This paper discusses a permanent magnet synchronous motor (PMSM) drive system based on direct torque control. First, in this paper we propose a novel torque-limiting and flux-weakening method. Torque limiting method capable of current limiting is based on the power equation instead of the motor model in the rotating d-q frame, which is synchronized to the rotor magnet. In this torque limiting method, the motor parameters need not be determined and this simplifies the limitation calculation. The proposed method incorporates a flux-weakening control that does not require motor parameters other than the armature resistance. These proposed schemes are implemented in a calculator for calculating the reference torque and reference flux. Second, we also propose an anti-windup scheme for torque control based on proportional and integral control. Generally, the controller winds up when the terminal output voltage of the inverter is saturated. The wind-up degrades the torque limiting and torque control performance. In the proposed anti-windup scheme, the gain of the integral element is varied on the basis of the degree of voltage saturation, which is detected by using the estimated flux-linkage. In this paper, the direct-torque-control-based drive system combined with a speed controller is presented, and the proposed system achieves stable operation. The proposed system is validated through experiments.