Pulse width modulation for current source inverters with arbitrary number of phases

Area of Science:

• Electrical Engineering
• Power Electronics
• Control Systems

Background:

• Traditional current source inverter (CSI) modulation techniques are often adapted from voltage source inverters (VSIs).
• Existing methods like space vector modulation (SVM) and pulse width modulation (PWM) have limitations when applied to CSIs due to their unique switching requirements.
• VSIs allow per-phase modulation, unlike CSIs which necessitate a holistic switch consideration.

Purpose of the Study:

• To propose a novel PWM method specifically designed for current source inverters (CSIs).
• To develop a modulation technique that bypasses the complexities of SVM, such as sector identification.
• To provide a universally applicable modulation strategy for CSIs of any phase number.

Main Methods:

• A PWM method tailored for CSIs is derived using linear algebra to compute averaged duty cycles.
• A specialized multi-threshold pulse width modulator is designed for CSIs to generate gate signals from these duty cycles.
• The proposed method avoids sector identification and other SVM-specific requirements.

Main Results:

• The proposed PWM method for CSIs was validated through both simulation and extensive experimental results.
• The technique successfully generates gate signals for CSIs without requiring SVM's sector identification.
• The approach is demonstrated to be general and applicable to CSIs with varying numbers of phases.

Conclusions:

• The developed PWM technique offers a simplified and effective modulation strategy for current source inverters.
• This method provides an alternative to traditional VSI-derived techniques, addressing CSI-specific challenges.
• The approach is suitable for a wide range of CSI applications, regardless of the number of phases.