Current control for IPMSM drives: Direct discrete-time pole-placement design

Abstract

Abstract-This paper deals with discrete-time models and current control methods for synchronous motors with a magnetically anisotropic rotor structure, such as interior permanent-magnet synchronous motors (IPMSMs) and synchronous reluctance motors (SyRMs). Dynamic performance of current controllers based on continuous-time models is limited, especially if the ratio of the sampling frequency to the fundamental frequency is low. An exact closed-form hold-equivalent discrete motor model is derived. The zero-order hold of the stator-voltage input is modeled in stationary coordinates, where it physically is. An analytical discrete-time pole-placement design method for a two-degree-offreedom state-space current controller with an integral action is proposed. The proposed method is easy to apply: only the desired closed-loop bandwidth and the three motor parameters (Rs, Ld, Lq) are required. The robustness of the proposed current control design against parameter errors is analyzed. The controller is experimentally verified using a 6.7-kW SyRM drive.

Discrete-Time Observer Design for Sensorless Synchronous Motor Drives

“…Higher fundamental frequencies and improved robustness at a given sampling frequency can be achieved by designing the control system directly in the discrete-time domain [16]- [22]. For the direct discrete-time control design, a holdequivalent discrete model-including the effects of the zeroorder hold (ZOH) and sampler-of the motor drive is needed.…”

IPMSM torque control strategies based on LUTs and VCT feedback for robust control under machine parameter variations

“…Nowadays, Interior Permanent Magnet Synchronous Machines (IPMSMs) are receiving a considerable attention in a number of high performance applications, such as Electric Vehicles (EVs) and Hybrid Electric Vehicles (HEVs) due to their high power density and high efficiency over wide speed and torque ranges [1]- [4].…”

Discrete-time observer design for sensorless synchronous motor drives

“…Higher fundamental frequencies and improved robustness at a given sampling frequency can be achieved by designing the control system directly in the discrete-time domain [16]- [22]. For the direct discrete-time control design, a holdequivalent discrete model-including the effects of the zeroorder hold (ZOH) and sampler-of the motor drive is needed.…”

“…The exact closed-form model for surface permanent-magnet synchronous motor (SPMSM) drives can be found in [17], [18]. For the IPMSM drives, an approximate discrete model has been proposed in [19], [20] and the exact closed-form model has been recently published in [22].…”