power systems loss

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

TYPES OF FUSES FOR ELECTRIC MOTORS PROTECTION Different types of fuses for electric motor protection Fuses are over-current protective devices that are placed in an electrical circuit to protect the control components, wiring, insulation, and motor from damage caused by excessive current and associated heat. Overcurrents are considered any increase in continuous current above the normal operating current level. In motor circuits, overcurrents are classified in two different categories. Motor overloads are any overcurrents up to or slightly above locked rotor current (6-8 times FLA). This range of overcurrent is protected by overload relay protection devices which will be discussed in more detail later. Short-circuit overcurrents are those produced by short-circuit or ground fault conditions with fault current levels in excess of 8 times FLA. In today’s industrial facilities, short-circuit overcurrents can easily reach 50,000A. If the short-circuit overcurrents are not interrupted

ELECTRIC MOTOR SHORT CIRCUIT PROTECTION OVERVIEW How are electric motors protcted from short circuits? A short circuit is a direct contact between two points of different electric potential: 1. Alternating current: phase-to-phase contact, phase-to-neutral contact, phase-to-ground contact or contact between windings in a phase. 2. Direct current: contact between two poles or between the ground and the pole insulated from it. This can have a number of causes: damage to the varnish insulating the conductors, loose, broken or stripped wires or cables, metal foreign bodies, conducting deposits (dust, moisture, etc.), seepage of water or other conducting fluids, wrong wiring in assembly or maintenance. A short circuit results in a sudden surge of current which can reach several hundred times the working current within milliseconds. A short circuit can have devastating effects and severely damage equipment. It is typified by two phenomena. A thermal phenomenon A thermal phenomenon co

BASICS FOR ELECTRIC MOTORS PROTECTION Overview on the importance of electric motor protection. Every electric motor has operating limits. Overshooting these limits will eventually destroy it and the systems it drives, the immediate effect being operating shutdown and losses. This type of receiver, which transforms electrical energy into mechanical energy, can be the seat of electrical or mechanical incidents. Electrical a. Power surges, voltage drops, unbalance and phase losses causing variations in the absorbed current. b. Short circuits where the current can reach levels that can destroy the receiver. Mechanical a. Rotor stalling, momentary or prolonged overloads increasing the current absorbed by the motor and dangerously heating its windings. The cost of these incidents can be high. a. It includes production loss b. Loss of raw materials, c. Repair of the production equipment, d. Non-quality production and delivery delays. The economic necessity for businesses to be m

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

Authored by: Puthireddy Umapathi Reddy*, Sirigiri Sivanagaraju, Prabandhamkam Sangameswararaju ABSTRACT In rural power systems, the Automatic Voltage Regulators (AVRs) help to reduce energy loss and to improve the power quality of electric utilities, compensating the voltage drops through distribution lines. This paper presents selection of optimal location and selection of tap setting for voltage regulators in Unbalanced Radial Distribution Systems (URDS). PSO is used for selecting the voltage regulator tap position in an unbalanced radial distribution system. An algorithm makes the initial selection, installation and tap position setting of the voltage regulators to provide a good voltage profile and to minimize power loss along the distribution network. The effectiveness of the proposed method is illustrated on a test system of 25 bus unbalanced radial distribution systems.

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