Terminology, structure and model of the electrical systems operation process

Abstract

The content of operation as one of the most important stages of the life cycle of a technical system is revealed. The structure of the process of technical operation of electrical engineering systems is considered. The essence of the individual stages of operation is revealed, their functional purpose is given. It is shown that some fundamental concepts related to operation do not have an unambiguous interpretation. The well-known definitions of these concepts are considered and a one-digit formulation of each of them, which corresponds to the current standards, is given. Special attention is paid to the disclosure of the content of the concept of state and consideration of various types of technical states of the system. The definition of the “condition” category, the formulation of which differs from the known definitions and allows more fully and accurately solving the problems of diagnosing the studied electrical systems, is given. An important feature of this definition is that it fixes the continuous variability of the state of any system in a function of time. At the same time, stable technical conditions that differ significantly from each other and correspond to the current version of the standard are distinguished. Such states are serviceable, faulty, operable, inoperable, partially inoperable, marginal. Functional conditions that are determined by the operating modes of the system are considered. The current definitions of the most important properties and events, among which a special place is occupied by reliability, survivability, safety, failure, damage, defect, are given. For the selected technical states, a model in the form of an oriented graph is synthesized. It is shown that the actual process of an electrical system operation has two features. The first one is that the probability of transition from one state to another does not depend on the type of state the system is in at the moment. The second feature is that the time spent in each technical condition can be either deterministic or random. The conclusion about the possibility of modeling the process of changing the technical states of the system by semi- Markov models with a discrete set of states is made. A mathematical model in the form of Kolmogorov differential equations, which makes it possible to estimate the probabilities of the system being in a particular state, has been compiled.