Abstract: A new high-order phase-locked loop (HOPLL) for sensorless control of permanent magnet synchronous motor (PMSM) is proposed to solve two shortcomings of the conventional phase-locked loop (PLL), i.e., incapability in realizing speed reversal and an unsatisfactory balance between dynamic and steady-state position tracking error. By constructing a new input error signal, the sign of the speed variable in position error signal is eliminated. Nevertheless, this constructed error signal contains double-fundamental frequency position information, resulting in two sets of convergence points, i.e., 0 or 180 degrees error from the actual position. To solve this problem, based on the relationship between the estimated q-axis back electromotive force and the estimated speed, a polarity correction function is designed to cooperate with the HOPLL. Then, the sensorless drive can converge into the correct position both in positive and negative rotation conditions. Furthermore, an estimated speed feedforward compensation is added into the HOPLL, then the position tracking error can be reduced in linear acceleration and deceleration conditions, which enhance the control accuracy and anti-disturbance ability of the sensorless drive. The proposed HOPLL method is comprehensively verified in a PMSM sensorless drive using a Luenberger observer in experiments.