Control of a Reactive Electric Motor When Feeding the Windings With a Sinusoidal Current

Abstract

Vector control of the electromagnetic moment of a reactive machine is considered. The control task is to eliminate pulsations of the electromagnetic moment. It can be shown that to achieve this goal, sinusoidal currents must flow through the windings, whose inductance must pulse according to the sinusoidal law. It is shown that when sinusoidal currents flow through the phase windings, the voltage of the main and third harmonics occurs on them. At the same time, in a three-phase machine whose phase windings are connected to a star, the third harmonic disappears as part of the line voltage. In this case, a standard frequency converter can be used to synthesize the voltages applied to the stator windings using pulse-width modulation, which makes it easier and cheaper to practically control the reactive electric machine with concentrated phase windings. The ratio of size of the stator and rotor teeth, at which the coefficient of non-sinusoidal pulsations of the phase windings inductances during the rotor rotation will be minimal, is found. Electromagnetic processes in the reactive machine are described by the linear differential equations with periodic coefficients. Lyapunov transformations for differential stress equations, which allow converting the initial equations with periodic coefficients into stress equations with constant coefficients, are found. The resulting Lyapunov equations are the basis for the synthesis of a system for controlling the dynamics of electromagnetic processes, which allows sinusoidal currents to flow through the phase windings of the machine. The control system of the reactive electric machine is represented by a structural diagram. An algorithm for controlling the electromagnetic moment of the reactive machine with a constant magnetization current is considered. The use of this algorithm allows to obtain the maximum performance of the management. A virtual scattering loop is also used to increase the speed of load current regulation. Simulation of electromechanical processes at the reactive electric machine control is carried out.

Energetically Optimal Control of the Electromagnetic Torque of a Jet Electric Motor

“…Исследование энергетически оптимального управления выполнено в координатных осях d-q. Далее приводятся выражения токов и напряжений РД в этих осях [12]. Ток в фазе X:…”

“…2 и 3 -блоки преобразования координат напряжения и тока Условные обозначения: А -регулятор продольного тока; Б -регулятор поперечного тока; Г -узел компенсации влияния поперечного тока на продольный ток; Д -узел ограничения тока нагрузки; Е -блок ограничения скорости вращения ротора; Ж -регулятор скорости вращения ротора; И -узел ограничения модуля напряжения на обмотке статора; К -узел ограничения модуля тока статора; Л -блок вычисления тока нагрузки Данная структурная схема отличается от структурной схемы управления при постоянном токе намагничивания [12] сигналами задания на контуры управления токами намагничивания и нагрузки, которые, исходя из соотношений (32), определяются выражениями: 1 , (…”

“…рис. 3 и 4 [12]) показывает, что применение алгоритма энергетически оптимального управления не оказывает отрицательного влияния на динамику электромагнитных процессов.…”