The coordination study a coor dination study consists of the selection or setting of all series prote ctive devices from the load up stream to the power supply. Typically, studies begin with the main circuit devices and work down through the feeders and branches. Must operate when required proper system design backup to operate when main system fails to cover any parts that may fall inbetween protected zones fall in between the cracks reliability of hardware. Personnel protection is accomplished by using groundfault circuit interrupters gfci in the form of gfci receptacles or gfci circuitbreakers. An experience report conference paper pdf available may 2018. Protective device coordination intuitive intelligent integrated etap star provides intelligent tools and powerful capabilities to analyze system protection and troubleshoot false trips, relay and breaker misoperation, miscoordination, and more. Guide to power system selective coordination 600v and below.
It is vital then, to investigate the cause and location of the prob. In selecting or setting these protective devices, a comparison is made of the operating times of all the devices in response to various levels of overcurrent. A protection coordination study will consist of timecurrent curves tcc of all the electrical equipment, protective devices and large motors. Protection of electrical power systems can reduce the extent and duration of an interruption, as well as reduce equipment damage or personal injury. Manufacturers data each protective device has unique response characteristics, documented on manufacturers timecurrent. In this study, a simulationbased evaluation for a smart grid based distribution system is performed. Selective coordination study recommended procedures. Relay coordination analysis and protection solutions for smart grid distribution systems. The selection of protective device primary and backup zones of protection is achieved through a protective device coordination analysis, also referred to as protection coordination study. Introduction to protective device coordination analysis. The term selective coordination refers to the selection and setting of protective devices in an electric power system in such a manner as to cause the smallest possible portion of the system to be deenergized due to an abnormal condition. Bolted grounfault current results when phase d conductors become solidly connected to ground i.
If many branches are taken off one feeder, and the branch loads are similar, the largest rated branch circuit should be checked for coordination with upstream devices. Pdf protection coordination assessment and improvement. Protection coordination assessment and improvement of electrical network of an industrial complex in connection to power grid. Pesias joint chapter protection reliability dependability. This study is very important in order to ensure the least service interruption arising from a fault or shortcircuit.
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