Abstarct: Induction machines (IM) are the most popular and widely used electric machines (EM) in the industry due to their reliability, robustness and relatively low cost. The rotor of IMs is generally subjected to thermal, mechanical and magnetic stresses that can cause the rotor cage bars to break. Failure to recognize this failure in time causes heavy and irreparable damages; Therefore, it is necessary to condition monitoring of EMs to reduce downtime, reduce costs and increase useful life. Recently, non-invasive approaches baxsed on motor flow analysis have gained attention due to their simplicity and low cost. Sideband frequency component analysis is the basis of most motor current signature analysis (MCSA) approaches. The frequency characteristic of the broken rotor bar (BRB) in the current spectrum is modulated by the fundamental frequency, which appears as sidebands around the fundamental frequency. In large machines with very little slip, these bands are very close to the fundamental frequency, making it extremely difficult to characterize the fault frequencies. baxse frequency leakage can mask fault components until the damage increases dramatically and leads to catastrophic motor failures. In addition, in IMs that work at low speeds, the speed reduction caused by the inverter and frequency reduction causes the baxse frequency to approach the fault characteristic frequency (2sfs). This makes the fault detection operation more complicated and increases the need for innovative and efficient methods. Considering the many advantages of MCSA, this thesis presents a new method that is designed baxsed on the rectified orthogonal axes technique (ROAT) of one-phase stator current. In this method, in addition to maintaining the characteristic frequency range of the fault in its real value, the fundamental frequency energy is transferred to the fourth harmonic (4fs) of the fundamental frequency. This transfer of fundamental frequency energy to higher harmonics will be particularly important in inverter driven IMs at low speeds. The proposed method has been applied to states 1, 2 and 3 of BRBs and the simulation results have been verified experimentally.