The significance of phase-lead compensation is revealed for repetitive control systems in terms of tracking accuracy and transient. A real-time noncausal phase-lead FIR filter is proposed to improve the performance of add-on repetitive controlled constant-voltage constant-frequency PWM dc¿ac converters. The experiment results show that nearly perfect tracking, low total harmonics distortion, and satisfactory transient are achieved in the proposed repetitive-controlled PWM converter under both linear load and rectifier load.@en