Marcin Morawiec

The Adaptive Backstepping Control of Permanent Magnet Synchronous Motor Supplied by Current Source Inverter

The sensorless control system of permanent magnet synchronous motor (PMSM) fed by current source inverter is presented in this paper. The adaptive backstepping control system and the backstepping speed observer are presented. The control systems are based on multiscalar variables. The control variables are dc-link voltage and the output current vector pulsation. The control system was named the voltage control system because of the fact that the first control variable is voltage in dc-link. The machine inverter is treated as a commutator. It works with constant modulation index. The proposed control system is robust on mechanical and electromagnetical parameters of the motor. The adaptive estimator of the stator resistance is introduced. Such an approach to control of the PMSM motor gives better performance. It is robust to dynamic uncertainties and does not require knowledge of the system parameters. The mathematical equation was introduced. Simple method limitation of control variables is explained. The reference variables must be limited to a constant or various value if the motor system has to be used in the industrial applications. The simulation and experimental test are shown.

Z-Type Observer Backstepping for Induction Machines

This paper contains a relatively new synthesis method for nonlinear objects, which is named backstepping. This method can be used to obtain the observer structure. This paper presents the structure of the speed observer, which is a new proposition of observer backstepping with additional state variables marked Z. The rotor speed can be estimated in three different ways. The first is based on the adaptive approach, the second on the nonadaptive approach, and the third on improvement of the adaptive approach. The stability of the Z-type observer is determined by the Lyapunov stability criteria. Despite this, stability analysis around the machines working point is undertaken. All the machine tests are prepared in the sensorless control system based on multiscalar variables. The experimental results show the effectiveness of the proposed solution. The squirrel-cage model parameter estimation is not presented in this paper.

Advances in CSI-fed induction motor drives

The application of current source inverters (CSI) in induction motor (IM) drives offers a number of advantages, including: voltage boosting capability, natural shoot-through short-circuit protection and generation of sinusoidal voltages. The exact generation of sinusoidal voltages is possible thanks to thanks to the effect of the output ac filter capacitors and may improve the accuracy of sensorless IM control. The elimination of high dv/dt in CSI fed IM drives provides also a noticeable electromagnetic interference (EMI) reduction. The paper presents recent achievements of current source inverters (CSI) which are the use of new genertion silicon carbide (SiC) devices (normally-off SiC JFETs and SiC Schottky diodes) and the application of modern nonlinear control which may considerably improve the performance of CSI fed IM drives.

Speed observer based on extended model of induction machine

An universal structure of the speed observer is proposed for induction machines. The speed observer is based on extended model of induction machine, in which additional variables are added to a set of state variables. Properties of the proposed observer are presented using simulations of full control systems for the induction machine and experimental results.

Sensorless control system of an induction machine with the Z-type backstepping observer

The paper presents the sensorless control of induction machine based on multi-scalar variables in which the rotor angular speed is estimated by the novel structure of the speed observer. The novel speed observer structure is constructed by using the backstepping approach. This observer structure is named Z-type observer backstepping. A comparison between the standard adaptive backstepping and the Z-type observer backstepping is made. The experimental results show the properties of the control system and in particular the Z-type observer backstepping.

Voltage multiscalar control of induction machine supplied by current source converter

Control systems for the induction motor fed by current source converter based on a multiscalar models are presented in this paper. The topology of current source inverter is shown. Equations of multiscalar model of the induction motor are derived. The multiscalar model is the new approach to the control of induction motor based on DC-link current and rotor flux vector. The speed observer system is applied to receive sensorless drive. Properties of the sensorless control system are presented. The investigation carried out on experimental drive system confirms simulation results.

Sensorless control system of induction machine supplied by voltage source inverter with output filter

The paper focuses on sensorless control of the induction machines supplied by inverter with the output filters. “The novel” idea of the speed observer which is based on the backstepping approach is shown. The standard structure of the exponential observer is extended by the integrators and additional Z vector. The simulation and experimental results validate the proposed solution.

Control strategy for the multilevel cascaded H-bridge converter

The control system for Cascaded H-bridge (CHB) converter is proposed in this paper. The converter output voltage is controlled using a Space-Vector Pulse Width Modulation (SV-PWM). The DC-link voltages are controlled by appropriate choice of H-Bridges, used to output voltage generation. The simulation researches of two multilevel CHB rectifiers are presented. These rectifiers were utilized to coupling of two AC grids. Proposed control strategy allows to good voltage stabilization on the DC-link capacitors.

Sensorless control of five-phase induction machine supplied by the VSI with output filter

In this paper, a novel sensorless control structure based on multi-scalar variables is proposed. The static feedback control law is obtained by using the multi-scalar variables transformation, where the multi-scalar variables approach allows a full linearization of the nonlinear system. The control system could be described as “optimized” because of the minimized number of controllers. Furthermore, control system is divided into two independent control systems which are synchronized by additional controllers. The first control system is responsible for the generation of the 1st fundamental harmonic, while the second control system is responsible for the generation of the 3rd harmonic. Both control systems are synchronized and ensure a trapezoidal shape of air gap induction waveform regardless of the machine operation point. In order to ensure a sensorless control system the rotor angular speed and the state variables are estimated by a speed observer. This speed observer is based on the backstepping approach. All analytical proposed assumptions are confirmed by simulations and experimental results.

Sensorless field oriented control of five phase induction motor with third harmonic injection

In this paper, a sensorless field oriented control system of five-phase induction machine with the 3^rd harmonic rotor flux is presented. Two vector models, α<inf>1</inf>-β<inf>1</inf> and α<inf>3</inf>-β<inf>3</inf>, were transformed into d<inf>1</inf>-q<inf>1</inf>, d<inf>3</inf>-q<inf>3</inf> models oriented in rotating frames, which correspond to the 1^st and 3^rd harmonic plane respectively. The authors proposed the linearization of the model in d-q coordinate frames by introducing a new variable “x” which is proportional to the electromagnetic torque. Based on the static feedback control law, a dual mathematical model of the five-phase induction machine was linearized to synthesize a control structure in which electromagnetic torque and the rotor flux in each plane can be independently controlled. The control system proposed includes two uninfluenced subsystems (related to the 1^st and 3^rd harmonic), which are specifically synchronized to obtain a quasi-trapezoidal air gap flux distribution. This pattern provides a better iron utilization without saturating it, which consequently, increases the output torque. To accomplish a sensorless control configuration the state machines variables and the rotor speed are estimated by an extended speed observer. The proposed control algorithm was verified on an experimental setup. The results presents the desired air gap flux in steady as well transient states under various load conditions.