RELIABILITY INDICATORS AT PARAMETRICAL SYNTHESIS OF THE AUTOMATED ELECTRIC DRIVES
The main objectives of parametrical synthesis of the automated electric drives are considered. It is noted that at the choice of indicators of quality it is necessary to consider reliability indicators. For the automated electric drives such indicators are the probability of no-failure operation and a stock of working capacity. The mathematical formulation of these concepts based on information on border of area of working capacity is provided. The mathematical formulation of a standard availability as which understand property of the automated electric drive to keep output parameters in the set limits at the time of an exit them from mass production is provided. It is shown that for the majority of electric drives there is no information on laws of change of their internal parameters. At the same time the only indicator characterizing reliability is the working capacity stock. Different forms of record of this indicator are received. In the presence of aprioristic information on properties of internal parameters of the electric drive the coefficients characterizing the speed of change of these parameters are entered into a formula for calculation of a stock of working capacity. It is proved that in the field of working capacity the probability of providing any tolerance condition is not decreasing monotonous function of a stock of working capacity. It is established that for any dimension of space of internal parameters of the electric drive in a point of an extremum of the minimum stock of working capacity the value of probability of no-failure operation also is in vicinity of an optimum of this probability. On the basis of the received results the conclusion is drawn on need of use of a stock of working capacity at parametrical synthesis of the automated electric drives and also on expediency of its application as criterion function at limited information on laws of change of internal parameters of the automated electric drive or its total absence.