Rotor Speed Control Research Articles

The Optimization of Marine Diesel Engine Rotational Speed Control Process by Fuzzy Logic Control Based on Particle Swarm Optimization Algorithm

The marine main diesel engine rotational speed automatic control plays a significant role in determining the optimal main diesel engine speed under impacting on navigation environment conditions. In this article, the application of fuzzy logic control theory for main diesel engine speed control has been associated with Particle Swarm Optimization (PSO). Firstly, the controller is designed according to fuzzy logic control theory. Secondly, the fuzzy logic controller will be optimized by Particle Swarm Optimization (PSO) in order to obtain the optimal adjustment of the membership functions only. Finally, the fuzzy logic controller has been completely innovated by Particle Swarm Optimization algorithm. The study results will be represented under digital simulation form, as well as comparison between traditional fuzzy logic controller with fuzzy logic control–particle swarm optimization speed controller being obtained.

Development and experimental verification of a 5 kW small wind turbine aeroelastic model

Aeroelastic modelling is regularly used in the design and analysis of commercial scale wind turbines, but has seen comparatively little use in the development of small wind turbines. Fewer studies still have considered experimental validation of model performance with field measurements. This study details the development of an aeroelastic model of a 5 kW horizontal-axis Aerogenesis turbine within FAST. The model includes rotor aerodynamics, blade and tower structural freedom, free-yaw tail fin dynamics, and a self-excited induction generator incorporating maximum power point tracking variable speed control. This model was compared to measured operating data to assess aerodynamic and structural performance. Blade loadings and deflections were simulated within 8% and 10% respectively at design conditions in the azimuthal domain. Simulated rotor speed control and tail fin motions were bounded by measured field data. The simulated control system model was found to act aggressively, with a mean over-prediction in tip speed ratio of 11%. Areas for future model improvement are discussed in this paper. The resulting aeroelastic model and methodologies presented here are expected to further the use of aeroelastic modelling in the small wind turbine field. Particular applications may include the verification of performance and design loads specified in IEC 61400.2.

Robust Control of Doubly Fed Induction Generator Using Fractional Order Control

In this paper, we present a robust control of a variable speed Doubly Fed Induction Generator (DFIG)-based Wind Energy Conversion System (WECS), using Fractional Order Control (FOC) to prevent system deterioration under different critical conditions (external disturbance, measurement noise and DFIG parameters variation). In order to extract the maximum power from the wind, a Maximum Power Point Tracking (MPPT) strategy based on rotor speed control is proposed. Furthermore, a vector control strategy is used for controlling active and reactive powers of DFIG. Additionally, a simple design method of Fractional Order Proportional Integral (FOPI) controller is proposed. Finally, the system’s performance is tested and compared according to reference tracking, robustness, disturbance rejection and noise minimization.

Ship Trajectory Tracking Control System Design Based on Sliding Mode Control Algorithm

Abstract The paper reports the design and tests of the planar autopilot navigation system in the three-degree-of-freedom (3-DOF) plane (surge, sway and yaw) for a ship. The aim of the tests was to check the improved maneuverability of the ship in open waters using the improved nonlinear control algorithm, developed based on the sliding mode control theory for the ship-trajectory tracking problem of under-actuated ships with static constraints, actuator saturation, and parametric uncertainties. With the integration of the simple increment feedback control law, the dynamic control strategy was developed to fulfill the under-actuated tracking and stabilization objectives. In addition, the LOS (line of sight) guidance system was applied to control the motion path, whereas the sliding mode controller was used to emulate the rudder angle and propeller rotational speed control. Firstly, simulation tests were performed to verify the validity of the basic model and the tracking control algorithm. Subsequently, full scale maneuverability tests were done with a novel container ship, equipped with trajectory tracking control and sliding mode controller algorithm, to check the dynamic stability performance of the ship. The results of the theoretical and numerical simulation on a training ship verify the invariability and excellent robustness of the proposed controller, which: effectively eliminates system chattering, solves the problem of lateral drift of the ship, and maintains the following of the trajectory while simultaneously achieving global stability and robustness.

Numerical evaluation of the power output of an oscillating water column wave energy converter installed in the southern Brazilian coast

Although studies show high wave energy potential in several coastal regions around the world, its evaluation and detailed characterization are necessary to optimize its harvest. This study aims at numerically evaluating the power output of an Oscillating Water Column (OWC) wave energy converter installed in the southern Brazilian coast. The FLUENT® numerical model, based on the Reynolds Averaged Navier-Stokes (RANS) equations and the Volume of Fluid (VoF) technique, is used. The turbine diameter optimization (TDO) model, which considers the motion of the water surface inside the OWC chamber as a piston movement in response to the hydrodynamic forces from the incoming waves, is also employed. The OWC is equipped with a Wells turbine, with pressure control (relief valve) and regulation of the turbine rotational speed. The turbine diameter is chosen by taking into account the wave characteristics in the region where the device is installed. An OWC device 10 m wide, 10 m long, 16 m high (10 m submerged) with a front wall 2.5 m submerged reaches its optimum performance with an annual-averaged power output of 36.48 kW (efficiency of 54.6%), by using a turbine with 2.25 m diameter.

Control strategy of PMSG based wind energy conversion system under strong wind conditions

This paper presents a control approach for the Permanent Magnet Synchronous Generator (PMSG) based Wind Energy Conversion Systems (WECS) under a wide range of wind speeds. Generally, most of the wind turbines are turned-off and disconnected from the power grid, in case wind velocity is gone over 25 m/s. It may cause wind power supply shortage from wind farms. This research introduces a pitch angle controller as well as a rotational speed control system so that the PMSG based WECS can generate power if the wind speeds are above 25 m/s. The proposed method reduces the mechanical stress of the wind turbine by preferential reducing of the rotational speed rather than the mechanical torque during strong wind condition. As a result, the chance of turning-off the is reduced compared to the conventional control system because the PMSG based WECS can temporarily tolerate the wind speed up to 35 m/s. A 2 MW WECS with the electrical and mechanical characteristics is modeled in the MATLAB/SimPowerSystems® to verify the proposed research.

Pitch Angle Control of Wind Turbine Using Adaptive Fuzzy-PID Controller

The control strategy for wind turbine is very important an equipage that diverts the kinetic energy of the wind to electrical power. The rotation speed control of wind turbine is necessary for highest degree energy capture and pitch angle advanced control planning depending on traditional PID cont

Characterization of Near-Propeller Bubbles and Thrust Fluctuation in a Constant Rotational Speed Control Motor Propulsion System

Characterization of Near-Propeller Bubbles and Thrust Fluctuation in a Constant Rotational Speed Control Motor Propulsion System

Permanent magnet DC motor control by using arduino and motor drive module BTS7960

This study proposes a control system for permanent magnet DC (PMDC) motor. PMDC drive control system has two critical parameters: control and monitoring. Control system includes rotation speed control and direction of rotation of motor using motor drive module BTS7960. The PWM signal has a fixed frequency of waves with varying duty cycles (between 0% and 100%), so the motor rotation can be regulated gradually using a potentiometer already programmed on the Arduino Uno board. The motor rotation direction setting uses the H-bridge circuit method using a 3-way switch to set the direction of forward-reverse rotation of the motor. The monitoring system includes measurements of rotational speed, current, and voltage. Motor rotation speed can be adjusted from the armature voltage settings through the duty cycle PWM setting so that the motor speed can be increased or decreased by the desired duty cycle. From the unload PMDC motor test results it has also been shown that the torque of the motor is relatively constant when there is a change in speed from low rpm to high rpm or vice versa.

Multi-Layer Artificial Neural Networks Based MPPT-Pitch Angle Control of a Tidal Stream Generator.

Artificial intelligence technologies are widely investigated as a promising technique for tackling complex and ill-defined problems. In this context, artificial neural networks methodology has been considered as an effective tool to handle renewable energy systems. Thereby, the use of Tidal Stream Generator (TSG) systems aim to provide clean and reliable electrical power. However, the power captured from tidal currents is highly disturbed due to the swell effect and the periodicity of the tidal current phenomenon. In order to improve the quality of the generated power, this paper focuses on the power smoothing control. For this purpose, a novel Artificial Neural Network (ANN) is investigated and implemented to provide the proper rotational speed reference and the blade pitch angle. The ANN supervisor adequately switches the system in variable speed and power limitation modes. In order to recover the maximum power from the tides, a rotational speed control is applied to the rotor side converter following the Maximum Power Point Tracking (MPPT) generated from the ANN block. In case of strong tidal currents, a pitch angle control is set based on the ANN approach to keep the system operating within safe limits. Two study cases were performed to test the performance of the output power. Simulation results demonstrate that the implemented control strategies achieve a smoothed generated power in the case of swell disturbances.

Non‐linear tip speed ratio cascade control for variable speed high power wind turbines: a backstepping approach

This study presents a non-linear tip speed ratio (TSR) cascade controller for high power wind turbines (WTs) considering the effects of the large rotor inertia and torsional behaviour of the shafts. A model-based non-linear rotor speed controller is proposed for the inner loop. The required speed reference is provided by an outer loop. A design procedure for cascade control of WTs is based on a backstepping design. It is shown that the above two-loop control schemes lead to a nice cascade structure for the closed-loop systems. Stability result adapted for analysis of this particular kind of systems is developed. The effectiveness of the proposed control approach is evaluated on a WT by comparing with typical control strategies such as non-linear TSR control, optimal torque control, and sliding mode control. Simulation results show that the proposed two-loop controller exhibits better performance than the above typical control strategies.

Design and Characterization of a Trailer-Based Horizontal-Axis Wind Turbine Test Rig

This paper presents a mobile testing rig developed for small wind turbine (SWT) experimental work to orchestrate, cost-effectively, turbine performance characterization in both controlled wind inflow speeds and turbulent ambient flows. It facilitates off-grid testing of up to a 1 kW wind turbine. It is a dual-purpose machine that can be towed behind a vehicle to conduct steady-state tests (track testing) or be parked to collect unsteady field data (field testing), all with the same rotor and instrumentation. Its mechanical design included computational fluid dynamics (CFD) analysis to gauge the potential impact of towing vehicle disturbance on the free stream available to the rotor. To provide a compelling platform for full rotor speed control, a reconfigurable control system coupled to an electric vehicle controller with regenerative braking technology has been modeled and implemented into its electrical design. Uncertainty analysis has also been rigorously conducted to project the error bounds pertaining to both precision and bias components of the testing results. The rig has been tested in a towed scenario and blade element momentum (BEM) simulations have been compared with the actual aggregate performance curves obtained experimentally. Future work involves testing in unsteady winds, for which the rig was ultimately designed in order to better understand unsteady rotor performance and adaptive design.

Water cycle algorithm–based airflow control for oscillating water column–based wave energy converters

The stalling behavior is a feature of the Wells turbine that limits the generated output power of power plants using this turbine. The NEREIDA wave power plant installed in the harbor of Mutriku in the northern Spanish shoreline constitutes an excellent example of this phenomenon. This article deals with the modeling, simulation and control of an oscillating water column unit within the NEREIDA wave power plant. The stalling behavior is investigated and two control strategies are proposed to avoid it. The first control approach is the airflow control which aims to adjust the airflow in the turbine duct using a proportional–integral–derivative controller tuned with the water cycle algorithm. The second control approach is the rotational speed control adjusting the rotor speed using the rotor-side converter of the back-to-back converter which is wired to the doubly fed induction generator. Results of comparative studies show a power generation improvement even relative to the real measured data.

Flow Control in Wells Turbines for Harnessing Maximum Wave Power.

Oceans, and particularly waves, offer a huge potential for energy harnessing all over the world. Nevertheless, the performance of current energy converters does not yet allow us to use the wave energy efficiently. However, new control techniques can improve the efficiency of energy converters. In this sense, the plant sensors play a key role within the control scheme, as necessary tools for parameter measuring and monitoring that are then used as control input variables to the feedback loop. Therefore, the aim of this work is to manage the rotational speed control loop in order to optimize the output power. With the help of outward looking sensors, a Maximum Power Point Tracking (MPPT) technique is employed to maximize the system efficiency. Then, the control decisions are based on the pressure drop measured by pressure sensors located along the turbine. A complete wave-to-wire model is developed so as to validate the performance of the proposed control method. For this purpose, a novel sensor-based flow controller is implemented based on the different measured signals. Thus, the performance of the proposed controller has been analyzed and compared with a case of uncontrolled plant. The simulations demonstrate that the flow control-based MPPT strategy is able to increase the output power, and they confirm both the viability and goodness.

Rotor speed control strategy to avoid resonance frequencies of turbo-molecular pump

A novel design of composite turbo-molecular pump (CTMP) is proposed. The major configuration of CTMP is composed by a coarse pump, a turbo-molecular pump (TMP) and a magnetic gear unit (MGU) capable of speed amplification. The modal analysis and the study on rotor/bearing dynamics are undertaken at first to estimate the resonance frequencies of the TMP blade rotor itself solely and the interactive dynamics of blade rotor/radial active magnetic bearing (BR/RAMB) subsystem. Secondly, an economical and efficient method by adjusting the angular acceleration speed of BR, namely RDPS, is proposed to ensure the natural frequencies of BR/RAMB sub-system are not driven by the rotor speed all the time. Besides, a speed route of rotor during the take-off cycle of TMP is proposed to satisfy the requirements of system stiffness and prevention of system resonance being driven. Finally, a position conversion method is introduced to solve the problem of distinct locations of gap sensors and the actual gap between rotor and the auxiliary bearings such that the measurement feedback to the controller, RDPS, becomes applicable to formulate the correct actions for providing enough gap margin to prevent collision of rotor against bearings. To sum up, the CTMP possesses the merit of reduction of electrical energy consumption by 17%, compared with the conventional TMP unit. By intensive computer simulations, the RDPS indeed manifests its outstanding performance to efficiently skip or bypass the natural frequencies of the closed-loop system within a very short time period and guarantee the system stability.

In-process Control of Rotational Speed in Friction Stir Welding of Sheet Blanks with Variable Mechanical Properties

In the present work, an adaptive control constraint system was applied in the friction stir welding of AA6082 aluminum alloy with the aim of tailoring the mechanical properties of the sheet blank to the subsequent forming processes. To this purpose, blanks in the solution heat-treated and artificially aged (T6), and in the annealed (O) conditions were welded according to a well defined layout. Such in-process control strategy was based on the variation of the controlled variable (rotational speed of the pin tool) in order to keep the measured one (vertical force) constant during the welding stage of the process. To this end, a preliminary investigation on the effect of the rotational speed, varying from 1000 to 2500rpm, on the vertical force during FSW was performed. The capability of the proposed approach in friction stir welding sheet blanks with variable mechanical properties along the welding line was proven.

Actual State of Main Pump Rotation Speed Control in Sewage Treatment Plants and Energy-saving Measures

Actual State of Main Pump Rotation Speed Control in Sewage Treatment Plants and Energy-saving Measures

Iterative tuning of engine speed controller for launch control applications in sport motorcycles

In this work, engine rotational speed controller tuning issue is analyzed. To cope with actuation limitations, controller tuning is addressed in an iterative framework by means of the Iterative Feedback Tuning method. Subsequent iterations are needed to gain information on the controlled system and to meet closed-loop performance defined by means of a reference model. Finally, tuning results are discussed and closed-loop performance are analyzed.

Load Frequency Control of Multi-Area Interconnected System Comprising DFIG-Based Wind Turbine Equipped with Coordinated Control

Traditionally, wind power generation has not contributed to power system frequency regulation due to decoupling between generator speed and grid frequency by power electronics devices. It has an adverse effect on load frequency control problem with increasing wind power level. The major focus of this article is to demonstrate load frequency controller for multi-area interconnected system comprising DFIG-based wind power plants equipped with coordinated frequency control technique. Single control technique such as inertial control, pitch angle control, or rotor speed control is not sufficient for all zones of wind speed. Therefore, coordination between theses controllers is required for frequency regulation of grid. In the present paper, two-area and three-area interconnected power systems comprising non-reheat thermal unit and wind power plant with coordinated control technique have been implemented. Two-area interconnected power system has been analyzed for different step load perturbations in each area. The novelty of this work is apparent from the fact that coordinated control of wind turbine for load frequency control problem of two-area and three-area interconnected power systems has not been reported in literature so far. Load frequency control incorporating coordinated control of wind turbine has been compared with inertial controller, combination of inertial and droop controller, and combination of inertial, droop and pitch angle control techniques in the case of the two-area interconnected power system, whereas it has been compared with combination of inertial, droop, and pitch angle control for the three-area interconnected power system. It has been established from the simulation results of the proposed controller that frequency and tie line power deviations have shown remarkable improvements for all wind speed zones.

IMITATION MODEL OF A HIGH-SPEED INDUCTION MOTOR WITH FREQUENCY CONTROL

Purpose. To develop the imitation model of the frequency converter controlled high-speed induction motor with a squirrel-cage rotor in order to determine reasons causes electric motor vibrations and noises in starting modes. Methodology. We have applied the mathematical simulation of electromagnetic field in transient mode and imported obtained field model as an independent object in frequency converter circuit. We have correlated the simulated result with the experimental data obtained by means of the PID regulator factors. Results. We have made the simulation model of the high-speed induction motor with a squirrel-cage rotor speed control in AnsysRMxprt, Ansys Maxwell and Ansys Simplorer, approximated to their physical prototype. We have made models modifications allows to provide high-performance computing (HPC) in dedicated server and computer cluster to reduce the simulation time. We have obtained motor characteristics in starting and rated modes. This allows to make recommendations on determination of high-speed electric motor optimal deign, having minimum indexes of vibrations and noises. Originality. For the first time, we have carried out the integrated research of induction motor using simultaneously simulation models both in Ansys Maxwell (2D field model) and in Ansys Simplorer (transient circuit model) with the control low realization for the motor soft start. For the first time the correlation between stator and rotor slots, allows to obtain minimal vibrations and noises, was defined. Practical value. We have tested manufactured high-speed motor based on the performed calculation. The experimental studies have confirmed the adequacy of the model, which allows designing such motors for new high-speed construction, and upgrade the existing ones.