Study On Special Load Modeling In Power System

A large number of simulation calculations show that load model can produce significant influencehas on stability and economy for power system. Load model gained a large number of promising results of recent years. It has provided a guarantee to improve the accuracy of power system simulation. As the diversity of power load, the current study addresses the conventional power load, while generally not involved in the special power load. Special load consists mainly of two different types of load:generalized load and shock load. The former mainly to solve the problem of load modeling that containing power source in the load side; the second mainly resolves the shock loading modeling problem, which mainly consist of steel, electrolytic aluminum and others.Based on the experience of load modeling that ours group worked nearly 20 years, this paper studied for special load modeling. First, reaearch on the equivalent of synchronous generator that belong to generalized load. This kind of synchronous generators has regared as a negative load, this thesis first presents a equivalent model that simple model structure and parameter easy identificated in certain prerequisite condition. Further, studied the validity of equivalent model using measured data.The most important feature of generalized load is the load side include power sources. Based on the study of generaliaed load modeling of constaining synchronous generator, induction generator in paralled with static characteristics generalized load model structure is first proposed, study the model parameters. However, this new model cannot apply conveniently into another new system. Therefore utilizing Kpm which unifies the composite load model and the ZIP in Parallel with asynchronous generator model to a load model could solve the above problem:ZIP in Parallel with induction machine load model. Meanwhile, study the impact of DFIG-based wind farm on load modeling, applied the ZIP in Parallel with induction machine load model in generalized load modeling generalized load containing wind farm.Shock load as a kind of load, this paper mainly concern two important types of load:electrolytic aluminum and ferrosilicon. First proposed the "proactive" feature of shock load, thereby complement the concept of shock load model and proposed the start criterion that measuring shock load; study the production characteristics of shock load. Then, find out the reasons that casued power shock by shock load first time. Futher, proposed a practical engineering design plan that shock load modeling. Based on above, this thesis first time established load characteristics model and shock characteristics model, this two styles has different applications; then, first proposed the measured shock load modeling system which holds a system methods and steps for shock load modeling.In summary, the establishment of special load model is ultimately to improve the accuracy of the power system simulation. In this paper, based on the theory of load modeling in conjunction with special load characteristics, proposed the train of thought and methods for generalized load and shock load modeling separately, thereby establishing their own load model and survey model validation. The theoretical results have already been used in engineering practice to guide completion of the special load characteristics on-line identification studies of the Northwest Power Grid. Real power system calculation results shows the correct and effective of special model.