Model Predictive Torque Control with Synchronized Sampling Frequency for High Frequency Induction Machine Drives

Abstract

Model Predictive Control (MPC) is a promising technique for control of electric drives, as it enables to optimize multiple parameters and offers operation with non-linear systems. Implementation of MPC for high speed/high-pole drives with high rated fundamental frequency-from few hundred up to thousand Hz-poses many challanges due to the low G sampling to fundamental frequency ratio around the rated speed of the machine. The paper proposes a novel MPC scheme, where the sampling frequency is sychronized to the fundamental frequency to improve the performance. The algorithm can be implemented on a digital device by the recursive equations given in the paper. As it is shown, the method can reduce the number of switchings, achieve better harmonic performance and reduce the torque ripple at the same sampling frequency without synchronization at low G values.

Model Predictive Torque Control for Multilevel Inverter fed Induction Machines Using Sorting Networks

“…As the value of the rotor flux is crucial to have an accurate and stable response, in the current paper the so-called trapezoidal (Tustin) integral approximation is utilized. The discrete version of the rotor flux estimator using Tustin approximation is derived by one of the author in [22] and [23] aŝ…”

“…In the current paper, the torque and flux errors are evaluated separately by using two cost functions [17], [18], [23]…”

Failure analysis of a high-speed induction machine driven by a SiC-inverter and operating on a common shaft with a high-speed generator

“…The development of high-speed drives has been made possible by, among others: (i) the development of new-generation power electronic converters with fast silicon carbide (SiC) and gallium nitride (GaN) semiconductor devices that enable precise generation of sinusoidal voltages with fundamental harmonic frequencies of several kilohertz-while reducing the production cost of power electronic converters [8,13,23]; (ii) the improved efficiency of high-speed motors and generators [11,16], which operate at speeds above 100,000 rpm [3,17,36]; (iii) improvements in bearing technology [36] and (iv) the development of high-speed digital signal processors (DSPs) for industrial applications-which enables the use of advanced con-trol algorithms at high rotational speeds [12,33]. The development of these technologies affects both high-speed induction motors/generators that are valued in the industry for their reliability, simple rotor design, low inertia, and ability to operate in high temperatures, as well high-speed permanent magnet motors/generators with high torque density and power density.…”