Based on the reliability theory,the fault modes of self-contained safety system and redundant safety system are analyzed;the quantitative calculation models for the explicit failure rate,implicit failure rate and availability of those systems are given.

In order to understand the performance of short-circuit at fault in system, this paper investigated the short-current failures of the 500 kV power system in East China in recent years, statistically analyzed the short-currents and waveforms, and obtained such parameters as time constant of system, amplitude of short-current, and failure property.

Simplified the computing of fault,thereby we improve the discuss of the serial problem of multi-system.

Analytic method for relay protection importance with consideration of hidden failures;

The basic process and theory of power system cascading failure considering protection system hidden failures were analyzed to decrease bulk blackout failure.

For the purpose of investigating how the failures spread in the power grids, finding out the key-lines affecting the cascading failures, this paper presents an approach to calculate the risk of line outage and identify key-lines causing blackouts based on the hidden failure model and risk theory.

Countermeasures for common faults in VTC254-13 turbocharger;