Maria Pietrzak-David

Dual Direct Torque Control of Doubly Fed Induction Machine

The main idea developed in this paper is a novel biconverter structure to supply a doubly fed induction machine (DFIM). Two voltage source inverters (VSIs) feed the stator and rotor windings. The outputs of the two VSIs are combined electromechanically in the machine, and as a result, novel features can be obtained. For example, for high power drive applications, this configuration uses two inverters dimensioned for a half of the DFIM power. A new dual direct torque control is developed with flux model of DFIM. Two switching tables linked to VSI are defined for stator and rotor flux vector control. The satisfactory experimental and simulation results are shown, and they confirm good dynamic behavior in four quadrants of the speed-torque plane. Moreover, experimental results show the correct flux vector control behavior and speed tracking performances.

Minimum Copper Loss and Power Distribution Control Strategies of Double-Inverter-Fed Wound-Rotor Induction Machines Using Energetic Macroscopic Representation

A double-inverter-fed wound-rotor induction machine (DIF-WRIM) requires two inverters whereas standard configuration using induction machines requires one. This supplementary inverter leads to more possibilities with respect to energy management. Indeed, it allows new DOFs to be used. Energetic macroscopic representation (EMR) is used to represent the system in a graphical way. The model of the system is thus organized to highlight the DOFs of the system. An inversion-based control is then graphically deduced from the EMR of the system. Two strategies regarding the energy management are then used to exploit all DOFs. First, the distribution of the active power between the stator and rotor is achieved as in other works. A new minimum loss strategy is then added to increase the efficiency of the system. Experimental results validate the suggested control with both strategies, and good dynamic performances are achieved.

Simple Low-Speed Sensorless Dual DTC for Double Fed Induction Machine Drive

In this paper, a doubly fed induction machine (DFIM) operating in motor mode and supplied by two voltage source inverters-in stator and rotor sides-is presented. The aim is to analyze the sensorless rotor position operation of a dual direct torque control (DDTC) of the DFIM. This paper presents a sensorless DDTC for a DFIM speed drive in order to guarantee the static and dynamic system performances. The sensorless DFIM operation provides an analytical redundancy in the case of mechanical sensor failure and ensures the service continuity of the drive. SABER simulation and experimental results illustrate the satisfactory behavior of the system with or without the use of the rotor position sensor. These confirm the preservation of system performances, particularly during the low-speed sensorless control operation. The proposed solution is particularly relevant due to its simplicity.

DFIM vector control sensitivity with current sensor faults

Purpose – The purpose of this paper is to present a doubly fed induction machine (DFIM) operating in motor mode and supplied by two voltage source inverters (in stator and rotor sides).Design/methodology/approach – The aim is to analyze the current sensor fault effects on the stator flux‐oriented control according to the current input‐output decoupling. This justifies the necessity of a reconfiguration control in order to satisfy the system service continuity. Also, a theoretical development of sensitivity coefficients gives an idea about control robustness toward a current sensor fault.Findings – This paper emphasizes the system performance close dependency to the current sensor outputs accuracy. Moreover, simulation results point out the operation system deterioration in case of current sensor fault, which leads in most cases to its shut down in contrast with the industrial expectations. In this paper, the suggested solution is the DFIM speed drive control reconfiguration when a current sensor fault occ...

Sensitivity of the currents input-output decoupling vector control of the DFIM versus current sensors fault

The goal of this paper is a Doubly Fed Induction Machine (DFIM) working in motor mode and supplied by two voltages PWM inverters, in stator and rotor sides. Effects of current sensors faults on the currents input-output decoupling in the Stator Flux Oriented Vector Control (SFOVC) are analyzed. A sensitivity study is carried out considering both stator and rotor current sensors failure, under different working conditions and a large speed range. Stator flux coefficient sensitivities emphasize the required accuracy of the currents sensors to guaranty the correct angle orientation and the required level of control performances. Matlab-Simulink simulation results are given and illustrate this sensitivity analysis.

Modeling of 3-phase induction machine as single phase generator for electricity generation from renewable energies in rural areas

This paper presents modeling, simulation and experimental results of a three phase induction motor running as single phase generator. Modeling is performed on a small power induction motor with squirrel cage, one phase for excitation and the others for load supply It includes a new model of the total losses, i.e. mechanical, copper and iron losses thanks to the design of experiment method (DoE). Experimental results obtained in Cambodia for load and voltage excitation variations on a reduced power test bench are good agreement with simulations, confirming the validity of the proposed models. Target application is electricity production form pico-hydropower in rural areas in developing countries.

Non-Linear Control with Adaptive Observer for the Sensorless Induction Speed Drives

Abstract In the framework of the sensorless non-linear control of a PWM fed induction motor drive, an original strategy is proposed. The latter is an association of the control based on the Inputs-Outputs (I/O) system lineatharion [2], with a MRAS (Model Reference Adaptive System) state observer [7]. The observer design and synthesis uses Popov’s hyper-stability theory. For the sensorless drive, the rotation speed adaptive law is proposed [5]. All control and observation parameters are determined analytically. The precise simulations of the global system allow to testing the basic Operation functions of this drive and especially the good behaviour at very low rotation speed. Significant experimental results are discussed to illustrate the dynamic performances of this induction motor drive in the four quadrants of the torque – speed plane.

INFLUENCE OF QUANTIZATION EFFECTS AND PARAMETERS DEVIATIONS ON THE PERFORMANCE OF A FIELD ORIENTED ASYNCHRONOUS DRIVE

SUMMARY During the last few years, the control of induction machine by the field orientation method has become the preferred technique which yields very good performances. This method allows to define the dynamic structure of an induction machine which is similar to that of D.C machine. This is obtained by controlling the angular position of the rotor flux so that the flux and torque can be decoupled. The process to be controlled is composed of an autopiloted induction machine fed by a voltage inverter. In this paper the authors study the influence of different problems due to the numerical processing of informations by the computer on the system performances. These problems, usually neglected, are closely related to the performances and the dynamic of the system to be controlled. It should be noted that the vector control method is very sensitive to the precision with which the angular position of the rotor flux has been determined. The use of a computer in the regulation chain implies a sampling time an...

An experimental test bench for a distributed railway traction mechanical load emulator

The purpose of this paper is to design an emulator of a railway traction bogie. This bogie consists of two induction motors coupled by common load. This mechanical load is replaced by an emulator using two induction motors. This permits to validate the drive controls and the behaviour of traction motors by homothety of the real system and taking into account different disturbances.

Flux-weakening strategy for high speed PMSM for vehicle application

High speed Permanent Magnet Synchronous Motors (PMSM) are used in electrical vehicles because of their strong power density. The high speed implies a big electromotive force and requires flux-weakening. Usual control algorithms do flux-weakening by adding negative Id current when the required voltage by the current regulation exceeds the maximum voltage depending on the battery. If the magnet can be totally defluxed then it is better to use a Maximum Torque Per Volt (MTPV) strategy. Furthermore there is no speed regulation in the control and the driver gives a torque reference that has to be limited to the reachable operating points; the battery power limit has to be taken into account in addition to the voltage and current limits. The d-q current reference are calculated to minimize the total current magnitude required to reach the reference torque. This paper presents a salient pole PMSM control that calculates the minimum magnitude current references to obtain the reference torque while respecting the voltage, current and power limits with a flux-weakening strategy and including MTPV operation in a unified algorithm. The effectiveness of the proposed method is observed through simulations.