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.