Influence of the modulation method on the conduction and switching losses of a PWM converter system

• Published in: IEEE transactions on industry applications Vol. 27; no. 6; pp. 1063 - 1075
• Main Authors: Kolar, J.W., Ertl, H., Zach, F.C.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.11.1991; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Bridges; Electrical engineering. Electrical power engineering; Exact sciences and technology; Frequency modulation; Leg; Optimization methods; Phase modulation; Power electronics, power supplies; Power system harmonics; Pulse shaping methods; Pulse width modulation; Pulse width modulation converters; Shape
• ISSN: 0093-9994; 1939-9367
• DOI: 10.1109/28.108456

The authors explore the dependency of the conduction losses of a bridge leg of a pulsewidth modulation (PWM) power converter system with a high pulse rate on the shape of the phase modulation functions. This is done for modulation methods that are optimized with respect to minimum harmonic current RMS values. The results are compared to the results gained for simple sinusoidal modulation. Besides conduction losses, the switching losses of the electric valves are calculated. The main topic is the determination of those power loss components of a PWM converter system that can be (besides the harmonic losses) influenced by the modulation method selected. As the calculations show, these modulation methods allow a significant increase of the effective switching frequency. The optimal modulation as calculated leads to a reduction of the harmonic power loss in the upper modulation region. Furthermore, due to the frequency modulation the spectrum is spread out to a wider frequency band as compared to operation with constant pulse frequency.< >