| Abstract |
The harmonic losses and peak currents in motors supplied by PWM inverters can be significantly reduced by means of optimized pulse patterns. In the past, the design engineer has been presented with a bewildering variety of pulse patterns and optimization methods for finding the desired optimum. With all these processes, there is always the uncertainty with respect to high pulse numbers as to whether the absolute optimum or merely a local optimum has been found. The purpose of this paper is to structure and classify the numerous optimized pulse patterns, and to illustrate their appearance and characteristics. The classificatlon of pulse patterns results in a number of criteria which can serve with a high degree of reliability for deciding whether the optimum has been found. The paper also presents a vector-oriented optlmization method which allows optimization up to very high pulse numbers and requires only little computation time. In this case, minimizing the harmonic losses in the motor was chosen as the criterion for optimization. |
