Analysis of distorted unbalanced waveforms in inverter drives
Abstract
A technique for determining the degree of unbalance in a three-phase electrical system is developed and demonstrated. Expressions for the distorted and unbalanced waveforms are derived; the effects of such waveforms on the performance of induction motors are estimated; the analysis of a typical system is outlined; and the errors inherent in FFT harmonic analysis are evaluated. A PC-based experimental digital measurement system is implemented, tested, and applied to a commercial three-phase PWM inverter with continuous output power 11 kVA, output voltage 380 V, and output frequency 5-50 Hz. The results are presented in extensive tables and graphs and characterized in detail, demonstrating the effectiveness of the procedure.
- Publication:
-
IEEE Transactions on Power Electronics
- Pub Date:
- April 1989
- DOI:
- 10.1109/63.24915
- Bibcode:
- 1989ITPE....4..298A
- Keywords:
-
- Analog To Digital Converters;
- Induction Motors;
- Inverters;
- Pulse Duration Modulation;
- Waveforms;
- Digital Techniques;
- Equivalent Circuits;
- Fast Fourier Transformations;
- Microprocessors;
- Electronics and Electrical Engineering