Fault Ride Through Capability Improvement of DFIG Based Wind Farm Using Nonlinear Controller Based Bridge-Type Flux Coupling Non-Superconducting Fault Current Limiter

Abstract

High penetration of Doubly Fed Induction Generator (DFIG) into existing power grid can attribute complex issues as they are very sensitive to the grid faults. In addition, Fault Ride Through (FRT) is one of the main requirements of the grid code for integrating Wind Farms (WFs) into the power grid. In this work, to enhance the FRT capability of the DFIG based WFs, a Bridge-Type Flux Coupling Non-Superconducting Fault Current Limiter (BFC-NSFCL) is proposed. The effectiveness of the proposed BFC-NSFCL is evaluated through performance comparison with that of the Bridge-Type Fault Current Limiter (BFCL) and Series Dynamic Braking Resistor (SDBR). Moreover, a dynamic nonlinear controller is also proposed for controlling the operation of the BFC-NSFCL. Extensive simulations are carried out in the MATLAB/SIMULINK environment for both symmetrical and unsymmetrical temporary as well as permanent faults. Based on the simulation results and different numerical analysis, it is found that the proposed nonlinear controller based BFC-NSFCL is very effective in enhancing the FRT capability of the WF. Also, the BFC-NSFCL outperforms the conventional BFCL and SDBR by maintaining a near-seamless performance during various grid fault situations.

Neuro Fuzzy Logic Controlled Parallel Resonance Type Fault Current Limiter to Improve the Fault Ride Through Capability of DFIG Based Wind Farm

“…The effectiveness of cooperative control of hardware solutions with software control strategy is discussed in the previous section. As the power system characteristic is highly nonlinear in nature, any nonlinear controller with FCL would yield better performance instead of using the FCL alone [37], [38]. The controllers which work on the basis of feedback are more effective than the conventional controllers [37].…”

“…As the power system characteristic is highly nonlinear in nature, any nonlinear controller with FCL would yield better performance instead of using the FCL alone [37], [38]. The controllers which work on the basis of feedback are more effective than the conventional controllers [37]. Feedback controller takes different actions on the basis of fault severity, but in case of conventional controller, some predefined actions are done without measuring the severity and system condition.…”

“…where the symbols used in (1) have their usual meanings, which can be found in [37]. However, the performance coefficient is also known as a power coefficient which can be expressed as a function of the blade pitch angle, β and tip speed ratio, λ as follows:…”

“…It is noted here that the generated reference frame is very useful to analyze the electrical characteristics of a DFIG based wind turbine under both normal and fault conditions. Therefore, to accomplish the aforesaid objective, the stator voltage and rotor voltage of a DFIG can be represented using the following equations [5], [37], [48], [49]:…”

Negative Imaginary Theory-Based Proportional Resonant Controller for Voltage Control of Three-Phase Islanded Microgrid

“…In this portion, the stability and the robustness of the NI-PR controller are accomplished in the presence of symmetrical three lines to ground (3LG) fault and unsymmetrical single line to ground (1LG) fault. Here, 3LG and 1LG faults are considered as 3LG is the most severe and 1LG is the most common fault in power system (Islam et al 2019(Islam et al , 2020a. The faults are considered in the system with a time span of 100 ms (t = 0.22-0.23 s).…”