Direct Transient Stability In The Online Dynamic Security Assessment Of Power System Applications

With the expansion of interconnected power systems, research and development of on-line dynamic security assessment system(DSA) is urgent to power system security operation. Based on the recent advance of DSA research and applications, the contingency screening and ranking method and the sensitivity analysis method of transient stability limit are studied in detail in this thesis. The main contents and contributions are as follows:(1) The theory and implementation of Potential Energy Boundary Surface(PEBS) method and Extended Equal Area Criterion(EEAC) method are introduced.(2) With the sparse vector method and a new fault solution method, the PEBS and EEAC methods of Power System Analysis Software Package(PSASP) are improved.(3) A contingency screening and ranking method, integrated PEBS and EEAC, is proposed.(4) A sensitivity analysis method based on PEBS and EEAC is proposed to determine the transient stability limit of tie lines.The proposed methods are illustrated on the New England 39-bus system and the realistic 121-generator 795-bus Northeast China Power System. The simulation results show that the calculating speed of PEBS and EEAC is greatly improved to meet the requirement of on-line DSA's contingency screening and ranking, and the integrated method of PEBS and EEAC is effective.