PWM Precise Synchronous Control Method Based on EtherCAT Distributed Ring Net Topology

The circulating current is present generally in the parallel inverter system due to the asynchronous PWM. Aiming to the circulating current of the parallel inverter system, a PWM precise synchronous control method based on EtherCAT distributed ring network topology is proposed. By using the distributed clock of EtherCAT, the initial offset, transmission delay and clock drift between the clocks of each slave station are reduced to achieve PWM synchronization at each station. The establishment of the distributed ring network topology control experiment platform with EtherCAT and DSP as the core has verified the validity and feasibility of the above ring topology and synchronization algorithm.