Abstract
The maximum-torque-per-ampere (MTPA) scheme is widely used in the interior permanent magnet synchronous machine (IPMSM) drive system to reduce copper losses. However, MTPA trajectory is complicated to solve analytically. In order to realize online MTPA trajectory tracking, this paper proposes a novel torque control strategy. The torque control is designed to be closed form. Considering the machine reluctance torque as the torque feedback, when this is compared with the torque reference, then the excitation torque reference can be obtained. Since the excitation torque is proportional to the q-axis current, the q-axis current reference can be fed by the excitation torque reference through a proportional regulator. Once the q-axis current reference is given, the d-axis current reference can be calculated based on the per-unit model, which aims to simplify the calculation and make the control strategy independent of machine parameters. In this paper, the stability of the control system is demonstrated. Meanwhile, simulation and experiment results show this torque control strategy can realize MTPA trajectory tracking online and have success in transients.
Highlights
Due to outstanding characteristics, such as high-power density, wide speed range, and a high torque-to-inertia ratio, interior permanent magnet synchronous machines (IPMSMs) are suitable for many industrial applications [1,2,3]
The per unit model can be applied to all IPMSMs, because it is independent of machine parameters
To validate the proposed torque control strategy, the whole system was simulated in Matlab/Simulink
Summary
Due to outstanding characteristics, such as high-power density, wide speed range, and a high torque-to-inertia ratio, interior permanent magnet synchronous machines (IPMSMs) are suitable for many industrial applications [1,2,3]. In order to avoid complex calculation procedures and get rid of machine parameters, some approaches have been proposed—for instance, the searching algorithm and signal injection method. Instead of finding the optimal current directly, some approaches propose using an outer loop controller for MTPA operation [16,17,18]. In these methods, the relationship between the d- and q-axis stator currents is used for MTPA operation. Combined with the MTPA condition expressed in the per unit model, the torque controller can provide the reference stator currents for the current regulators.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
