Health evaluation index and failure predication method for DC (Direct Current)-DC convertor

Abstract

The invention discloses a health evaluation index and failure predication method for a DC (Direct Current)-DC convertor. The method comprises the following steps of: collecting state signals of input voltage, input current, output voltage and output current of a DC-DC circuit, calculating the average values (Uin, Iin, Uout, Iout) of the signals, as well as the equivalent load impedance modulus value |Z| and power consumption equivalent resistance (Rloss) of the circuit; and establishing a relation model of Uin, |Z| and Rloss by utilizing a fractional order nerve network; then calculating the equivalent load impedance modulus value, which is utilized as model input, of a health circuit under the conditions of rated input voltage and rated output power, acquiring the corresponding Rloss used as a circuit health evaluation index, calculating the difference value between the circuit health evaluation index and a reference value, and determining the circuit health index according to the difference value and a set change threshold so as to realize the circuit health evaluation; and finally carrying out time sequence predication on the circuit health evaluation index, acquiring a health evaluation index of the next moment, and predicating the health condition of the circuit. According to the method disclosed by the invention, the power consumption equivalent resistance under the conditions of rated input voltage and rated load is utilized as the circuit health evaluation evaluation index, the influence of the input voltage and load changes on the power consumption equivalent resistance is avoided, and thus the health evaluation and the failure predication of the circuit are accurately realized.

Description

technical field [0001] The invention relates to a DC-DC converter health evaluation index and a fault prediction method, belonging to the field of reliability evaluation and fault prediction. Background technique [0002] With the development of power electronics technology, various power electronic circuits are emerging. As an important conversion circuit in power electronic circuits, DC-DC converters are usually the core component of power supplies in engineering systems and the basic components for normal operation of equipment. Causing casualties. Especially in applications with high reliability requirements, such as avionics systems, its failure will bring more serious losses. Therefore, it is necessary to conduct real-time health assessment and fault prediction for DC-DC converters, so as to predict the time of fault occurrence in time, and take corresponding maintenance measures to reduce the fault loss. [0003] The degradation of the overall performance of the DC...

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Problems solved by technology

[0004] In order to solve the problem that most of the current DC-DC converter health assessment indicators are at the component level, and the fluctuation of circuit working conditions is not considered, the present invention proposes a new DC-DC converter health assessment index, which eliminates the impact of circuit input voltage and load fluctuations. The impact of health assessment indicators, and use this indicator in health assessment and fault prediction

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