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In this paper, modelling and control of a batch bioreactor is studied. A main disadvantage of batch bioreactors compared to other types of bioreactors is their inability to introduce biological or/and chemical substances during operation. Therefore, possibility of bioreactor’s control by means of changing temperature was proposed, analyzed, and implemented. A new supplementary input/output dynamical mathematical model, which considers influence of heating and cooling on a bioprocess, was developed. On a basis of this model, a control system was designed and a method for tuning of the controller was suggested. Results show characteristics, applicability, and advantages of the presented approach.

Based on an analysis of CO release transients in the case of non-simultaneous stepwise changed input quantities, two differential equations were defined that describe the influence of the two input quantities on the output quantity. The simulation results were verified by experiments. The proposed model can be used for a comprehensive analysis of the process that is being studied and for the design and synthesis of advanced control systems, which will ensure a controlled CO release at the industrial level. © 2018 Society of Chemical Industry.

PurposeThe purpose of this paper is to develop a controller for damping of oscillations of a synchronous generator connected to the electric network. The goal is to determine the configuration of the controller and to set up the procedure for determination of the controller parameters.Design/methodology/approachOn the basis of the analytical and numerical analysis of the so‐far proposed stabilizers, the new directions towards improved and efficient stabilizer have been established. The advantage of the proposed approach has been confirmed with simulations and experimental results.FindingsThree main contributions can be highlighted: on the basis of the synchronous generator analysis, it is shown that the conventional power system stabilizer is inappropriate for optimal oscillation damping through the entire operating range; the possibility of application of the model reference adaptive control theory for stabilizer design is confirmed; and the rules have been set up for selection of the stabilizer parameters.Research limitations/implicationsThe power system control is rather conservative and does not allow new approaches to the control concepts.Originality/valueThe paper's originality lies in the fact that the proposed adaptive approach for realizing the control system for damping of oscillations is presented completely. The configuration of the controller is presented, as well as the method for determining the adaptation mechanism parameters.

In this paper, a non-linear 7 th order dynamic model and a linearized 3 rd order dynamic model of a synchronous generator connected to an infinite bus are presented and compared in details. Parameters and equations of the both models are explained and summarized. They represent a useful starting point for work in areas of synchronous generators' construction, analysis, control systems design and synthesis. Novelty of this work represents a detailed research of applicability of the linearized model in an entire operating range. Established theoretical conclusions were confirmed with numerical results. Restrictions of utilizing the linearized model are presented. On a basis of the analysis for the synchronous generators of different power, their applicability with feasibility and accuracy was evaluated by certain objective criteria.