Fully decentralized modular approach for parallel converter control

A completely decentralized solution (real masterless) for parallel converter control is presented. A control module dedicated to each switching cell, communicating with its neighboring modules, is presented in detail. It is able to provide the computation of the common mode duty cycle, the balancing of the leg currents and the proper phase shift for the interleaved carriers of the converter in a decentralized manner. The implementation of a converter using a large number of parallel legs becomes easy because an identical control module is associated with each switching cell and the modules are connected together in a daisy-chain configuration. This approach eliminates the use of a centralized control circuit. It works regardless of the number of legs and provides the ability to add or remove dynamically a leg easily. A characterisation board has been made and demonstrates the validity of the solution. Moreover it shows that, using this modular control approach, a leg of the converter may be add or remove dynamically without any additional control consideration.