Govt. Exams
Entrance Exams
For Type 0 system with unit step input, e_ss = 1/(1 + Kp) where Kp is the position error constant.
Zero-sequence currents (equal in all three phases and same direction) require a return path through neutral or ground.
IS 16001:2017 defines power quality parameters including THD (Total Harmonic Distortion) and voltage flicker limits.
PV buses represent generators where active power injection and voltage magnitude are specified; reactive power is calculated.
Modern non-linear loads like switch-mode power supplies, VFDs, and renewable energy inverters are major sources of harmonics in contemporary Indian grids.
Voltage instability occurs when reactive power demand cannot be met, causing voltage collapse, particularly at weak points in the grid.
Over-excitation increases the magnetic field, causing the generator to supply lagging reactive power to support system voltage.
At no-load, a synchronous motor supplies only magnetizing current (reactive power) to maintain the magnetic field.
Differential relays compare currents at both ends of a line and trip if there is a mismatch indicating an internal fault.
Per-unit system normalizes all quantities relative to chosen base values, simplifying analysis and comparison across different voltage levels and equipment ratings.
