Variable Pitch Control Research Articles

Adaptive fuzzy coordinated control design for wind turbine using gray wolf optimization algorithm

Due to the randomness and intermittency of wind speed, the actual output power curve of a wind turbine (WT) deviates greatly from the theoretical power curve, thereby reducing the power generation capacity of the WT. An adaptive fuzzy coordinated control (AFCC) of WT is presented in this study to improve the power generation of WT. Firstly, a multi-objective optimization model (MOOM) for WT output power, generator speed and pitch angle is established, and its optimal solution set is used as the input eigenvector of a novel effective wind speed soft sensor (NEWSSS) model, which is modeled with kernel extreme learning machine (KELM). Secondly, a novel improved gray wolf optimization (NIGWO) algorithm is presented by improving the convergence factor and adaptive weights, which is used to solve MOOM and optimize the parameters of KELM. A variable pitch control (VPC) is designed by estimating the effective wind speed. Finally, an adaptive fuzzy control (AFC) is presented for WT. Based on the AFC and VPC, an AFCC for pitch angle and generator torque is designed for WT. The high measuring precision of NEWSSS and the good robustness and dynamic performance of AFCC are demonstrated by the simulation results.

Variable-pitch power regulation of tethered-wing systems based on robust gain-scheduling H-infinity control

In this paper, we address the power regulation of tethered-wing systems and illustrate the benefits of employing variable-pitch control to alleviate dynamic mechanical loads and power fluctuations. The proposed control scheme is based on a strategy to maximize the generated power during low-speed wind and prevent force and power overloads during the high-speed wind. To implement this strategy, we employ a tether reeling-speed controller to maintain optimal generator speed in low-speed winds, and a MIMO speed-force controller to prevent power surges in high-speed winds. Additionally, the minimization of the wing’s pitch angle activity during high-speed wind is considered as another control objective in the proposed scheme. The controllers are synthesized using H∞ method and are made robust with respect to the system’s dynamic and parametric uncertainties. The synthesis procedure is predicated on a linear parameter varying (LPV) expression of the dynamics of the system. The effectiveness of the strategy and the performance of the controllers are showcased through simulations conducted with a comprehensive 3-dimensional simulator for tethered-wing systems.

Study on Dynamic Response Characteristics of Offshore Floating Wind Turbine Pitch System

Due to its special working conditions, offshore wind turbine will bear large direct and indirect loads under the combined action of air flow and wave flow. In this paper, a variable pitch system composed of variablepitch motorand variable pitch bearing is improved, and the characteristics of system's bending moment, torque, vibration and other physical quantities under the action of multiple physical loads are verified, and the mechanical response characteristics of floating wind turbine under the control of unified variable pitch and independent variable pitch are studied under the running conditions at sea. The results show that mechanical structure of uniform pitch is compared with that of independent pitch, the independent variable pitch structure can effectively reduce the mean oscillation value of wind turbine tower in the parallel direction of air flow by optimizing control strategy, and reduce the thrust at the hub of wind turbine and the bending moment at the root of tower, but increase the vibration frequency and fatigue load of offshore wind turbine tower along parallel direction of air flow. Reduce the fatigue life of equipment. The research results can be used as a reference to reduce the variable pitch control and vibration suppression of offshore wind turbines and improve the reliability of wind turbines.

Design and strength simulation of hub mechanism of variable pitch propeller

The hub mechanism is an important force bearing mechanism of variable pitch propellers and an important actuator of variable pitch control in tilting ducted propeller UAV. To solve the problem of the connection between the blades and the fuselage of the tilting ducted propeller UAV, according to the parameters of the blades, the force of the hub mechanism is analyzed, and the design parameters of the hub mechanism are obtained by using the theoretical calculation method, such as the power density method. The strength of the parts is analyzed by using the finite element method. A variable-pitch propeller hub mechanism was developed for tilting ducted unmanned aerial vehicles. A design flow of the hub mechanism is formed, including the design of the parts of the hub mechanism and the strength check. This will facilitate the design and development of ducted UAVs.

Research on wind turbine variable pitch control based on wind speed estimation

With the continuous promotion of the “double carbon” strategy, the capacity of wind turbines is increasing, and the dimensions of key parts such as the diameter of the wind turbine wheel, the height of the tower, and the radius of the tower tube are also increasing. Large wind turbines have a large inertia, so the execution time of the pitch actuator and the response time of the pitch action are usually longer, which leads to large fluctuations in the output power of the wind turbine when the wind speed changes rapidly under the working conditions above the rated wind speed and leads to complex loading problems. Therefore, in this paper, the design of pitch control is carried out by estimating the effective wind speed at the wind turbine surface and using the inverse system method to transform the nonlinear wind turbine system into a linear decoupled form. This method improves the pitch response speed, reduces the output power fluctuation, and better suppresses the load of the turbine to ensure the safe and stable operation of the turbine

Optimization of the Powers Exchanged between a Cascaded Doubly Fed Induction Generator and the Grid with a Matrix Converter

The use of an electromagnetic converter of great reliability in wind energy, like the cascaded doubly fed induction generator (CDFIG), can solve several problems compared to the doubly fed induction generator (DFIG), among them the elimination of the brushes and copper rings. The work consists of studying the performance of a CDFIG-based wind system using a matrix converter and a variable pitch control system. The traditional PI is able to successfully solve a number of linear control problems. The fuzzy logic controller used can dramatically improve the system's performance. The active and reactive energy transferred between the CDFIG and the grid can be controlled by adjusting the machine inverter. The DC bus voltage has been kept stable by controlling the grid inverter. The pitch controller's objective is to maximise aerodynamic power while staying within the converter's power limits. Numerical simulation results implemented in the MATLAB/Simulink package will be provided in this study to show that the suggested control strategy is both possible and effective.

Comparative analysis of fixed-pitch and variable-pitch control systems for multirotor drones: Acoustic characteristics and rotor phase control

In this study, the aerodynamic and aeroacoustic characteristics of multirotor electric vertical take-off and landing aircraft in hovering and forward flight are compared using two representative control methods: fixed-pitch control and variable-pitch control (i.e., revolution per minute (RPM) control and collective pitch control). To this end, a comprehensive multirotor noise assessment framework is used to predict the aerodynamics and noise of multirotors controlled by RPM and collective pitch. High-resolution time–frequency analysis is used to clarify the differences in noise spectral characteristics. The findings indicate that blade passage frequency characteristics vary significantly depending on the control method. The phase differences between the rotors of variable-pitch control remain constant irrespective of disturbances or attitude control. In other words, the frequencies of the tone noise do not exhibit short-periodic modulation, unlike those of RPM-controlled multirotor. Additionally, the aeroacoustic characteristics of fixed-pitch and variable-pitch controlled multirotor in response to wind velocity fluctuation are investigated by considering the direction of noise radiation and interference effects. The impact of the turbulent kinetic energy of wind on the noise characteristics is examined by quantifying the noise components associated with aerodynamic unsteadiness in flight. Furthermore, the rotor phase control method can be applied to reduce noise in both control methods. The optimization of rotor phases reduces tone noise significantly at the target observer point without causing aerodynamic losses in variable-pitch controlled multirotor. In contrast, the reduction in tone noise remains relatively limited for fixed-pitch controlled multirotor, as the rotor phase differences are not maintained.

H-infinity Variable-Pitch Control for Wind Turbines Based on Takagi-Sugeno Fuzzy Theory

H-infinity Variable-Pitch Control for Wind Turbines Based on Takagi-Sugeno Fuzzy Theory

On the estimation of the angle of attack for vertical axis wind turbines

PurposeThis paper aims to investigate the problem of estimating the angle of attack (AoA) and relative velocity for vertical axis wind turbine (VAWT) blades from computational fluid dynamics data.Design/methodology/approachTwo methods are implemented as function objects within the OpenFOAM framework for estimating the blade’s AoA and relative velocity. For the numerical analysis of the flow around and through the VAWT, 2 D unsteady Reynolds-averaged Navier–Stokes (URANS) simulations are carried out and validated against experimental data.FindingsTo gain a better understanding of the complex flow features encountered by VAWT blades, the determination of the AoA is crucial. Relying on the geometrically-derived AoA may lead to wrong conclusions about blade aerodynamics.Practical implicationsThis study can lead to the development of more robust optimization techniques for enhancing the variable-pitch control mechanism of VAWT blades and improving low-order models based on the blade element momentum theory.Originality/valueAssessment of the reliability of AoA and relative velocity estimation methods for VAWT’ blades at low-Reynolds numbers using URANS turbulence models in the context of dynamic stall and blade–vortex interactions.

Research on Control Strategy of Polar Unmanned Vehicle Wind Power Generation System

Due to the abundant scenery resources in Antarctica, for the unmanned vehicle working in the polar region, the scenery power supply system is built on it, and the control strategies for wind power systems is studied. The max power of the system is tracked by the climbing method, and the variable pitch control ensures that the output power of the generator is near the rated power when the air speed exceeds the rated air speed of the wind turbine. The system is modeled using Matlab/Simulink, and the two control methods are simulated. The simulation results of the system as a whole show that the control strategy can ensure the stable and reliable operation of the system under the environmental conditions of extreme cold and strong wind.

Hover Dynamics and Flight Control of a UAM-Scale Quadcopter With Hybrid RPM and Collective Pitch Control

Hover analysis is performed on a 1200-lb gross weight UAM-scale quadcopter with both variable rotor speed and collective pitch control. With these redundant controls, the hover performance and flight dynamics are considered at three trim points, where power consumption can be increased to improve authority of the pitch inputs for changes in rotor thrust. An explicit model following control laws is optimized using CONDUITR to meet ADS-33E-PRF handling qualities specifications, with design margin optimization on each axis. The responses of the linearized system are examined with either control type, and pitch control is shown to outperform RPM-control in heave, while the opposite is true for yaw. Trim in axial climb is simulated, where the collective pitch can be scheduled with the climb rate to maintain effective stall margin. Hybrid control mixing is implemented using a complementary filter, allowing the aircraft to use pitch control for short-term responses and RPM control for trim. The benefits of this hybrid control scheme are demonstrated through simulation of hot/high/heavy conditions, where trimming with RPM control allows the pitch actuators to maintain margin for maneuvers. It is concluded that hybrid control allows the aircraft to reap the benefits of pitch control for maneuverability while maintaining stall margin by using RPM control for trim.

Design of Variable Pitch Control Method for Floating Wind Turbine

Because of the randomness of wind speed and the nonlinearity of the dynamic equation of variable pitch control, it is difficult to establish an accurate dynamic equation of variable pitch of floating fan. In view of this situation, this paper takes the 5 MW floating wind turbine of the NREL (National Renewable Energy Laboratory) as the research object, establishes the dynamic equation under the basic control of FAST, uses the L-M (nonlinear least square method) to identify the dynamic parameters of the system and obtains the dynamic model of the floating fan under variable pitch stability control. Compared with the output of FAST in the same case, the accuracy of the control model is verified; the FAST base pitch control adopts PI control, but the effect of FAST base control is relatively poor. This paper proposes a disturbance-adaptive pitch control method based on fractional PID feedback; the results show that compared with the FAST base pitch control, the control method is more suitable for variable pitch control of a floating wind turbine. The generating power is more stable, the overshoot of generating power is smaller and the fluctuation of wind speed is smaller. Except for surge and heave, the fluctuation of the other four degrees of the freedom of the floating wind turbine platform is reduced, making it more suitable for the variable pitch control of the floating wind turbine.

Accounting for Environmental Conditions in Data-Driven Wind Turbine Power Models

Continuous assessment of wind turbine performance is a key to maximising power generation at a very low cost. A wind turbine power curve is a non-linear function between power output and wind speed and is widely used to approach numerous problems linked to turbine operation. According to the current IEC standard, power curves are determined by a data reduction method, called binning, where hub height, wind speed and air density are considered as appropriate input parameters. However, as turbine rotors have grown in size over recent years, the impact of variations in wind speed, and thus of power output, can no longer be overlooked. Two environmental variables, namely wind shear and turbulence intensity, have the greatest impact on power output. Therefore, taking account of these factors may improve the accuracy as well as reduce the uncertainty of data-driven power curve models, which could be helpful in performance monitoring applications. This paper aims to quantify and analyse the impact of these two environmental factors on wind turbine power curves. Gaussian process (GP) is a data-driven, nonparametric based approach to power curve modelling that can incorporate these two additional environmental factors. The proposed technique's effectiveness is trained and validated using historical 10-minute average supervisory control and data acquisition (SCADA) datasets from variable speed, pitch control, and wind turbines rated at 2.5 MW. The results suggest that (i) the inclusion of the additional environmental parameters increases GP model accuracy and reduces uncertainty in estimating the power curve; (ii) a comparative study reveals that turbulence intensity has a relatively greater impact on GP model accuracy, together with uncertainty as compared to blade pitch angle. These conclusions are confirmed using performance error metrics and uncertainty calculations. The results have practical beneficial consequences for O&M related activities such as early failure detection.

DESIGN AND ANALYSIS OF THE CHAMELEON SCHEDULING ALGORITHM FOR RECONFIGURABLE COMPUTING

Conventional power generation is the source of widespread worry over the depletion of nonrenewable energy sources and the environmental difficulties that this would inevitably cause. As a direct consequence of this, an increasing number of people are gravitating toward renewable energy sources like as photovoltaic boards and wind generators. Wind power is being put to use for a vast array of applications, some of which include the charging of batteries, the pumping of water, the generation of electricity for homes, the heating of swimming pools, the operation of satellite power systems, and many more. However, despite the fact that they do not need any sort of upkeep and do not result in any kind of pollution, their installation costs are high in many different contexts. Wind energy is quickly becoming a more significant contributor to the total installed power capacity around the globe. In the field of wind energy, the PMSG-based wind turbine equipped with a variable-speed and variable-pitch control system are the most common type of wind power generator. This device is capable of operating either independently or while linked to an existing grid. It is necessary to have a complete understanding of the machine's modelling, control, dynamic, and steady-state analyses in order to obtain the maximum possible amount of power from the wind, researchers must make an accurate prediction of the machine's performance in either mode of operation. The complexity of the systems, the sensors required, the speed of combination, the cost, the breadth of effectiveness, the technology employed, and the popularity of the systems all vary. Multiple control computations are performed on the Wind Energy Conversion System (WECS) in order to produce maximum power in a variety of wind speed scenarios. This is done so that the system can respond appropriately. The purpose of this work is to suggest several methodologies for obtaining dynamic features from the WECS integrated grid. The first technique makes use of the Firefly Algorithm (FA) as well as the Artificial Neural Network (ANN) methods. Both are classification algorithms. By utilizing the most effective parameters for design, the design of the grid-integrated power system design was able to achieve a voltage THD of 11.47 percent.

Variable pitch control of a quadrotor using adaptive sliding mode controller

PurposeThis paper aims to describe the characteristics and modeling of the variable pitch quadrotor. In a variable pitch quadrotor, unlike ordinary quadrotors that the force is generated by the rotors, the speed of the rotors is constant, and the force is generated by varying the pitch angle of blades.Design/methodology/approachIn this paper, a sliding mode controller and an adaptive sliding mode controller are used to control the variable pitch quadrotor to have better performance.FindingsThe variable pitch mechanism has a wider control bandwidth, and it is able to produce a negative thrust that facilitates trajectory tracking and aggressive maneuvers. The simulation results indicate high performance of the proposed control scheme in presence of disturbance and changes in mass of the quadrotor.Originality/valueThe performance of the controllers for the variable pitch quadrotor is investigated through computer simulation with MATLAB software.

A parallel Archimedes optimization algorithm based on Taguchi method for application in the control of variable pitch wind turbine

Archimedes optimization algorithm (AOA) is a recent metaheuristic algorithm that offers several advantages, including a few parameters, an easy-to-understand interface, and easy implementation. Still, some drawbacks exist, e.g., lack of diversity for search-exploring capacity, drop-trap local optimum. This study suggests a new variant of AOA based on the parallel and Taguchi method (TPAOA) for the global optimization problems and the wind turbine parameter adjust-tuning variable pitch controller problem. The parallel mechanism with communication strategy and the Taguchi orthogonal combination deal with the AOA’s drawbacks. The experimental results show that the proposed algorithm is more competitive than the other algorithms under the CEC2017 test suite. The wind turbine problem of parameter tuning difficulty of variable pitch controller is solved by applying the TPAOA. Compared solution results show that the TPAOA proves the feasibility smooth the output power of wind turbines and reducing the impact of wind speed fluctuations on the power grid, which has high feasibility.

A New combined MPPT-Pitch Angle control of a Large Variable Speed Wind Turbine in Different Operating Areas based on Synergetic control

The aim of this paper is to create a novel combination between two controls, maximum power point tracking (MPPT) and Pitch angle control system of a variable-speed wind turbine. The main objective sought is to achieve the maximization of the power produced by the fixed pitch angle turbine through the MPPT control in the zone 02 of operation. Then, limit the power to its nominal value by using the Pitch control with variable pitch angle in zone 03 of operation. Our contribution will be to propose strategies based on two types of controllers. The first is the control by the MPPT control, it is applied in light winds to extract the maximum power. The second is Variable Pitch Control, which is applied in strong winds to keep power constant at its nominal value, as well as protecting the wind turbine from high winds. For this, linear and non-linear control laws (PI, SC) respectively are implemented to achieve the defined objective. The simulation results show the feasibility and effectiveness of the techniques used.

Influence of pitch control method of offshore medium speed wind power based on lateral damping strategy on blade vibration

The operating conditions of offshore wind turbines are complex due to the coupling effects of wind waves and other factors. The blade is subjected to uneven load for a long time, which not only increases the difficulty of control and causes fatigue damage, but also leads to the vibration of the tower and affects the service life of the wind turbine. This article mainly GH simulation software was used to simulate sea under variable load condition, based on join the lateral damping strategy, by comparing the independent variable pitch and variable pitch unified control method, analyzed the low frequency vibration of blade root and spindle hub, verified the effectiveness and control advantages of the independent variable pitch control method with lateral damping. It provides effective control measures to solve the vibration problems of the unit and improves the operation reliability.

Variable Pitch Control of Wind Turbine Based on Fuzzy Feedforward and Feedback Linearization Sliding Mode

When the wind turbine operates above the rated wind speed, the pitch angle is usually adjusted to make the output power stable at the rated value. As the traditional linear controller is difficult to achieve better control effect for the large inertia and strong nonlinear wind power generation system, a variable pitch control method combining fuzzy feedforward and feedback linearization sliding mode is proposed in this study. Firstly, the nonlinear wind power model is globally linearized by input/output feedback linearization, and then the feedback controller is designed by combining with sliding mode control. The fuzzy feedforward controller can give the appropriate pitch angle according to the change of wind speed and realize dynamic feedforward compensation. The simulation results show that the proposed control method can make the output power of the wind turbine stable, and has better control accuracy and robustness.

Research on variable pitch control strategy of direct-driven offshore wind turbine using KELM wind speed soft sensor

This study proposes a modeling method of soft measurement of offshore wind speed using Kernal Extreme Learning Machine (KELM). The soft measurement model of offshore wind speed is presented based on the data-driven method and kernel function extreme learning machine. An improved gray Wolf optimization algorithm is applied to optimize its parameters to enhance the measurement accuracy. Finally, based on the established offshore wind speed measurement model, a feedforward and feedback variable rotor controller is designed and verified by simulation, which proves the effectiveness of the research in this study.