Sequence operation theory (SOT) is a powerful tool for solving complex probabilistic problems in power system. However, the basic single dimension SOT cannot satisfy the requirement of multi-state; multi-attribute analysis, which is often the case in actual power system practice. To address this problem, multidimensional sequence operation theory (MSOT) is developed. On the basis of previous research, this paper first categorizes the situations by the number of state variables; the number of attribute values,; defines the multidimensional sequence for single state variable; multiple attribute values, as well as the multidimensional sequence for multiple state variables; multiple attribute values. Corresponding to those definitions, four types of operations between two discrete multidimensional sequences are derived respectively. Therefore, the sequence is extended from single dimensional to multidimensional, establishing an integrated theory of multidimensional sequence operation. In particular, the basic single dimension SOT can be viewed as a special case of MSOT with only one state variable; one attribute value. Finally, the paper demonstrates the effectiveness of MSOT through an example of risk evaluation in power system generation scheduling.
Understanding reliability value for electricity customer is important to market-based reliability management. This paper proposes a novel approach to evaluate the reliability for electricity customers by using indifference curve between economic compensation for power interruption and service reliability of electricity. Indifference curve is formed by calculating different planning schemes of network expansion for different reliability requirements of customers, which reveals the information about economic values for different reliability levels for electricity customers, so that the reliability based on market supply demand mechanism can be established and economic signals can be provided for reliability management and enhancement.