Sang-Yule Choi

Artificial intelligent application to service restoration considering load balancing in distribution networks

Service restoration is an emergency control in distribution constrol centers to restore out-of-service area as soon as possible when a fault occurs in distribution networks. therefore, it requires fast computation time and high quality solutions for load balancing. In this paper. a load balance index and heuristic guided best-first search are proposed for these problem. The proposed algorithm consists of two parts. One is to set up a decision tree to represent the various switching operations available. Another is to identify the most effective the set of switches using proposed search technique and a feeder load balance index. Test results on the KEPCOs 108bus distribution system show that the performance is efficient and robust.

Loss reduction in distribution networks using cyclic best first search

Network reconfiguration in distribution systems is realized by changing the status of sectionalizing switches, and is usually done for loss reduction or load balancing in the system. This paper presents an effective heuristic based switching scheme to solve the distribution feeder loss reduction problem. The proposed algorithm consists of two parts. One is to set up a decision tree to represent the various switching operations available. Another is to apply a proposed technique called cyclic best first search. The proposed algorithm identifies the most effective the set of switch status configuration of distribution system for loss reduction. To demonstrate the validity of the proposed algorithm, numerical calculations are carried out the 32 bus system models.

Optimal Configuration of Distribution System considering the Economic Operations of a Microgrid

With the diversification of distribution facilities, existing distributed generation can be subdivided into Microgrids, which are smaller units for application. These Microgrids, subdivided as such and connected to distribution systems, should operate under driving plans that will ensure their economic efficiency and, accordingly, the configuration of those distribution systems that include Microgrids should also be changed. The perception of the necessity to secure the economic efficiency of distribution systems is gradually increasing and studies intended to assess the economic efficiency of Microgrids and Smartgrids are ongoing. In this paper, the power generation capacity of an economically operative Microgrid was calculated using the MonteCarlo simulation, which is a method based on the probability theory considering the power generation cost of Microgrids linked with power supply systems and reverse sales costs, etc., and an optimum distribution systems was configured based on the results of these calculation.

A Study of Optimizing Cathodic Protection in Comparison of Design Methodologies

The principal factor determining an optimum design method for cathodic protection is finding the protection current for preventing the corrosion of existing, already laid pipe. Some factors currently used to test designs include the sizes and lengths of pipes, soil resistivity, and the coating damage rate. We believe this method and current formulae are not optimum due to the uncertainty of determining the coating damage rate and the corrosion protection currents density. This paper analyzes the amount of protection current obtained by performing a temporary current test using data describing existing laid pipe. We then propose determining the corrosion protection current by using the temporary current test after modifying the formula. In addition, we suggest a way to choose optimized cathodic protection and the process of design by executing the design and taking account of such factors as a site condition of 34km-long non-protected water supply pipe lines (stages Ⅰ and Ⅱ) in ○○ region, climate. interferences, and durability.

The Time Variant Power Signal Processing of Wind Generator using Buneman Frequency Estimator Algorithm

On wind turbine generators, the speed and volume of the wind affect the turbine angle speed which finally determines the output level of the electric power. However it is very difficult to forecast correctly the future power output and quality based on previous fixed sampling methods. This paper proposes a variable sampling method based on Buneman frequency estimation algorithm to reflect the variations of the frequency and amplitude on wind power outputs. The proposed method is also verified through the performance test by comparing with the results from previous fixed sampling methods and the real measurement data.

A study of mitigated interference Chaotic-OOK system in IEEE802.15.4a

Recently, IEEE 802.15.4a(low-rate UWB) technique has been paid much attention to the LR-UWB communication system for WPAN. However, there are various interferences such as MPI(Multi Path Interference) or IPI(Inter Piconet Interference) in IEEE 802.15.4a wireless channel. In order to cancel various interferences occurred to WPAN environment, in this paper, we propose a UWB wireless communication system with high QoS(Quality of Service) which is a chaotic-OOK(On-Off Keying) system using unipolar ZCD(Zero Correlation Duration) spreading code in physical layer level. Furthermore, we analyze its performance via simulations and verify the availability of proposed system with prototype implementation.

SERVICE RESTORATION CONSIDERING LOAD BALANCING IN DISTRIBUTION

Abstract Service restoration is an emergency control in distribution control centers to restore out-of-service area as soon as possible when a fault occurs in distribution networks. therefore, it requires fast computation time and high quality solutions for load balancing. In this paper. a load balance index and heuristic guided best-first search are proposed for these problem. The proposed algorithm consists of two parts. One is to set up a decision tree to represent the various switching operations available. Another is to identify the most effective the set of switches using proposed search technique and a feeder load balance index. Test results on the KEPCOs 108 bus distribution system show that the performance is efficient and robust.

Distribution data security system based on web based active database

The electric utility has the responsibility to provide a good quality of electricity to their customers. Therefore, they have introduced DDSS(Distribution Data Security System) to automate the power distribution data security. DDSS engineers need a set of state-of-the-art applications, eg. managing distribution system in active manner and gaining economic benefits from a flexible DDSS architectural design. The existing DDSS functionally could not handle these needs. It has to be managed by operators whenever feeder faults data are detected. Therefore, it may be possible for propagating the feeder overloading area, if operator makes a mistake. And it utilizes closed architecture, therefore it is hard to meet the system migration and future enhancement requirements. This paper represents web based, platform-independent, flexible DDSS architectural design and active database application. The recently advanced internet technologies are fully utilized in the new DDSS architecture. Therefore, it can meet the system migration and future enhancement requirements. And, by using active database, DDSS can minimize feeder overloadings area in distribution system without intervening of operator, therefore, minimizing feeder overloadings area can be free from the mistake of operator.

Interference-Free ZCD-UWB for wireless home network applications

Interference-free ZCD-UWB for Wireless Home Network Applications(WHNA) are presented in this paper. Interference-free ZCD-UWB could be a very useful solution for an enhanced wireless home network applications having interference-cancellation property without employing complicated multi user detection (MUD) or other interference cancellation techniques.

Feeder Reconfiguration Using Cyclic Best-First Search

Abstract Network reconfiguration in distribution systems is realized by changing the status of sectionalizing switches, and is usually done for loss reduction or load balancing in the system. This paper presents an effective heuristic based switching scheme to solve the distribution feeder loss reduction problem. The proposed algorithm consists of two parts. One is to set up a decision tree to represent the various switching operations available. Another is to apply a proposed technique called cyclic best frrst search. The proposed algorithm identifies the most effective the set of switch status configuration of distribution system for loss reduction. To demonstrate the validity of the proposed algorithm, numerical calculations are carried out the 32, 69 bus system models.