How to synchronize multiphase power line EMC in a power line carrier PLC?

EMC considerations for synchronous multiphase power line carrier PLCs include phase balance and noise cancellation. In a three-phase system, each phase is equipped with the same EMI filter, using a common-mode inductor CML4532A-510T and safety capacitors with consistent parameters to ensure balance. The carrier signal is injected through a three-phase coupling transformer, using a star connection with a neutral ground. Software algorithms adjust the phase of each phase carrier to cancel out radiation. A synchronous clock source ensures synchronized modulation of each phase carrier. Simulation analysis of the superposition effect of the three-phase radiation fields optimizes the phase difference. In actual testing, radiated emission tests are performed; the radiation of the three-phase system should be 10 dB lower than that of a single-phase system. Synchronous design enables the system to meet stringent EMC standards, such as CISPR 32 Class A.