The maximum entropy probability distribution and the improvement of its solving method for negative sequence current of a traction substation

In this paper, improved solving method are proposed to calculate the maximum entropy probability distribution of negative sequence current. Negative sequence current is got from the process of the measured data obtained from power quality monitoring system first. Second, curve fitting method is used to calculate probability distribution of negative sequence current based on maximum entropy method. Logarithmic function and the method of deleting small probability value points at ends of probability distribution are proposed to improve the parameters solution method of curve fitting. The probability distribution obtained from the improved solving method is more consistent with the actual distribution of measured data compared with the original parameter solution method. Finally, fitting error parameters are used to evaluate the fitting effect of probability distribution and prove the feasibility of the method.