Sensorless control of matrix converter-fed synchronous reluctance motor drives

Abstract

This paper presents a sensorless control technique based on direct flux vector control (DFVC) method for synchronous reluctance (SyR) motor drives fed by a three-phase to three-phase matrix converter (MC). Rotor position is estimated based on active flux (AF) concept down to 50 [rpm]. Furthermore, the effect of nonlinear voltage errors of the MC is compensated, and a self-commissioning method capable of identifying the voltage error before compensation is presented and tested. The proposed drive combines the advantages of matrix converters and SyR motors in sensorless fashion, for application into a number of fields, spanning from compact drives for aviation to line-supplied drives for industry applications. Experimental results are provided to prove the feasibility of the proposed technique.

A Novel High Performance Discrete Flux Integrator for Control Algorithms of Fast Rotating AC Machines

“…A rotation of the rotor angle θ(t) is needed and, since the equations use for elements vectors, a slightly modified Park transformation is used. The matrices that operate the transformation are shown in (11). To simplify the writing, time dependency will be omitted.…”

“…Using Park (11) to keep the measurements in the natural reference frame, but operating the necessary conversion to rotor frame, the complete machine equations become (12) and (13).φ…”

“…The difference is in the calculation of any inverse rotation matrix [T k ] −1 or [∆T i ] −1 . Taking advantage of the fact that the inversion of [T k ] is the same matrix with just two sign changes, there is a significant simplification by not using a separate calculation of the inverse matrices at every iteration, but just multiplicating for −1 the two elements in position 12 and 21 of (11).…”

“…For example, the sliding mode algorithm [2,3] requires a double integration for currents and fluxes; the Butterworth method presented in [4] present the same double integration plus the need for an additional PI regulator; the dead-beat direct control in [5] is not really ideal for flux estimation, since it looks only at the end torque result; the adaptive model of [6] or, more recently, [7,8] could be very calculation heavy; the methods compared in [9] are just for machines with magnets. Moreover, a flux observer is required for any sensorless application such as permanent magnets [10], reluctance [11], or induction machines [12] that all use the machine equations to find the rotor flux angle, since this operation is intended for applications without the direct measurement of the rotor position and speed.…”

An Accurate Self-Commissioning Technique for Matrix Converters Applied to Sensorless Control of Synchronous Reluctance Motor Drives

“…Then, a compensation technique was proposed in stationary αβ frame to omit nonlinear voltage errors. The same technique was applied for sensorless control of MC-fed synchronous reluctance motor drives in [22].…”