Wide Speed Control of Permanent Magnet Synchronous Motors with Improved Torque Capacity

• Author / Creator

  Moscardi Pauka, Gabriel

• This research deals with wide speed control of permanent magnet synchronous machines (PMSMs) driven by voltage-source converters (VSCs). The objective is to develop a current control algorithm that allows said machines to optimize their torque for any speeds within their operational range, for any torque requested: from maximum motoring torque to maximum regenerative braking, including a no torque operation known as "coasting" This optimization will have as main objective to minimize the amount of current needed to maximize the machine's torque for a certain operating point, while taking into consideration the current and voltage limitations of the VSC and the machine in a wide-speed operation, which requires the need of field-weakening, where a portion of the machine's current is dedicated to weaken its permanent magnets in order to reduce its induced voltage. It is also discussed the concepts of finite and infinite speed machines, which difference is having valid operating points up to a maximum speed or for any rotational speeds. In order to reach this goal, the first step is to analyze the mathematical modeling of PMSMs in the dq-frame in a MATLAB script, and, with the aid of a graphical interpretation of those equations, regions of operation and boundary conditions are defined in order to determine which equations of the algorithm must be used for the reference currents generation. The mathematical modeling is then proven in a PLECS simulation, showing that the algorithm developed can be executed in a two-level three-phase VSC, successfully controlling the machine. This serves as a base for an experimental implementation of a small-scale PMSM using dSPACE MicroLabBox. The experimental results prove the control algorithm is capable of achieving its goals in a VSC-driven PMSM.

• Subjects / Keywords

  • electrical engineering
  • motor control
  • permanent magnet synchronous machine
  • field oriented control
  • wide speed control
  • field weakening
  • voltage-source converter

• Graduation date

  Spring 2023

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-hq4n-8s25

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.