Vector Control Strategy for Multidirectional Power Flow in Integrated Multi-Drives Starter-Alternator Applications

Abstract:The paper deals with the analysis and implementation of a vector control strategy devoted to Integrated Multi-Drive systems used in starter alternator applications with several DC buses at different voltage levels. The electromechanical system of the considered multi-drive topology is obtained by splitting the conventional stator winding of an induction machine into different n three-phase sub-units, maintaining the same mmf distribution and sharing same rotor. Each stator unit together with rotor can be considered a submotor, thus the entire electromagnetic system behavior can be considered as the combination of all sub-motors contributions. The sub-motors are suitably supplied through standard three phase inverters whose technical specifications are also established according to the storage unit voltage levels. Firstly, a detailed mathematical representation of the electromagnetic system has been developed; then, the conditions to carry out the field orientation in each generic sub-drive are determined. Addressing a starter-alternator system, the integrated multidrive configuration has been experimentally tested, highlighting the capability of the proposed approach to efficiently handle multidirectional power flows among the storage units and mechanical system while ensuring high dynamic performance.