Voltage Sag Sensitivity Assessment of Sensitive Equipments by Optimal Square Approximation

The key of voltage sag sensitivity assessment of sensitive equipments consists in the determination of random distribution regularity of voltage tolerate curve. Serving Legendre polynomial as basis function, a method to determine probability density function of characteristic parameter stochastic distribution of voltage sag sensitivity of sensitive equipments by optimal square approximation is proposed. Needing not subjective assumption and being faithful to sample characteristic, the principle of the proposed method is simple and its calculation burden is light. In this paper the approximation algorithm of probability density function and the assessment principle are researched. Taking personal computer (PC) for example and using Monte Carlo stochastic simulation samples, the voltage sag sensitivity of PC is assessed by the proposed method. Assessment results show that the proposed method is accurate and adaptable.