Overmodulation Range Of Inverter Research Articles

Direct-Flux Vector Control of IPM Motor Drives in the Maximum Torque Per Voltage Speed Range

The high-speed operation region of interior permanent magnet (PM) (IPM) motor drives is investigated, with particular attention to the maximum-torque-per-voltage operation. A technique is proposed for the control of the drive in such region, based on direct-flux field-oriented vector control. The proposed control is easy to implement, does not require the accurate knowledge of the motor model, and showed to be robust toward the effects of iron losses, position estimation errors, and dc-link variations. Moreover, it is suitable for operation in the inverter overmodulation range. Experimental results are provided for a 600-W IPM drive for home appliances.

Current Control System for PMSM in Overmodulation Range of Inverter

This paper proposes a novel current control system for a PMSM that can stably operate even in the overmodulation range of an inverter. Because an inverter generates harmonic components in this range, an instability problem in the conventional current control system usually occurs. For solving this instability problem, the idea of harmonic current compensation scheme has already been proposed. However, the effectiveness of this method depends directly on the harmonic current estimation accuracy.There are two new topics in harmonic component estimation that we use in our proposed current control system as follows: (1) the harmonic voltage estimation method that is based on the conventional sinusoidal PWM modulation technique, and (2) the harmonic current estimation method that estimates correctly both in the steady state and transient condition. The effectiveness of the proposed methods is confirmed by computer simulation and experimental results.