Stator Flux-Based Field-Oriented Position-Sensorless Control of Permanent Magnet Synchronous Motors With Limited Parameter Knowledge

Permanent magnet synchronous motors (PMSMs) are traditionally operated in the field-oriented control (FOC) framework based on rotor-fixed coordinates. To set up a proper torque control in this framework, numerous motor parameters are required (e.g. inductance matrix) and, therefore, engineering effort is needed to extract the parameter values from experimental testing or finite element analysis. Moreover, the torque plant model becomes coupled and nonlinear. While the effort to handle these issues is usually acceptable in premium drives (e.g. in electrical vehicles), low-cost applications require control approaches with minimum commissioning complexity. To achieve that objective, this contribution proposes a very simple stator flux-oriented FOC framework requiring only limited parameter knowledge. As a positive side-effect, the proposed framework is operating inherently position-sensorlessly. Experimental tests in the constant torque and flux weakening area proof the principle functionality of the proposed method, but also limitations are highlighted (e.g. decreased torque accuracy). The found results motivate further investigations in this field.