Vanin - Saint-Petersburg State Tech. Univ. RUSSIA
Al Tallak - Saint-Petersburg State Tech. Univ. RUSSIA

In energy systems and in particular in relay protection devices the current, voltage, resistance, power values are used as input signals of the anti-fault automation. As a rule,the industrial friquency signals are used for the purpose. When stability is disturbed the asynchronous regimes are characterized by existence of various friquenciy energy sources that may cause to the false operation of the antifault automation and consequently to further progress of the failure. The paper offers mathematical description of controlled values at the asynchronous process allowing to evaluate the automation control reliability both at the design phase and during service operation and develop measures to provide correct automation operation. The process description is based on the concept of analytical signal. The time dependence characteristics of the controlled electrical values (resistance, power, etc.) are presented with operation posibility of different types of relays.