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The economy is undergoing a radical transformation in all its structures, completely changing the methods of management. Changes are taking place on a global scale based on the digital technologies being implemented. The role of the state and executive authorities is being completely rethought. They are transforming themselves into “digital governments”, IT platforms, and forming their own digital structures with a list of services that are necessary for the population. In this study the following 4 directions of development of the public administration system were identified and reviewed in detail: digital reforms in the public administration system; long-term balance and sustainability of public administration; focusing on improving the quality and efficiency of public services; implementation of project management methods for the development and implementation of state programs. Based on the conducted research, current trends in public administration have been highlighted, and it was concluded that the trends in the development of modern economies include the mandatory participation of the state.

The economy is undergoing a radical transformation in all its structures, completely changing the methods of management. Changes are taking place on a global scale based on the digital technologies being implemented. The role of the state and executive authorities is being completely rethought. They are transforming themselves into “digital governments”, IT platforms, and forming their own digital structures with a list of services that are necessary for the population. In this study the following 4 directions of development of the public administration system were identified and reviewed in detail: digital reforms in the public administration system; long-term balance and sustainability of public administration; focusing on improving the quality and efficiency of public services; implementation of project management methods for the development and implementation of state programs. Based on the conducted research, current trends in public administration have been highlighted, and it was concluded that the trends in the development of modern economies include the mandatory participation of the state.

High penetration of renewable energy sources into isolated microgrids (µGs) is considered a critical challenge, as µGs’ operation at low inertia results in frequency stability problems. To solve this challenge, virtual inertia control based on an energy storage system is applied to enhance the inertia and damping properties of the µG. On the other hand, utilization of a phase-locked loop (PLL) is indispensable for measuring system frequency; however, its dynamics, such as measurement delay and noise generation, cause extra deterioration of frequency stability. In this paper, to improve µG frequency stability and minimize the impact of PLL dynamics, a new optimal frequency control technique is proposed. A whale optimization algorithm is used to enhance the virtual inertia control loop by optimizing the parameters of the virtual inertia controller with consideration of PLL dynamics and the uncertainties of system inertia. The proposed controller has been validated through comparisons with an optimized virtual inertia PI controller which is tuned utilizing MATLAB internal model control methodology and with H∞-based virtual inertia control. The results show the effectiveness of the proposed controller against different operating conditions and system disturbances and uncertainties.

High penetration of renewable energy sources into isolated microgrids (µGs) is considered a critical challenge, as µGs’ operation at low inertia results in frequency stability problems. To solve this challenge, virtual inertia control based on an energy storage system is applied to enhance the inertia and damping properties of the µG. On the other hand, utilization of a phase-locked loop (PLL) is indispensable for measuring system frequency; however, its dynamics, such as measurement delay and noise generation, cause extra deterioration of frequency stability. In this paper, to improve µG frequency stability and minimize the impact of PLL dynamics, a new optimal frequency control technique is proposed. A whale optimization algorithm is used to enhance the virtual inertia control loop by optimizing the parameters of the virtual inertia controller with consideration of PLL dynamics and the uncertainties of system inertia. The proposed controller has been validated through comparisons with an optimized virtual inertia PI controller which is tuned utilizing MATLAB internal model control methodology and with H∞-based virtual inertia control. The results show the effectiveness of the proposed controller against different operating conditions and system disturbances and uncertainties.

In this paper, the mathematical analysis of the robot effective mass is presented. The calculation of this effective mass and its ellipsoid are included. The relationship between the robot effective mass and the external force (collision) affecting the robot end-effector is investigated. The effective mass is analyzed using different robot configurations and different end-effector positions. This analysis is conducted using 2-DOF and 3-DOF planar robots and executed using MATLAB. The results from this analysis prove that the robot effective mass depends on the its configurations and end-effector position. Effective mass can thus be considered as one of the criteria in optimizing robot kinematics and configuration.

In this paper, the mathematical analysis of the robot effective mass is presented. The calculation of this effective mass and its ellipsoid are included. The relationship between the robot effective mass and the external force (collision) affecting the robot end-effector is investigated. The effective mass is analyzed using different robot configurations and different end-effector positions. This analysis is conducted using 2-DOF and 3-DOF planar robots and executed using MATLAB. The results from this analysis prove that the robot effective mass depends on the its configurations and end-effector position. Effective mass can thus be considered as one of the criteria in optimizing robot kinematics and configuration.

Main characteristics and advantages of static VAR compensators (SVC) based on thyristor-switched schemes are presented. The operating features of compensator circuits when forming inductive and capacitive reactive power are considered. The reactive power regulation principles that provide the sinusoidal form of reactive current are explained on examples of operation of inductive and capacitive SVCs. The specificity of the operation of SVC control systems ensuring reliable operation in transient and steady-state working modes is discussed. The tasks of experimental research of SVC physical models are formulated. Experimental results obtained on the SVC physical models illustrating main characteristics of such devices are presented.