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M. Krammer:
"Aufbau einer demonstrationsfähigen sensorlosen zweiachsigen Positionsregelung mit industriellen permanent magneterregten Synchronmaschinen";
Betreuer/in(nen): E. Robeischl; Institut für Elektrische Antriebe und Maschinen, 2002.

The subject of this diploma thesis is the realisation of a highly dynamical sensorless biaxial positioning system with industrial manufactured components for the purpose of public demonstrations. In the used range of performance so called permanent magnet synchronous motors (PMSMs) are advantageous because of their high reliability (no commutator) and their good controllability.
The term "sensorless" denotes, that there is no mechanical sensor for the detection of the rotor position or for the detection of the linear position of the system. The actual rotor position will be detected only by the aid of mathematical models and current measurements. This leads to a substantial minimisation of costs and to a higher ease of maintenance.
Because of the claimed highly dynamical control a program architecture with interrupts is used. Therefore needful modifications of the INFORM-method, which was developed at the institute of electrical drives and machines for the rotor position detection at low velocities down to standstill, and of an emf-based model for higher velocities will be discussed in a separate chapter.
Interim test runs showed the necessity of limitation of the DC-link voltage because of the usage of a voltage source inverter with uncontrolled diode rectifier bridge on the line side. Therefore a brake chopper control print was developed. The possibility of energy transformation in the stator resistance of the PMSM was implemented in a digital signal processor (DSP) additionally.
The algorithms of the sensorless position detection and of the field oriented control are also implemented in the DSP.
To indicate signals on a scope a print with a digital-analog-converter was designed. In addition there is a 25-pin SUB-D-socket on it to read in an external position encoder.
A third function is given by the both 16k-RAM-chips. They can be written with data in real time, the readout can be done with a suited communication software. So it is possible to make statistic recordings e.g. of the exactness of the sensorless position detection.
Onto the both possibilities of energy transformation (external brake chopper / stator resistance) the possibilities of DC-link voltage detection are described. The whole voltage limitation is discussed in an own chapter.
Finally, in consideration of the exactness the reached dynamics are treated and measurements are presented.