Protection Coordination Analysis
The study evaluates degree of overcurrent protection in the system, and proposes relay/breaker setting to maximize selectivity in the system.
When required, study can be augmented by Relay Philosophy Document which specifies settings for other protection types (beyond overcurrent).
Short Circuit Analysis
The study verifies that all the equipment is properly sized for mechanical and thermal short circuit effects. ( includes breakers, switches, busbars, cables, etc) under different operation scenarios in order to assess the maximum fault level.
The study complies with all the applicable ANSI / IEEE requirements.
Arc Flash Analysis
Study is based on the latest version of IEEE-1584 and NFPA-70E. It evaluates multiple network configurations in order to obtain the worst case results
Printing of arc flash stickers is included
Cable Ampacity Analysis
Cable Ampacity Analysis is based on Neher-McGrath method.
Calculated cable ampacity is based on all installation cases. This typically includes: cables in trenches, bores, duct-banks, cable crossings, parallel runs, cables on riser poles, etc.
Cables are modeled per manufacturer’s specifications. Generic cable models are not used.
Concentric Shield/Wire Induced Voltage Analysis
Study calculates the induced voltage levels on the medium voltage cable concentric neutral wires. Keeping the induced voltage below 25V (industry standard practice) insure that additional grounding of concentric neutrals is not required.
Grounding Analysis
• Study ensures that any person in the vicinity of grounded facility is not exposed to a critical electrical shock.
• Study ensures that grounding system meets IEEE-80 safety requirements.
• If Geotechnical Report is not available, soil resistivity measurements are performed.
• Impact of frost penetration on grounding system is considered.
Harmonic Analysis
• Study verifies if harmonic levels (for both: current and voltage) exceed the recommendation given in IEEE-519 standard.
• If the requirements are exceeded, study compares harmonic distortion indices with equipment withstand limits.
• Study considers all operational scenarios that may impact network resonant frequency; this includes but is not limited to: tie breaker open/closed, capacitor banks on/off etc.
• Long lines are modeled using distributed parameters R, C, L, and G.
• In case where multiple harmonic sources exist, diversification injection as per IEC 61000-3-6can be considered to account from cancelation effect from multiple sources.
Insulation Coordination Analysis
Study shall confirm that insulation coordination requirements are met according to IEEE standard C62.22 “IEEE Guide for the Application of Metal-Oxide Surge Arresters for Alternating-Current Systems”.
Power Flow Analysis
• Power flow analysis is performed to confirm that there is no excessive voltage drop and that no equipment is overloaded.
• Analysis considers all feasible active and reactive power consumptions (or injections).
• Analysis includes all possible configurations of shunt reactive power devices at the substation.
• When necessary Power Flow Analysis is augmented with the Reactive Power Study as explained next.
Reactive Power Analysis
• Reactive Power analysis is performed to confirm that facility meets Interconnection reactive power requirements. Study is used to size shunt capacitors adn reactors needed , dynamic Var resources can be sized too.
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• The study determines the step size of shunt reactive devices assuring that the device switching shall not cause maximum allowed voltage variation.
System Power and Energy Loss Analysis
• Energy loss is calculated typically during the design of new facilities. Even though cable are properly sized for power flow and short circuit, upsizing cables typically yields reduction of system losses. Economic analysis is performed to decide on cable sizing based on NPV of the investment in cables.
Single Machine Equivalent
For renewable energy projects (wind, PV) calculates single machine equivalent circuit, typically required by Interconnection Authorities.
