icing situation is not severe.
2. Mechanical de-icing, install a copper-based powder metallurgy slide plate on the pantograph of the no-load EMU, and remove the ice on the catenary through mechanical cutting when the no-load EMU is moving. This method is inefficient and may cause damage to the catenary.
3. Manual de-icing, through manual beating, the ice layer on the catenary is removed. This method requires a power outage and grounding, which is time-consuming, labor-intensive, and unsafe.
Fourth, high-frequency and high-voltage excitation de-icing, apply high-frequency excitation current outside the icing wire area, so that heat is generated inside the icing. This method requires power-off operation, is inefficient, and interferes with normal communication.
5. Electric pulse de-icing, using the energized coil near the catenary to generate a strong magnetic field, and the short-term mechanical force generated by the strong magnetic field on the contact line causes the ice to rupture and fall off. This method can be operated without electricity, but it still has the problems of low efficiency and damage to the contact wire.
Sixth, the hot ice melting method, in the original contact line embedded with an insulating sheath of soft copper stranded wire, when encountering low temperature weather, through the soft copper stranded wire electric heating, can quickly solve the problem of icing of the external contact line. According to the test, the contact line of the icing warmed up from minus 5 degrees Celsius to 5 degrees Celsius in just 20 minutes. The hot ice melting method is the most efficient solution at present, but it needs to be embedded and heated soft copper stranded wire, which is only suitable for new lines and renovated lines, and the investment is large and the maintenance is difficult.
Engineering and technical personnel are studying more efficient, safer, easier to implement, and less expensive ice melting schemes, which are believed to be implemented on high-speed rail and bullet train lines with serious icing in the near future.