5.4.5. Zero-Speed / Maximum Torque (ZS/MT)

5.4.5.1. Overview

Zero-Speed / Maximum Torque (ZS/MT) provides high torque capability at standstill and at moderate speeds for some permanent-magnet synchronous motors with rotor saliency, such as interior permanent-magnet synchronous motors (IPMSM).

ZS/MT applies a high-frequency excitation signal to estimate position from the motor’s inductance characteristics. (This makes it an intrusive estimator.) Figure 5.74 shows a high-level block diagram containing the excitation, phase detection, and phase-locked loop blocks of ZS/MT.

Figure 5.74 ZS/MT block diagram

5.4.5.2. Further information

This feature is freely available as of MCAF R7, but documentation is provided only by request. For more information, please contact Microchip.