Forecasting of dynamics of starting and transient currents for increase of selectivity of microprocessor devices for relay protection of catenary feeders

A big percent of false actuations of relay protection devices is connected not only with emergency operation modes of a traction power supply system, but also with starting and transient currents flowing in the catenary at movement of heavy-loaded trains, united freight trains, at realization of batch schedule, movement of trains on difficult grading of track and also at the application of recuperation mode by currently used locomotives. The study shows that it is possible to decrease the number of actuations of relay protection devices in described cases by the application of alternative method of analytical presentation of measured signals and the forecasting of dynamics of measurement of starting and transient currents flowing in the catenary.

Batch Scheduling In A Two-Stage Flexible Flow Shop Problem

We study a special two-stage flexible flowshop, which consists of several parallel identical machines in the first stage and a single machine in the second stage. We assume identical jobs, and the option of batching, with a required setup time prior to the processing of a new batch. We also consider the option to use only a subset of the available machines. The objective is minimum makespan. A unique optimal solution is introduced, containing the optimal number of machines to be used, the sequence of batch sizes, and the batch schedule. The running time of our proposed solution algorithm is independent of the number of jobs, and linear in the number of machines

Batch Scheduling on Two-Machine Flowshop with Machine-Dependent Setup Times

We study a batch scheduling problem on a 2-machine flowshop. We assume unit processing time jobs, batch availability, and machine-dependent setup times. The objective is to find a job allocation to batches of integer size and a batch schedule that minimize makespan. We introduce a very efficient closed form solution for the problem.