Sm. Islam et Mg. Mostafa, NOVEL MICROPROCESSOR-BASED NEGATIVE PHASE SEQUENCE RELAY AND METER, INTERNATIONAL JOURNAL OF ELECTRICAL POWER AND ENERGY SYSTEMS, 18(8), 1996, pp. 547-552
Microprocessor application in relaying and condition monitoring techno
logy is becoming increasingly popular. In this paper, a novel micropro
cessor based negative phase sequence (NPS) current detector for motor
condition monitoring and relaying for motor/generator protection is de
veloped. The proposed meter eliminates the need of a negative phase se
quence filter and does not require complicated digital signal processi
ng techniques. Instead it uses a phase sensitive rectifier. A prototyp
e based on Intel's 8085 A microprocessor was built and rested. Complet
e circuitry, main and interrupt software flowcharts are provided. Resu
lts show the proposed NPS relay and meter can provide a high degree of
accuracy and satisfactory results. Copyright (C) 1996 Elsevier Scienc
e Ltd.