Slawomir Stepien

Modeling and optimal control of variable reluctance stepper motor

Purpose – The purpose of this paper is to present a method of modeling the variable reluctance stepper motor using the time‐stepping finite element technique. The proposed model is used to obtain the optimal control law for the input circuit solving the linear‐quadratic problem.Design/methodology/approach – A strongly coupled field‐circuit model of the stepper motor is presented. Also, the method of the optimal control that minimizes the power loss in the motor windings is proposed.Findings – The proposed optimal control method can be applied to the electrical machines connected to the electronic converters. Calculated control signals may be used to obtain the optimal waveforms of the input voltages at each phase of the analyzed machine.Originality/value – The paper examines the application of the presented control method to minimize the power loss in the stator windings of the four‐phased variable reluctance stepper motor.

Multi-modelling as new estimation schema for high-gain observers

The presented paper proposes a novel method of observer design. A new two-layer observer structure is introduced. The first layer consists of multiple high-gain observers. The latter is built to connect the first layer observers into single one. As the new contribution, the new mapping is defined between an unknown state and measurable outputs allowing to explore new estimation schema. Hence, the proposed method enhances the estimation process for linear and nonlinear systems. Furthermore, it is shown that the introduced observation scheme improves the transients. Illustrative examples are calculated to show the properties of the new observation method.

The study on the model reference adaptive control with proportional derivative action

This article presents a study on the novel method of model reference adaptive control (MRAC). As a new contribution, the derivative action is included into MRAC control to improve the controller performance and efficiency. The stability is analysed using a recent technique called immersion and invariance. The simulations of derived laws are presented based on nonlinear models.

Modelling and position control of voltage forced electromechanical actuator

Purpose – To present modelling and control technique of an electromagnetic actuator.Design/methodology/approach – A 3D modelling technique of voltage‐forced electromechanical actuator takes into account: motion, magnetic non‐linearity and eddy current phenomena. Control problem of closed loop system is described by coupled electro‐magneto‐mechanical equations and non‐linear PID controller equations.Findings – Presented methodology offers a powerful tool for analysis of control systems with distributed parameters models and may contribute to the improvement of the electromechanical performance of electrodynamic devices.Originality/value – As original contribution a position feedback control using conventional PID controller is applied for iterative determining inverse dynamic problem, that is finding input voltage for a given position of an actuator.

Minimum energy control analysis of the switched reluctance stepper motor considering a nonlinear finite element model

Abstract A method of modeling and numerical simulation of a minimum energy control of the switched reluctance motor using time stepping finite element (FE) technique is presented. In proposed model, the nonlinear electromagnetic field equations and the circuit equations are strongly coupled and solved together with motion equation at each time step. The nonlinearity problem is solved employing the Newton–Raphson (NR) procedure. Presented control technique is based on linear–quadratic problem and adopted to the nonlinear finite element model. The optimal control strategy is numerically investigated and compared with commonly used control strategy for the square wave excitation.

Adaptive control of permanent magnet synchronous motor with constrained reference current exploiting backstepping methodology

The presented paper proposes a novel control method of Permanent Magnet Synchronous Machine. Thanks to a recent technique called adaptive backstepping, adjustment of all motor parameters is obtained considering well known dq model. Furthermore, the introduction of a new trajectory generator gives the possibility to limit the reference current without breaking the adaptation process. Examples are calculated to illustrate the properties of the new control method.

Determination of electromagnetic torque with on‐line computation of the optimal radius of the integration contour

Purpose – The purpose of this paper is to calculate the electromagnetic torque at a radius of an integration contour for which an optimal value is determined.Design/methodology/approach – To analyze electrical machine dynamics, the electromagnetic torque should be precisely determined. This paper presents a method for calculating the torque, where the radius of the integration contour is variable and estimated from the field distribution.Findings – The electromagnetic torque of the three‐phase AC motor model proposed in TEAM Problem No. 30 is estimated using the proposed method. The obtained results are compared to solutions obtained analytically.Originality/value – This paper examines the application of the presented method to determine the electromagnetic torque in three‐phase AC motors.

The adaptive torque controller for the brushless DC motor

Abstract This research presents a new adaptive torque controller for the brushless DC motor. The command torque is achieved by the phase current reshaping. The recursive least square algorithm is used for the online parameters estimation, hence the indirect adaptive controller is built.

Power losses analysis in the windings of electromagnetic gear

Presents 3D method for the computation of the winding current distribution and power losses of the electromagnetic gear. For a prescribed current obtained from measurement, the transient eddy current field is defined in terms of a magnetic vector potential and an electric scalar potential. From numerically obtained potentials the power losses are determined. The winding power losses calculation of an electromagnetic gear shows that a given course of the current generates skin effect and significantly changes the windings resistances. Also presents the designing method for reducing power losses.

The Adaptive Speed Controller for the BLDC Motor Using MRAC Technique

Abstract This research presents a new adaptive speed controller for the brushless DC motor. The methodology of model reference adaptive control is applied to a novel model of BLDC motor. This novel model provides the possibility to compensate the torque ripples and load torque. The system stability is proven using Lapunov function.