Description

Power System Analysis

Power system analysis is in essence the solution of power flow equations in a power system. ETAP is one of the best software to perform various power system analyses. Calculations and simulations are performed to verify that the electrical power system, including the system components such as generators, lines, transformers, shunt elements, perform as intended, withstand expected stress, and protected against failures.

Objectives

WHY IS POWER SYSTEM STUDY & ANALYSIS DONE?

The objective of Power system analysis is for designing entire power systems consisting of generators, transformers, capacitor banks, shunt elements, transmission lines and so on. Power system analysis makes sure the equipment work together so that the required power is delivered to the load centers at the prescribed voltage and frequency, and no component in the network is overloaded and no fault condition jeopardizes the system.

STANDARDS & GUIDELINES

International standards and local regulations form the basis for evaluation of calculation and simulation results for power system designs. It include requirements and recommendations for protection of personnel and equipment, system response and equipment performance.

Scope

SCOPE OF POWER SYSTEM ANALYSIS

Power system analyses include:

• Load Flow Analysis
• Short Circuit and Fault Analysis
• Protective Device Co-ordination Study
• Arc Flash Study
• Harmonic Analysis
• Dynamic and Transient Analysis
• Earthing Study

1) Load Flow Analysis – Load Flow Analysis or Power Flow Analysis is the most crucial tactic to exploring problems in power system operating and planning. Based on a specified generating state and transmission network structure, load flow analysis solves the steady operation state with node voltages and branch power flow in the power system. Load flow provides sinusoidal steady state of complete system – real and reactive power generated, voltages and absorbed and line losses.

2) Short Circuit and Fault Analysis – A short circuit is the flow of electricity in an unintended path of lower resistance or diversion of electricity. Short circuits result from unintended connections to ground, two points of different voltages coming into contact, or two phases contacting each other. In many cases the flow of electricity is through near-zero resistance connection, resulting in very high electricity levels.

3) Relay Coordination Study and Analysis: – In power system protection relay and circuit breakers is the major instrument for large interconnected power system. We need proper protection to isolate the faulted region from healthier network. When two protective apparatus installed in series have certain characteristics, which provide a specified operating sequence, they are said to be coordinated or selective. Relay coordination is an important aspect in the protection system design as coordination schemes must guarantee fast, selective, and reliable relay operation to isolate the power system faulted sections.

 

4) Arc Flash Study : – The purpose of the arc flash study is to determine the protective clothing requirements for persons working on live or electrically energized equipment (whenever feasible and possible).

• Determine the risk of personnel injury as a result of exposure to incident energy (IE) released during an arc-flash event
• Provide reduced incident energy exposure if possible by using alternate protective device settings
• Provide recommendations for appropriate arc-flash hazard protection
• Comply with OSHA, NEC, and NFPA 70E requirements

5) Harmonic Analysis : – Harmonic analysis or harmonic modelling is an arithmetical method of foreseeing potential resonances and harmonic distortion levels depending on the available power system data. All but the simplest of systems will require a computer to perform this analysis. A number of software packages are available specifically for this purpose.

Equipment like transformers, capacitors and utility system impedance are considered and non-linear loads are represented by several frequency harmonic current sources. Such a modelling study will indicate if harmonic levels will fall within IEEE or utility limits.

6) Dynamic and Transient Analysis : – As generators work in synchronism sudden load changes or faults could cause one or more of them to go out of step, which has to be dealt with.

In a power system there are always small load changes, switching actions, and other transients occurring, yet, these variations are so small that a power system is considered to be in steady state regardless of these variations.

A short circuit in a power system is clearly not a steady state condition and such an event can create a variety of dynamic phenomena in that system. Dynamic models are used to study those phenomena.

However, to study fault currents in the system, a steady state model with appropriate parameters can be used. A fault current consists of two components, a transient part, and a steady state part, but since the transient part can be estimated from the steady state one, fault current analysis is commonly restricted to the calculation of the steady state fault currents.

7) Earthing  Study

Process

POWER SYSTEM ANALYSIS PROCESS

• Data Collection
• Power System Modelling using electrical power system analysis software such as ETAP
• load flow analysis
• Short Circuit Study
• Stability Study
• Document review
• Management Briefing
• Draft Report Submission
• Final Report Submission

Certification & report

POWER SYSTEM ANALYSIS FINAL REPORT WILL CONTAIN

Upon completion of the calculations, we will prepare your Power System Analysis Report. This will be provided to you for a short review period, during which your team can evaluate modifications. At this point, we can hold meeting to deduce the report results. Upon approval, we will provide a final report and full sized one-line diagrams, stamped by our Registered Professional Engineer. The drawings and report will also be supplied to you in a digital format.

• Introduction
• Executive Summary
• Single Line Diagram
• Observations and Recommendations
• Report

BENEFITS

BENEFITS OF POWER SYSTEM STUDY & ANALYSIS

• Compliance with statutory regulations, and follow minimum safety standards
• Increased levels of safety
• More efficient use of resources
• Clarification of electrical safety responsibilities
• The identification and elimination of safety hazards
• Ensuring longevity of your expensive electronic equipment like computers and other machines
• Improvement of employee morale
• Development of a dynamic record of safety performance
• Creation of positive cycle of safety improvement
• Improvement of management awareness of problems
• Ensuring compliance with Government and industry safety related work practices