• KIEE International Transactions on Power Engineering
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• v.5A no.1
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• pp.31-39
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• 2005

This paper illustrates a tie line constrained equivalent assisting generator (TEAG) model considering forced outage rates of transmission systems for reliability evaluation of interconnected power systems. Interconnections between power systems can provide improved levels of reliability. It is expected that the TEAG model developed in this paper will prove useful in the solution to problems related to the effect of transmission system uncertainties in the reliability evaluation of interconnected power systems. It is important that interconnection between power systems can provide the improved levels of reliability. Therefore, It is expected that the TEAG model developed in this study will provide some solution among many problems for interconnected power systems as an optimal tie line capacity and a connected point between assisting systems and assisted system. The characteristics and validity of this developed TEAG considering transmission systems are introduced by case study of three IEEE MRTS interconnected.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.12
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• pp.1577-1586
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• 2018

The emergence of the Smart Grid is an integrated solution for the next generation power system that combines IT technology in the power system to create optimal energy utilization and various services. However, these convergence technologies (power systems and information communications) are not only improving the related technologies but also producing various problems especially exposure to cyber risk. In particular, the intelligent power grid has security vulnerabilities through real-time information sharing among various organically linked systems, and it is more complicated than the cyber risk problem in the existing IT field and is directly connected to national disaster accidents. Therefore, in order to construct and operate a more stable smart grid, this paper analyzes the system of power system control system in Korea, and proposes a cyber security element definition and a countermeasure establishment method of power monitoring & control systems based on security standards of smart grid (No. SPS-SGSF-121-1-1).

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.99-103
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• 2002

IEC 61800 is an international standard on adjustable speed electrical power drive systems, which consists of three parts. IEC 61800-1 and IEC 61800-2 apply to DC power drive systems and AC power drive systems, respectively, which include power conversion, control equipment, and also a motor or motors. IEC 61800-3 specifies EMC ( Electro Magnetic Compatibility ) requirements for adjustable speed AC or DC motor drives connected to main supplies up to AC 1,000 volts. This paper studies the standards related to EMC and the text summary of international standard IEC 61800-3 which is an EMC product standard including specific test methods.

• Journal of Electrical Engineering and Technology
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• v.8 no.6
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• pp.1276-1282
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• 2013

This paper proposes a stochastic modeling of plug-in electric vehicles (PEVs) distribution in power systems, and analyzes the corresponding clustering characteristic. It is essential for power utilities to estimate the PEV charging demand as the penetration level of PEV is expected to increase rapidly in the near future. Although the distribution of PEVs in power systems is the primary factor for estimating the PEV charging demand, the data currently available are statistics related to fuel-driven vehicles and to existing electric demands in power systems. In this paper, we calculate the number of households using electricity at individual ending buses of a power system based on the electric demands. Then, we estimate the number of PEVs per household using the probability density function of PEVs derived from the given statistics about fuel-driven vehicles. Finally, we present the clustering characteristic of the PEV distribution via case studies employing the test systems.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.64-68
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• 2001

This paper presents an innovative prototype of a new conceptual electromagnetic induction heated type far infrared rays radiant heating appliance using the voltage-fed edge-resonant ZVS-PWM high frequency inverter using IGBTs for food cooking and processing which operates under a constant frequency variable power regulation scheme. This power electronic appliance with soft switching high frequency inverter using IGBTs has attracted special interest from some advantageous viewpoints of safety, cleanliness, compactness and rapid temperature response, which is more suitable for consumer power electronics applications.

• Journal of Power Electronics
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• v.16 no.2
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• pp.805-814
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• 2016

Electric-field coupled power transfer (ECPT) systems have been proposed as an alternative wireless power transfer (WPT) technology in recent years. With the use of capacitive plates as a coupling structure, ECPT systems have many advantages such as design flexibility, reduced volume of the coupling structure and metal penetration ability. In addition, wireless communications are effective solutions to improve the safety and controllability of ECPT systems. This paper proposes a power and signal shared channel for electric-field coupled power transfer systems. The shared channel includes two similar electrical circuits with a band pass filter and a signal detection resistor in each. This is designed based on the traditional current-fed push-pull topology. An analysis of the mutual interference between the power and signal transmission, the channel power and signal attenuations, and the dynamic characteristic of the signal channel are conducted to determine the values for the electrical components of the proposed shared channel. Experimental results show that the designed channel can transfer over 100W of output power and data with a data rate from 300bps to 120 kbps.

• Journal of Power Electronics
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• v.9 no.2
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• pp.320-333
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• 2009

A Photovoltaic (PV) system's power output varies with the change of climate. Frequency deviations, tie line voltage swings are caused by the varying PV power when large PV power from several PV systems is fed in the utility. In this paper, to overcome these problems, a simple coordinated control method for smoothing the variations of combined PV power from multiple PV systems is proposed. Here, output power command is formed in two steps: central and local. Fuzzy control is used to produce the central smoothing output power command considering insolation, variance of insolation and absolute average of frequency deviation. In local step, a simple coordination is kept between the central power command and the local power commands by producing a common tuning factor. Power converters are used to achieve the same output power as local command power employing PI control law for each of the PV generation systems. The proposed method is compared with the method where conventional Maximum Power Point Tracking (MPPT) control is used for each of the PV systems. Simulation results show that the proposed method is effective for smoothing the output power variations and feasible to reduce the frequency deviations of the power utility.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.3
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• pp.384-392
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• 2015

This paper presents an economic assessment of large-scale Li-ion battery energy storage systems applied to Korean power system. There are many applications of the battery energy storage systems (BESSs) and they can provide various benefits to power systems. We consider BESSs to the energy time-shift application to Korean power system and evaluate the benefits from the application of BESS in the social perspective. The mixed integer programming (MIP) algorithm is used to resolve the optimal operation schedule of the BESS. The social benefits can include the savings of the fuel cost from generating units, deferral effects of the generation capacity, delay of transmission and distribution infra construction, and incremental CO2 emission cost impacts, etc. The economic evaluation of the BESS is separately applied into Korean power systems of the Main-land and Jeju island to reflect the differences of the load and generation patterns.

• International Journal of Computer Science & Network Security
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• v.24 no.1
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• pp.31-44
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• 2024

People have been using more energy in the last years. Several research studies were conducted to develop sustainable energy sources that can produce clean energy to fulfill our energy requirements. Using renewable energy sources helps to decrease the harm to the environment caused by conventional power plants. Choosing the right location and capacity for DG-RESs can greatly impact the performance of Radial Distribution Systems. It is beneficial to have a good and stable electrical power supply with low energy waste and high effectiveness because it improves the performance and reliability of the system. This research investigates the ideal location and size for solar and wind power systems, which are popular methods for producing clean electricity. A new artificial intelligent algorithm called Nutcracker Optimization Algorithm (NOA) is used to find the best solution in two common electrical systems named IEEE 33 and 69 bus systems to examine the improvement in the efficiency & reliability of power system network by reducing power losses, making voltage deviation smaller, and improving voltage stability. Finally, the NOA method is compared with another method called PSO and developed Hybrid Algorithm (NOA+PSO) to validate the proposed algorithm effectiveness and enhancement of both efficiency and reliability aspects.

• Journal of Power Electronics
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• v.11 no.4
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• pp.471-478
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• 2011

This paper addresses the establishment of a kVA-range plug-in hybrid electrical vehicle (PHEV) integration test platform and associated issues. Advancements in battery and power electronic technology, hybrid vehicles are becoming increasingly dependent on the electrical energy provided by the batteries. Minimal or no support by the internal combustion engine may result in the vehicle being occasionally unable to recharge the batteries during highly dynamic driving that occurs in urban areas. The inability to sustain its own energy source creates a situation where the vehicle must connect to the electrical grid in order to recharge its batteries. The effects of a large penetration of electric vehicles connected into the grid are still relatively unknown. This paper presents a novel methodology that will be utilized to study the effects of PHEV charging at the sub-transmission level. The proposed test platform utilizes the power hardware-in-the-loop (PHIL) concept in conjunction with high-fidelity PHEV energy system simulation models. The battery, in particular, is simulated utilizing a real-time digital simulator ($RTDS^{TM}$) which generates appropriate control commands to a power electronics-based voltage amplifier that interfaces via a LC-LC-type filter to a power grid. In addition, the PHEV impact is evaluated via another power electronic converter controlled through $dSPACE^{TM}$, a rapid control systems prototyping software.