Position Sensorless Control System within Over-modulation Range Based on Mathematical Model Robust against Magnetic Saturation of IPMSMs

Abstract

This paper proposes a position sensorless control system for interior permanent magnet synchronous motors (IPMSMs) within the inverter over-modulation range. In general, using the position sensorless control method in the middle-and high-speed regions requires q-axis inductance, which varies significantly owing to magnetic saturation. Therefore, parameter mismatch may occur, which decreases the motor efficiency and causes control system instability. Furthermore, in the inverter over-modulation range, the performance of the auto current regulator deteriorates significantly because disturbance components, which consist of low-order harmonic current components, are fed back to the controller. As a result, the operation range is not appropriately expanded if no measurements are obtained for these components. First, the robustness against magnetic saturation is increased by constructing a position sensorless control system based on the L d model. Next, a comb-filter-based harmonic current countermeasure method is proposed. The position sensorless control system can expand the operation range in this method. Finally, the effectiveness of the proposed control system is confirmed by several experiments.

Design of band elimination filter for PMSM vector control operable in overmodulation region of inverter

“…[2][3][4][5][6][7][8][9][10][11][12][13][14][15] Using the overmodulation region makes it possible improve the inverter output voltage up to about 27% compared to control methods that drive in the linear region, which results in improvements in the drive region and the torque response of the PMSM. As such, there have been many studies on control methods that utilize the overmodulation region where the output voltage of an inverter can be raised using the same power supply.…”

“…[11][12][13][14][15] Reference 11 proposes a method of providing a band elimination filter (BEF) in the current feedback portion, but the design assumes use in applications where demands for current response and frequency fluctuation are low. [11][12][13][14][15] Reference 11 proposes a method of providing a band elimination filter (BEF) in the current feedback portion, but the design assumes use in applications where demands for current response and frequency fluctuation are low.…”

“…To answer the questions and problems with these studies, scientists have reported on a method for removing the harmonic components without using motor parameters by installing a filter in the current control loop. [11][12][13][14][15] Reference 11 proposes a method of providing a band elimination filter (BEF) in the current feedback portion, but the design assumes use in applications where demands for current response and frequency fluctuation are low. As such, this method is not fit for motor drives.…”