孙晗毕业设计英文翻译.doc

山东理工大学 毕业设计 （外文翻译材料） Low-order dynamic equivalent estimation of power systems using data of phasor measurement units Abstract This paper utilizes data measured by phasor measurement units (PMUs) to extract a low-order dynamic equivalent model for power system stability studies. The estimated model is a 2-order model for synchronous machines. This model has the advantage of simplicity of classical model and considerably reduces the oversimplifying error of classical model. This method offers an alternative approach to analytical model reduction techniques based on the detailed system models. The proposed method uses the synchronized bus voltage and current phasors measured by PMUs. Using post disturbance data, electrical and mechanical parameters of the equivalent generator are estimated sequentially. Furthermore, a new approach for estimation of two-machine and single machine infinite bus (SMIB) equivalent systems are presented for analysis of electromechanical oscillations. To evaluate the performance of the proposed approach, simulations are performed on a two area 13-bus test system and real measured PMU data. Simulation results show that the estimated model can represent the dynamic behavior of the studied system with good approximation. Keywords Phasor measurement unit;? Model estimation;? Power system model reduction;? Power system oscillations Introduction With the development of electrical industry, the scales of power systems have become larger than ever. Owing to the dimension of interconnected power systems, it is often impractical to represent the entire system model in detail. Therefore, reduced order dynamic equivalents are used to represent groups of generators or external systems?[1]. Many efforts are devoted to reduce power system model using analytical approach?[1],[2],?[3]?and?[4]. Analytical approaches based on the concept of coherency have the benefit of saving power system structure. However, these approaches need detailed parameters of all