ح#2 عناصر الوقايه و حساب زمن الفصل Protection System.

الوقايه الكهربيه Protection System. عناصر الوقايه الكهربيه. #coursefree #electrical #mvsg #protection #الوقاية #مهندس_عمرو_عفيفي Protection systems usually comprise five components Current and voltage transformers to step down the high voltages and currents of the electrical power system to convenient levels for the relays to deal with Protective relays to sense the fault and initiate a trip, or disconnection, order Circuit breakers or RCDs to open/close the system based on relay and autorecloser commands Batteries to provide power in case of power disconnection in the system Communication channels to allow analysis of current and voltage at remote terminals of a line and to allow remote tripping of equipment. For parts of a distribution system, fuses are capable of both sensing and disconnecting faults. Failures may occur in each part, such as insulation failure, fallen or broken transmission lines, incorrect operation of circuit breakers, short circuits and open circuits. Protection devices are installed with the aims of protection of assets and ensuring continued supply of energy. Switchgear is a combination of electrical disconnect switches, fuses or circuit breakers used to control, protect and isolate electrical equipment. Switches are safe to open under normal load current (some switches are not safe to operate under normal or abnormal conditions), while protective devices are safe to open under fault current. Very important equipment may have completely redundant and independent protective systems, while a minor branch distribution line may have very simple low-cost protection. [1]