Characteristic curve parameter identification method and system for operating impact lower voltage limiter

Abstract

The invention discloses a characteristic curve parameter identification method and system for operating an impact lower voltage limiter. The method comprises: measuring a current signal of the operation impact lower voltage limiter, and determining parameters of equivalent resistance, inductance and capacitance of an operation impact discharge loop; obtaining a voltage limiter operation impact loop equivalent model according to the equivalent resistance, inductance and capacitance parameters, and constructing an impact circuit differential equation containing nonlinear curve parameters; calculating a polynomial chaotic configuration point coefficient matrix X according to the constructed impact circuit differential equation; calculating operation matrixes Dyy and DXy by utilizing the polynomial chaotic configuration point coefficient matrix, and constructing a maximum likelihood estimation objective function according to the formula shown in the specification; calculating based on an L-M optimization method, to obtain an identification value of a random variable [epsilon] related to a nonlinear curve parameter [theta] and identification of the nonlinear curve parameter. The identification value of the random variable related to the nonlinear curve parameter is shown in the specification. According to the identification result (shown in the specification), the identification reliability is ensured, and the implementability of the identification method is improved at the same time.

Description

technical field [0001] The invention belongs to the field of electric technology power system and its automatic relay protection, in particular to a method and system for identifying characteristic curve parameters of a voltage limiter under operation impact. Background technique [0002] Power system equipment in actual operation will suffer from various types of overvoltage shocks. For example, lightning strikes in the natural environment will directly generate obvious overvoltages in the transmission lines, and the action process of electrical switches in the lines will also generate similar high voltages. The duration of these shocks is usually at the level of nanoseconds to milliseconds, but the corresponding peak current may be as high as tens of thousands of amperes, which will cause serious harm to line equipment. Therefore, research on overvoltage protection measures has always been an important part of engineering design, and the effectiveness of protection measure...

AI Technical Summary

Problems solved by technology

If there are too many influencing factors of uncertainty, the phenomenon of effect accumulation will inevitably lead to a decrease in the reliability of the identification parameter results, especially for some MOV parameters that do not change significantly.

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