Energy-Shaping Speed Controller with Time-Varying Damping Injection for Permanent-Magnet Synchronous Motors

This brief presents a novel energy-shaping technique-based speed controller for permanent-magnet synchronous motors (PMSMs) considering machine nonlinearities and load and parameter changes. There are three features: The time-varying damping term is injected into the speed loop, which is automatically updated by the proposed self-tuner. The disturbance observers are designed for both the speed and current loops to achieve better disturbance rejection performance with removal of offset errors without the use of tracking error integral actions. Furthermore, the closed-loop analysis result is provided to demonstrate its beneficial closed-loop properties. The practical advantages are experimentally verified in several convincing scenarios with a prototype 500-W PMSM driven by a three-phase inverter.