No abstract

This article provides a simulation model of the process of functioning and restoration of a network clock network (CNS), which is distinguished by the completeness of accounting for the states of the process of functioning of the CNS network. The key indicator of the process of functioning of the CNS network is the duration of the control cycle of the CNS network, which is understood as the time from the moment a failure occurs on the CNS network until the moment the mode of transmission of synchronization signals is restored. On the basis of the developed simulation model of the process of functioning and restoration of the CNS network, the duration of the control cycle of the CNS network is estimated depending on the time spent in individual states of the process of functioning of the TSS network and on the characteristics of individual subsystems of the CNS system. The results obtained can serve as a basis for developing sound strategies and plans for managing the CNS network.

Objective: To develop a formalized algorithm of carrier class network Carrier Ethernet operation and, by means of the latter, obtain an assessment of control cycle duration for intelligent control system (ISU) of the network in question. The given operation scenario is different from those currently in use by an account of processes of the new generation Carrier Ethernet network, failures’ identification and reconstruction of network elements by means of core control technologies of elements’ status (OAM technologies) and application of statistically defined change traffic (distributive laws) of Carrier Ethernet network elements’ status. Methods: In order to achieve the objective in question the following methods were applied: signature method, statistical method and neural networks. Results: The building principles of Carrier Ethernet network were presented and its OAM architecture was formed. In accordance with the analyzed types of Carrier Ethernet network connections and failure control mechanisms on the basis of OAM, control process and Carrier Ethernet network operation scenario was developed. Practical importance: The obtained operation scenario of the new generation network and the assessment of ISU control cycle of Carrier Ethernet network makes it possible to formulate the requirements to perspective operation system, whereas the assessment result of Carrier Ethernet network operation cycle duration allows one to determine probabilistically time response characteristics of network functioning and assess the input of different subprocesses in the total process time. The presented building principles of Carrier Ethernet network make it possible to solve the task halfway, which is aimed at the necessity of building a unified methodological basis for the formation of perspective operation system for the network in question.

Objective: To define the reasons, that prevent the implementation of electrical brake for multiple unit rolling stock (MVPS) with asynchronous traction drive as an automatic brake (emergency brakes). To find the method for eliminating of found reasons. To determine, using mathematical simulation, the time indexes of traction drive readiness to the electrical braking in case of no voltage in catenary system. Methods: Mathematical model of traction drive is built in Matlab Simulink software. By using this model the empirical relations of the time from the moment of command input, made by the control system, to start an emergency braking, to the moment of charging of input capacitors to nominal voltage (in case of no voltage in catenary system) from the train speed and equivalent resistance of stator circuit were obtained. Results: The problems, preventing the implementation of electrical brake for MVPS as an automatic brakes, are examined. The methods of solving these problems are suggested. By using the mathematical model the principal possibility of suggested methods is presented, as well as the estimation of the time of traction drive preparing for readiness for braking, depending on the train speed and equivalent resistance of stator circuit. Also, the engineering solutions, are found, that allow to implement the electrical brake for multiple unit rolling stock as an automatic one. Practical importance: Electrical for brake multiple unit rolling stock with asynchronous traction drive has several benefits in comparison with the pneumatic brake. It provides smaller braking distance, not influenced by low temperatures and provides better resistance for sliding and skidding. Implementation of electrical brakes for multiple unit rolling stock in the function of automatic brake will positively influence on the safety of operation and will allow to increase the operating speed of multiple unit rolling stock.