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With reference to speed controlled induction motor drives, an algorithm which allows the on-line estimation either of the speed and one motor parameter or, alternatively, of two motor parameters, is presented in the paper. The results obtained by simulation fully confirm the validity of the proposed algorithm. At last, the problems arising from the implementation of the proposed algorithm on a DSP-based control hardware are analysed. Keywords: induction motor drives, velocity control.

A novel modulation technique for optimizing the performances of voltage source inverter feeding induction motor drives is presented. It is based on a variable frequency modulation technique, changing step-by-step the switching frequency of the power modules in order to achieve a reduction both of the switching losses and of the output voltage distortion. In addition, this technique is combined with the "single switch commutation" one, which allows to reduce the blank time imposition during the switches commutations. The proposed modulation strategy has been implemented by means of a digital modulator and several tests have been performed in order to verify its validity and feasibility. [ABSTRACT FROM AUTHOR]

Analysis of the internal electromagnetic compatibility of digitally controlled power converters is discussed. In particular, the optimum layout of the circuit configuration is designed on the basis of the actual electromagnetic interference between the power and the control section of a power converter. Besides, further improvements can be achieved by means of an auto-tuning additional board, which scans all the possible converter switching frequencies and analyses the distortion on the control signals corresponding to each frequency. Its main task is to select only the ones which produce low disturbances on the control signals as operating frequencies for the converter. [ABSTRACT FROM AUTHOR]

A self-commissioning algorithm for the determination of the parameters of an induction motor fed by a VSI is proposed. It is based upon the consideration that when the motor is fed by a distorted voltage waveform, in no-load steady-state operating conditions, the slips corresponding to harmonics are very near to the unity. This circumstance can be exploited in order to perform an evaluation of the motor parameters only by means of a no-load test, provided that an adequate harmonic content of the feeding voltage is imposed. The validity and feasibility of the proposed algorithm are proved by experimental implementation. [ABSTRACT FROM AUTHOR]