SPRUJ53A April 2024 – June 2024 TMS320F28P550SJ , TMS320F28P559SJ-Q1
The idea of multiple modules controlling a single power stage can be extended to the 3-phase inverter case. In such a case, six switching elements are controlled using three PWM modules, one for each leg of the inverter. Each leg must switch at the same frequency and all legs must be synchronized. A sync receivers configuration easily addresses this requirement. Figure 18-66 shows how six PWM modules control two independent 3-phase inverters; each running a motor.
As in the cases shown in the previous sections, we have a choice of running each inverter at a different frequency (module 1 and module 4 are sync sources as in Figure 18-66), or both inverters can be synchronized by using one sync source (module 1) and five sync receivers. In this case, the frequency of modules 4, 5, and 6 (all equal) can be integer multiples of the frequency for modules 1, 2, and 3 (also all equal).