Rotor-flux model for sensorless vector-control of super-high-speed IPMSM

Abstract

The paper describes a new algorithm for speed and position estimation for Interior Permanent Magnet Synchronous Motor. The estimator is implemented in a vector controlled system for motion control of a super-high speed (tens of thousands of revolutions per minute) and high power (hundreds of kilowatts) IPMSM. The estimator uses the so-called rotor-flux components in the estimated rotor reference frame that is rotating with the estimated speed. The stator flux components in the estimated rotor reference frame will be calculated using the rotor flux components and q-inductance flux components. To obtain the q-inductance flux, it was used the fictitious/active flux in the actual rotor reference frame that was calculated from the reference of the direct current in the actual rotor reference frame. Using the Lyapunov error states energy function, the speed/position estimator leads to a low position error, which decrease with speed increasing, and no speed error in steady-state and full load operation. It has been developed an experimental vector controlled system consisting of a PWM rectifier and a PWM inverter, in order to assure the regenerative braking, considering that the rated and starting currents are relatively large-hundreds of amps. There are presented some experimental results to prove the operation of the sensorless vector-control system at super-high speed. The algorithm is implemented using a floating-point TMS320F28335-150MHz Digital Signal Controller. This proposed observer can be applied even if the d-q inductances are very low. The presented experimental results show good performances in the dynamic operation with low errors in position estimation and no errors in speed estimation in steady-state operation and different load conditions.