Field breaker tripping options for generator static excitation systems with AC field circuit breakers - A case study
Short circuit contributions from synchronous generators can persist for several seconds even after the field circuit breaker is opened. Delayed tripping of an AC field circuit breaker can allow faster reduction of generator field current in some circumstances. Faster reduction of generator field current will reduce the energy in a short circuit and consequently reduce the damage caused by the short circuit. This paper describes a case study examining the issues associated with the decision to delay tripping of AC field circuit breakers.
Modern technical aspects of Field Discharge equipment for excitation systems
The ANSI/IEEE C37.18 1979 ldquostandard enclosed field discharge circuit breakers for rotating electrical machineryrdquo [1] has passed through several reaffirmations and still valid until 2008. This standard provides excellent information and is widely used as basis for the specification, design and testing of field discharge equipment. However, the content of this standard still reflecting the technological state of the art for equipments designed and manufactured during the time that this standard was being approved for the first time (1976). This paper contains an overview of the actual technological aspects of field discharge equipment in terms of available technology, design criteria and practical executions. The information of this paper could be partially used for future actualization of the IEC37.18.
Modelling of alternating-current machines having multiple rotor circuits
The modeling of a synchronous or an asynchronous machine forms the basis of simulation investigations made with high-powered computers. Many phenomena and processes require corresponding refinement of the models used, and an increase in input in the form of fictive rotor circuits. A method is presented which has been tested out over a relatively long period of time. The general equations contain none of the usual approximations, and can be programmed quite readily. Numerical examples are given as an aid in applying the procedures. >