Power System Studies

Product Details:

We offer energy auditing service with the purpose of an energy audit also known as energy assessment or energy study or energy accounting is to find out why, where, how and when is energy utilized in a facility, and to discover occasions to increase efficiency. Energy auditing services are provided by energy services companies, energy experts and engineering organizations. The energy auditor directs the audit process but functions watchfully with staffs, building owners and other key participants all the way through to make sure precision of data collection and correctness of energy efficiency suggestion.

1. It helps reduce energy costs in your facility
2. With a reduction in production costs, the competitiveness of your company will be improved
3. It helps reduce the dependence on foreign energy sources
4. It helps reduce environmental damage and pollution
5. It can increase the security of your energy supply
6. It can reduce the consumption of natural resources
7. It can reduce damage to the environment associated with the exploitation of resources
8. It helps reduce the impact of greenhouse gas emissions

WHAT IS DONE DURING ENERGY AUDITING?

Similar to any other audits, energy audit will evaluate all of your facility’s energy usage and sketch all of the details. It is a procedure that assists you to check where your property is wasting energy and what actions you can take to increase energy efficiency. An energy audit is something that all facilities must undergo every two to three years in order to make sure utmost efficiency and expenditure.

There are three phases in an audit based on the requirements of the client for Energy Auditing Service:

INVESTIGATION PHASE

This phase is about getting all the information concerning:

• Historical energy consumption for the past 1 to 2 years
• Tariffs and related energy supply contracts
• Floor areas, staff numbers, production levels
• Occupancy hours
• Industry energy use/cost benchmark levels
• Sub electrical and gas metering equipment
• After-hours air conditioning usage
• Mechanical plant configuration, as-installed drawings, electrical single line drawings, and operational & maintenance manuals
• Lighting configuration, condition and controls
• Compressed air system including rating, presence of air leaks, hours of usage
• Steam and hot water boilers
• Building Management Systems and control strategies
• Building envelope, shading, orientation, insulation levels
• Energy management process and policy information
• Asset management plan, if any

MONITORING PHASE

This phase is about getting data related to the entire site and the main energy usage groups. The function of main plant and gear is checked, and measurement of a scale of parameters i performed where necessary, including:

• Electrical & gas load profiles
• Internal temperature/humidity
• Ventilation rate
• Light levels
• Boiler flue combustion analysis

Explore the comprehensive range of services offered by us for Power system Studies. click here!

Product Details:

Relay Co-ordination Study & Analysis service : In power system studies, the power system protection relay and circuit breakers are the major instruments 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.

If the study is on a new system or already existing system, attain or create a one- line diagram of the system or the part of the system concerned. The diagram should show the following data:

1. Apparent power and voltage ratings as well as the impedance ratings and connections of all transformers.
2. Normal and emergency switching conditions.
3. Nameplate ratings and sub-transient reactance of all major motors and generators as well as transient reactance of synchronous motors and generators, plus synchronous reactance of generators.
4. Conductor sizes, types, and configurations.
5. Current transformer ratios.
6. Relay, circuit breaker and fuse ratings, characteristics, and ranges of adjustment.

Obtain or perform a complete short-circuit study providing momentary and interrupting ratings. It must also contain highest and lowest anticipated fault interrupting duties, as well as inputs from every single short-circuit current source. Gather time-current characteristic curves for each protective device under consideration.

Because the whole aim of the study is to attain time-sequenced tripping of overcurrent protective equipment, the characteristic curve of the device closest to the load is plotted as far to the left of a 4- by 4-cycle graph as possible so that the source side characteristic curves are not packed to the right of the paper. The highest short-circuit current of the system is the right-hand limit of the curves.

Plot on the time-current, Iog-log paper the fixed and continuous points of all electrical devices under consideration. In the process of plotting the time-current characteristic curves, it must be remembered that all currents must be referred to a common voltage, either primary or secondary, before attempting to determine coordination. On a delta-wye system, the current that the primary fuse sees due to a secondary fault depends on the type of fault, as well as the severity of the fault.

The time-current characteristic curves of protective devices should not overlap if selective coordination is to be achieved, nor should the primary device of the transformer trip on inrush. The protective equipment should be set to defend motors, cables and system gear from overlay as well as short-circuit states.

To explore the comprehensive range of our power system studies click here!

Product Details:

HARMONIC STUDY AND ANALYSIS

We are harmonics study service provider for harmonics analysis in power system studies using electrical transient analyzer program (ETAP). Harmonics are electric voltages and currents on an electric power system that can cause power quality problems. Because equipment and machinery can malfunction or fail in the presence of high harmonic voltage and/or current levels, harmonic distortion has become a growing concern for facility managers, users of automation equipment, and engineers.

Harmonics can cause:

1. Circulating currents and high voltages caused by harmonic resonance
2. Equipment malfunctions due to excessive voltage distortion
3. Increased internal energy losses in connected equipment, causing component failure and shortened life span
4. False tripping of branch circuit breakers
5. Metering errors
6. Fires in wiring and distribution systems
7. Generator failures
8. Lower system power factor  

1. Current and Voltage Distortion Analysis

   The discrete and whole current and voltage harmonic distortions are estimated at several buses then the outcome are judged against the predetermined limits.

   Impedance versus Frequency Analysis

   A chart of the system impedance at different buses is plotted against the frequency. This analysis is important in predicting the system resonances prior to energizing the electrical system. A rise in the impedance plot implies a parallel resonance while a depression in the impedance plot denotes a series resonance.

   If harmonic analysis denotes extreme harmonic levels or a potentially harmful resonance condition, there are numerous substitute corrective actions that can be performed.

   1. Implement a rectifier with a pulse number higher than 6.
   2. Relocate or disconnect a small amount of power factor correction capacitance to shift a resonant frequency away from a characteristic harmonic.
   3. Harmonic filters can also be added to the system.
   4. Implementing a Pulse Width Modulated (PWM) rectifier.

Harmonics can cause:

1. Circulating currents and high voltages caused by harmonic resonance
2. Equipment malfunctions due to excessive voltage distortion
3. Increased internal energy losses in connected equipment, causing component failure and shortened life span
4. False tripping of branch circuit breakers
5. Metering errors
6. Fires in wiring and distribution systems
7. Generator failures
8. Lower system power factor
9. TWO TYPES OF ANALYSIS ARE PRESENT IN A HARMONIC ANALYSIS AND STUDY:

   Current and Voltage Distortion Analysis

   The discrete and whole current and voltage harmonic distortions are estimated at several buses then the outcome are judged against the predetermined limits.

   Impedance versus Frequency Analysis

   A chart of the system impedance at different buses is plotted against the frequency. This analysis is important in predicting the system resonances prior to energizing the electrical system. A rise in the impedance plot implies a parallel resonance while a depression in the impedance plot denotes a series resonance.

   If harmonic analysis denotes extreme harmonic levels or a potentially harmful resonance condition, there are numerous substitute corrective actions that can be performed.

   1. Implement a rectifier with a pulse number higher than 6.
   2. Relocate or disconnect a small amount of power factor correction capacitance to shift a resonant frequency away from a characteristic harmonic.
   3. Harmonic filters can also be added to the system.
   4. Implementing a Pulse Width Modulated (PWM) rectifier.

Product Details:

We offer arc flash analysis program and provide arc flash analysis report  for safety and efficiency of power systems. Arc Flash Study and Analysis was first introduced by IEEE about a decade ago.

An arc flash is the light and heat produced during an arc fault. It happens when current flows through air gap in between conductors. Arc flash causes ionization of air and expels large amount of energy. The arc flash temperatures can reach upto 35,000 degrees farenheit and that is hotter than the surface of the sun.

Objective 

The Purpose of Arc Flash Hazard Study and Analysis 

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).

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

Most commercial, institutional, and industrial electrical systems are prone to arc flash hazards. OSHA requires that those systems be individually analysed and, if hazards exist, labelled to identify the arc flash boundary. This will increase personnel safety, reduce shock hazards and reduce arc flash injuries. Reliserv provides arc flash studies using the ETAP software.

Working within NFPA and IEEE guidelines, our experienced power systems engineers will perform accurate systematic Arc Flash Hazard Analysis to:

1. Protect electrical workers from injuries due to arc flash.
2. Determine the Flash Hazard Boundary.
3. Determine the PPE needed to minimize the possibility of injury due to arc flash.

 Scope 

1. Data Collection
2. Power System Modeling using electrical power system analysis software such as ETAP
3. Short Circuit Study
4. Overcurrent Protective Device Coordination Study
5. Arc Flash Study
6. Arc Flash Hazard Calculations
7. Documentation
8. Unsafe Work Locations
9. Arc Flash Hazard Mitigation
10. Produce full sized one line diagrams
11. Final Report stamped by professional engineer
12. Arc Flash Hazard Labels
13. Installation of Arc flash labels
14. Final Report

Process

Reliserv offers excellent services and/or will support your site team, local electrical contractor or engineering firm with any services you need. Our expertise is widely recognized in the industry and our engineers are members of IEEE, NFPA and IEC which set the standards for arc flash studies. Our work process is:

1. Data Collection
2. Power System Modeling using electrical power system analysis software such as ETAP
3. Short Circuit Study
4. Overcurrent Protective Device Coordination Study
5. Arc Flash Study
6. Arc Flash Evaluation

Product Details:

FREQUENCY STABILITY ANALYSIS

The mid 1960s marked the beginning of the field of frequency stability analysis. Frequency instability is caused by problems, like poor coordination of operation control, protection devices, weakness of equipment response and deficiency in generation reverse. Because of the non-linear behavior of electrical power system, the categorizing has become crucial for electrical power system stability troubles. In order to understand the instability problems and develop solutions regarding the physical nature of the instability, the size of disturbance anime frame are necessary to be deliberately estimated.

The aim of a frequency stability study is to portray the frequency and phase flickering of a frequency source in the frequency and time domains. Frequency stability is a crucial consideration in power system operation and planning, particularly as a consequence of recent increase in load demand. Consideration of load-generation balance so as to avoid system from splitting into islands has become a necessity in power system. It can be realized, whether system is stable from frequency viewpoint or not. Now threshold of under frequency load shedding protective device can be determined effectively. Frequency stability is crucial in isolated island grids when these small systems are open to different range of interruptions, like loss of generation or loads.

IEEE Standard Definitions of Physical Quantities for Fundamental Frequency and Time Metrology- IEEE Standard 1139-1999, is the standard used for frequency stability analysis.

A frequency stability study is usually done on a single device, and not on a group similar devices. The output of the device is generally assumed to exist indefinitely before and after the particular data set was measured, which are the (finite) population under analysis. It is also generally assumed that the stochastic characteristics of the device are constant (both stationary over time and ergodic over their population).

The analysis may show that this is not true, in which case the data record may have to be partitioned to obtain meaningful results. It is often best to portray and eliminate deterministic factors like frequency drift and temperature sensitivity, before analysing the noise. Environmental effects are often best handled by eliminating them from the test conditions. It is also presumed that instrumental effects and the frequency reference instability are either insignificant or eliminated from the data. A usual crisis for time domain frequency stability study is to create outputs at the lengthiest probable averaging times so as to reduce test time and expense. Analysis time is generally not as much of a factor.

Product Details:

VOLTAGE DROP STUDY AND ANALYSIS

In an electric circuit the existing energy of a voltage supply decreases as electric current travels through the components that does not supply voltage i.e. passive elements of an electrical circuit. This is called Voltage Drop. Each point in a circuit can be assigned a voltage thats proportional to its electrical elevation, so to speak. Voltage drop is simply the arithmetical difference between a higher voltage and a lower one. The National Electrical Code states that a voltage drop of 5% at the furthest receptacle in a branch wiring circuit is acceptable for normal efficiency

There are two methods by which voltage drop study and analysis can be done:

1. Manual
2. ETAP

Voltage drop of the circuit conductors is calculated by multiplying the complete resistance of the circuit conductors by the current through the circuit:

VD = I x R

I = Load in amperes

R = Resistance of the conductor

This method cannot be used for 3 phase circuits.

The voltage drop of circuit with already installed conductors can be calculated by:

VD = 2 * K * Q * I * D/CM - Single Phase

VD = 1.732 * K * Q * I * D/CM - Three Phase

VD = Volts Dropped

K = Direct Current Constant

Q = Alternating Current Adjustment Factor

I = Amperes

D = Distance

CM = Circular-Mils

Since 1970s, ETAP has been a significant designing podium utilized for designing, analyzing, and optimizing electrical power systems. ETAP is a completely assimilated Electrical software solutions comprising of load flow, arc flash, short circuit and more. Its flexible performance makes it apt for all companies in any shape or form.

Operation Technology, Inc. is the developer of ETAP, the most wide-ranging analysis software for the simulation, design, operation, control, monitoring and automation of power systems. ETAP is the industry leader used worldwide in all types and sizes of power systems such as manufacturing, oil and gas, steel, mining, cement, and more.

We can approximate the voltage drop along a circuit as:

Vdrop= |Vs| - |Vr| ~ IR·R + IX·X

Where, Vdrop= voltage drop along the feeder

R= line resistance

X= line reactance

IR= line current due to real power flow (in phase with the voltage)

IX= line current due to reactive power flow (90 degree out of phase with the voltage)

The biggest fault happens under leading power factor and heavy current. The approximation has an error less than 1% for an angle between the sending and receiving end voltages.

This estimation brings two crucial factors about voltage drop into the light:

Resistive load: At large power factors, the voltage drop is related directly to the resistance of the conductors. The resistance plays a crucial role, even though the resistance is generally less than the reactance.

Reactive load: At medium or small power factors, the voltage drop relates mostly to the reactance of the conductors. Because the reactance is usually larger than the resistance, the reactive load causes most of the voltage drop. Poor power factor significantly increases voltage drop.

Product Details:

VOLTAGE IMBALANCE STUDY

Electrical equipment like motors will not function consistently on unbalanced voltages in systems. Usually, the variance between the maximum and the minimum voltages must not surpass four percent of the lowest voltage. Larger unbalances may lead to overheating of components, particularly motors.

1. A three phase equipment such induction motor with unbalance in its windings.
2. Any large single phase load, or a number of small loads connected to only one phase cause more current to flow from that particular phase causing voltage drop on line.
3. Switching of three phase heavy loads results in current and voltage surges which cause unbalance in the system.
4. Unequal impedances in the power transmission or distribution system cause differentiating current in three phases.

The effects of extensive voltage imbalances on power systems and equipment are broad and serious. A severe imbalance might dramatically decrease the equipment life cycles, considerably speed up the replacement cycle of equipment, and significantly increase system operation and maintenance costs. Furthermore, for a 3 phase 4 wire system, voltage imbalance leads to bigger neutral wire current and cause relay malfunction.

Voltage imbalances will create extra power loss, reduce system efficiency, decrease motor life cycles, etc. Also few abnormal functioning and maintenance circumstance also causes voltage imbalance and result in negative effects on equipment and systems. These conditions include such problems as bad electrical contacts, unsuitable shunt capacitor bank installation, single-phase operation of a motor, etc. These kinds of operation and maintenance conditions may not occur frequently. However, if they do occur they will bring about very serious problems for systems or equipment

1. Extra power loss
2. Safety deficiency
3. Motor failure
4. Life cycle decrease
5. Relay malfunction
6. Inaccurate Measurement
7. Transformer failure

1. To determine the causes and effects of voltage unbalance on the distribution system and in user facilities.
2. To determine the accepted definitions for calculating voltage unbalance and to clarify the related standards.
3. To identify mitigation techniques for the distribution system and for industries.

Product Details:

We offer power quality study and analysis, power quality management service to ensure energy efficiency. When any electrical system becomes unsuccessful in meeting its objective, the facility should undergo checking to examine the fault, find the root, and perform remedial steps. The aim of the electrical distribution system is to sustain the correct functioning of the loads. The quality of electric circuit it’s the main cause or improper functioning of the load. In case it is used for troubleshooting or to get marginal data, calculating/studying electrical system components is known as power quality analysis.

Data Collection and Power System Measurements

These values are taken at different locations all through the property to allow precise modelling of harmonic sources.

Following measurements are taken:

1. System Voltage RMS
2. System Current RMS
3. Active & Reactive Power
4. Power Factor (Instantaneous)
5. Data collection from site
6. Harmonic measurements along with specific harmonic filtering at normal operating conditions
7. Voltage Improvement & stability study
8. Three phase balancing study
9. Surge & Transient Protection, study
10. KVA Capacity Release
11. Broadband Harmonic reduction requirement if any

Harmonic Analysis

This includes the usage of computer programs to recognise and forecast possible harmonic problems and reduction methods.

Surges & Transient Analysis

This analysis will record the transient and surges.

Voltage Dips Swells Analysis

This analysis will record the small term fall & rise along with value and route.

Reactive Power Analysis

This analysis will calculate the preferred reactive power at distribution &load end.

Captive Power Analysis

This analysis will calculate and synchronise the captive power so as to cater to demands and decrease utility surcharge and fuel consumption.

Load Flow Analysis

This analysis predicts power flow magnitudes, power factor, voltage levels, and losses in branches of the system based on the specified operating conditions.

IEEE Power Quality Standards and NFPA 70B are outstanding assets to assist identify power quality terms, errors, and remedial actions. The equipment utilised to obtain actual readings and also gather information for downloading to computers for study and analysis is called Power Quality Analysers. Though some are permanently installed in the distribution system, handheld analysers are also used for numerous applications, mainly troubleshooting.

Always follow manufacturer guidelines for setting up the analyser or else following faults may occur:

1. Failure to observe current polarity.
2. Not matching current/voltage probes.
3. Relying on battery power to complete a lengthy monitoring session.

Explore the comprehensive range of services offered by us for Power system Studies click here!

Product Details:

electrical switchgear risk assessment study and hazard analysis service

in an electric power system, switchgear is the combination of electrical disconnect switches, fuses or circuit breakers used to control, protect and isolate electrical equipment. Switchgears are used both to de-energize equipment to allow work to be done and to clear faults downstream. This type of equipment is directly linked to the reliability of the electricity supply

one of the basic functions of switchgear is protection, which is interruption of short-circuit and overload fault currents while maintaining service to unaffected circuits. Switchgear also provides isolation of circuits from power supplies. Switchgear is also used to enhance system availability by allowing more than one source to feed a load.

switchgear can be classified on the basis of voltage level in to the following

• low voltage (lv) switchgear
• medium voltage (mv) switchgear
• high voltage (hv) switchgear

risk assessment is the determination of quantitative or qualitative estimate of risk related to a well-defined situation and hazard.

if you use switchgear you must assess the risks and manage them to ensure safe operation and minimise the risk of injury. A risk assessment is about identifying and taking sensible and proportionate measures to control the risks in your workplace

the hazards are divided into several main categories, where each category is further subdivided describing specific sources of hazards. The complete list facilitates a thorough check whether all aspects of safety are covered.

the main categories are:

1. hc 1 essential health and safety requirements
2. hc 2 design and construction
3. hc 3 information requirements
4. hc 4 control systems
5. hc 5 guards and protective devices
6. hc 6 installation, operation and maintenance

inspection of switchgear environment, for example the switchroom or substations, regularly is mandatory. During the inspection you should prioritise any remedial actions as follows:

1. immediate. This should always be the case when security of the substation enclosure has been interfered with.
2. earliest possible opportunity.
3. next scheduled maintenance. You should include the following items in the inspection schedule:
4. switchgear environment (switchroom access and surrounds, including fence and external walls if outdoors):

signs of water getting in/dampness

1. signs of unauthorised access and/or interference
2. condition of firefighting equipment and warning notices
3. general housekeeping
4. signs of abnormal conditions such as high temperature, smell of hot substances or ozone, presence of smoke, signs of fresh leakage of oil or compound, distortion and evidence of sooting on enclosures
5. general condition of switchgear, such as corrosion, evidence of leaks, fluid levels, presence/condition of labels, padlocks and key exchange interlocks, condition of instruments and protection equipment
6. condition of ancillary equipment such as batteries and chargers, control panels etc

Product Details:

LOAD FLOW STUDY AND 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. Since the load is a static quantity and it is the power that flows through transmission lines it is also known as Power Flow studies.

Power flow studies are undertaken for various reasons, some of which are the following:
The line flows

1. The bus voltages and system voltage profile
2. The effect of change in configuration and incorporating new circuits on system loading
3. The effect of temporary loss of transmission capacity and (or) generation on system loading and accompanied effects.
4. The effect of in-phase and quadrative boost voltages on system loading
5. Economic system operation
6. System loss minimization
7. Transformer tap setting for economic operation
8. Possible improvements to an existing system by change of conductor sizes and system voltages

Through the load flow studies we can attain the voltage levels and angles at every bus in steady state. This is rather important as the magnitudes of the bus voltages are required to be held within a specified limit. Once the bus voltage angles and levels are calculated using the load flow, reactive and real power drift through every line can be calculated. Also based on the difference between power flow in the sending and receiving ends, the losses in a particular line can also be computed. Moreover, from the line flow we can also find out the over and under load states. Power flow or load flow solution is essential for continuous evaluation of the performance of the power systems so that suitable control measures can be taken in case of necessity.

1. Development of load flow equations.
2. Solving the load flow equations using numerical techniques.
3. HOW IS LOAD FLOW STUDY PERFORMED?
4. MATHEMATICAL ANALYSIS

There are number of steps to be done while mathematically analysing load flow. They are:

Step 1: Represent the system by its one line diagram.

Step 2: Convert all quantities to Per Unit. We need to find all the parameters that we are given with respect to one common base value. This base value is normally clearly mentioned, but if not we can presume one and move on.

Step 3: Draw the Impedance Diagram.

Step 4: Obtain the Ybus matrix.

Step 5: Classify the buses

Step 6: Start answering the missing variables, by assumptions (unless it is specified otherwise).

Step 7: Find approximations for the Real and Reactive Power that we are given, using the assumed and given values for voltage/angles/admittance.

Step 8: Write the Jacobian Matrix for the first iteration of the Newton Raphson Method.

Step 9: Solve for the unknown differences, using Cramers Rule.

Step 10: We now need to repeat step 7 - 9 iteratively until we obtain an accurate value for the unknown differences as the [Symbol]0. Normally we only do 2 iterations. And other indefinite parameters are calculated.

Software is utilized in most of the realistic or real-time conditions since they are easier. In doing this, the electrical engineer builds a network of nodes interconnected by admittance (impedance).

Product Details:

Power system analyses include:

1. 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

1. Provide reduced incident energy exposure if possible by using alternate protective device settings
2. Provide recommendations for appropriate arc-flash hazard protection
3. Comply with OSHA, NEC, and NFPA 70E requirements
4. 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.
5. 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

Product Details:

We offer Short Circuit Study & Analysis service to keep your power systems safe from hazard by conducting short circuit current calculation. 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.

Protective devices designed to detect a fault condition and shut off the electricity before significant damage. There are a number of different types of protective devices, the two most common are:

Fuses and circuit breakers used to protect an electrical circuit from an over-current situation, usually resulting from short circuit, by cutting off the power supply. Fuses can only be used once. Circuit breakers may reset and used multiple times.

This device detects when the electricity flow in the energized conductor are not equal to return electricity in the neutral conductor. The Ground Fault Interrupter protects people by quickly cutting off the electric flow preventing injuries resulting from shock.  Ground Fault hecklers are typically used in homes for bathroom, kitchen, and outdoor electrical sockets. The Ground Fault Interrupter will typically be built into the electrical socket.

A Ground Fault Interrupter does not give over-current protection, and the circuit that includes a Ground Fault Interrupter will include a fuse or circuit breaker.

As well as fuses, circuit breakers, and GFIs, there are electrical protection devices that:

1. Detect changes in current or voltage levels
2. Guide the ratio of voltage to current
3. Give over-voltage protection
4. Give under-voltage protection
5. Detect reverse-current flow
6. Detect phase reversal

Conducting a short circuit analysis has the following benefits:

1. Helps avoid unplanned outages and downtime.
2. Is critical for avoiding interruptions of essential services
3. Reduces the risk of equipment damage and fires
4. Increases safety and protects people from injuries
5. Determines the level and type of protective devices that needed.
6. Provides the information needed for NEC and NFPA required labels
7. Keeps you compliance NEC requirements

Short Circuit Study & Analysis service :  SHORT CIRCUIT CURRENT CALCULATION

NEC 110 requires that a short circuit analysis done for all electrical equipment and panels. The most accepted standards for short circuit analysis are the ANSI/IEEE C37.010-1979 standard and the International Electrotechnical Commission (IEC) 60909 standard.

The ANSI C37.010 standard intended to use for power circuit breaker choice, but it does give information needed for NEC 110 required labelling. The IEC 60909-3:2009 standard is more generic. It proposed to give general guidance for short-circuit analysis of any asymmetrical short circuit in three-phase 50 Hz or 60Hz A.C. electrical system.

Either the ANSI or the IEC short circuit current calculation method can be used. They compared and found to produce similar results. The ANSI method is generally used in short circuit analysis software. Sometimes it may feel that the IEC method lends itself to manual calculations.

Product Details:

VIBRATION STUDY AND ANALYSIS

Technicians and operators every so often notice unusual vibrations or noises on the plant or shop floor where they work daily. In order to determine if a serious problem actually exists, they could proceed with a vibration analysis. Vibration analysis implies, state of a machine is identified on the basis of an analysis and study of vibration.

Successful application of vibration diagnosis requires in practice staff with considerable degree of knowledge and experience. Standard work of data gathering may be performed by skilled personnel without academic educations, but data assessment and processing of the machine condition is the task for an engineer who has expertise in different areas like mathematics, design of machines, dynamics, signal processing etc. and who is capable to use this expertise in context.

The vibration analysis is a very important technique, in terms of mechanical vibrations for machine diagnosis. It is based on the high information content provided by the machine vibration signals that are an indicator of machine condition, used for the diagnosis of faults. Vibration analysis in a predictive maintenance program, is widely used for monitoring and detection of initial and critical faults in machinery parts, like shafts, bearings, rotors, couplings, motors etc. Some problems that are usually detected by vibration analysis are: unbalance, misalignment, bent shaft, rolling bearing faults, eccentricity, resonance, looseness, rotor rub, fluid-film bearing instabilities, gear faults, belt/sheave problems.

Following are the reasons that makes vibration study and analysis important:

1. Reduces equipment costs:
2. Reduces labor costs
3. Reduces lost production time
4. Increases safety
5. Increases revenue
6. Increases efficiency of employee time

The main objectives when performing a vibration study typically fall into one or more of three categories:

1. Capacity: Map the dynamic behavior of the machine from current to targeted speeds, yielding the most cost-effective approach by foreseeing problems.
2. Rebuild:  Evaluate how rebuilds will affect the dynamic behavior of the machine and its consequences at current or increased speeds.
3. Troubleshooting: Locate and eliminate vibration sources currently having a detrimental effect on the machinery or process.

Vibration analysis is performed by Fourier transform (by its decomposition into Fourier series). All actions related to the study and analysis, given below are employed in analyzers that are utilised in vibration diagnostics.

There are different types of analyzers:  operational or laboratory, with one or more channels - but the principle of their operation is always the same.

1. Determination of the dynamic behavior of machine sections
2. Determination of the mechanical condition of the machine
3. Determination of the feasibility of a possible capacity increase
4. Most cost-effective implementation of rebuilds
5. Forecast future mechanical issues and reduce unintended shutdowns
6. By repositioning old rolls to where they can still be utilised, we can save on roll remakes.
7. Solutions to problems such as barring and gear train failures

Product Details:

UNBALANCED LOAD FLOW STUDY AND ANALYSIS

Load flow analysis is an important function for power system planning and practical studies. Certain applications, particularly in distribution automation and optimization of a power system, require repeated load flow solutions and in these applications, it is very important to solve the load flow problem as efficiently as possible.

As the power distribution networks become more complex, there is greater demand for efficient and reliable system operation. Consequently, the most important system analysis tool, load flow studies, should be capable of handling various system configurations with adequate accuracy and speed.

In several situations, it observed that the radial distribution systems remain unbalanced due to single-phase, two-phase and three-phase loads. Thus, load flow solution for unbalanced cases, special analysis is necessary.

Usual load flow methods cannot directly apply to distribution systems. The mode used for three phase power flow analysis in unbalanced systems cannot develop by extending the single phase balanced methods. A three-phase load flow method has to analyze problems like modeling of different forms of fundamental connections that would regulate starting point for three phase power flow solutions as there are phase shifts and transformation ratios for each phase and at different buses. For untransposed lines and cables the balanced models are no longer useful.

The symmetrical component transformation can decouple the three phases. For three phase networks the burden matrix is obtained. A method to measure power losses in unbalanced radial distribution systems.