A New Synthesis Technique of Control Signals for Power Converters Based on Pulse Position Modulation

Over the last years there has been plenty of research activity about modulation techniques with the aim of optimizing power converters performance. Traditional methods such as Pulse Width Modulation and Selective Harmonic Elimination/Mitigation are widely used but have limitations in harmonic performance and dynamic response. This paper aims at presenting a completely new approach in the synthesis process of control signals referred to as Pulse Position Modulation, which can generate the best possible control signal by adding up not-centered pulses in each control period. In particular, the proposed technique can optimize the positions of all the pulses making up the overall control signal thus allowing better harmonic performance compared to Pulse Width Modulation techniques featuring fixed position of the pulses. Moreover, the proposed technique allows for largely better dynamic performance in comparison to techniques such as Selective Harmonic Elimination/Mitigation that can similarly optimize the harmonic quality by modifying the position of the pulses. The paper includes a thorough mathematical analysis of the control signal synthesis technique, essential for correctly identifying the optimal pulse positions. A complete campaign of experimental tests proves the remarkable enhancement of this innovative approach in harmonic quality and dynamic performance compared to the above-mentioned techniques.