Voltage Stability Analysis Of Power Systems Based On Equivalence Integration Load Model

Now, with the development of science and technology and the growing demand for electrical energy, power systems get increasingly large and long-distance EHV power transmission, large capacity electric generating set, as well as the various new control devices have been widely used. This has important significance to rationally utilizing energy resources, making full use of the existing electric systems' delivery potential and protecting the environment. On the other hand, with the fast growth of the national economy, city-centered regional power consumption is rising more and more rapidly, power demand in large electric systems' load centers is growing faster and faster, and long-distance and heavy-duty power transmission is more and more popular. To the safe operation of power systems, this brings many problems, one of which is the problem of voltage stability, that is, voltage instability or voltage collapse results in local power system load partial loss, or even the collapse of the entire network, following by large-area blackout. In the analysis of voltage stability, load model has rather big impact for the calculating results; inappropriate load model will make the results inconsistent with the actual situation, tending to be optimistic or conservative, thus this may constitute a potential danger or cause unnecessary waste. Therefore, constructing a load model suitable for the voltage stability analysis turns to be particularly pressing.Considering the two aspects of the analysis of voltage stability and many reactive power compensators existing in distribution network, this paper investigates static and dynamic equivalent loads model fitting to the analysis of voltage stability. And these loads models are built up in this paper. Model tests are mainly completed in Matlab simulated platform. Simulation tests show: the static load model in this paper can reflect the static load characteristic accumulation well under small interference; as for big interference, the error becomes larger, and then describing capacity lacks; the dynamic load model in this paper, under various kinds of interference, voltage and current behavioral performance is good, but the power is of big error. However, given "suitable for voltage stability analysis", and seen from the view of voltage error, the load model is able to meet the requirements, and it is applicable for transient voltage stability analysis.The research findings mainly reflect in the establishment of the integrated static and dynamic load model, which can meet the requirements for transient voltage stability analysis. Meanwhile, it is of great significance dealing with the difficulties caused by the practical use of the load model, load variability and the time-variation to the establishment of load model...