Induction Motor Direct Torque Control with Synchronous PWM

Abstract

A novel induction motor direct torque control (DTC) algorithm with synchronous modulation is presented. Compared to the traditional DTC method, whose main drawback is the presence of low-frequency torque harmonics (sub-harmonics), in the proposed method, the PWM switching frequency is imposed to be an integer multiple of the main supply frequency. This is achieved by continuously adjusting the PWM switching period to significantly reduce low-frequency harmonics. The devised algorithm has been tested on an inverter-fed induction motor drive system, and the obtained results show an important reduction of the sub-harmonic spectral content of the developed torque with respect to a conventional direct torque control while maintaining at the same time a high dynamic response.

Induction Motor Field-Oriented Sensorless Control with Filter and Long Cable

“…The algorithms presented for estimation and compensation can be used also with other types of induction machine control, such as Direct Torque Control [15] and V/Hz control [16] to compensate for the cable effects. The major limitation of the compensation algorithm that resulted from this preliminary study was mainly due to the oscillations generated by the system composed by cable, filter, and motor and how the control algorithm of induction machines was affected by them.…”

“…A speed estimation algorithm for an induction machine has already been discussed in [7], and it is shown in Figure 2. Measured stator currents and observed stator currents are compared using a vector product, as shown in Equation (15):…”

“…The presence of the denominator in Equation (15) means that the alpha signal can be subject to strong oscillations and pulses, which can affect the speed estimation. To eliminate these problems a saturation is introduced in the algorithm.…”

“…In the discussion below, we will show how to obtain these variables starting from the available measures. Another challenge of this application is the parameter variation, such Energies 2022, 15, 1484 2 of 20 as cable resistance, inductance, capacitance, and induction machine rotor resistance, as shown in [6].…”

Nonlinear Backstepping with Integral Action for Wind Power Plant Based on Doubly Fed Induction Generator Connected to the Non-Ideal Grid

“…Therefore, Cherifi et al [9] have proposed the Space Vector Modulation to reduce the oscillations observed in the created torque (SVM-DTC). Additionally, Y Benevieri et al [10] have suggested the synchronous DTC for reducing the harmonic spectrum content in the torque. The SMC has been proposed to control the DFI generator [11,12].…”