This paper presents a transducerless rotor position and velocity estimation scheme for induction, synchronous, and reluctance machines driven by PWM inverters. The method involves injecting a balanced three-phase high-frequency signal (500 to 2 kHz) generated by the inverter, followed by signal demodulation and processing combined with a closed-loop observer. This enables the tracking of rotor magnetic saliencies from the machine terminals, which are inherent in reluctance and synchronous machines and introduced via modulation of the rotor slot leakage in induction machines. The approach overcomes limitations of previous methods by providing robust and accurate dynamic estimation independent of rotor position, speed, and load at high speeds and under various loading conditions. Experimental verification is provided for induction machines, demonstrating the viability of the proposed method. The paper also discusses machine design considerations to enhance rotor saliency tracking and highlights the applicability of the approach to other types of polyphase AC machines.This paper presents a transducerless rotor position and velocity estimation scheme for induction, synchronous, and reluctance machines driven by PWM inverters. The method involves injecting a balanced three-phase high-frequency signal (500 to 2 kHz) generated by the inverter, followed by signal demodulation and processing combined with a closed-loop observer. This enables the tracking of rotor magnetic saliencies from the machine terminals, which are inherent in reluctance and synchronous machines and introduced via modulation of the rotor slot leakage in induction machines. The approach overcomes limitations of previous methods by providing robust and accurate dynamic estimation independent of rotor position, speed, and load at high speeds and under various loading conditions. Experimental verification is provided for induction machines, demonstrating the viability of the proposed method. The paper also discusses machine design considerations to enhance rotor saliency tracking and highlights the applicability of the approach to other types of polyphase AC machines.