A novel dynamical reactive power reserve optimization approach for improving mid-long term voltage stability of large-scale AC-DC hybrid power systems

Practical and analytical analysis has demonstrated a strong link between dynamical reactive power reserve and power system stability. Proper evaluation and optimization on dynamical reactive power reserve will be of great significance to enhancing reactive support and maintaining system operation in secure and stable manner, especially for the receiving-end AC-DC hybrid systems. According to the different response characteristics of dynamical reactive resources, the concept of effective reserve and weighting factor for reactive resources in mid-long term scale is presented. Dynamical reactive power reserve for mid-long term voltage stability is defined as the weighted sum of effective reserve of reactive power resources. A dynamical reactive power reserve optimization model for improving mid-long term voltage stability of large-scale AC-DC hybrid power systems is formulated and a solving algorithm is proposed. Based on an analysis of the mid-long term voltage stability characteristics of a modified 3 generators and 10 nodes system, the effectiveness of the proposed dynamical reactive power reserve optimization approach for improving mid-long term voltage stability of AC-DC hybrid power systems is verified.