Flux Weakening Voltage Stabilizing Strategy for Permanent Magnet Synchronous Generator base on Model Predictive Control

• 1、School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin 150006, China

Abstract：Due to the excellent speed regulation performance and high power density of permanent magnet synchronous generator systems, it has been widely used in mobile electrical systems such as multi electric aircraft in recent years. Compared with classical field oriented control, model predictive control has more advantages in handling nonlinear constraints and achieving multi-objective optimization.Flux weakening control is an important way to broaden the voltage stabilization range of generators. However, in model predictive control, the output of the current predictive controller is the optimal switching state of the power transistor, and there is a lack of feedback input to the flux weakening controller. In this paper, the stator voltage amplitude is estimated by the voltage vector output from the switch, and the estimated value is used as a feedback to achieve flux weakening control. Firstly, the mathematical model of the generator is analyzed, and on this basis, model predictive control is used to control the generator; After that, the switch voltage vector is analyzed, and a flux weakening control strategy based on the average switch voltage is proposed; Finally, by analyzing and calculating the optimal number of samples for the average value, the proposed flux weakening control strategy is improved. The research results show that the improved method can output a more stable DC voltage when the rotational speed changes, and expand the working range of the generator. Simulation verifies the correctness of the proposed method.

Keywords： Electric machines and electric apparatus Flux weakening control Model predictive control Permanent magnet synchronous generator