State space model of a modular speed-drooped system for high reliability integrated modular motor drives

Future transportation challenges include a considerable reduction in pollutant emissions at a time when significant increase in demand is predicted. One of the enabling solutions is the electrification of transport systems as this should lead to improved operability, fuel savings, emission reduction and maintenance. In this framework, the electrical power drivetrain is central. Whilst state-of-the-art technology has demonstrable benefits there needs to be considerable advancement to meet future transportation affordability and emission targets. Primarily, electrical drives need an improved power density, an increased reliability and a reduced specific cost. For this reason, Integrated Modular Motor Drives (IMMD) presents an attractive solution. Modularity leads to redundancy and easier integration. A novel speed-drooped control system applied to motors fed by modular converters is proposed. This control technique allows to control the speed and to share the power among different segments without any direct communication between the modules. The state space model is provided and validated with Matlab/Simulink.