The analysis and design of the switching signal generator for three phase voltage source inverters (VSI) is proposed in this work. Different from the space vector pulse width modulation (SVPWM) that achieves the three phase input voltage by combination of the basic space vectors, the proposed method is designed to minimize the filtered measure of quantization error. Analysis of error signal is discussed and the conditions to bound the system states are suggested. Various input signal are applied in the simulation. It is shown that the switching number is reduced to 60-700/0 of the switching number of SVPWM method, conforming the effectiveness of the proposed scheme.