FPGA-based rapid control prototyping of permanent magnet synchronous motor servo drives

The position control problem in permanent magnet synchronous machine (PMSM) drives is a challenging problem which is subject to tight time constraints and unknown disturbances. This paper presents experimental validation of a cascade control structure for position control in PMSM drives. A PI-based control algorithm is used in the inner loop to control the stator currents in the rotor d - q reference frame. Then an optimal controller is synthesized in the error space of the outer loop to control the position and velocity of the PMSM. A disturbance observer is employed to estimate the load torque and parameter mismatch of the drive and a control algorithm is deployed on a real-time system with a field-programmable gate array (FPGA) board, thereby performing an experimental validation in real-time.