Figure 4 shows the response of the RMFR to a distorted
input due to CT saturation. As can be observed from Figure
4-a, even when the CT is substantially saturated and the input
current waveform is distorted the relay still operates with a
small observational error. In this case signal correction is
achieved via inherent use of the open-circuit mode of the
RMFR secondary windings as well as due to complex
interdependency of the higher harmonics in the RMFR. The
response time of the relay to a 10-kA fault in this case is about
1.5 cycles.