Application Of All-electronic Logic Control System In Power Supply Neutral-section-passing System

The technology of neutral-section-passing in traction power supply of electrified railway has always been a technical problem that plagues the domestic traction power supply industry.The technology of electronic switch ground automatic neutral-section-passing is the development trend of power supply neutral-section-passing at present.Domestic research is mainly focused on the electronic switch structure,train’s position detection technology and the suppression method of overvoltage when the train passes through the neutral-section.In contrast,the research on logic control system is less.The logic control system is responsible for the data acquisition,logical operation and circuit control of whole device,and it is the core system of whole power supply neutral-section-passing system.According to the site survey of Shen-Shuo line,the system faults that caused by the traditional logic control system with single PLC and relay combination frame as the executive unit account for a large proportion of all system faults.Therefore,an all-electronic logic control system with safety redundancy structure is proposed,which is applied to electronic switch ground automatic neutral-section-passing.According to the working principle of electronic switch ground automatic neutral section passing and the analysis of three kinds of safety platforms,double 2-Vote-2 redundancy structure with the highest safety is adopted as the working platform of all-electronic logic control system.On this foundation,the overall architecture of the all-electronic logic control system and the internal logical operation module circuit,communication module circuit and drive module circuit are designed and explained.Logical operation function,communication function,state collection function and drive control function of the external controlled equipment can be realized by the system.Then,the reliability of the system is calculated by constructing the reliability logic block diagram of the all-electronic logic control system.In order to solve the problems of fuzziness,subjectivity and easy omission of different personnel in the process of building trees,HAZOP method is used to analyze the risk of all-electronic logic control system,and fault tree is constructed based on the analysis results,and calculate the safety of the full electronic logic control system according to the generated system fault tree.After that,the electronic switch control strategy of the neutral-section-passing system is analyzed,and the electronic switch control strategy state machine is designed and implemented with reference to the dual machine hot standby state machine,and the implementation of electronic switch control strategy is described in detail in the form of pseudo code.Finally,according to the actual business requirements of the phase separation Institute,the corresponding working mode of the all-electronic logic control system is designed.The control of the electronic switch can be realized by the design of all electronic logic control system,and solve the shortcomings of the core control unit of the field logic control system,such as no backup,large volume and easy failure of the execution unit.It improves the reliability and safety of the system,provides a theoretical basis for the research and development of the electronic switch ground automatic neutral-section-passing,and it has strong practical application value.