Comparative analysis of switched reluctance motor control algorithms

Nowadays it has become possible to develop inexpensive modern control systems for nonlinear complexity electromechanical objects due to the development of microprocessor technology and power electronics. Switched reluctance electric machines are among these devices. It makes it possible to widely use such electric machines in various practical implementations, in particular, in traction drives, electric drives of oil and gas drilling rigs, and in other applications. The switched reluctance electric machine is a non-linear object, and its control methods require formalization and grouping. The manuscript considers the design and functional features of switched reluctance electrical machines. The main methods of controlling these electrical machine types are given. Comparative analysis of the most known methods is carried out. The main classical methods of switched reluctance electric machine control are considered, such as a relay current controller with a limitation, the method of controlling the turn on/off angles and controlling the DC link voltage. Transient responses in the electric drive system are demonstrated using the considered methods. It is shown that by adjusting the on/off angles, it is possible to reduce the torque oscillation coefficient. The identified features of the presented methods will make it possible to simplify and reduce the development time for an effective control system for switched reluctance electrical machines as well as to reduce the torque ripple

Magnus wind turbine

Due to its special features, the Magnus effect wind turbine allows you to produce energy at a very low speed of the wind. This fact, as well as the growing interest in the of blockchain technology, makes it possible to use this type of wind turbine in private household as part of a distributed energy system in addition to solar panels. The article describes a two blades Magnus wind turbine whose cylinders rotate by means of embedded motors. To avoid a von Karman vortex street effect that occur when the cylinders rotate in the air flow, as well as to ensure maximum power, the optimal ratio between the wind speed and the cylinder rotation speed is determined using finite element analysis. Further, the obtained relations are used in the algorithms of the wind turbine control system.Peer reviewe

Time dependency of current harmonics for switch-mode power supplies

This paper presents the time-dependent variance in the current harmonics emission by power supplies during power quality measurements. Power quality problems are becoming more significant with the adoption of power electronic-based circuits such as power supplies. The switch-mode power supplies are widespread as industrial, commercial, and domestic electrical loads. They draw non-sinusoidal current from the utility and inject current harmonics. Therefore, they are the reason for poor power quality and reduction in the power factor. The current harmonics emission from these power supplies depends on the circuit topology, operating conditions, and filter inside them. The harmonic emission estimations are critical for network operators; however, various uncertainties have made it a complicated task. The time-dependent stability affects the magnitude and phase angle of the harmonic current measurements and estimation of power quality indices. This paper investigates the variation in current harmonics emitted by the power supply during the initial unstable period under constant load and operating conditions.Peer reviewe

Travel activity based stochastic modelling of load and charging state of electric vehicles

The uptake of electric vehicles (EV) is increasing every year and will eventually replace the traditional transport system in the near future. This imminent increase is urging stakeholders to plan up-gradation in the electric power system infrastructure. However, for efficient planning to support an additional load, an accurate assessment of the electric vehicle load and power quality indices is required. Although several EV models to estimate the charging profile and additional electrical load are available, but they are not capable of providing a high-resolution evaluation of charging current, especially at a higher frequency. This paper presents a probabilistic approach capable of estimating the time-dependent charging and harmonic currents for the future EV load. The model is based on the detailed travel activities of the existing car owners reported in the travel survey. The probability distribution functions of departure time, distance, arrival time, and time span are calculated. The charging profiles are based on the measurements of several EVs.Peer reviewe