Search

This paper proposes a transient stability constrained optimal power flow model of VSC-MTDC transmission system. Using the concept of transient stability margin based on phase-plane trajectory concavity-convexity, the transient stability constraints are converted to generator active power constraints. Combined with the traditional optimal power flow model and constraints of VSC-MTDC system, the transient stability constrained optimal power flow model can be established. The optimization procedure is also given. According to the desired value of transient stability margin, the optimal generator active power output can be determined. The simulation results in the modified New England 39-bus system validate the effectiveness of the proposed method.

Considering the demand of installing energy storage system by industrial users to reduce the basic electricity cost and increase the income of electricity sale, this paper proposes a detailed charging and discharging strategies calculation method to obtain the annual income. Based on the annual load historical data of industrial users, the charging and discharging modes and detailed strategies are determined according to the load characteristic and the electricity price period. Considering the influence of large and dense load on the peak load after peak shifting by storage system, a method of new peak load correction based on dichotomy iteration and backtracking mechanism is proposed. The case verification show that the monthly income is significantly affected by the industrial load characteristics. This method provides accurate income analysis for industrial users to ensure validity and economy of storage system investment.