This paper is devoted to the development and research of an advanced approach to automatic control of the heat output of the boiler when compensating the load disturbances by regulating the composition of the combusted hydrocarbon fuel mixture. The proposed approach gives the opportunity to design the boiler’s automatic control system (ACS) with the possibility of creating the conditions for the formation and determination of the current calorific value of the gases mixture, which corresponds to the current heat load of the boiler, as well as determining the flue gas flow and temperature in the boiler. The implementation of the developed approach of the boiler’s load control allows for providing a constant nominal flue gas flow at any level of heat output. The fuel composition control process consists of mixing certified and non-certified hydrocarbon gases, which ensures maximum efficiency and compliance with environmental emission standards. The effectiveness study of the proposed approach is carried out in the development of the heat output ACS for the GM-50 boiler and conducting a computational experiment of operating at a power different from the nominal one. The obtained results fully confirm the high efficiency of the developed approach, as well as the expediency of its application for boilers of various types and capacities when operating at a power different from the nominal one.

Purpose. Development of a method for controlling the volume of combustion products at different load of boiler equipment. Achieving the objective may allow controlling the flue gas temperature and, consequently, the efficiency to increase it. Methodology. Control of the flue gas volume value on the basis of determining the appropriate composition of the fuel gas mixture. Findings. The effect of flue gas temperature increase at use of fuel gases of lower calorific value and increase in ballast gases quantity is revealed. The latter can be the air used as an oxidising agent at its considerable excess. The mechanism of such an effect due to the increase in the quantity and velocity of flue gases is suggested. A parameter determining the volume of flue gases produced per unit calorific value of various fuel gases is proposed. On the basis of this parameter the method for calculating the composition of the mixture of different gases to ensure the constancy of the flue gas volume at variable load is proposed Originality. On the example of the results of verification thermal calculation the change in flue gas temperature and efficiency value is considered. The non-standard character of their change is revealed. In contrast to the case of using fuel gas of constant composition with increasing load, the temperature of flue gases remained close to constant, and the value of efficiency increased. Practical value. The obtained results indicate the possibility of controlling the flue gas temperature and boiler efficiency at a given load. This allows one, unlike the case of using fuel gas of constant composition, to increase the efficiency exactly at maximum load avoiding getting into the condensate mode at minimum load. There is a possibility to save fossil gas and, consequently, to reduce the greenhouse share in CO2 emissions.

The study established that the application of graph theory enables the creation of a model of a country’s power system structure in the form of a tiered graph. This allows complex structural elements of the system, such as generating units, electrical substations, and power transmission lines, to be represented as nodes and edges in simulation models that can be used for analysis, dispatch control, and optimization of system operation. A simulation model of the unified power system has been developed to analyze operational efficiency and performance under various planned disturbance scenarios. To solve the given task, it is necessary to develop a model of the power system in the form of a tiered graph, where the nodes are generating equipment stations, transmission system substations with voltages from 330 kV to 750 kV, and distribution system substations with voltages from 110 kV to 220 kV, and the edges are power transmission lines with voltages from 110 kV to 750 kV. The model takes into account the generated and transmitted power, the nominal capacity and the number of transformers at the substations, the cross-section and maximum throughput of the power transmission lines, which made it possible to determine complex interconnections between its nodes and integrate the equipment into a unified power system for efficiency and performance analysis.

Control of the pyrolysis process of municipal solid waste (MSW) of variable composition and moisture content. The fuzzy control method is developed and studied that makes it possible to carry out the proper automatic control of the pyrolysis plant with the determination of the optimal ratio of air/MSW for various types of waste and with different moisture content values to ensure high efficiency of the MSW disposal process. The effectiveness study of the proposed fuzzy control method is performed in this paper on a specific example, in particular, when automating the pyrolysis plant for the MSW disposal with the reactor volume of 250 liters. The obtained simulation results confirm the high efficiency of the developed method, as well as the feasibility of its use for designing automatic control systems of various pyrolysis plants that operate under conditions of changes in the composition and moisture content of input waste.

The object of research is the process of regulating power imbalances due to automated control of steam turbine parameters. The work solves the problem of minimizing power imbalances in the electric power system by developing a model of automated control of steam turbine parameters. This will ensure high-quality regulation of frequency and power, increase the efficiency and stability of the electric power system, and provide a new management method for reliable power supply to consumers. The paper analyzes existing models and methods of power imbalance regulation, develops a dynamic model of automated control of K-300-240 steam turbines, which includes a mechanical-hydraulic system, a steam boiler and a steam superheater. As a result of the study, an improved power regulation method was proposed, which ensures efficient operation of the electric power system. The evaluation of the effectiveness of the regulation of imbalances was carried out on the basis of the proposed criterion of the efficiency of electricity supply and consumption, which is based on the convolution of partial criteria into the general criterion of the efficiency of electricity supply. The following criteria were proposed as partial criteria for electricity supply and consumption: volume criterion, quality criterion, and electricity supply efficiency criterion. The research results indicate the need for a reserve on each steam turbine in the amount of 10 % of its nominal power, which is explained by the assessment of the efficiency of electricity supply among the considered modes of operation of the systems. The presence of a power reserve on each steam turbine in the amount of 10 % of their nominal power ensures the most efficient power supply within the considered modes of operation of the power system, taking into account disturbances and as an imbalance of power generation and power consumption. The obtained research results can be applied in the strategy of primary regulation of power imbalances in the electric power system, thanks to the creation of a power reserve in the amount of 10 % of the nominal power on each steam turbine, and the organization of automated control of steam turbine parameters.

The necessity of keeping in working condition the sources of traditional electricity generation for dispatching the supply of electricity from the capacities of "green" electricity generation has been realized. Potentially, one of these sources may be nuclear power plants. An obstacle to their use as a participant in dispatching is the impossibility of maneuvering with power in a wide range. One of the reasons for limiting the range is the complexity of automatic compensation for the reactivity of the xenon oscillation reactor. Existing physical and mathematical models for calculating the parameters of processes in the reactor due to changes in its power because of its complexity cannot be used in operational automatic control systems. The task of constructing an approximation linear model of processes in the reactor in the form of a transfer function is set. To build an approximation model, the inverse problem is solved. The desired model is based on the condition of coincidence at some time interval of the results of solving it with the results of a detailed physical-mathematical model. To this end, a number of sequential actions are performed, including approximation of the results of the expanded physical-mathematical model using a series, the application of the Laplace transformation to this series, as well as Pade approximation obtained in the space of the images of the series. The method of control was proposed and an automatic control system (ACS) for energy production of nuclear power plant has been synthesized. To this end, the management system was integrated with the approximation model of the active zone, which provided the possibility for adjusting the quantitative degree of stability of the active zone. ACS consists of three control circuits. Such a structure has made it possible to compensate for the xenon oscillations that occur. Additionally, ACS reduces the movement of adjusting rods in the active zone, which reduces local power surges in nuclear fuel and leads to an increase in its durability