Non-cascaded position controllers for servo motor drives


Generally, position controllers for servo motor drives utilize cascaded structures with speed and current controllers in inner loops. This structure provides easy gain setups and independent limits for control variables such as maximum torque or speed. However, it suffers from a large computation time and poor dynamic characteristics for the position control since the bandwidth must be low enough to guarantee those of the speed and current controllers. To cope with this, two non-cascaded position controllers where speed controller is removed are proposed. The first one is equivalent to the conventional controller in terms of the dynamic characteristics. However, the number of gains for the position control is reduced. The second one is aimed at improving the dynamic characteristics with more complicated structures. The proposed methods are effectively validated through MATLAB/Simulink simulations and 3.7 kW IPM motor drive experiments.

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Correspondence to Byung-Geuk Cho.

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Cho, BG., Hong, C. & Lee, J. Non-cascaded position controllers for servo motor drives. J. Power Electron. 21, 672–682 (2021).

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  • Position control
  • Non-cascaded position controller
  • Servo motor drive systems