I FIND that Mr. Wallace in his new work on the “Geographical Distribution of Animals” when stating the limits of his Ceylon sub-region (vol. i. p. 327), gives among mammals the genus Tupaia and among birds “a species of Mviophonus, whose nearest ally is in Java” as characteristic of that sub-region. Further, in the tabular statement (vol. ii. p. 187), Tupaia is altogether omitted from the Indian sub-region.

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Geographical Distribution of Animals

Fault-ride-through (FRT) is an imperative capability in wind turbines (WTs) to ensure grid security and transient stability. However, doubly fed induction generator-based WTs (DFIG-WTs) are susceptible to disturbances in grid voltage, and therefore require supplementary protection to ensure nominal operation. The recent amendments in grid code requirements to ensure FRT capability has compelled this study of various FRT solutions. Therefore, for improving FRT capability in pre-installed WTs, re-configuration using external retrofit-based solutions is more suitable and generally adapted. The most relevant external solutions based on retrofitting available are classified as (a) protection circuit and storage-based methods and (b) flexible alternating current transmission system-based reactive power injection methods. However, for new DFIG-WT installations, internal control modification of rotor-side converter (RSC) and grid-side converter (GSC) controls are generally preferred. The solutions based on modifications in RSC and GSC control of DFIG-WT are classified as (a) traditional control techniques and (b) advanced control techniques. This study ensures to curate and compare the FRT solutions available based on external retrofitting-based solutions and internal control modifications. Also, the future trends in FRT augmentation of DFIG-WTs are discussed in this study.

https://ietresearch.onlinelibrary.wiley.com/doi/pdf/10.1049/iet-rpg.2018.5249

Review on FRT solutions for improving transient stability in DFIG-WTs

Wind energy has been widely explored in recent decades and the integration of this renewable resource is increasing due to many factors, e.g., the need to mitigate climate change and reduce energy dependence on fossil fuels. Unfortunately, the stochastic characteristic of wind may have an impact on the reliability and power quality of electrical grids due to short-term power fluctuations. For wind power smoothing purposes, many researchers have been using energy storage systems (ESSs) as they perform extremely well, and are becoming less costly. In this context, this article presents a comprehensive review of the significant research conducted on the topic of wind power smoothing using high-power ESSs. Firstly, some energy storage technologies are discussed and compared, and a brief description of the main short-term applications of these technologies is provided. Afterwards, a literature review on wind power smoothing is conducted, showing evidence of the development of methods over the years. A bibliometric analysis is also presented, showing an increasing number of publications on this subject. Finally, this review indicates that more research is still needed to overcome wind power fluctuation issues and that further attention to topics such as hybrid ESSs and smoothing impacts on electrical grids should arise over the next years.

A review on wind power smoothing using high-power energy storage systems

Whale optimization algorithm-based Sugeno fuzzy logic controller for fault ride-through improvement of grid-connected variable speed wind generators

This paper presents a novel design process of decoupled PI current controller for permanent magnet synchronous generator (PMSG)-based wind turbines feeding a grid-tied inverter through a back-to-back converter. Specifically, the design methodology consists of combining disturbance observer-based control (DOBC) with feedback linearization (FBL) technique to ensure nominal transient performance recovery under model uncertainty. By simplifying the DOBC under the feedback linearizing control, it is shown that the composite controller reduces to a decoupled PI current controller plus an additional term that has the main role of recovering the nominal transient performance of the FBL, especially under step changes in the reference. Additionally, an antiwindup compensator arises naturally into the controller when considering the control input saturation to design the DOBC. This permits removal of the effect of the saturation blocks required to limit the control input. The proposed control scheme is implemented and validated through experimentation conducted on 22-pole, 5 kW PMSG. The results revealed that the proposed technique can successfully achieve nominal performance recovery under model uncertainty as well as improved transient performances under control saturation.

A Novel Design of PI Current Controller for PMSG-Based Wind Turbine Considering Transient Performance Specifications and Control Saturation

Increased penetration level of the wind power generation has brought new issues and challenges of power quality. One of these issues is low-voltage ride through (LVRT). This study proposes an LVRT scheme for the permanent magnet synchronous generator (PMSG) variable speed wind turbine at grid faults. The machine side converter controller is used to control the dc-link voltage using interval type-2 fuzzy logic control taking into account the non-linear relationship between the generator speed and the dc-link voltage. Under grid faults, there is a power mismatch between the generated active power and the active power delivered to the grid. This excess power is stored in the generator inertia to keep the dc-link voltage constant. To validate the proposed control strategy, simulation results for 1.5 MW PMSG-based wind energy conversion system are carried out by MATLAB-Simulink under symmetrical and asymmetrical faults.

https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/iet-rpg.2014.0453

Enhancement low-voltage ride through capability of permanent magnet synchronous generator-based wind turbines using interval type-2 fuzzy control

This paper introduces a discrete-time L 1 adaptive controller design for collective pitch control for variable speed variable pitch wind turbines. In this control algorithm, the blades’ pitch angles are regulated to manipulate the generator speed and generated power during high speeds wind airflow. The main merits of the proposed controller are its robustness against the wind turbine model uncertainties, guaranteeing the closed loop system stability and performance, and applicability during implementation in real life. Commonly used industrial gain-scheduled PI controller is used to be compared with the proposed controller. The proposed scheme is simulated using a 5-MW offshore turbine model and the obtained results illustrates the superior performance of the proposed controller. Further, a reduced scale wind turbine emulator is used to provide hardware in the loop to test the implementation of the proposed controller. The controller is implemented using laboratory equipment to demonstrate the feasibility of the controller for real time applications. The obtained experimental results validate the closed loop system performance enhancement due to replacing the traditional PI controller with the proposed design.

Adaptive control design and implementation for collective pitch in wind energy conversion systems

This paper introduces a technique for optimally obtaining the gains of the proportional integral (PI) controllers for the direct drive permanent magnet synchronous generator (PMSG) wind turbine system. The technique is based on developing a state space model of the wind turbine and obtaining the eigenvalues of the matrix A of the state space model. These eigenvalues are utilized for determining the optimum values of the PI controller s gains in order to perform the optimal system operation using Linearized biogeography-based optimization (LBBO) technique. Simulation and experimental results are obtained by MATLAB/SIMULINK for 1.5-MW PMSG wind turbine and reduced scale PMSG wind system respectively to prove the effectiveness of the proposed control scheme. The results from simulations and experiments show that LBBO can determine the controllers' parameters successfully if its fitness function is carefully chosen.

Design and implementation of PI controllers of direct drive PMSG wind turbine system tuned by Linearized biogeography-based optimization technique

This paper proposes a low voltage ride through (LVRT) scheme for the permanent magnet synchronous generator (PMSG) variable speed wind energy conversion system (WECS) at the grid faults to follow the requirements defined by the grid codes. The dc-link voltage is controlled by the machine-side converter instead of the grid-side converter. Taking into consideration the nonlinear relationship between the generator speed and the dc-link voltage, the machine-side converter controller is designed using interval type-2 fuzzy logic control (IT2-FLC). To validate the proposed control strategy, simulation results for 1.5-MW PMSG-based WECS are carried out by MATLAB-SIMULINK.

Low voltage ride-through technique for PMSG wind turbine systems using interval type-2 fuzzy logic control

The penetration level of wind energy conversion systems is increasing steadily. The random and stochastic nature of wind energy may lead to serious problems onto the electrical system Stability, Controllability, and Power quality. Generally, Energy Storage Systems (ESS) can improve wind generation grid interconnection in terms of power quality, and System Controllability. Flywheel Energy Storage Systems (FESS) have long life span, and high number of charging and discharging cycles that make them a perfect companion to wind integration as compared to other energy storage technologies. In this paper, low speed PMSM based flywheel energy storage system is integrated with Direct-Drive (DD) variable speed PMSG based Wind Energy Conversion System. This integration is proposed in two schemes named as First Topology (Modified STATCOM), and Second Topology (ON DC LINK). Matlab / Simulink model is conducted for the both configurations. Simulation results will show effectiveness of the integrated system in Active Power Smoothing while maximizing the harvested wind power through Optimal Torque Control Maximum Power Point Tracking, and Dynamic VAR Compensation as well. A comparative study is performed between the two topologies to highlight the merits, demerits, and suitability of each one.

H.M. Yassin

Papers

Enhancement low-voltage ride through capability of permanent magnet synchronous generator-based wind turbines using interval type-2 fuzzy control

Adaptive control design and implementation for collective pitch in wind energy conversion systems

Design and implementation of PI controllers of direct drive PMSG wind turbine system tuned by Linearized biogeography-based optimization technique

Low voltage ride-through technique for PMSG wind turbine systems using interval type-2 fuzzy logic control

Enhancement of wind energy conversion systems active and reactive power control via flywheel energy storage systems integration