New Energy Storage And Power Supply Device For Rail Flash Welding Machine

Flash welding is the most widely used welding method in the construction of seamless track in China.The mobile rail flash welding machine uses diesel generator set as the flash welding power source,but the diesel generator set has problems such as unbalanced three-phase load,environmental pollution,health damage,unstable welding electrical parameters and so on.In order to fundamentally solve the problems existing in the traditional diesel generator flash welding machine,it is of great significance to study and design a new energy storage power supply system for rail flash welding machine,which is composed of lithium battery and super capacitor,for the stability and environmental protection of rail welding.In this paper,firstly,the load power consumption of flash welding machine is measured and the related parameters of load and auxiliary system are calculated,and the requirements of flash welding machine for power supply performance are summarized.On this basis,the supercapacitor energy storage system and battery system are designed by using lithium ion battery and supercapacitor composite power supply scheme,and the cost of energy storage system is estimated.In the system,supercapacitors are connected in parallel with lithium batteries through DC/DC,and the composite energy equivalent model of the main circuit of the welding machine is established.The bidirectional DC/DC converter is selected as the DC conversion unit to simplify the main circuit structure.Single-phase full-bridge inverter and three-phase bridge inverter are used as the power supply to provide the required alternating current for the main welding circuit and auxiliary system,and meet the rail welding requirements.According to the welding test,the total electric energy,internal resistance and voltage fluctuation range of the new rail flash welding machine meet the design requirements,and the welded rail has passed the technical requirements of TB/T 1632.2-2014 "Rail Welding Part 2: Flash Welding",which can be used for on-site welding production.The power supply of the new rail flash welder has the advantages of zero emission and low noise during welding;The fluctuation degree of primary voltage of welding transformer is 15.4%,37.3% and 40% of that of diesel generator set in high voltage stage,low voltage stage and flash stage,respectively,and the output impedance of power supply is 0.012? less than that of diesel generator set.The 40 rails consumed in commissioning process are less than the50-100 rails of diesel generator set.The new rail flash welding machine is superior to diesel generator in stable power supply performance,which is more conducive to the guarantee of welding quality and can fundamentally solve a series of problems existing in the traditional diesel generator flash welding machine.