PAPER ON FEEDER RECONFIGURATION FOR LOSS REDUCTION IN THREE PHASE DISTRIBUTION SYSTEM UNDER UNBALANCED LOADING CONDITION

Authored by: N. Rugthaicharoencheep and S. Sirisumrannukul

Unbalanced loading in electrical networks creates higher losses compared to balanced lines having the same loads. Reconfiguring the set up of the loads reduces the line losses not only to its phase conductors but also to the neutral wire for four-wire system.

ABSTRACT - This paper presents a method to find the optimal implementation of feeder reconfiguration in unbalanced loading of distribution systems with the objective of power loss reduction. The optimization problem is subjected to system constraints consisting of load-point voltage limits, radial configuration format, no load-point interruption and feeder capability limits.

The system power losses and bus voltages are solved by a three-phase power flow algorithm. The solution technique developed based on Tabu search is employed to search switch statuses for feeder reconfiguration under different unbalanced loading conditions.

The performance of the developed methodology is demonstrated by a radial distribution system with 69 buses, 7 laterals and 5 tie-lines (looping branches). The study results how that the optimal on/off patterns of the switches can be identified which give the minimum power loss while satisfying all the constraints.

CONCLUSION-A Tabu search-based optimization technique has presented in this paper to find the most appropriate topology of the distribution system under unbalanced loading conditions. With the presence of unbalanced distribution systems, three phase power flow analysis is required. The objective function of feeder reconfiguration is to minimize the total system active power loss.

The objective function is subjected to the threephase power flow equations, bus voltage limits, current transfer capability of feeders, radial configuration format, and no loadpoint interruption. A 69-bus distribution system is used to demonstrate the effectiveness of the proposed technique.

The study results with different unbalanced loading conditions show that the optimal on/off patterns of sectionalzing switches and tie switches can be identified to give the minimum power loss, introducing significant savings on the annual cost of energy loss in the system.

TO VIEW COMPLETE ARTICLE

Comments

PARTS OF A POWER TRANSFORMER

What are the name of the basic parts of a Power Transformer? We can not deny the fact that only a handful of electrical engineering students are presently familiar with power transformers especially on what it looks like. Unlike a transformer we found in our homes, a power transformer’s appearance and construction is somewhat more complicated. It is not just a simple winding with a primary and secondary terminal although basically any transformer has one. The function that a power transformer plays in an electrical system is very important that an electric utility can not afford to loss it during its operation. Our discussion here will focus more on the basic parts and functions of a power transformer that are usually tangible whenever you go to a substation . Although not all power transformers are identical, nonetheless they all have the following listed parts in which the way of construction may differ.

click here to continue

ELECTRIC MOTOR FRAME SIZE STANDARD SPECIFICATIONS

ELECTRIC MOTOR FRAME SIZE STANDARD SPECIFICATIONS How is electric motor frame size being specified? Motor frame dimensions have been standardized with a uniform frame size numbering system. This system was developed by NEMA and specific frame sizes have been assigned to standard motor ratings based on enclosure, horsepower and speed. The current standardized frames for integral horsepower induction motors ranges from 143T to 445T. These standards cover most motors in the range of one through two hundred horsepower. Typical example of where you can locate the frame is shown in Fig 1.2.D – Frame No. The numbers used to designate frame sizes have specific meanings based on the physical size of the motor. Some digits are related to the motor shaft height and the remaining digit or digits relate to the length of the motor. The rerate, or frame size reduction programs were brought about by advancements in motor technology relating mainly to higher temperature ratings of insulating mate...

click here to continue

ELECTRIC MOTOR NAMEPLATE SPECIFICATIONS

How do we interpret an electric motor nameplate? Motor standards are established on a country by country basis.Fortunately though, the standards can be grouped into two major categories: NEMA and IEC (and its derivatives). In North America, the National Electric Manufacturers Association (NEMA) sets motor standards, including what should go on the nameplate (NEMA Standard MG 1-10.40 "Nameplate Marking for Medium Single-Phase and Polyphase Induction Motors").

click here to continue

power systems loss

Search This Blog