• 대한전기학회논문지:전력기술부문A
• /
• 제51권1호
• /
• pp.37-44
• /
• 2002

This Paper suggests reasonable pricing mathod fur Reactive Power in Optimal Power Flow for the system analysis. Under restructuring, not only real power pricing but also reactive power pricing is important for the system analysis and operation. If people just focus on real power pricing, the Generators may no generate reactive power voluntarily, because the Generators may not recover the cost of the reactive power generation. So making a reasonable reactive power pricing is becoming more important than any other time. In this paper, the authors set a Proper Power factor and price the portion of the reactive power that exceeds the power factor using Interior Point Method. By applying this method, the System operator can use this strategy for the analysis of reactive power generation pricing and the Generator can get the motivation to generate reactive power. The author develops fully optimized fast Primal Dual Interior Point Method with sparsity technique and applies this method to Reliability Test System (RTS24) and KEPCO 674 bus system (684 buses. 1279 lines). It shows adaptability and usefulness.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 춘계학술대회 논문집 전력기술부문
• /
• pp.58-61
• /
• 2001

Under restructuring, not only real power pricing but also reactive power pricing is important for the system operation Especially, making a reasonable reactive power pricing is becoming more important than any other time. In this paper, the authors set a proper power factor and price the portion of the reactive power generation that exceeds the power factor. To apply this method to an optimization problem, we developed optimal power flow based on interior point method. By using this IPM for the power system, the System operator can use this strategy for reactive power generation pricing and also the Generators can got the motivation to generate reactive power.

• KIEE International Transactions on Power Engineering
• /
• 제5A권3호
• /
• pp.228-234
• /
• 2005

This paper presents the evaluation of reactive power pricing through the control of generator voltages under the assumption that the reactive power market has been transformed into the real power market. By applying the concept of economic dispatch, which minimizes the total cost of real power generation to reactive power generation, the algorithm for implementing reactive power pricing is proposed to determine the optimum voltage profiles of generators. It consists of reactive power voltage equation, the objective function that minimizes the total cost of reactive power generation, and linear analysis of inequality constraints in relation to the load voltages. From this algorithm, the total cost of the reactive power generation can be yielded to the minimum value within network constraints as the range of load voltages. This may provide the fair and reasonable price information for reactive power generation in the deregulated electricity market. The proposed algorithm has been tested on the IEEE 14-bus system using MATLAB.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 하계학술대회 논문집 A
• /
• pp.533-535
• /
• 2001

This paper proposes a methodology to compute the servicing price of reactive power in electrical power market of competitive environment. The result of proposed method is proved by a 6-bus sample test system. In this paper we propose the real-time pricing method assigning to variable charges, the downstream power flow tracing assigning to fixed charges. The reactive power will be active by the proposed method through competitive electrical power market.

• 전기학회논문지
• /
• 제64권8호
• /
• pp.1145-1153
• /
• 2015

The paper analyzes reactive power flow characteristic in power system by reactive power tracing. In addition, virtual buses are inserted in the algorithm to consider losses of transmission lines, and shunt capacitor treated as a reactive power generator. The results of simulation are analyzed by two points of view. The one is load’s point of view and another is generator’s point of view. Classic purpose of the reactive power tracing consists in the reactive power pricing. However, it is significantly used to select vulnerable area about line outage in this paper. To find the vulnerable area, reactive power tracing variations between pre-contingency and post-contingency are calculated at all load buses. In heavily load area, buses which has highest variation become the most vulnerable bus. This method is applied to the IEEE 39-bus system. It is compared with voltage variation result and VQ-margin to verify its effect.

• 대한전기학회논문지:전력기술부문A
• /
• 제52권7호
• /
• pp.429-436
• /
• 2003

This paper presents a new approach for evaluating the transmission marginal loss factors (MLFs) considering the reactive power. Generally, MLFs are represented as the sensitivity of transmission losses, which is computed from the change of the generation at reference bus by the change of the load at the arbitrary bus-i. The conventional evaluation method for MLFs uses the only H matrix, which is a part of jacobian matrix. Therefore, the MLFs computed by the existing method, don't consider the effect of the reactive power, although the transmission losses are a function of the reactive power as well as the active power. To compensate the limits of the existing method for evaluating MLFs, the power factor at the bus-i is introduced for reflecting the effect of the reactive power in the evaluation method of the MLFs. Also, MLFs calculated by the developed method are applied to energy spot markets to reflect the impacts of reactive power. This method is tested with the sample system with 5-bus, and analyzed how much MLFs have an effect on the bidding/offer price, market clearing price(MCP), and settlement in the competitive energy spot market. This paper compared the results of MLFs calculated by the existing and proposed method for the IEEE 14-bus system, and the KEPCO system.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 하계학술대회 논문집 A
• /
• pp.692-694
• /
• 2004

As the electric power industry has gone for a deregulated environment from a vertically integrated structure, operations and controls of systems invite new challenges. In the past certain activities, such as voltage and frequency control, were considered as a part of integrated power supply. But now, these become parts of ancillary services which are independent and detailed, and have situations non-disregardable for operation of systems. This paper examines a management of reactive power services adopted in deregulated foreign and domestic markets.

• Asia Marketing Journal
• /
• 제14권1호
• /
• pp.83-98
• /
• 2012

신차와 중고차가 함께 경쟁하는 시장에서 신차의 경쟁만을 모형화한다면 가격이나 기타 프로모션 탄력성의 추정이 왜곡될 수 있다. 그러나 자동차 시장을 연구대상으로 한 선행연구의 대부분이 신차 시장의 경쟁에만 관심을 기울였던 바, 합리적인 가격결정이나 프로모션 기획에 도움을 주기에 미흡한 점이 있었다. 본 연구는 신차의 가격결정 및 프로모션 기획이 향후 중고차 시장을 통해 리바운드되어 신차 매출에 다시 영향을 미친다는 점을 반영하여 모형을 설정하였다. 즉, 서로 다른 신차간의 (혹은 서로 다른 중고차간의) 교차탄력성보다, 동일 모델의 신차와 중고차간의 교차탄력성이 높다는 가정하에 모형을 설정하였다. 방법론적으로는 네스티드 로짓(Nested Logit) 모형을 설정하여 소비자의 자동차 선택은 단계적으로 이루어진다고 가정하였다. 즉, 1단계에서 자동차 모델을 선택하고, 모델이 정해지면 2단계에서 신차와 중고차 중 선택하는 구조를 가정하였다 실증분석은 미국 전역에서 2009년 1월부터 2009년 6월까지 판매된 모든 컴팩트 카 모델 중에서 시장점유율 상위 9개 모델의 신차와 중고차를 대상으로 하였다. 실증분석을 통하여 비교 대상 모형보다 제안된 모형이 모형 적합도 측면에서 우월하고 예측타당성도 높다는 것을 보여주었다. 제안된 모형으로 부터 추정된 모수를 사용하여 몇 가지 시나리오를 상정하여 시뮬레이션을 실시한 결과, 신차(중고차)가 점유율을 높이고자 리베이트를 실시할 경우 중고차(신차)는 현재의 시장점유율을 유지하기 위해 대응 가격할인을 실시하게 되는데 할인 폭은 반대의 경우에 비해 높다는(낮다는)점을 확인하였다. 또한 시뮬레이션 결과가 시사하는 바는 신차와 중고차가 함께 경쟁하는 시장에서 IIA(Independence of Irrelevant Alternatives)모형을 적용할 경우 동일모델의 신차와 중고차간의 교차 탄력성을 과소평가하게 되어 현상유지를 위한 가격할인을 실시할 경우 적정한 수준이하로 하게 된다는 것이다.