This paper analyzes a novel optimization strategy of current control trajectories for hybrid excited synchronous machines (HESMs). The analytical solution for the Extended MTPA condition for HESM is provided for the first time, filling a gap from a theoretical perspective toward the optimization of the overall Joule losses of the machine, both rotor and stator, for each operating condition. Furthermore, a transient torque compensation strategy is proposed to address the torque actuation lag issue due to the slow dynamics of the rotor current, ensuring optimal actuation while recovering the lost torque. A dynamical model of the machine, focusing on the interaction between stator and rotor windings, is first established, and a torque equation that highlights the different sources and their interaction is derived, generalizing the conventional permanent magnet synchronous machines (PMSM) model by defining an "equivalent permanent magnet"flux linkage component. The flux-weakening (FW) operation of the machine is analyzed with the aim of developing a control strategy. A closed-loop control scheme for a wide speed range, including the flux-weakening region for HESM, is proposed. Simulation results are reported to validate the effectiveness of the proposed control strategy, showcasing improved speed dynamics and reduced torque transient errors compared to conventional approaches.
Comprehensive Flux-Weakening and Analytical Extended MTPA Control Featuring Transient Torque Compensation for Hybrid Excited Synchronous Machines
Calligaro S.;Petrella R.
2024-01-01
Abstract
This paper analyzes a novel optimization strategy of current control trajectories for hybrid excited synchronous machines (HESMs). The analytical solution for the Extended MTPA condition for HESM is provided for the first time, filling a gap from a theoretical perspective toward the optimization of the overall Joule losses of the machine, both rotor and stator, for each operating condition. Furthermore, a transient torque compensation strategy is proposed to address the torque actuation lag issue due to the slow dynamics of the rotor current, ensuring optimal actuation while recovering the lost torque. A dynamical model of the machine, focusing on the interaction between stator and rotor windings, is first established, and a torque equation that highlights the different sources and their interaction is derived, generalizing the conventional permanent magnet synchronous machines (PMSM) model by defining an "equivalent permanent magnet"flux linkage component. The flux-weakening (FW) operation of the machine is analyzed with the aim of developing a control strategy. A closed-loop control scheme for a wide speed range, including the flux-weakening region for HESM, is proposed. Simulation results are reported to validate the effectiveness of the proposed control strategy, showcasing improved speed dynamics and reduced torque transient errors compared to conventional approaches.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
