The protection of the electrical system is a branch of electrical power engineering that deals with the protection of electrical systems from faults through the insulation of parts damaged from the rest of the electrical network. The purpose of a protection scheme is to keep the power supply system stable, isolating only those components that are in fault, while leaving as much of the network as possible still in operation. Therefore, protection schemes should be applied with a very pragmatic and pessimistic approach to eliminate system failures. Devices used to protect faulty power systems are called protection devices.
Components
Protection systems generally comprise five components:
• Current and voltage transformers to reduce the high voltages and currents of the electrical power system at convenient levels for relays to treat
• Protection relays to detect fault and start a trip, or disconnection, order;
• Circuit breakers to open / close the system depending on the relay and self-locking commands;
• Batteries to provide power in case of power disconnection in the system.
• Communication channels to allow the analysis of current and voltage at remote terminals of a line and to allow the remote firing of equipment.
For parts of a distribution system, the fuses are capable of detecting and disconnecting faults. Failures can occur in each part, such as insulation failure, dropped or broken transmission lines, incorrect operation of circuit breakers, short circuits and open circuits. The protective devices are installed with the aim of protecting the assets and ensuring the continuous supply of energy.The switch is a combination of electrical switches, fuses or circuit breakers used to control, protect and isolate electrical equipment. Switches can be safely opened under normal load current, while protection devices can be safely opened under fault current.