Hybrid phase comparator applied to distance protection

The paper describes the operation of a 1 bit processor which can be used to measure phase difference, and hence can be applied to distance protection. The processor averages over one cycle the sign coincidence between its two input signals and gives an analogue output proportional to their phase difference. Examples are given of its application to mho and quadrilateral impedance characteristics. Where appropriate its performance is compared with a block-average comparator.