| As the large-scale power grid has been basically established recently, the representation of power system stability problem is getting much complicated than before, the online dynamic security analysis (DSA) is attracted too much attention, and the high speed simulation method is extremely required. A new fast simulation approach, hierachical tree model and bi-directional iteration based power system area-partitioning simulation approach, was proposed in this dissertation. It is composed of the construction of tree model, structured description of the power components, standard formulation of the variable's correction factors, the calculation procedure and the settlement of high voltage DC transmission line. The details of the above are summarized as follows.Taking advantage of the power network inherent characteristic, strongly internal conjunction and loosely external connection, a practical area-division method is proposed to partition the large-scale power network into many subareas, which are represented by the hierachical tree model. In the tree model, the connection lines between the tree nodes denote the relationship among the subareas and the dynamic component in the power system.A bi-directional iteration technique was introduced to calculate the correction factors of variables in the proposed simulation method by the tree-traversing procedure, called forward reduction and backward evaluation. It is systematically described the power components'location in the tree structure and the computation model, the feature of this description approach are normalized and structured, and expediently to program the calculation procedure. In case studies, the simulation result obtained by the proposed approach is compared with that of BPA, a kind of power system commercial simulation software validates the correctness and efficiency of the new approach.The area partitioning based simulation method is extended to the other analytical methods in the power system stability evaluation, such as quasi steady state simulation and trajectory sensitivity simulation method. By the particular analysis of their computation characteristic, it is achieved that the standard formulation and the calculation procedure of the above two simulation method in the tree model, and it would be potentially useful in developing fast calculation tool for preventive control in the power system.As the development of AC/DC transmission technology, the AC/DC mixed huge power network will come true in our country, so the DC line's affection on the proposed tree structure is fully evaluated and form a modified tree model for AC/DC mixed network. By the bi-directional iteration technology, the DC transmission equation is converted into standard formulation in the tree structure, and achieved the AC/DC mixed power system simulation.Finally, it is deeply researched on the continuous power flow method in this dissertation and achieved some success, denoted as"local-arc"parameter and fixed diagonal step-controlling method, besides; the area-partitioning calculation method is introduced, and formed a novel continuous power flow method, which is tested on the Northeast and North China power system. |
