*3.3. PWM Generation*

For the power electronics and inverter-based machine drive, the PWM generation strategy is the final step of the digital implementation. Since both the proposed method and SVM strategy apply two adjacent active vectors and two null vectors during each sampling period, their PWM generations are essentially the same, as illustrated in Figure 4. For example, assuming that the two selected active vectors are *V*<sup>1</sup> and *V*2, the sequence of vector actions is *V*0-*V*1-*V*2-*V*7-*V*2-*V*1-*V*0, as shown in Figure 4a. This operation provides two interesting features simultaneously. On the one hand, just one-phase switching state alters at any instant and reduces the switching loss to some extent. On the other hand, similar to the conventional PI-SVPWM method, the switching frequency is unified since the switching state changes twice during each sampling period. This feature creates an advantage worth mentioning in terms of filter design.

**Figure 4.** The sequence of vector actions for different vector combinations: (**a**) *V*<sup>1</sup> and *V*2; (**b**) *V*<sup>2</sup> and *V*3; (**c**) *V*<sup>3</sup> and *V*4; (**d**) *V*<sup>4</sup> and *V*5; (**e**) *V*<sup>5</sup> and *V*6; (**f**) *V*<sup>6</sup> and *V*1.
