Direct Torque Control for Dual Three-Phase Induction Motor Drives

Abstract

A direct torque control (DTC) strategy for dual three-phase induction motor drives is discussed in this paper. The induction machine has two sets of stator three-phase windings spatially shifted by 30 electrical degrees. The DTC strategy is based on a predictive algorithm and is implemented in a synchronous reference frame aligned with the machine stator flux vector. The advantages of the discussed control strategy are constant inverter switching frequency, good transient and steady-state performance, and low distortion of machine currents with respect to direct self-control (DSC) and other DTC schemes with variable switching frequency. Experimental results are presented for a 10-kW DTC dual three-phase induction motor drive prototype.Index Terms-Deadbeat algorithm, digital control, direct torque control, dual three-phase induction machine, multiphase drives.

Comparison of Efficiency for Different Switching Tables in Six-Phase Induction Motor DTC Drive

“…In this technique, two different two-level flux hysteresis controllers are used separately for two stator fluxes (Ψ s1 ,Ψ s2 ). In [10] the switching table DTC of a sixphase induction machine is a topic requiring further research. Because of the small stator impedance of the (z 1 − z 2 ) domain, the voltage harmonics of the order 6k ± 1, (k = 1, 3, ...) generate large stator current harmonics.…”

“…The other subspace is (z 1 − z 2 ), and the harmonics of the order 6k ±1, (k = 1, 3, ...) are mapped on it [5]. Because of the isolation of the neutrals of the two windings, the (o 1 − o 2 ) voltage vectors are all equal to zero [3], [8], [10].…”

“…Speed control of a six-phase induction machine can be accomplished by many approaches such as FOC [2], [6], [7] and DTC. Direct Torque Control of a six-phase induction machine has been reported in [3], [8]- [10]. Similar to a three-phase induction machine, there are two basic approaches for the DTC of a six-phase induction machine.…”

“…Designing an optimal switching table in six-phase direct torque control drives to reduce this loss is important. In [10] PWM-DTC of a symmetrical six-phase induction machine is presented. Accuracy in stator flux estimation is very important in the PWM-DTC of a six-phase induction motor.…”

Modelado e implementación de un manejador eléctrico para un motor de inducción trifásico

“…Antes de 1980, los manejadores de velocidad de motores de corriente directa (CD) * * * a diferencia de los de corriente alterna (CA) realizaban un control directo del torque desarrollado por el motor, generando dispositivos con una respuesta dinámica rápida y estable [3], [4]. Ya en la década de los noventa el desarrollo acelerado de los procesadores permitió la implementación de técnicas de control de motores de inducción muy robustas [2] como Control escalar [1], [4], [5], control vectorial [2], [6] - [8] y control vectorial sin sensores [9]. En esta década se introdujo el concepto del manejador eléctrico [1], [10] - [13], desde esta óptica existe un sistema unifi cado objeto del control, en el cual las variables controladas son tanto eléctricas como mecánicas.…”