No 104 (2023)
Systems analysis
methods for modelling and optimization of the level of autonomy of maintenance, overhaul and repair of the civil aircrfat fleet
Abstract
The organization of maintenance, repair and overhaul of the aircraft fleet is fundamentally different for different classes of aircraft. Frequently, maintenance and repairs are considered only as part of the total operating costs, but for aircraft with short range and speed, transferring the aircraft to specialized repair facilities or manufacturing facilities can cause significant time costs. The article deals with the problem of organizing maintenance and repair of the aircraft fleet of local airlines in remote and sparsely populated regions. Various approaches to the technical maintenance of the aircraft fleet are considered: operation according to the regulations and according to the actual state, maintenance and repair in accordance with the maintenance manual and the transition to a more autonomous maintenance and repair. The obsolescence of highly loaded equipment, which causes an increase in the arrival rate of equipment failures with an increase in operating time, is not considered in this paper. Simulation of the performance of passenger transportation in the region is carried out, taking into account the maintenance and repair of the aircraft fleet. The economic characteristics of passenger transportation are calculated.
Large-scale systems control. 2023;(104):5-35
5-35
Control systems analysis and design
Vanadium redox flow batteries: models of dynamics and measurements
Abstract
This article introduces readers to vanadium redox flow batteries, their operating principles, and state-space models. Vanadium redox flow batteries (VRFBs) are a promising technology for stationary storage of electric energy, which has a number of advantages over traditional storage batteries based on lithium-ion batteries. One of the features of VRFBs is a hydraulic system with pumps that provide a continuous supply of electrolyte from the tanks where it is stored to the stacks where the electrochemical reactions take place. This entails the need to build dynamic models of such systems, which are used for monitoring and control tasks. The article presents the basic models of vanadium battery dynamics with concentrated parameters, along with models of available measurements, and analyzes their features. In addition, new models are proposed that allow a more accurate and convenient description of the change in concentrations during VRFB operation.
Large-scale systems control. 2023;(104):36-72
36-72
Control of social-economic systems
Developing the air transportation system quality assessment tools to define the main requirements for future aircraft
Abstract
The aim of this article is to define and to describe the calculation methodology for both on-point and general quantitative indicators of air transportation system quality for a passenger. The indicators can be based on any of the three common measures of path-passing (time, cost, and distance). The pair of values that is proposed to be used as indicators is (1) a guaranteed value of the selected measure of path-passing defined for (2) a share of the population inside the air transportation system. As an application example the article describes the use of program module based on the proposed methodology to assess the potential benefits from the substitution of a Russia-based fleet of gas turbine powered regional aircraft with a fleet of “more electric” aircraft that have a twice less passenger capacity. The proposed indicators may be used as either optimization criteria or a boundary condition while developing the requirements for future civil aircraft.
Large-scale systems control. 2023;(104):73-99
73-99
Control of technological systems and processes
Measurement-based lyapunov modal analysis using prony analysis
Abstract
Modern power grids are in need of advanced stability analysis tools due to their generation and consumption development trends. Lyapunov modal analysis combines two stability analysis approaches: modal analysis and Lyapunov functions spectral decomposition. Related currently available research requires a linear model of a studied system. Nevertheless, there is a significant interest in data-driven stability analysis methods based on measurements rather than pre-existing models. This motivates the presented study of measurement-based Lyapunov modal analysis feasibility. We derived new formulas for Lyapunov modal contributions calculation that based on data provided by Prony analysis of measurements captured in a nonlinear models or systems. We also conducted case studies using our software implementation of measurement-based Lyapunov modal analysis and node voltage transients measured in IEEE 68 power system model. The paper concludes with comparative analysis between measurement and model-based implementations.
Large-scale systems control. 2023;(104):100-117
100-117
Data assimilation in neutronics modelling: current status and development prospects
Abstract
The article presents an analysis of the current state and prospects for the development of data assimilation procedures in neutronics modelling. These procedures are used to refine the parameters of neutronics models based on reactor experiment results, improve the accuracy of calculations predicting the characteristics of nuclear facilities under development, and plan informative experiments that closely match the neutronics properties of the facilities being designed. The article provides a classification of the approaches used in data assimilation for neutronics modelling, discusses the areas of application, advantages, and disadvantages of various implementations, identifies the main trends and directions for further development, and considers the current scientific and applied problems in the subject area.
Large-scale systems control. 2023;(104):118-134
118-134