Torque characteristics of TSCAOI configured induction generators

Author(s):  
Zhijia Wang ◽  
Udaya K. Madawala ◽  
Tian-Hua Liu ◽  
D. Mahinda Vilathgamuwa ◽  
Duleepa J. Thrimawithana
Keyword(s):  
1998 ◽  
Vol 34 (3) ◽  
pp. 664-670 ◽  
Author(s):  
R. Rabinovici
Keyword(s):  

2019 ◽  
Vol 11 (9) ◽  
pp. 2604 ◽  
Author(s):  
Arzhang Yousefi-Talouki ◽  
Shaghayegh Zalzar ◽  
Edris Pouresmaeil

In this paper, a direct power control (DPC) technique is proposed for matrix converter-fed grid-connected doubly fed induction generators (DFIGs). In contrast to what has been investigated in the past for direct torque control (DTC) or DPC of matrix converter-fed DFIGs, the active and reactive powers are regulated in a fixed switching frequency using indirect space vector modulation (ISVM) technique. Hence, designing input filters for matrix converters (MCs) becomes convenient. In addition, the reactive component of input side of MC is controlled which leads to reduction of distortion in grid current waveform. Also, an extensive discussion is addressed for nonlinear voltage errors of MC that may cause inaccurate power control. Simulation results done in MATLAB/Simulink show the effectiveness of the proposed method.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Ali Goodarzi ◽  
Ali Mohammad Ranjbar ◽  
Moslem Dehghani ◽  
Mina GhasemiGarpachi ◽  
Mohammad Ghiasi

AbstractIn this study, an auxiliary damping controller based on a robust controller considering the active and reactive power control loops for a doubly-fed induction generator for wind farms is proposed. The presented controller is able to improve the inter-area oscillation damping. In addition, the proposed controller applies only one accessible local signal as the input; however, it can improve the inter-area oscillation damping and, consequently the system stability for the various working conditions and uncertainties. The oscillatory modes of the system are appointed using the linear analysis. Then, the controller’s parameters are determined using the robust control approaches ($${H}_{\infty }/{H}_{2})$$ H ∞ / H 2 ) with the pole placement and linear matrix inequality method. The results of the modal analysis and time-domain simulations confirm that the controller develops the inter-area oscillation damping under the various working conditions and uncertainties.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4461
Author(s):  
Ahsanullah Memon ◽  
Mohd Wazir Mustafa ◽  
Muhammad Naveed Aman ◽  
Mukhtar Ullah ◽  
Tariq Kamal ◽  
...  

Brushless doubly-fed induction generators have higher reliability, making them an attractive choice for not only offshore applications but also for remote locations. These machines are composed of two back-to-back voltage source converters: the grid side converter and the rotor side converter. The rotor side converter is typically used for reactive current control of the power winding using the control winding current. A low voltage ride through (LVRT) fault is detected using a hysterisis comparison of the power winding voltage. This approach leads to two problems, firstly, the use of only voltage to detect faults results in erroneous or slow response, and secondly, sub-optimal control of voltage drop because of static reference values for reactive current compensation. This paper solves these problems by using an analytical model of the voltage drop caused by a short circuit. Moreover, using a fuzzy logic controller, the proposed technique employs the voltage frequency in addition to the power winding voltage magnitude to detect LVRT conditions. The analytical model helps in reducing the power winding voltage drop while the fuzzy logic controller leads to better and faster detection of faults, leading to an overall faster response of the system. Simulations in Matlab/Simulink show that the proposed technique can reduce the voltage drop by up to 0.12 p.u. and result in significantly lower transients in the power winding voltage as compared to existing techniques.


Author(s):  
Shenghu Li

The induction generators (IGs) are basic to wind energy conversion. They produce the active power and consume the reactive power, with the voltage characteristics fragile compared with that of the synchronous generators and doubly-fed IGs. In the stressed system states, they may intensify var imbalance, yielding undesirable operation of zone 3 impedance relays.In this paper, the operation characteristics of the zone 3 relays in the wind power systems is studied. With the theoretical and load flow analysis, it is proved that the equivalent impedance of the IGs lies in the 2nd quadrature, possibly seen as the backward faults by the mho relays, i.e. the apparent impedance enters into the protection region from the left side. The undesirable operation may be caused by more wind power, larger load, less var compensation, and larger torque angle.


Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1582
Author(s):  
Yingzong Jiao ◽  
Feng Li ◽  
Hui Dai ◽  
Heng Nian

This paper presents the analysis and mitigation of sub-synchronous resonance (SSR) for doubly fed induction generators (DFIG) under virtual synchronous generator (VSG) control, based on impedance methods. VSGs are considered to have grid-supporting ability and good stability in inductance-based weak grids, and are implemented in renewable power generations, including DFIG systems. However, stability analyses of VSGs for DFIG connecting with series capacitor compensation are absent. Therefore, this paper focuses on the analysis and mitigation of SSR for DFIG under VSG control. Impedance modeling of DFIG systems is used to analyze SSR stability. Based on impedance analysis, the influence of VSG control parameters and the configuration of damping factor of reactive power are discussed. Next, a parameter configuration method to mitigate SSR is proposed. Finally, time-domain simulation and fast fourier transform (FFT) results are given to validate the correctness and effectiveness of the impedance model and parameter configuration methods.


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