A Magnetic Equivalent Circuit Based Modeling Framework for Electric Motors Applied to a PMSM With Winding Short Circuit

Accurate and real-time capable mathematical models are an essential prerequisite for the design of model-based controller and estimation strategies for electric motors. Magnetic equivalent circuit (MEC) models have proven to be an interesting alternative to classical inductor models that are typically utilized for the controller design. MEC models allow for a systematic inclusion of magnetic saturation and nonfundamental wave behavior of motors, while still having a manageable model complexity. The systematic derivation of the model equations can be rather involved, if in addition to the magnetic circuit of the motor also the electric interconnection is taken into account. For this reason, a modeling framework for electric motors based on MEC models including the electric interconnection is proposed. It makes use of network theory, which allows to systemize and automate major parts of the modeling task. The presented framework can be applied to a wide range of electromagnetic actuators. The feasibility of the proposed framework is demonstrated by the application to the modeling of a PMSM with (turn-to-turn) winding short circuit. A comparison with measurement results shows a high model accuracy of the resulting real-time capable model both for healthy and faulty conditions.