<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Properties and control of a doubly fed induction machine operating under unbalanced grid voltage conditions have been presented. The proposed method does not include symmetrical sequences decomposition and is realized in a rotating frame not synchronized either with the grid voltage vector or with the stator flux vector. The method uses a reference torque and the reference <italic>q</italic> component of instantaneous power for calculation of the reference stator current. Next, calculation of magnetizing current for a given unbalanced grid voltage is used to assign the reference rotor current. Due to the fact that the reference current contains both a positive and a negative sequence, a proportional-integral-resonant controller is used. The main control target is the non-oscillatory waveform of torque, whereas other separate strategies like symmetrical stator current or sinusoidal rotor current can be easily obtained by adequate filtration of the reference control signals of the stator or rotor currents, respectively. The simulation results of the 2 MW model have been presented for a doubly fed induction generator as well as the results of laboratory tests with the use of a small scale 7.5 kW machine.</p></abstract>

Properties and control of a doubly fed induction machine operating under unbalanced grid voltage conditions have been presented. The proposed method does not include symmetrical sequences decomposition and is realized in a rotating frame not synchronized either with the grid voltage vector or with the stator flux vector. The method uses a reference torque and the reference q component of instantaneous power for calculation of the reference stator current. Next, calculation of magnetizing current for a given unbalanced grid voltage is used to assign the reference rotor current. Due to the fact that the reference current contains both a positive and a negative sequence, a proportional-integral-resonant controller is used. The main control target is the non-oscillatory waveform of torque, whereas other separate strategies like symmetrical stator current or sinusoidal rotor current can be easily obtained by adequate filtration of the reference control signals of the stator or rotor currents, respectively. The simulation results of the 2 MW model have been presented for a doubly fed induction generator as well as the results of laboratory tests with the use of a small scale 7.5 kW machine.

Control of a Doubly Fed Induction Generator at Grid Voltage Imbalance

Power Electronics and Drives

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

{"article-title":"Control of a Doubly Fed Induction Generator at Grid Voltage Imbalance"}

Properties and control of a doubly fed induction machine operating under unbalanced grid voltage conditions have been presented. The proposed method does not...

Control of a Doubly Fed Induction Generator at Grid Voltage Imbalance

Published Online: Dec 29, 2017

Page range: 31 - 48

Received: Oct 07, 2017

Accepted: Nov 28, 2017

DOI: https://doi.org/10.5277/ped170210

Keywords
doubly fed induction generator, power and torque control, unbalanced grid

© 2017 Tomasz Łuszczyk et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Control of a Doubly Fed Induction Generator at Grid Voltage Imbalance

Published Online: Dec 29, 2017

Page range: 31 - 48

Received: Oct 07, 2017

Accepted: Nov 28, 2017

DOI: https://doi.org/10.5277/ped170210

Keywordsdoubly fed induction generator, power and torque control, unbalanced grid

© 2017 Tomasz Łuszczyk et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
doubly fed induction generator, power and torque control, unbalanced grid