DSP-Based Current Control with Dead-Time Compensation for Full-Bridge-Fed Permanent-Magnet Electrodynamic Shaker

Abstract

Permanent-magnet electrodynamic shaker (PMEDS) can be seen as a single-phase reciprocating machine and its equivalent circuit model are an inductance, a resistance and an induced voltage in series. The induced voltage of PMEDS is near zero as the current frequency is far from the resonant frequency and its maximum operating frequency is several kHz near ten times larger than that of rotating AC machine. From the result of analysis, the dead time in gate signals has large effect on the high-frequency current tracking performance. In this paper, the PI-type controller and simple dead-time compensation loop are used to improve the current tracking performance during the range from 10Hz to 2kHz. The proposed current control is implemented in the digital DSP-based system and the full-bridge converter is connected directly to PMEDS without any LC filter. The effectiveness of the proposed current control is verified by the provided simulation and measured results.