Operation and Maintenance
 
Capacitor Bank Switching Studies
Topics:
Outrush currents, inrush currents, voltage magnification, restrikes,
power quality, harmonic impedances, resonance, and phase-to-phase/
phase-to-ground overvoltages, current limiting reactor placement, insulation ratings for reactors, arresters, and capacitors banks
Focus:
Capacitor bank Mvar total and step-sizes, current limiting reactors, circuit breakers/switchers, surge arresters, other capacitor bank-specific
equipment
 
Recommendations:
Sizing and location determination for current limiting reactors and surge arresters, synchronous switching (opening and closing control), pre-insertion resistors, pre-insertion reactors, specific breaker ratings, and TRV control capacitance, and grounding configurations
 
Shunt Reactor Switching Studies
Topics:
Inrush currents, transient recovery voltages (TRV), restrikes, power
quality, harmonic impedances, resonance, phase-to-phase/
phase-to-ground overvoltages
Focus:
Circuit breakers, surge arresters, TRV control capacitors, other reactor bank specific equipment
 
Recommendations:
Requirements for synchronous control, surge arresters (sizing and location), pre-insertion resistors, breaker ratings, TRV control capacitance (size and location), and other potential operating restrictions
 
Transmission Line Switching Studies
Topics:
Switching/transient overvoltages, fault/clear/re-close events, voltages across circuit breaker contacts,
trapped charge conditions, Ferranti
Rise, series compensation, shunt compensation, single and three-pole
re-closing, secondary arc extinction,
p.u. voltage withstand insulation
levels, impacts of switching on radial corridors, phase-to-phase/phase-to-ground overvoltages
Focus:
Circuit breakers, pre-insertion
resistors, surge arresters,
transmission lines, cables,
transformers, series compensation, shunt compensation
 
Recommendations:
Surge arresters, pre-insertion resistors, synchronous switching, series compensation, shunt compensation, and modification to switching procedures