Safety requirements parameter derivation for maglev train propulsion and protection systems based on stochastic petri nets

This paper presents a formal approach to model the traffic operational processes on a Maglev train example based on Stochastic Petri nets. The Maglev train is modeled with respect to process, function and dependability. Process model describes the normal running status and abnormal protected status of the Maglev train from departure to stopping and function model shows the working principle of propulsion and protection function. Dependability model describes the failure and recover rate of this two functions. The relationship between process, function and dependability is also described in this model based on the propulsion and protection principle. The relationship between individual risk and accident rates is built up and then simulations based on the model show that the dependability parameters of the propulsion and protection functions can be derived based on the safety requirements of the CENELEC standards. Finally the availability of the propulsion and protection systems is analyzed.