Design And Installation Of Transformation Of Logic Control Unit For Shaoshan 3 Electric Locomotive 4000 Series

With increasing electrification mileage in China railway,the number of electric locomotives is increasing year by year,as well as the performance requirements of electric locomotives control.At present,the traditional contact-relay control is still widely used in the electrical control of locomotives regarding,some main vehicle models such as SS3,SS4 and SS6B.After the long-term operation of locomotive,several inevitable defects of this control mode has appeared,such as the dirty contact surfaces,the oxidation problem,the concave-convex unsmooth caused by arc erosion in contact surfaces.Particularly,the concave-convex unsmooth in contact surfaces may change the surface contact into point contact,resulting in the poor contact of static and dynamic contact and the false action of control circuit.Meanwhile,due to the increased locomotive speed,the vehicle body vibration is intensified,which will aggravate the violent vibration of relay contact and endanger the security of operation.In order to overcome the shortcomings of relay control and improve the control performance of locomotive,the logic control device system is adopted to replace the traditional relay control system.For the LCU,the logic control unit is composed of advanced micro-computer technology and power electronic technology,thus,the safety of locomotive operation has been improved.In this paper,the logic control unit(LCU)of the 3 type 4000 series electric locomotive is designed,which mainly includes the circuit classification,the design of the ladder diagram,the design of the box,the power supply design and the main control circuit.The verification result of the designed logic control unit(LCU)shows that it can fully meet the requirement of practical application of locomotive.In addition,this paper also developed the detailed implementation for the LCU of Shaoshan 3-type electric locomotive overhaul installation,mainly involving the aspects of allocation of high-voltage and low-voltage cabinet,the lay out changes of low-voltage cabinet and wiring diagram design of LCU.Finally,several predicted problems in the locomotive operation are summarized with the application,maintenance and fault analysis of the logic control unit taken into consideration.The results show that this method is feasible and effective to add the logic control unit of Shaoshan 3 electric locomotive.The electric locomotive after installation is more convenient to use and maintain.Meanwhile,some input and output channels are reserved to provide the conditions for the later logic control function expansion.Finally,the analysis of the practical problems in the daily use of logic control unit,the corresponding maintenance.measures,described by the fault phenomenon,analysis of the cause of the failure and develop solutions to the follow-up troubleshooting,grading and processing,have some help.