In accordance with the geometric equations of elastic mechanics in the sphere coordinates, the displacement equation of blocks on asphere consisting of 6 deforming parameters is developed. The formula for distance bet...In accordance with the geometric equations of elastic mechanics in the sphere coordinates, the displacement equation of blocks on asphere consisting of 6 deforming parameters is developed. The formula for distance between blocks is derived under the supposition that all block boundaries are prime arcs. The kinematic constraint and the penalty function for reasonable contact between blocks are developed. The normal equations and their coefficient matrix, based on the Least Squares Principle, are derived. The problem of adjudging penetration between blocks is discussed, and a solution is proposed.展开更多
Co-ordination of directional over current relays(DOCR) requires the selection and setting of relays so as to sequentially isolate only that portion of the power system where an abnormality has occurred.The problem of ...Co-ordination of directional over current relays(DOCR) requires the selection and setting of relays so as to sequentially isolate only that portion of the power system where an abnormality has occurred.The problem of coordinating protective relays in electrical power systems consists of selecting suitable settings such that their fundamental protective function is met,given operational requirements of sensitivity,selectivity,reliability and speed.Directional over current relays are best suited for protection of an interconnected sub-station transmission system.One of the major problems associated with this type of protection is the difficulty in coordinating relays.To insure proper coordination,all the main/back up relay pairs must be determined.This paper presents an effective algorithm to determine the minimum number of break points and main/back up relay pairs using relative sequence matrix(RSM).A novel optimization technique based on evolutionary programming was developed using these main/back up relay pairs for directional over current relay coordination in multi-loop networks.Since the problem has multi-optimum points,conventional mathematics based optimization techniques may sometimes fail.Hence evolutionary programming(EP) was used,as it is a stochastic multi-point search optimization algorithm capable of escaping from the local optimum problem,giving a better chance of reaching a global optimum.The method developed was tested on an existing 6 bus,7 line system and better results were obtained than with conventional methods.展开更多
文摘In accordance with the geometric equations of elastic mechanics in the sphere coordinates, the displacement equation of blocks on asphere consisting of 6 deforming parameters is developed. The formula for distance between blocks is derived under the supposition that all block boundaries are prime arcs. The kinematic constraint and the penalty function for reasonable contact between blocks are developed. The normal equations and their coefficient matrix, based on the Least Squares Principle, are derived. The problem of adjudging penetration between blocks is discussed, and a solution is proposed.
文摘Co-ordination of directional over current relays(DOCR) requires the selection and setting of relays so as to sequentially isolate only that portion of the power system where an abnormality has occurred.The problem of coordinating protective relays in electrical power systems consists of selecting suitable settings such that their fundamental protective function is met,given operational requirements of sensitivity,selectivity,reliability and speed.Directional over current relays are best suited for protection of an interconnected sub-station transmission system.One of the major problems associated with this type of protection is the difficulty in coordinating relays.To insure proper coordination,all the main/back up relay pairs must be determined.This paper presents an effective algorithm to determine the minimum number of break points and main/back up relay pairs using relative sequence matrix(RSM).A novel optimization technique based on evolutionary programming was developed using these main/back up relay pairs for directional over current relay coordination in multi-loop networks.Since the problem has multi-optimum points,conventional mathematics based optimization techniques may sometimes fail.Hence evolutionary programming(EP) was used,as it is a stochastic multi-point search optimization algorithm capable of escaping from the local optimum problem,giving a better chance of reaching a global optimum.The method developed was tested on an existing 6 bus,7 line system and better results were obtained than with conventional methods.
