A Textured Model for Computationally Efficient Reactive Power Control and Management

Abstract
The texture of the power system which govern, the interplay of reactive power and voltage is emulated by a textured model which assembles local groups of buses into a multi-leaf structure. Groups on the same leaf of the model are not coupled with each other, groups on different leaves overlap partially and are thus coupled. The paths of computational information are organized in an efficient manner and inefficient computation and information paths are eliminated, yet the computation converges to the exact solution, not an approximate one. The resulting model is ideally suited for parallel processing especially since there is no sequential component in the computation no computation overhead and (if the size of the groups and their numbers per leaf are uniform) there is no waiting time. Computation time savings of as much as 100÷1 (i.e. a hundred fold saving) were observed in experiments on steepest descent algorithms with systems of around 100 buses. Computation times also favorably compare with existing speed up techniques such as block pivoting. Computation times for common algorithms (like matrix manipulations, Newton-Raphson, linear and nonlinear programming) increase with the system size at a fast non- linear rate. The computation times remain essentially constant for the textured model in parallel processing. Thus very large computation time savings are implied on larger systems. Consequently this new model should prove to be a valuable tool for on line computations in the course of reactive power control and management.