High performance controllers for Interior Permanent Magnet Synchronous Machines using look-up tables and curve-fitting methods

Interior Permanent Magnet Synchronous Machines (IPMSM) used in hybrid powertrain applications are required to deliver high efficiency over wide speed and torque ranges. The performance of any control algorithm is directly dependent on the accuracy of the parameters. Saturation and cross-saturation of permanent magnet synchronous machines are well recognized phenomena. Developing a controller utilizing either a two-dimensional look-up table or linear approximation of the machine parameters generated from characterization data will include the effects of saturation and cross-saturation and thereby achieve the desired performance. Both the look-up table and curve-fitting methods are implemented on a microcontroller. A 125kW IPMSM drive is used to experimentally evaluate both methods. The work presented here demonstrates that both the look-up table and curve-fitting methods provide satisfactory performance over the entire operating range. A comparison of the complexity of implementing both methods is included.