power systems loss

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.

RUS BULLETIN 1724E-300 SUBSTATION VOLTAGE REGULATORS Voltage Regulators for Distribution System General Both three-phase and single-phase voltage regulators are used in distribution substations to regulate the loadside voltage. Substation regulators are one of the primary means, along with load-tap-changing power transformers, shunt capacitors, and distribution line regulators, for maintaining a proper level of voltage at a customer’s service entrance. A very important function of substation voltage regulation is to correct for supply voltage variation. With the proper use of the control settings and line drop compensation, regulators can correct for load variations as well. A properly applied and controlled voltage regulator not only keeps the voltage at a customer’s service entrance within approved limits but also minimizes the range of voltage swing between light and heavy load periods. The substation regulators may be located on individual feeders or in the transformer secondary

LINE VOLTAGE REGULATORS CHARACTERISTICS AND OPERATION Line voltage regulators' discussion and operation. Primary distribution feeders in rural areas often extend so many miles that maintaining proper voltage over the entire length of the feeder will supply poit regulators alone is impossible. Line regulators located approximately at the mid-point of such feeder provide additional regulation to support the voltage on the remote parts of the feeder. Characteristics of Line Regulators The most common types of line regulators operate similarly to substation regulators. However, line regulators are usually smaller, are more likely to be formed from single-phase units, and are physically constructed for platform mounting on a pole or poles. The discussion above of loss characteristics of substation regulators also applies to line regulators. The major operational difference is that line regulators normally are used only for boosting voltage, and there is no way to center t

How to minimize loss on Voltage Regulators Operation? To minimize losses on substation regulators , either separate units or substaton load tap changers, the high-voltage tap setting on the substation transformer should be set so the regulators will spend the maximum amount of time near the neutral position, since regulator losses increase as the regulator tap position farther away from neutral. Ideally substation regulators should spend approximately the same amount of time bucking voltage as they do boosting voltage. This keeps the regulators near neutral under average system conditions.

System Voltages in Transmission Lines Table shown is the standard system voltages from ANSI standards C84 and C92.2 According to ANSI standards C84 and C92.2, system voltages are recommend to be within the table shown below. 345kV, 500kV and 765kV are considered to be in the Extra High Voltage (EHV) level. The choice of system voltage is in the decision of the utility. However, some points needs to be considered in choosing such, like voltage economics, conductors, distances, equipments, etc.