kas This paper proposes two thermal monitoring meth- machines with direct tormue control (OTC). The eesistamce R, isased as a direcnndicator of average winding atsugeesaure sad is estitanated via a du current offset in the stator wisilang a DTc drive system, the major challenge is how to the current offset via the only existing flux and torque brags. The quantitative relationship between the desired theset and the corresponding changes in fiux linkage a is derived, and this shows that the de current offset can be achieved either by superimposing flux linkage bias com- in the flux control loop (method 1) or torque riveie command AT ms ret in the torque control loop (method 2L budh shown in Fig. 1. Simulation results confirm the analyti- cal analysis the two proposed methods; while the experimental auta prove that beth methods achieve accurate temperature esti maatiaa under various operating conditions. The proposed simple and efficient signal injection-based temperature estimation tech- se is particularly advantager as since it eliminates the need for mmhedded temperature sensors requires no hardware change to crementional DTc e systems, and has a minimal impact on the induction machine's normal operation. Index Tamms--Direct torque control DTC), induction machines signal injection, stator vesistance estimation, temperature estimaitism.