The protection functions of the relay and the transient currents and voltages are still the same, but it is the present state of technology that offers new possibilities and makes the number of functions in the relay more complex. It is generally agreed that testing numerical protection should be different from older techniques. Some basic aspects of numerical protections generally address this.

The protection functions of the relay and the transient currents and voltages are still the same, but it is the present state of technology that offers new possibilities and makes the number of functions in the relay more complex. It is generally agreed that testing numerical protection should be different from older techniques. Some basic aspects of numerical protections generally address this.