Study on Semi-Tensor Product Theory in Suppressing Negative Effect of Reactive Power Surge of Power Distribution System

Since there are nonlinear loads in power grid, the online characteristics of the power supply is changing with the unexpected reactive power surge, influencing the stability of the system. Therefore, this paper proposes a fault predicting method to eliminate negative effects generated by surge current of reactive power and harmonics of power distribution system. As semi-tensor product theory can be specifically utilized to solve nonlinear differential equations, in paper it is used to analyze the stability region boundary of a nonlinear dynamic system. Particularly, CUEP (controlling unstable equilibrium point) is applied to analyze the stable region of the distribution power system. Finally, the feasibility and effectiveness of the proposed method is validated by a SVC (Static Var Compensator) whose capacity is 450kVar, designed for a 10kV power system of a coal mine. The measured data shows that the harmonic current injecting into power system is up to the standard of national criterion GB/T-14549-93 and the power factor increases from 0.82 to 0.96.