Introduction

• Power system studies systematically analyses a customer’s electrical network to provide recommendations on how to optimize its performance while improving the security of the supply.
• This is done by capturing the behavior of electrical network, its element, its control, protection and their response under different time frames, spanning few a micro seconds to several hours or even years of time.
• Power system benefits the client by giving the valuable technical information when the system is under normal and fault conditions and recommendations on solution to power safety related problems faced by the plant.
• Power system studies also gives reports highlighting problem areas in the facility, helps to avoid damage and injuries and knowledge of where the energy is being used.
•  The results we get from power system studies can help us determine the amount of safety gears needed by workers in various parts of the plant.

Some advantages of conducting a power system Studies.

• 
  Reductions  outage  time in the plant  because  the system  design and equipment are modified to  reduce  mean  time  between failures and mean time to repair
• Power Quality will be significantly improves due to reduction in harmonic currents and voltages
• Electrical Safety is also improved as as potential harmonic resonance conditions corrected and also because of identification and elimination  of overvoltage  and  overcurrent  situations  .

• Reduction  in  outages  due  to  unstable  generator  power  swings  following  fault clearing. '
• Improved  operations  while   islanded conditions  because of   implementation  of  load shedding scheme.

Short Circuit Study

The short circuit study tell us the capability of each component in an electrical system. Here during this study all kind of inputs expected   is delivered to the equipment under consideration. The results are tabulated and analyzed.

Coordination Study

The coordination study is conducted to determine the extent of overcurrent protective device coordination within an electrical system .A Well-engineered system will allow only the protective device nearest the fault to open, leaving the remainder of the system undisturbed so that the systems remain in service

Arc-Flash Hazard Analysis

Arch-Flash studies analysis the results from short-circuit and coordination studies to find the arc-flash incident energy levels. This studies are conducted under all conditions and all modes of operation that the component may face.

Load Flow Studies

Load flow analysis is a numerical algorithm used to understand the steady state operating characteristics of a power system network from the line data or bus data. Load flow Studies helps in decreasing unexpected downtime, and it reduces opera rating and maintenance costs.

Stability Studies

This study is mathematical method which checks the ability of a synchronous machines within an electrical system to remain in step with one another following a disturbance.

MOTOR STARTING STUDY

In this study, the objective is to investigate the behavior of the motor that is being started and its effect on system operations. As such, the motor terminal voltage, motor starting current and bus voltage is plotted.

This section describes the Motor starting study basis and results. Motor Starting studies have been performed to determine the method of motor starting successfully while maintaining the voltage at the motor terminal and in other buses within acceptable limits.

Methodology

Input Required

• Overall key Single Line Diagram
• List of switch gear-Plant wise
• Protection single line diagram
• Previous power system studies
• Load schedules
• Protective Relay Setting sheets type
• And make of relay
• Data sheet and Name plate Details of all Generators, transformers, VFDs and HT motors

Team/Expert Detail

Lead Engineer

Job engineer/Senior engineer / Senior ETAP engineer

Deliverables

• Complete assessed input data report of all Equipment
• Load/power flow study
• Report on Transformer/Generator size based on Load Flow Study
• Short Circuit reports for  worst Case Scenario Conditions and its Associated Results
• Motor Starting Current Analysis
• Transient/Load Shedding report For the said worst case  Scenario for large area distribution
• Harmonics Evaluation on individual load clusters and harmonic Filter sizing calculation
• Coordination Study
  Report including computer generated time-current characteristics Curves(TCC)
• Reliability study for major switchboards/Panels.

Software And Standards

Important Standards

Studies will performed by using the version not less than (Or latest) of the approved software

IEEE 141 – Recommended Practice for Electric Power Distribution and Coordination of Industrial and Commercial Power Systems

IEEE 242 – Recommended Practice for Protection and Coordination of Industrial and Commercial Power Systems

IEEE 399 – Recommended Practice for Industrial and Commercial Power System Analysis

IEEE 241 – Recommended Practice for Electric Power Systems in Commercial Buildings

IEEE 1015 – Recommended Practice for Applying Low-Voltage Circuit Breakers Used in Industrial and Commercial Power Systems.

IEEE 1584 - Guide for Performing Arc-Flash Hazard Calculations

ANSI C57.12.00 – Standard General Requirements for Liquid-Immersed Distribution, Power, and Regulating Transformers

ANSI C37.13 – Standard for Low Voltage AC Power Circuit Breakers Used in Enclosures

ANSI C37.010 – Standard Application Guide for AC High Voltage Circuit Breakers Rated on a Symmetrical Current Basis

ANSI C 37.41 – Standard Design Tests for High Voltage Fuses, Distribution Enclosed Single-Pole Air Switches, Fuse Disconnecting Switches and Accessories.

NFPA 70 - National Electrical Code, latest edition

NFPA 70E – Standard for Electrical Safety in the Workplace, latest edition

IEEE 519- IEEE Recommended Practice and Requirements for Harmonic Control in Electric Power Systems

IEC 60909- Short-circuit currents in three-phase AC systems

Software-ETAP

Our Experience