PGCIL Field Engineer & DT case studies
PGCIL Field Engineer & DT · Put your knowledge to work in context.
The PGCIL Field Engineer & Diploma Trainee recruitment examination is the selection route through which Power Grid Corporation of India Limited hires engineers and diploma holders into roles that keep the national transmission network running - field engineering, substation operations and maintenance, and trainee positions that feed into them. It suits candidates with a diploma or degree in electrical engineering who want a public-sector career in EHV transmission rather than generation or distribution. The PGCIL Field Engineer & DT case studies are 5 cases and about 4,369 words.
1Repeated differential trips on a 40 MVA, 132/33 kV grid transformer
A 40 MVA, 132/33 kV, YNd11 transformer was retrofitted with a numerical differential relay rated 1 A, with pickup 0.20 pu, bias slope-1 of 25% and second-harmonic restraint of 15%. The CTs fitted are 250/1 A on the 132 kV side and 600/1 A on the 33 kV side.
894 words, about 4 min2Capacitor bank resonance on a 33 kV industrial bus with 6-pulse drives
An industrial plant is fed from a 33 kV bus with a three-phase short-circuit level of 250 MVA. The load is 8 MVA at 0.85 pf lagging, and a group of 6-pulse thyristor drives on the same bus injects 5th-harmonic current that already produces 3.2% voltage distortion.
847 words, about 4 min3VFD retrofit on a throttled 110 kW cooling-water pump
A 110 kW, 415 V, 4-pole, 1485 rpm cage induction motor with full-load efficiency 96% and power factor 0.86 drives a cooling-water pump through a partly closed discharge valve. At the design point the pump delivers 900 m3/h at 40 m head, of which 15 m is static (the cooling-tower elevation) and 25 m is friction.
827 words, about 4 min4DC bus overvoltage on a decelerating centrifuge drive
A 75 kW, 400 V, 4-pole, 1485 rpm motor drives a centrifuge. The total moment of inertia referred to the motor shaft is 22 kg-m2.
894 words, about 4 min5Feedwater flow loop reading low after a second indicator is added in series
Feedwater flow of 0-100 t/h is measured by an orifice plate and a 0-250 kPa differential-pressure transmitter. The transmitter is 2-wire, 4-20 mA, loop-powered from a 24 V DC supply, and needs at least 12 V at its terminals at 20 mA.
907 words, about 5 min