Classification method of operating states in Cost Based Pool (CBP) market in Korea

The operation of electric power network at any given time can be classified into one of the following states: normal, warning, alert, emergency and restoration, through reliability assessment. Typically, the classification into these states based on present method is useful for providing qualitative description of how reliably the network is being operated but lacks the quantitative valuation. In this paper we propose a new method for classifying operating states appropriate in Cost Based Pool (CBP) market in Korea. By taking the cost of control actions with respect to various plausible contingencies into consideration, the proposed method properly values the trade-off between technical reliability and economic efficiency. In applying the method the operational limits, such as maximum transfer capabilities and maximum voltages, are established at the planning stage. Established limits are then used to assess the reliability, and the control actions are applied by the system operator as needed at the operation stage. Several flowcharts are presented for showing how the proposed method is applied, and a case study is given for illustration purposes. It is shown that the proposed method properly incorporates the rational decision process by the system operator in detecting and responding to threats to system stability. In addition, it is shown that the classification by the proposed method is particularly useful for compensating network users participating in network control in the market environment.