Oleg V. Nos

Control strategy of active power filter for ineffective instantaneous power compensation

This paper considers basic concepts of a new approach to three-phase currents decomposition into active and reactive components. This general principle is used to design a control strategy for compensation the quaternion of inactive instantaneous power. Experimental research of active power filter (APF) with control system implementing based on the hypercomplex space will be discussed here.

Control strategy of shunt active power filter based on an algebraic approach

In the report the basic principles of an algebraic approach to generate instantaneous compensative actions in an active power filter by means of algebra of four-dimensional hyper-complex numbers are described. This approach is based on the separation of instantaneous power into real and imaginary terms. The experimental testing shows the control strategy of instantaneous compensation allows to achieve unity or leading power factor at sinusoidal waveform of source currents in the non-linear unbalanced load.

Linear transformations in mathematical models of an induction motor by quaternions

This report presents the analyze of linear orthogonal transformation for mathematical description of electromagnetic transients in a three phase squirrel-cage induction motor by quaternion basis.

The synchronous switching of motor power supply from frequency converter to grid for an AC drives with field-oriented vector control

The report is dedicated to the closed-loop design for a phase locking and a magnitude balancing of the three-phase inverter voltages to the three-phase grid voltages when the AC motor stator windings are switched to the AC power supply from the power frequency converter and backwards. The proposed control strategy for the AC drive with IGBT-inverter allows to decrease an inductance of current-balancing reactor and to avoid the operation under fault conditions after current surges.

State of charge control of the mixed-type battery energy storage system based on the modular multilevel converter

This work describes a symmetrical transformation approach for the state of charge control of a mixed-type energy storage system based on the modular multilevel converter. By decoupling of external and internal arm power flows the transformation offers a comprehensible insight into the state of the system. Storage unit current limitations are taken into account in the described control structure.

The instantaneous power quaternion of the three-phase electric circuit with linear load

The report deals with the study of a scalar (real) and a vector (imaginary) parts of instantaneous power quaternion in frame of algebraic approach applied to the different types of three-phase resistance-reactance and nonlinear loads. The target is to determine the inactive components of the total AC electrical energy flows per time unit for current compensation by means of active power filters. Based on made quantitative analysis, the different compensation objectives in the terms of hyper-complex numbers are have been formulated in the report. The compensation objectives permit to provide balanced or/ and sinusoidal source currents in the three-phase systems with the desired phase shift relative to the corresponding voltage.

The quaternion model of doubly-fed induction motor

In the report the stator and rotor equations of three-phase AC induction machine in the four-dimensional hyper-complex space are described. This motor model is based on the mathematical tool of quaternion algebra and allows to separate the electrical torque and instantaneous power into real and imaginary terms, thus giving new technique for improvement of dynamic and power performances of speed AC drives.

Dynamic model of induction motor in the hyper-complex space

In this paper, the stator and rotor voltage differential equations of an induction motor with a squirrel-cage rotor (IM) and electrical torque formula are presented in frame of the quaternion tools. The mathematical representation has been obtained after different coordinates transformations which are invariant with respect to the scalar quantities. The applying of the IM dynamic models based on the hyper-complex space allows the separation of the instantaneous power into real and imaginary components and by this to describe the electromechanical energy conversion in more detail.

Control strategy of inactive instantaneous power compensation in quaternion basis

The article describes the existing separation of instantaneous power conservation of three-phase generating system into active and reactive components, the control strategies of active power filter (APF) and suggests a new concept for compensation of an inactive electrical energy based on noncommutative algebra of hypercomplex numbers (quaternions). The control method of APF compensating references generation in case of nonlinear unbalanced three-phase load is presented.

DC-bus voltage control strategy of active power filter

This paper presents a PI-algorithm to control DC-bus voltage of an active power filter used for charging a capacitor bank with the desired performance of transient process and stabilizing the controlled variable with a zero steady-state error.