Coordinated design of fuzzy‐based speed controller and auxiliary controllers in a variable speed wind turbine to enhance frequency control

In order to smooth the system frequency disturbances caused by wind power fluctuation, this study proposes a novel load frequency control (LFC) strategy based on model predictive control (MPC) to regulate the system frequency. The proposed strategy mainly aims to improve the system frequency responses by considering the dynamics of wind turbine (WT) and forecasting the output power of WT. First, the frequency response model (FRM) of system including the power system LFC and WT is established. Second, through discretisation of the FRM, a predictive model of system is obtained. Then, system state and response in the next predictive period are forecasted by the predictive model. After obtaining the prediction information, the control signal of system is optimised for improving system frequency response. On this basis, a novel MPC-based LFC strategy is proposed based on the predictive model and the optimisation of control sequence. With the information of wind speed, this control strategy is able to forecast the system states and responses easily and adjust the control signal according to wind power fluctuation. Finally, numerical simulations are demonstrated to visualise the effectiveness and feasibility of the proposed MPCbased LFC strategy and its advantages over existing methods.

Section: Lfc Model Of Multi-area Interconnected Power Systemmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Model predictive control‐based load frequency control for power systems with wind‐turbine generators

Yang

Sun

Liao

et al. 2019

“…Based on the load–frequency model, an optimal robust first‐order frequency controller is proposed for a wind farm to emulate the inertial response and PFR by taking into account various uncertainties [20]. A fuzzy logic‐based rotor speed controller with its parameters optimised by the genetic algorithm is presented for DFIG‐WTG system to improve the power system frequency performance [21]. To enhance the system automatic generation control performance, a novel coordinated control strategy that utilises pitch angle control and rotor speed control are proposed for active‐power‐control‐based DFIG‐WTG system [22].…”

Section: Introductionmentioning

confidence: 99%

Comprehensive frequency regulation scheme for permanent magnet synchronous generator‐based wind turbine generation system

Gao¹,

Wu²,

Yan³

et al. 2018

Due to a growing penetration of permanent magnet synchronous generator-based wind turbine generation (PMSG-WTG) systems into the modern power grid, there is a strong interest in leveraging the potential capabilities of PMSG-WTG system to participate in the system frequency regulation during the grid event. In this work, a novel comprehensive frequency regulation (CFR) scheme is proposed specifically for rotor-speed-control-oriented PMSG-WTG systems. The step-wise inertial power response enables PMSG to perform the temporary frequency support. The rotor speed and pitch angle controllers are coordinated to curtail the wind power output for the persistent de-loaded operation, which can facilitate the primary frequency regulation through the variable-slope droop control. Furthermore, this CFR control scheme is implemented into the controls advanced research turbine 2 (CART2)-PMSG model, so as to investigate its potential impact on the structural loads of wind turbine. Simulation results show CFR can dramatically enhance overall frequency regulation capability of the PMSG-WTG's system and mitigate the frequency oscillations over a full range of wind speeds without causing large mechanical damages to the wind turbine.

“…In particular, when largescale power-electronic interfaced renewable energy sources penetrated into power systems, frequency regulation deemed challenging in terms of both intermittent generation and decreasing total system inertia [14,15]. Once considered as a part of the problem, wind power has proved useful in frequency regulation through droop function and synthetic inertia [16][17][18][19][20][21][22]. While power droop function is similar to governor action in synchronous generators, inertial response is in direct proportion to the rate of change of frequency (ROCOF), emulating the inertia of synchronous generators [23].…”

Section: Introductionmentioning

confidence: 99%

Optimal robust first‐order frequency controller design for DFIG‐based wind farm utilising 16‐plant theorem

Toulabi

Dobakhshari²,

Ranjbar

2017

Self Cite

With increasing the share of wind farms in generation profile, their contribution to frequency regulation has become crucial. This study presents an optimal robust first-order frequency controller in the wind farms, which collectively emulates the inertial response as well as governor droop of synchronous generators. To account for various uncertainties associated with system inertia, damping, and doubly-fed induction generator (DFIG)-based wind turbine's parameters, the robustness of controller is verified through the 16-plant theorem. An analytic method based on the small-signal model of the system is utilised to determine the stability region of the first-order controller. To evaluate the performance of the proposed controller, a DFIGbased wind farm equipped with this controller is added to IEEE 39-bus test system which is updated with wind farms in MATLAB/Simulink environment, and the response of proposed controller is investigated under different conditions. Simulation results verify the robustness as well as the effectiveness of the proposed controller in system frequency regulation. L rr and L ss DFIG rotor and stator self-inductances ρ, r, and v air density, rotor radius, and wind speed λ tip speed ratio C Q torque coefficient A, B, C, and F state, input, output, and disturbance matrices