Power System Load Model And Parameter Emendation Based On The Wide Area Measurement System

It is well known that load plays a very important role in the power system stability analysis. In the past decades many efforts have been made in power system load modeling and lots of achievements have been obtained. Power loads have been classified into various categories, such as residential load, commercial load, industrial load etc. However, deep research is still needed in the following aspects, modeling veracity and reliability, stability of the model parameters and aggregate load area modeling.This thesis aims to solve this problem by introducing the wide area measurement system (WAMS) into power system load modeling. WAMS with the help of the GPS can easily realize the synchronous sampling of the steady state information as well as the transient behavior for the wide spread power system. This provides the possibility to build an appropriate model for power system with high precision and to effectively verify the correctness of the existed power system models. It also provides a new way to solve the loading area modeling problem.The basic problems for load modeling lie in the selection of the structure for the load model, the algorithm for the identification and the stability of the parameter identified. The exponential recovering load model which is widely used for dynamic load modeling is chosen for the current research. The characteristics of two effective parameter identification methods, the Least Square (LS) and the Genetic Algorithm (GA), are analyzed and a new method which combines the advantages of both the LS and the GA methods is developed. The identifiability and the possible range of the parameters for load model are discussed in detail.Almost all the research on load modeling currently carried out in the world is based on the bus load. However, there exist some situations in which a complex load model is required for a wide loading area with multi-feeders. An aggregate load area model (ALAM) based on the fictitious bus is proposed for such situation. The identifiability of the parameters for the proposed model is proved and two equivalent modes are proposed. The effectiveness of the proposed methods is verified by the simulation with the IEEE 30-bus system. Very encouraging results are obtained by the simulation.At the end of the thesis, the summary of the main contents as well as the further work for the research are presented.