Decentralised Current Control for a Multiphase Permanent Magnet Machine Using EtherCAT

This paper outlines the design and implementation of a distributed current control architecture for a multiphase, independently excited permanent magnet (PM) machine. The high speed, low latency transmission of the EtherCAT protocol is exploited to create a communication and synchronisation network capable of supporting a control frequency of 5 kHz. Details of the EtherCAT data frame construction and an examination of the system timing are presented along with experimental results demonstrating excellent synchronisation amongst the distributed controllers and effective current reference tracking for an 11 phase, independently excited PM machine.