The armature current can be seen as torque producing current while the excitation current is the field producing current. Bandyopadhyay, Deepak and Kim have written a book [27] explaining forms of designing such a surface. In sliding mode observer SMO systems, theoretically, the gain can be expanded to the limit of the used data type. This corresponds to the claim of controlling the direct axis current to zero in FOC. Fortunately, due to the oscillating character, the investigated compressor does not deal with constant speed and has no steady-state operation in a common sense. Position error closed loop Fig. In Electrical Machines and Systems,

This precludes the possibility to control the simple rotor fixed model as it is done in FOC. Finding a hyperplane which can be reached by bang bang control of an equivalent scalar input. Reduction of hardware complexity and cost, increased mechanical robustness and overall ruggedness, operation in hostile environments, higher reliability, decreased maintenance requirements, increased noise immunity and unaffected machine inertia [3]. In Electrical Machines and Systems, In Industrial Electronics Society,

Three-dimensional lookup table blockin- and outputs Figure A. First order systems on the contrary perform zero error with infinite gain.

Elektrische Antriebe – Grundlagen. Thus, it is appropriate to use the concept of pole variation. Sensorless vector and direct torque control, volume 42 of Oxford science dissertagion. One group is based on estimation of the EMF, often called back-EMF, while the other extracts the position by measuring the position dependent inductances saliency tracking or signal injection [17].


eidesstattliche erklärung dissertation jku

The simulation showed best performance by choosing the linear feedback term K to zero, since the velocity estimation is mainly extracted from the sliding mode feedback term H. All coils carry a current which can vary arbitrarily in time.

The output is typically modulated by pulse width modulation PWM. Since the plant is described in the time domain, this method now gives the possibility to design an observer. The mechanical model is explained in detail in the last two works. For further information concerning the lookup tables see Appendix A. Although the estimation shows good performance in the first periods there is a divergent error in the following.

Position error simulation setup II Fig.

The sliding mode concept does not control all states actively to zero but brings the system on a hyperplane which is constructed by the desired trajectory. In conclusion the purpose of this work is to use only one of these concepts. Rs is the stator resistance, Ld and Lq are the direct and quadrature inductances. Thus, the dynamics between them can be diswertation.

Skip to main content. A crankshaft transforms the rotating motion in a translational movement and moreover restrains the mechanical end position.

McGraw-Hill series in electrical engineering. On the other hand in sensorless mode the amplitude control block and the observer are provided by the position estimation of the observer itself.

The baudrate, data, stop and eideestattliche bits can be configured in the corresponding block. Additionally, the thermodynamic force FLoad and the friction FF riction react on the mechanical system.


On the hyperplane the system is autonomous since all degrees of freedom are used to drive the system there. However, the electrical system and further elements of the control structure have to be implemented on a real-time capable system.

Fitzgerald, Charles Kingsley, and Stephen D. The DTFC controls the desired values flux and thrust without a transformation.

eidesstattliche erklärung dissertation jku

They are less vulnerable to noise, can be designed to be dissertatino and if an appropriate feedback term can be found, it is possible to force any divergent errors to zero. The feedback amplitude block compares the maximum of the last period and the desired value and feeds the error to the integrator block. Position error closed loop Fig.

The EKF is jiu used for sensorless control [22, 6, 9]. Since the field of sensorless control is immense it is necessary to restrict the requirements of the investigated motor. This section is based on the statements of [3] and [16].

eidesstattliche erklärung dissertation jku

Position error simulation setup I Fig. All other parameters are similar to setup I.