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.

A method for reducing the static error in control and increase of the current loop performance in the control system of the electric drive by increasing the transfer coefficient of the open loop is considered. This is achieved by introducing a hard negative feedback loop. The resulting structure is stable at any arbitrarily large open loop transfer coefficient. The proposed method of increasing the open loop transfer coefficient does not change the structure of the control object, so when setting the current loop to the technical optimum, the structure of the current regulator also does not change. Two ways for increasing the open loop transfer coefficient are considered: reaching the hard negative feedback or link of armature winding or link of semiconducting converter. Expressions for static errors and time constants of the current loop are obtained for each way. A comparison of static errors and time constants of the circuit between the above options, as well as each option with a standard structural circuit of the current circuit is given. It is shown that the introduction of hard feedback into the current loop increases its performance and reduces the static error compared to the standard structural scheme of the current loop. In this case, the coverage by hard feedback of the link of armature winding of the motor gives less static error and higher performance than the coverage of the link of semiconducting converter. For citation: Shiryaev, Eduard V., and Nikolay A. Ulisskiy. "Improving the accuracy and performance of the current loop by increasing the open loop transfer coefficient." Vestnik Gosudarstvennogo universiteta morskogo i rechnogo flota imeni admirala S. O. Makarova 11.5 (2019): 959-967.Рассмотрены способы уменьшения статической ошибки по управлению и увеличения быстродействия контура тока в системе управления электропривода путем неограниченного увеличения коэффициента передачи разомкнутого контура, что достигается введением в контур тока жесткой отрицательной обратной связи. При этом возникающая структура устойчива при любом сколь угодно большом коэффициенте передачи разомкнутого контура. Предлагаемый способ увеличения коэффициента передачи разомкнутого контура не меняет структуру объекта управления, поэтому при настройке контура тока на технический оптимум структура регулятора тока также не изменяется. Рассмотрены два варианта увеличения коэффициента передачи разомкнутого контура: охват жесткой отрицательной обратной связью либо звена обмотки якоря либо звена полупроводникового преобразователя. Для каждого варианта получены выражения для статических ошибок и постоянных времени контура тока. В качестве примера для заданных значений параметров двигателя постоянного тока и полупроводникового преобразователя выполнен расчет зависимостей показателей качества переходного процесса в контуре тока от значения коэффициента жесткой отрицательной обратной связи. Проведено сравнение статических ошибок и постоянных времени контура между рассмотренными вариантами и с вариантом, имеющим стандартную структурну...

No abstract

In this study, the energy characteristics of jet engines with a toothed stator and a toothed rotor are considered. These are active power, total power, power loss, power factor, first harmonic power factor (cosφ), and efficiency. It is shown that the power factor and the power factor for the first harmonic cannot exceed the values of 0,27 and 0,5, respectively. The study is performed with the representation of all variables of the electric drive with a jet engine in the coordinate axes d-q. Based on the expression for the total power losses, an algorithm for energetically optimal control of the electromagnetic torque of a jet engine is formed. At the same time, energetically optimal control is understood as providing a given electromagnetic torque with minimal power losses. The algorithm of energetically optimal control is found using the method of indefinite Lagrange multipliers. The solution of the system of Lagrange equations allows us to find expressions for the signals of setting to the control circuits of the magnetizing current and load current. Based on these setting signals, an optimal control algorithm is formed, where two control modes are implemented: the energetically optimal control mode on a linear section of the magnetization curve and the mode with constant nominal magnetization in the magnetic saturation zone of the magnetic circuit. A block diagram of the system of energetically optimal control of the electromagnetic torque, as well as the modeling results performed on the basis of this scheme is presented. The conditions under which energetically optimal control is provided are indicated. The results of modeling and limiting characteristics of the algorithm of energetically optimal control of the electromagnetic torque with the control algorithm with permanent magnetization are compared.

No abstract