• Proceedings of the KIEE Conference
• /
• 2006.07a
• /
• pp.329-330
• /
• 2006

The purpose of this paper is to compensate the voltage drop of the power system in the AC Electric Railway Systems. Reactive power compensation is often the most effective way to improve system voltage drop. The suitable modeling of the electric railway system should be applied to the EMTP. the dynamic characteristics of 3-Phase Induction Motor in Electric Railway Systems is considered for precise modeling. it is shown through EMTP simulation using EMTP MODELS that voltage drop can be compensated effectively by STATCOM.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.52 no.1
• /
• pp.17-28
• /
• 2003

Digital technology has advanced very significantly over the years both in terms of software tools and hardware available. It is now applied extensively in many area of electrical engineering including protective relaying in power systems. Digital relays based on digital technology have many advantages over the traditional analog relays. The digital relay is able to do what is difficult or impossible in the analog relays. However, the complex algorithms associated with the digital relays are difficult to test and verify in real time on real power systems. Although non real-time simulators like PSCAD/EMTDC are employed to test the algorithms, such simulations have the disadvantage that they cannot test the relay dynamically. Hence, real-time simulators like RTDS are used, but the latter needs large space and it is very expensive. This paper uses EMTP MODELS to simulate the power system and the distance relay. The distance relay algorithm is constructed and the distance relay is interfaced with a test power system. The distance relays performance is then assessed interactively under various fault types, fault distances and fault inception angles. The test results show that we can simulate the distance relay effectively and we can examine the operation of the distance relay very closely including debugging by using EMTP MODELS.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.61 no.8
• /
• pp.1077-1082
• /
• 2012

This paper analyzes the lightning-induced overvoltage and current in buried underground distribution cable. Based on analytical expressions, the lightning-induced overvoltage and current in buried underground distribution cable is calculated by EMTP/MODELS. The modeling is verified by comparing with the results in reference. Also, the type and buried arrangement of cables used in domestic distribution line are modeled by EMTP/ATPDraw. The various simulations according to the type and buried arrangement of cable are performed and the simulation results are analyzed.

• KIEE International Transactions on Power Engineering
• /
• v.4A no.1
• /
• pp.26-32
• /
• 2004

Digital technology has advanced significantly over the years both in terms of software tools and hardware availability. It is now applied extensively throughout many area of electrical engineering including protective relaying in power systems. Digital relays have numerous advantages over traditional analog relays, such as the ability to accomplish what is difficult or impossible using analog relays. Although non real-time simulators like PSCAD/EMTDC are employed to test the algorithms, such simulations are disadvantaged in that they cannot test the relay dynamically. Hence, real-time simulators like RTDS are used. However, the latter requires large space and is very expensive. This paper uses EMTP MODELS to simulate the power system and the distance relay. The distance relay algorithm is implemented and the distance relay is interfaced with a test power system. The distance relay's performance is then assessed interactively under various fault types, fault distances and fault inception angles. The test results show that we can simulate the distance relay effectively and we can examine the operation of the distance relay very closely including its drawbacks/limitations by using EMTP MODELS. Equally important, this approach facilitates any changes that need to be carried out in order to enhance the Distance Relay under test/examination.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.12
• /
• pp.2072-2077
• /
• 2007

The primary objective of all power systems is to maintain the reliability and to minimize outage time for fault or the others. The frequency relaying algorithm perceives a variation of system frequency and thereafter detects the unbalance between generation and load. A multi-agent system is composed of multiple interacting computing elements that are known as agents. In this paper, frequency relaying algorithm is designed by multi-agent system and is implemented by EMTP-MODELS. To verify performance of the frequency relaying algorithm based on multi-agent system, simulations by EMTP have been carried out.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.4
• /
• pp.537-542
• /
• 2008

The protection against transient instability and consequent out-of-step condition is a major concern for the utility industry. Unstable system may cause serious damage to system elements such as generators and transmission lines. Therefore, out-of-step detection is essential to operate a system safely. Also, a multi-agent system is one that consists of a number of agents, which interact with one another. Multi-agent systems(MAS) can offer the flexibility and the adaptability to the previous algorithm. In this paper, the detection algorithm of out-of-step is designed by multi-agent system and implemented by EMTP-MODELS. To verify performance of the proposed algorithm based on multi-agent system, simulations by EMTP have been carried out.

• Proceedings of the KIEE Conference
• /
• 2005.07a
• /
• pp.175-177
• /
• 2005

This paper analyzes transient behavior due to switching overvoltage in 22.9kV combined distribution systems. Computer models are consisted of distribution overhead line model, underground cable model and surge-arrester model in this paper. The computer models are made by EMTP/ATPDraw simulation and Line constants are calculated by ATP_LCC. This paper analyzes the various parameters affecting. These factors include closing angle and cable length.

• Proceedings of the KIEE Conference
• /
• 1995.07b
• /
• pp.634-636
• /
• 1995

This paper presents a new distance relay modeling techniques which avoids unnecessary computational procedure. A general-purpose simulation language, called MODELS, has been added to the software ATP(Alternative Transients Program) providing a new option to perform numerical and logical manipulations of variables of an electrical system. This language has been designed to replace the previous option TACS (Transient Analysis of Control Systems) which permits to simulate a control system in conjunction with a large power network. One purpose of this study is to build a structure for modeling of digital distance relays within EMTP MODELS. Contrary to the traditional methods, the new method using MODELS reduce the number of simulation steps in modeling the distance relay.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.1
• /
• pp.8-13
• /
• 2008

This paper presents auto-reclosing algorithms with reference to power system stability based on MAS(Multi-Agent System). And this paper shows auto-reclosing algorithms considering power system stability. It includes the variable dead time, optimal reclosing, sequential reclosing, emergency extended equal-area criterion(EEEAC) algorithm, and modified EEEAC algorithm. This paper divides Auto-reclosing algorithms into respectively agents according to their tasks. A separated agent is merely a software entity that is situated in some environment and is able to autonomously react to changes in the environment. And all the simulations in this parer were tested by EMTP MODELS.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.52 no.6
• /
• pp.295-300
• /
• 2003

Voltage instability has been studied for some decade now. But, There is not generally accepted definition of voltage instability because of the complex phenomenon and the variety of ways in which it can manifest itself. Both IEEE and CIGRE have the respective definitions. The areas of voltage instability research are the analysis, simulation and countermeasure of voltage instability. It needs to model the components of the power system to simulate the voltage instability and voltage collapse. At the beginning, the static simulation was used. This method provides the voltage stability indices and it requires less CPU resource and gives much insight into the voltage and power problem. However, it is less accurate than the dynamic simulation peformed in the time domain simulation. So, when it appears difficult to secure the voltage stability margin in a static stability, it is necessary to perform the dynamic simulation. To perform time-domain simulation, we have to model the dynamic component of the power system like a generator and a load. The dynamic simulation provides the accurate result of the voltage instability. But, it is not able to provide the sensitivity information or the degree of stability and it is time consuming and it needs much CPU resource. In this Paper, we perform a dynamic simulation of voltage instability and voltage collapse using EMTP MODELS. The exponential load model is designed with MODEIS and this load model is connected with test power system. The result shows the process of voltage change in time domain when the voltage instability or voltage collapse occurs.