power systems loss

Factors/Risks associated with increase in distribution’s systems loss Increase in utility’s system’s kWh loss can be attributed to many factors. We all know that the components of a utility’s systems loss can be from technical loss or from non-technical loss. As a review, technical loss is the inherent properties of electrical equipment and devices during operation while non-technical loss is the result of electricity pilferage, error in meter reading, etc. 

How to detect possible electricity pilferage? We all know that system’s loss is composed primarily of technical loss and non-technical loss. Technical loss is the inherent property of all electrical devices during operation while non-technical losses are caused by electricity theft and/or metering inaccuracies. Technical loss can be determined through computations and the use of measuring devices. On the other hand, non-technical loss cannot be measured nor be computed; instead one has to have various methods just to detect such loss.

Author: Sarang Pande and Prof. Dr. J.G. Ghodekar ABSTRACT: Power system losses can be divided into two categories: technical losses and non-technical losses. Technical losses are naturally occurring losses (caused by actions internal to the power system) and consist mainly of power dissipation in electrical system components such as transmission lines, power transformers, measurement systems, etc. Technical losses result from the impedance of the network components such as electric lines/ cables, transformers, metering and protecting equipment etc. Non-technical losses, on the other hand, are caused by theft, metering inaccuracies. In this paper a method for energy loss calculation is presented.

How to save energy in using inverter technology? An inverter used either in air conditioning or refrigeration basic benefit is its significant energy saving capabilities. Inverter technology allows the air conditioner/refrigerator automatically vary its power output to specifically maintain room temperature at a desired or comfortable level. Basically, the inverter is used to control the speed of the compressor motor to allow continuously regulated temperature. In contrast, a non-inverter appliance maintains the temperature by repeatedly switching power on and off, which consumes much more electrical energy upon starting.

SPEED CONTROL FOR ELECTRIC MOTOR TUTORIAL GUIDE How to control the speed of an electric motor? The relationship between rotational speed, supply frequency, number of poles and slip for induction motors is usually written: n = (2/p) x f x 60 x (1-s) Where: n = speed, r/min             f = frequency, hertz             p = number of poles             s = slip

CAPACITOR FUSING APPLICATION GUIDE RULES Basic points to consider in fusing a capacitor in electric system network 1) Purpose of fusing:                 a. to isolate faulted bank from system                 b. to protect against bursting                 c. to give indication                 d. to allow manual switching (fuse control)                 e. to isolate faulted capacitor from bank 2) Recommended rating:                                a. The continuous-current capability of the fuse should be at least 165 percent of the normal capacitor-bank (for delta and floating wye banks the factor may be reduced to 150 percent if necessary).                 b. The total clearing characteristics of the fuse link must be coordinated with the capacitor "case bursting" curves. 3)  Tests have shown that expulsion fuse links will not satisfactorily protect  against violent rupture where the fault current through the capacitor is greater than 5000 amperes. 4)  The c

FUSE APPLICATION GUIDE RULES Basic points to consider in installing fuses in electrical system network 1)  Cold load pickup -  after 15 minute outage,  200% for.5 seconds                                                                          140% for 5 seconds                                        after 4 hrs, all electric  300% for 5 minutes 2)  "Damage" curve - 75% of minimum melt 3)  Two expulsion fuses cannot be coordinated if the available fault current is great enough to indicate an interruption of less than .8 cycles. 4)  "T" - SLOW and "K" - FAST 5)  Current limiting fuses can be coordinated in the sub-cycle region. 6)  Capacitor protection: The fuse should be rated for 165% of the normal capacitor current.  The fuse should also clear within 300 seconds for the minimum short circuit current. If current exceeds the maximum case rupture point, a current limiting fuse must be used. Current limiting fuses should be used if a s

ELECTRIC MOTOR BRAKING METHODS TUTORIALS What are the methods in stoppng/braking an electric motor? MECHANICAL BRAKING Mechanical braking with magnetic lifting is the technique most widely used for the braking of electric motors . At standstill brakes of this type provide a holding torque, and are therefore used where loss of braking in the event of power failure could be dangerous. However, in certain cases it may be necessary to lift the brake without starting the motor. This can be done by supplying the brake coil from a separate power source, or with a manual release device. The mechanical brakes used for electric motors are shoe, multiple-plate or disc brakes. ABB Motors brakes are disc brakes with asbestos-free brake pads or linings. During braking , the braking torque is constant with mechanical braking . At standstill the brake has a holding torque. On some brakes the braking torque can be reduced for softer deceleration. When the motor is started again, the holdin

LOAD PROFILE SHAPE OBJECTIVES FOR DEMAND SIDE MANAGEMENT TUTORIALS Load profile management for demand side management action plan Customer load profile is an excellent guide in implementing demand side management . This serves as a monitoring tool for in which action plan method is to be applied. Levelling the load profile behaviour of the customer load will maximize the use the utilities generation capacity thus lowering the load factor . This is usually done by shifting some customer loads from peak loads hours to off-peak hours. Alternatively, off-peak load hours can also be increased to reduce the company’s load factor . PEAK CLIPPING Peak clipping refers to the reduction of utility loads during peak demand periods. This can defer the need for additional generation capacity. The net effect is a reduction in both peak demand and total energy consumption. This is usually implemented by direct utility control of consumer appliances or end use equipment. VALLEY FILLING Valley fil

PRESENTATION ON POWER DISTRIBUTION SYSTEM LOSSES BY TAO HONG Presented by Tao Hong, Ph.D., lecture at ABB, FL, April, 2011 This is a very good presentation prepared by Tao Hong. He is an Analytical Consultant in SAS Institute Inc. where he focuses on revenue optimization, retail forecasting and demand response. Sir Tao Hong is also a Business Knowledge Series Instructor in the same institute. He is an Engineer, Sr. Engineer, Principal Engineer in Quanta Technology, LLC where he is in charge of Load forecasting, T&D Planning, system loss evaluation, system reliability analysis, load modelling, and renewable energy. Abstract This presentation introduces the basic concept, assessment, and mitigation of power distribution system losses. During the seminar, the participants learn how to calculate transformer and line losses, and to optimally place capacitors to reduce losses. Overview     Introduction     Basic concepts     Definitions     Calculation     Causes and mitigatio

REA BULLETIN 160-2: MECHANICAL DESIGN MANUAL FOR OVERHEAD DISTRIBUTION LINES Overview on REA Bulletin 160-2 for overhead distribution line design guide The engineering input to an overhead line project can be divided into three principal categories; system planning, electrical design of system components, and the mechanical design of the line. This overview for the design manual deals primarily with the last mentioned of these categories. Preparation for an Overhead Distribution Line Project This part involves coordination with system planning especially in the field of route selection and acquisition. This includes securing of rights of way and permits needed for the implementation. Preparing a line project also means preparing of staking aids as well as review of existing design guides or preparation of new ones. The National Electrical Safety Code as a Basis for Distribution Line Design The second part in implementing distribution line projects is insuring that appropriate sta

SELECTION OF CONDUCTORS FOR OVERHEAD LINE DESIGN What are the guidelines to be considered in selecting conductors for overhead line design? Economically, conductors represent between 20 to 40% of the total cost of a line; consequently their selection is of prime importance. In earlier days of electrical power transmission, copper was mainly used as the material of overhead line conductors, however with the expansion of electricity networks, several factors, such as price, weight, availability and conductivity, have virtually compelled Overhead Line Design Engineers to concentrate on aluminium based conductors, eg. AAC = All Aluminium Conductor ACRS = All Aluminium Conductor Steel Reinforcement AAAC = All Aluminium Alloy Conductor Steel conductors are still widely used as overhead earth wires and also as phase conductors on rural distribution lines, eg. SC/GZ = Galvanised Steel Conductor SC/AC = Aluminium Clad Steel Conductor Phase Conductors The conductors fulfil an electromec

SELECTION OF INSULATORS FOR OVERHEAD LINE DESIGN What are the guidelines to be considered in selecting insulators for overhead line design? One of the most important and yet one of the most vulnerable links in transmission and distribution is insulators. Porcelain and toughened glass are the materials principally used for supporting conductors on overhead lines, and although these materials are relatively brittle and inelastic, they have proven service experience and are still widely used. The design of synthetic type insulators has improved both electrically and mechanically in recent times and they are being used in urban areas to minimise radio interference and in areas where gunshot or stone throwing is a problem. Insulator damage may occur due to such widely varying causes as lighting (puncture), power arcs, stone throwing, corrosion, gunshot and pollution. The following points must be considered in the selection of the appropriate insulation of an overhead line: • 50Hz perfor

STEPS IN LAYOUTING DISTRIBUTION LINE IN OVERHEAD LINE DESIGN TUTORIALS How to design overhead line especially in lay-outing distribution line? The following steps are suggested as the approach to be followed in designing a line from scratch. With experience or by reference to the tables of common applications in the Design manual section “Pole Structures” many of these steps will not be required for jobs of a standard nature. 1. Determine conductor size and type based on planning requirements and application. 2. Determine the proposed stringing tension based on the situation eg. Urban, semi urban or rural. Consideration in this decision should be given to the difficulty of staying and frequency of angles required by route restrictions. 3. Determine the Limit state design wind pressure on conductors appropriate to the location (eg 900 or 1200 pa). 4. Determine strain/angle pole locations taking into account the deviation angle limits on pin insulators as per the table in the Desig

OVERHEAD TRANSMISSION AND DISTRIBUTION LINE DESIGN GUIDELINES OVERVIEW What are the guidelines to be considered in designing overhead electrical lines? In order to minimise the risk of failure of an overhead line it is necessary to ensure that each component of an overhead line has been designed to meet all the electrical and mechanical loads likely to be experienced in service as far as reasonably practical. In order to achieve this, every line and every structure in that line could be individually designed to meet the project requirements. This would be extremely time consuming and is probably only justified for high value transmission lines. Another approach is to utilise a range of standard structures with pre-designed electrical and mechanical capabilities and apply them to a particular project. Selection of Insulators One of the most important and yet one of the most vulnerable links in transmission and distribution is insulators. Porcelain and toughened glass are the materia

ELECTRIC MOTOR MOUNTING USING NEMA DIMENSIONS TUTORIAL GUIDE What are the guidelines in mounting electric motors using NEMA? NEMA has standardized motor dimensions for a range of frame sizes. Standardized dimensions include bolt-hole size, mounting base dimensions, shaft height, shaft diameter, and shaft length. Use of standardized dimensions allows existing motors to be replaced without reworking the mounting arrangement. In addition, new installations are easier to design because the dimensions are known. NEMA divides standard frame sizes into two categories, fractional horsepower and integral horsepower. The most common frame sizes for fractional horsepower motors are 42, 48, and 56. Integral horsepower motors are designated by frame sizes 143 and above. A T in the motor frame size designation for an integral horsepower motor indicates that the motor is built to current NEMA frame standards. Motors that have a U in their motor frame size designation are built to NEMA standards

ETAP SOFTWARE REAL-TIME MONITORING WITH SCADA INTERFACE VIDEO TUTORIAL Video tutorial on how ETAP software is used for real-time monitoring In this video you will see how ETAP software is used for real-time monitoring of the system. Watch the video to understand more.

IEEE GUIDE FOR FIELD TESTING OF RELAYING CURRENT TRANSFORMER C57.13.1 A guide for field testing of relaying current transformer In the application of protective relays, the most widely used input quantity is current. A multiplicity of different protective relays either utilizes current directly, combines it with other currents as in differential schemes, or combines it with voltage to make impedance or power measurements. The source of relay input current is from current transformers which may be located on the bushings of power circuit breakers and power transformers, on the bus bars of metal clad switchgear, or installed as separate items of equipment located as required. Relaying accuracy classes have been established in ANSI/IEEE C57.13-1978, Requirements for Instrument Transformers, to specify the performance of relaying current transformers. During faults on the electric power system, relaying current transformers must operate at high overcurrent levels. ANSI classiÞcations,

DOWNLOAD FREE ETAP SOFTWARE DEMO ON ELECTRICAL POWER SYSTEM SIMULATION ETAP Electrical Power System Software Demo Download here Before buying the actual ETAP11 Software, the company offers a demo version for those newbie in using the software. Also, this would be helpful for students who wants to learn more on power system simulation. This is a 510MB file where you can download it directly to your PC. However, if you have a slow internet connection, a Demo CD mail can also be an option. By requesting an ETAP demo, you will also receive regular newsletters and information on our latest products and services. You will have the option to opt out at any time. Please see our privacy policy. ETAP and its affiliated companies do not sell or disclose any personal information obtained from our site visitors without their consent to any unaffiliated third party for purposes unrelated to servicing their requests, unless required to do so by law or other regulatory authority Download the demo

INSTRUMENT TRANSFORMER THEORETICAL DISCUSSIONS Basic theoretical concept of instrument transformers guide Instrument transformer is the standardized term used for current and voltage transformer. Theoretical Reminder: Current Transformers Current transformers have a similar composition to "conventional" transformers. A magnetic circuit (generally made of an iron alloy) in the shape of a toroid is surrounded by N1 turns on the primary and N2 turns on the secondary. The primary can be reduced to a simple conductor passing through the toroid (n1 = 1) (see figure 6-2). General Application Rule Current transformers feed measuring, control and monitoring devices. Galvanic insulation electrically seperates the primary circuit from the secondary circuit. It allows earthing of the electrical measuring device and thus ensures safety of operating personnel. The current transformer is designed to give the secondary a current that is proportional to the primary current. The seondary