The study of the isolated power supply system operation with controlled distributed generation plants, energy storage units and drive load

THE PURPOSE. Investigation of the operating modes of an isolated power supply system with controlled distributed generation plants, energy storage units and a drive load. Determination of the influence of the proposed prognostic controller of a distributed generation plant on the control parameters and quality indicators of the control process under various operating modes of an isolated power supply system.METHODS. The studies were carried out on a computer model of an isolated power supply system of an industrial enterprise with a turbine generator plant, a wind generator plant and a high-power electric storage unit, for which a fuzzy control system and a prognostic controller were used. The simulation was performed in MATLAB using Simulink and SimPowerSystems packages.RESULTS. The article describes a computer model of an isolated power supply system, as well as a structural diagram of the proposed autoprognostic speed controller. The simulation results showed that the combined use of an energy storage unit and an auto-prognostic generator rotor speed controller makes it possible to ensure the stability and survivability of an isolated power supply system, increasing its damping properties. The use of a fuzzy control system of a wind-generating plant made it possible to ensure its stable operation in all considered modes.CONCLUSION. The auto-prognostic speed controller, which does not require special settings, and the energy storage unit provide high quality control indicators in normal and emergency modes. It is advisable to conduct further studies to coordinate the actions of the control system of the electric energy storage unit and the auto-prognostic speed controller of the distributed generation plant.

Grey Wolf Optimizer in Design Process of the Recurrent Wavelet Neural Controller Applied for Two-Mass System

In this paper, an adaptive speed controller of the electrical drive is presented. The main part of the control structure is based on the Recurrent Wavelet Neural Network (RWNN). The mechanical part of the plant is considered as an elastic connection of two DC machines. Oscillation damping and robustness against parameter changes are achieved using network parameters updates (online). Moreover, the various combinations of the feedbacks from the state variables are considered. The initial weights of the neural network and the additional gains are tuned using a modified version of the Grey Wolf Optimizer. Convergence of the calculation is forced using a new definition. For theoretical analysis, numerical tests are presented. Then, the RWNN is implemented in a dSPACE card. Finally, the simulation results are verified experimentally.

The design of following controller for autonomous vehicle based on leader-follower strategies

Aiming at the problem of following control of autonomous vehicle, the following controller is designed based on Leader-follower strategies. First, the kinematic modeling is done. Next, Leader-follower model is used to describe the following structure and L − ϕ method is used to build error system. Then, The speed controller for the follower is designed to achieve the objectives. Finally, the simulation is done by Matlab, the results show that the controller is effective.

Enhanced Intelligent Closed Loop Direct Torque and Flux Control of Induction Motor for Standalone Photovoltaic Water Pumping System

This paper aims to search for a high-performance low-cost standalone photovoltaic water pumping system (PVWPS) based on a three-phase induction motor (IM). In order to control the IM, a fuzzy direct torque control (FDTC) is proposed in this paper for overcoming the limitations of the conventional direct torque control (CDTC). In fact, the CDTC suffers from several problems such as torque ripples, current distortion, and switching frequency variations. These problems can be solved with the proposed FDTC. To ensure high performance of the PVWPS, the reference torque is generated using a fuzzy speed controller (FSC) instead of a conventional proportional integral speed controller. In order to extract the maximum amount of power, the proposed maximum power point tracking controller is based on variable step size perturb and observe to surmount the weakness of the conventional perturb and observe technique. The performance of the proposed FDTC based on the FSC under variable climatic conditions is demonstrated by digital simulation using Matlab/Simulink. The obtained results show the effectiveness of the suggested FDTC based on the FSC compared with the CDTC in terms of pumped water, reduction in flux and torque ripple, diminution of losses, and decrease in the stator current harmonic.

Development and Performance Evaluation of a Solar Powered Lawn Mower

The continuous increase in the cost of fuel and the effect of emission of gases from burned fuel into the atmosphere when operating engine powered lawn mower has necessitated the use of the abundant solar energy from the sun as a power source of a lawn mower. A solar powered lawn mower was designed, fabricated and assembled on the basis of the general principle of mowing. The components of the lawn mower are; direct current (DC) motor, rechargeable battery, solar panel, galvanized steel blade of various thicknesses and shapes, and a speed controller. The required torque needed to drive the galvanized steel blade was achieved through the DC motor. The speed of the DC motor was controlled by the speed controller with the resistance in the circuit and allowed the motor to drive the blade at varied speeds. The battery recharged through the solar charging circuit, which comprises of a solar panel and charge controller. Performance evaluation was conducted on the developed mower with various thicknesses (1 mm, 1.5 mm and 2 mm) and shapes of the cutting blade (two, three and four blades). It was found that the cutting efficiency of the mower ranges from 70.50% - 84.10%, also the cutting capacity ranges from 0.05 ha h-1 - 0.27 ha h-1, the uncut area was also found to range from 15.90% - 29.50%.

Dynamics of Electromechanical Systems Containing Long Elastic Couplings and Safety of Their Operation

The electromechanical systems under analysis include electric drives, working machines that perform specific tasks in the technological process, and working mechanisms that transmit mechanical power between the electric drive and the working machine. The vast majority of electric motors included in drive systems require rotational speed control. This task is most often performed with the use of closed-loop control structures based on speed controllers. A step or overly rapid change in the speed reference causes a temporary lock of the speed controller due to the applied limitations at its output. Particularly, unfavorable effects of such a lock can be observed in drive systems in which there is a long elastic coupling (transmission shaft) between the electric motor and the working machine. As a consequence, shaft torsion and accompanying twisting moments of considerable amplitudes appear. This article proposes an uncomplicated active torque limiter structure, which enables the uninterrupted operation of the speed controller thanks to the automatic adaptation of the rate of the speed reference change to any moment of inertia of the rotor and attached rotating masses. The results of the investigations confirm the effectiveness of the proposed structure.