7. Conclusion

The design and choice of protective relays for alternators and motors meet the need for rapid elimination of electrical faults, with the aim of limiting damage to these machines, without unduly disrupting the operation of the equipment connected to them.

A protection scheme needs to be as comprehensive as possible, covering all probable faults, while keeping in mind the trade-off between completeness and the cost of protective equipment. From an economic point of view, this compromise will take into account, on the one hand, the cost of repairing damaged equipment and, on the other, the cost of protection: direct costs (investment), induced costs (measuring reducers, wiring, etc.) and indirect costs (probability of failure).

Each type of failure is usually matched by a protective relay, with some possibility of redundancy, or back-up by...