Adam Larson

Incorporating Dynamics in a Mesh-Based Magnetic Equivalent Circuit Model of Synchronous Machines

A mesh-based magnetic equivalent circuit has been derived to model the dynamics of wound rotor synchronous machines (WRSMs). A particular focus has been placed on the derivation of flux tubes to model machines with an arbitrary number of damper bars placed at an arbitrary depth in the rotor pole tip. Faradays Law is applied to establish a state model in which winding and damper bar flux linkages are selected as state variables. The resulting coupled magnetic equivalent circuit/state model is solved to predict machine dynamics. An important attribute of the model is that saturation is represented without the need for a relaxation factor, which enables its use as a practical tool in machine design. Data obtained from hardware experiment and a finite-element model are used to validate the proposed methods.

Incorporating Skew in a Magnetic Equivalent Circuit Model of Synchronous Machines

In this letter, a multislice method has been extended to model skew in a magnetic equivalent circuit for wound rotor synchronous machines. Within the model, the machine is divided into a user-defined number of slices along its axial direction. A system of equations is derived in which the magnetic equivalent circuit (MEC) loop flux and the axial currents in each slice are unknowns. A constraint is used to enforce that the axial currents across all slices are equal. The method overcomes challenges of alternative approaches used to model skew in MECs that have been documented by the community. Hardware experiments are used to validate the approach.

An efficient circuit model for design of synchronous machines

This paper highlights a magnetic equivalent circuit model for wound rotor synchronous machine design. The model includes provisions to calculate the performance of machines with an arbitrary number of damper windings in either the q- or d-axis. The computational cost of the model is considered on several modern computing platforms. Its use within design allows for a comprehensive, accurate exploration of a design space on a timeline that is consistent with most commercial product development.