Substantiation of diagnostic parameters of autonomous sources of electric energy on the basis of the internal combustion engine at development of system of technical diagnostics

Abstract


 
 
 The paper presents a method for selecting diagnostic parameters for creating a system for diagnosing autonomous sources of electricity based on an internal combustion engine (ICE). A literary search for autonomous sources of electricity was conducted. The expediency of using internal combustion engines as autonomous sources of electric energy is determined. The analysis of design features of the most widespread in the market of Ukraine reserve sources of electric energy on the basis of internal combustion engines is carried out. The analysis of the
 
 
 
 design features of autonomous power supplies allowed a developing of a logical model of the object of study. The developed logical scheme of the research allows to establish the relationship between the main structural elements of the system, as well as to determine the possible states of the system. The consequences of the occurrence of a faulty state of each element on the other elements of the system are analyzed, and the results of the analysis are summarized in the table. An informative criterion is proposed to determine the finite number of diagnostic parameters among the infinite number of possible combinations of physical parameters that characterize the system. The concept of information entropy of K. Shannon is offered as an informative criterion. Equally probable cases of exit from the working condition of each of the elements of the system are considered. Applying the concept of Shannon's information entropy, the residual entropies of the system at the faulty state of one of the nodes of the autonomous power supply are determined. The criterion of informativeness is the value of residual entropy. The application of this criterion allowed determine of the elements of the system that most effectively reduce the degree of uncertainty of the system. The element of the system that has the lowest residual entropy has the maximum effect on the state of the autonomous power source based on the internal combustion engine. Based on the values of residual entropy, the nodes of the system are selected, the state of which should be primarily monitored by the diagnostic system. For such elements diagnostic parameters are defined, and ways of their reception are resulted.