• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.2
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• pp.256-263
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• 2009

For the power system to keep in a stable operating state, sufficient ancillary services must be available to respond to credible contingency events and return the power system to a satisfactory operating state in the case of contingencies as well as blackout events within specified predefined limits. The logical and reasonable bases of valuing and pricing the ancillary services are required to reach the common ground among market participants. The total amount of black start service transactions is quite small compared to the total ancillary service transactions as well as energy market transactions. Black start services must be provided as one of the ancillary services in the deregulated electricity market. In order to procure and remunerate black start services, it is necessary to quantify the value of the black start sources within the power system. In this paper, an approach to assess the value of the black start service is presented based on the cost-of-service solution. Financial simulation of the influence on market participants for the proposed approach on the service is carried out. The cost of the black start service is allocated in accordance with the principle of "causer pays", and the cost is shared by the producers and consumers equally that created the requirement for the service. Under the present electricity market, the mechanism to recover the cost is not implemented, a new approach to the ancillary services to provide incentive for the service providers has to be studied in the near future.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.176-178
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• 2001

This paper presents the application draft of ancillary services for Korean Wholesale Electricity Market. This application draft of ancillary services is based on technical rules for ancillary services agreements prepared by KEMA and the present conditions of KEPCO system operations and future directions.

• Proceedings of the KIEE Conference
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• summer
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• pp.663-665
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• 2004

There are some demand response program which is Direct Load Control and so on in Korea. These are used to manage lack of power stability or shift peak time for shading load. It is very important not only using stability power system but controling and scheduling power system on the whole. Interruptible loads are essential resources to solve lack of energy and limit of constructing generator On recently days, Demand Response Program's reliability is recognized as ancillary or reserve service in many country. This paper presents a necessity to apply demand resource to our ancillary program. For this reason, it is introduce overseas ancillary program using load resource.

• Environmental and Resource Economics Review
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• v.33 no.2
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• pp.113-133
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• 2024

Variable renewable energy (VRE) such as solar and wind power is the main sources of achieving carbon net zero, but it undermines the stability of power supply due to high variability and uncertainty. Energy storage system (ESS) can not only reduce the curtailment of VRE by load shifting but also contribute to stable power system operation by providing ancillary services. This study analyzes how the allocation of ESS resources between load shifting and ancillary service can contribute to maximizing the efficiency of power supply in a situation where the problems caused by VRE are becoming more and more serious. A stochastic power system optimization model that can realistically simulate the variability and uncertainty of VRE was applied. The analysis time point was set to 2023 and 2036, and the optimal resource allocation strategy and benefits of ESS by varying VRE penetration levels were analyzed. The analysis results can be largely summarized into the following three. First, ESS provides excellent functions for both load shifting and ancillary service, and it was confirmed that the higher the reserve price, the more limited the load shifting and focused on providing reserve. Second, the curtailment of VRE can be a effective substitute for the required reserve, and the higher the reserve price level, the higher the curtailment of VRE and the lower the required amount of reserve. Third, if a reasonable reserve offer price reflecting the opportunity cost is applied, ESS can secure economic feasibility in the near future, and the higher the proportion of VRE, the greater the economic feasibility of ESS. This study suggests that cost-effective low-carbon transition in the power system is possible when the price signal is correctly designed so that power supply resources can be efficiently utilized.

• Journal of Electrical Engineering and Technology
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• v.4 no.3
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• pp.337-345
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• 2009

Deregulation in power industry has made the reactive power ancillary service management a critical task to power system operators from both technical and economic perspectives. Reactive power management in power systems is a complex combinatorial optimization problem involving nonlinear functions with multiple local minima and nonlinear constraints. This paper proposes a practical market-based reactive power ancillary service management scheme to tackle the challenge. In this paper a new model for voltage security and reactive power management is presented. The proposed model minimizes reactive support cost as an economic aspect and insures the voltage security as a technical constraint. For modeling validation study, two optimization algorithm, a genetic algorithm (GA) and particle swarm optimization (PSO) method are used to solve the problem of optimum allocation of reactive power in power systems under open market environment and the results are compared. As a case study, the IEEE-30 bus power system is used. Results show that the algorithm is well competent for optimal allocation of reactive power under practical constraints and price based conditions.

• Journal of Electrical Engineering and Technology
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• v.11 no.6
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• pp.1535-1547
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• 2016

This paper proposes various design procedures for computing Power System Ancillary Service Requirement Assessment Indices (PSASRAI) for a Two-Area Thermal Reheat Interconnected Power System (TATRIPS) in a restructured environment. In an interconnected power system, a sudden load perturbation in any area causes the deviation of frequencies of all the areas and also in the tie-line powers. This has to be corrected to ensure the generation and distribution of electric power companies to ensure good quality. A simple Proportional and Integral (PI) controllers have wide usages in controlling the Load Frequency Control (LFC) problems. So the design of the PI controller gains for the restructured power system are obtained using Bacterial Foraging Optimization (BFO) algorithm. From the simulation results, the PSASRAI are calculated based on the settling time and peak over shoot concept of control input deviations of each area for different possible transactions. These Indices are useful for system operator to prepare the power system restoration plans. Moreover, the LFC loop coordinated with Redox Flow Batteries (RFB) has greatly improved the dynamic response and it reduces the control input requirements and to ensure improved PSASRAI, thereby improving the system reliability.

• Journal of Satellite, Information and Communications
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• v.2 no.1
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• pp.27-34
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• 2007

A mobile satellite broadcasting service including an ancillary terrestrial component (ATC) takes advantage of the satellite's inherent capability to provide broadcast service over global coverage. We consider the downlink transmission concept using ATC with space=time code (STC) for the mobile satellite communication. We do not regard ATC as simply a repeater but consider it as an antenna for STC. First transmission scenarios for an application of STC are represented. Next, we apply STC in the mobile satellite system including ATC and compare the system performance in the proposed architecture of ATC to that in the conventional structure. The simulation results are compared to the conventional downlink transmission concept for the mobile satellite broadcasting service.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.5
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• pp.202-213
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• 2006

This paper presents a new approach for optimal dispatch of energy and frequency regulation reserve considering contingency in a competitive electricity market. It is necessary to introduce the reserve market with the spot energy market for operating efficiently and obtaining the security of the electricity market. However, the reserve market is closely connected with the energy market since the energy and reserve are produced from the same resources. Thus, it is inevitable to co-optimize the energy and ancillary service for efficient operation of energy and ancillary service market. Therefore, this paper proposes a new method for optimal dispatch of energy and frequency regulation reserve considering n-1 contingency of generator and transmission line using constraints and sensitivity based on AC power flow To verify the effectiveness of the proposed method, the numerical studies have been performed for 5-bus sample system and modified IEEE 14-bus system.

• Proceedings of the KIEE Conference
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• 2001.05a
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• pp.187-189
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• 2001

전력산업 구조개편에 따라 개설된 우리나라의 발전경쟁 시장에서 전력계통안정 및 전기품질 확보를 위하여 적용되는 계통운영서비스의 종류와 확보기준 및 운영방법을 소개하고 향후 전력시장의 발전에 따라 적용예정인 계통운영서비스에 대한 운영방향을 검토하였다.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.1
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• pp.13-18
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• 2000

The paper proposes a simple method to calculate the portion of real power losses of transmission lines allocated to individual loads. The method is implemented by defining loss distribution factors, and analyses the loads shares in the transmission line losses. The paper also performs calculation of sensitivities of the line losses with respect to load changes so as to be easily employed in on-line applications. Effectiveness of the algorithm is verified by computer simulations and it is estimated that the results can be used to compute the cost of one ancillary service under deregulated environment in electric power industries.