Study Of Reactive Power Optimization Considering Load Forecasting

The power system is continually expanding with the development of technology,it is required to run more securely,economically and efficiently.Also,electricity department is paying more and more attention to the economy and safety of power system. Reactive power optimization is an effective measure to improve power quality and reduce the network loss. Normally the static reactive power optimization does not take into account whether the controlling equipment could continuous act over time. Because the load is changing with time, the static reactive power optimization can't meet the requirements of real production system. But the dynamic reactive power optimization which take the changes of system load,constrained parameters to action times of control devices etc into consideration,can achieve optimization by rational division of control devices's action timing.In this paper, based on the grey theory method, an improved prediction model of grey– markov is presented combining with Markov algorithm. Results show that the application of the improved prediction model of grey– markov in short-term load forecasting can raise the forecasting accuracy effectively.Also a new algorithm of dynamic reactive power optimization is proposed.Firstly, daily load curve should be divided into 24 sections. Through static reactive power optimization of each section by using simulated annealing algorithm, the list of control equipments'action should be preliminary determined.There are non-linear loads in the grid which produces lots of harmonic. Under the influence of harmonic, compensative capacitors could make the harmonic amplification even shunt resonance. So the resonant constraint of capacitor switching should be takeen into account in order to shun the current resonance.Take IEEE 14-node system for example. Programming results testify the effectiveness of the proposed dynamic reactive power optimization algorithm. The new algorithm is proved to be satisfactory in reducing power losses, avoiding resonance, raising passing rate of voltage. So it can meet the needs of electric system operating requirements.