Based on Kane Hustons theory of multibody systems,the components of derivatives of relative translation and relative angular velocity of bodies are used as generalized speeds,and dynamic equations of a redundant multibody system are developed.

Uniqueness of nonnegative solution toredundant system with several failure states;

Also the reliability of the system and the advantage of the redundant system are analyzed.

Since general situation is that both environment load and component property are random variables,failure dependency is common for most redundant systems.

Application of Markov chain in researching the redundancy system’s reliability;

This paper discusses the reliability models of non-redundancy system,entirety redundancy system,portion redundancy system and standby system,and gives the reliability model of typical electric power communication system,which provides foundation for the reliability evaluation of electric power communication s.

Time synchronization is an important link in power system automation,by analyzing and examining GPS system,with using synchronous clock redundancy systems as interactive backup,the system has higher reliability ,multi-functioning ,greater accuracy ,higher cost performance and easier operating .