Angle Control Method Research Articles

Online Advanced Angle Adjustment Method for Sinusoidal BLDC Motors with Misaligned Hall Sensors

This letter presents an improved approach for high performance operation of brushless dc (BLDC) motors with hall sensors. The hall sensors in BLDC motors are ideally placed 120 electrical degrees apart. However, hall sensor placement may be significantly incorrect, particularly in high-pole and small-sized motors. These misaligned hall sensors can cause serious torque ripple, and it can be difficult to apply advanced angle control. Therefore, a position error compensator is needed before an advanced angle control method is applied. In this letter, on the basis of the position error compensator, an online advanced angle adjustment method using input voltage and input current is proposed. Using the proposed method, balanced hall sensor signals can be obtained and the high-performance operation can be achieved. The effectiveness of the proposed approach is verified through experimental results.

Output power levelling for DFIG wind turbine system using intelligent pitch angle control

ABSTRACTBlade pitch angle control, as an indispensable part of wind turbine, plays a part in getting the desired power. In this regard, several pitch angle control methods have been proposed in order to limit aerodynamic power gained from the wind turbine system (WTS) in the high-wind-speed regions. In this paper, intelligent control methods are applied to control the blade pitch angle of doubly-fed induction generator (DFIG) WTS. Conventional fuzzy logic and neuro-fuzzy-particle swarm optimization controllers are used to get the appropriate wind power, where fuzzy inference system is based on fuzzy c-means clustering algorithm. It reduces the extra repetitive rules in fuzzy structure which in turn would reduce the complexity in neuro-fuzzy network with maximizing efficiently. In comparing the controllers at any given wind speed, adaptive neuro-fuzzy inference systems controller involving both mechanical power and rotor speed revealed better performance to maintain the aerodynamic power and rotor speed at the rated value. The effectiveness of the proposed method is verified by simulation results for a 9 MW DFIG WTS.

Analysis of the Potential for Use of Floating PV Power Plant on the Skadar Lake for Electricity Supply of Aluminium Plant in Montenegro

This paper deals with a conceptual solution for the supply of a part of electrical energy for the needs of Aluminium Plant Podgorica (KAP) in Montenegro from a large Floating Photovoltaic Power Plant (FPPP), that would be installed on the nearby lake. The recommended FPPP, with an innovative azimuth angle control method and total installed power of 90 MWp, would consist of 18 power plants having an installed power of 5 MWp each. An analysis using the NREL solar insolation database ascertained that the recommended FPPP power plant can achieve a significantly higher production in comparison with previous solutions. An economic analysis has shown that the recommended power plant would yield positive economic indicators. Additionally, such a power plant would significantly contribute to the reduction of CO2 emissions.

Design and Performance of a Phase Angle Control Method Based on Digital Phase-locked Loop

Controlling of the phase angle of the output current or voltage of the resonant inverter is crucial for the proper operation of the power converters in the application of energy engineering. This paper proposed a novel phase angle control method based on digital phase-locked loop (DPLL). The new method features accurate phase control and flexible phase adjustment. Also we established a mathematical model of the DPLL based on the analysis of the operating characteristic of each module. Several experiments were also implemented to verify the effectiveness of the proposed phase angle control method in the end.

DEVELOPMENT OF A WALKING ASSISTANCE APPARATUS INCLUDING A TORQUE LIMITER IN A GEAR

A walking assistance apparatus using a torque limiter was developed. We used the servo motor for hobby, it is relatively small, light weight, and included not only a motor and transmission gear, but also a driver and encoder. At first, we controlled the device using angle control method, according to the walking phase along to the mean data of able bodied people while walking. However, when the user stops walking suddenly or walk on outdoor various roads, the final gear was broken frequently. Because the gear was designed to break easily, to defend the motor from the inverse inputting overload torque. Then we developed a torque limiter mechanism in the final gear. This is a traction drive sandwiched a soft material plate between two circular disk. We carried out the experiment to measure the limit torques of eight kinds of the rubber material. In this paper, the results of the experiment were shown.

Proposition of Tightening Method with High Accuracy by Combining Torque and Angle Control Methods

Proposition of Tightening Method with High Accuracy by Combining Torque and Angle Control Methods

장거리 공중-지상 영상정보용 데이터링크의 수신 안테나 최적 고각 제어 방법

영상정보용 데이터링크는 장거리의 공중-지상 환경에서 영상과 신호정보를 전송하도록 설계된 통신 시스템이다. 본 논문은 장거리 공중-지상 채널환경의 신호 분석에 적합한 곡면지구 2-Ray 모델을 사용하여 영상정보용 데이터 링크의 통신거리에 따른 수신전력 변화 폭을 분석하고 지면 반사파에 의한 수신전력의 변화폭을 경감할 수 있는 수신 안테나의 최적 고각 제어방법을 제안한다. 제안된 방법은 추가적인 하드웨어 성능 향상 없이도 기존의 고각 제어 방법에 비하여 추가적인 링크마진을 확보할 수 있다. Common data link systems are designed to transmit the imaginary and signal intelligence data at long distance air-ground line of sight(LOS) link. In this paper, we analyze the received power variation according to the communication distance of the common data link using curved earth 2-Ray model suitable for received signal power analysis of long distance air-ground wireless channel. We propose optimal elevation angle control method of the receiving antenna to reduce a power variation caused by ground-reflected wave. Proposed method can get additional link margin compared to the conventional method without any additional hardware performance enhancement.

Torque-Overlay-Based Robust Steering Wheel Angle Control of Electrical Power Steering for a Lane-Keeping System of Automated Vehicles

We propose a torque-overlay-based robust steering wheel angle (SWA) control method of electrical power steering (EPS) for a lane-keeping system of automated vehicles. The proposed method consists of an augmented observer and a nonlinear damping controller to guarantee the semiglobal uniform ultimate boundedness of the SWA tracking error using only SWA feedback. The key idea of the proposed method is that the system functions with unknown parameters and external disturbance, along with their derivatives, are combined into an augmented state variable for designing the nonlinear observer in the absence of Lipschitz conditions. The augmented observer is designed to estimate the full state and disturbance. The nonlinear damping controller is developed via backstepping to suppress the angle tracking error using the input-to-state stability property when the estimation error becomes large. Since the proposed method is designed based on torque overlay, a torque integration using basic functions of the EPS for SWA control is available for driver convenience. Furthermore, no modification of the EPS is required. The performance of the proposed method was validated through experimentation with a test vehicle.

Modeling and Stability Analysis of Hybrid PV/Diesel/ESS in Ship Power System

Due the concern about serious environmental pollution and fossil energy consumption, introducing solar generation into ship power systems has drawn greater attention. However, the penetration of solar energy will result in ship power system instability caused by the uncertainties of the solar irradiation. Unlike on land, the power generated by photovoltaic (PV) modules on the shipboard changes as the ship rolls. In this paper, a high-speed flywheel energy storage system (FESS) is modeled to smooth the PV power fluctuations and improve the power quality on a large oil tanker which contains a PV generation system, a diesel generator, a FESS, and various types of ship loads. Furthermore, constant torque angle control method combined with sinusoidal pulse width modulation (SPWM) approach is proposed to control the FESS charging and discharging. Different ship operating situations and the impact of the ship rolling is taken into consideration. The simulation results demonstrate the high efficiency and fast response of the flywheel energy storage system to enhance the stability of the proposed hybrid ship power system.

交差点での右左折における目標操舵角生成手法

交差点での右左折における目標操舵角生成手法

Corrective finishing of a micro-aspheric mold made of tungsten carbide to 50 nm accuracy.

The increasing demand on the optical performance of micro-aspheric glass lenses used for consumer, medical, as well as industrial applications places a high requirement on the surface quality of the molds used for replicating these lenses. However, it is difficult, almost impossible to generate a supersmooth surface with extremely high form accuracy by using the current cutting or grinding techniques. Therefore, this paper presents a corrective polishing process to finish micro-aspheric molds made of tungsten carbide by applying the vibration-assisted polishing method, aiming to obtain tens-of-nanometer form accuracy and subnanometer surface roughness. A polishing system which provides precise position, angle, and force control in 5 degrees of freedom (DOF)is employed for the experiments, and a tilting angle control method is introduced for the ease of the precisely controlling polishing force so as to keep the material removal rate stable. Then a dwell time algorithm is proposed by considering the scanning path of the polishing tool and the tilting angle of the workpiece. The experimental results show that after corrective polishing, the form accuracy of a micro-aspheric mold with high numerical aperture (NA) is successfully improved from 230nm peak-to-valley (PV) to under 50nm PV, while the surface roughness is reduced from 7.2nm root-mean-square (rms) to 0.5nm rms.

Extended Reference Signal Generation Scheme for Integration of Unified Power Quality Conditioner in Grid-connected Photovoltaic System

—This article proposes an extended reference signal generation scheme for the integration of a three-phase four-wire unified power quality conditioner in a grid-connected photovoltaic system. The photovoltaic–unified power quality conditioner provides compensation against voltage harmonics, current harmonics, and voltage interruption for the whole day. It also transmits the power generated in the photovoltaic system to the load. The proposed topology utilizes the green energy source with an energy storage unit to address the DC-link voltage requirement of the shunt and series active power filters of the unified power quality conditioner. The high-selectivity filter is used in the shunt inverter control scheme for reference current generations. The series inverter in the unified power quality conditioner is used for supplying a part of reactive power required by the load and for compensation of sag/swell, supply voltage unbalance, and distortions. This is achieved by controlling the phase angle and magnitude of series-injected voltage called the power angle control method. The simulation and experimental studies are carried out to validate the effectiveness of the proposed photovoltaic-based three-phase four-wire unified power quality conditioner.

Performance Evaluation of UPQC for Interconnecting Photovoltaic Systems to the Electric Grid

This paper proposes the efficient operation of a unified power-quality conditioner (UPQC) for interconnecting the photovoltaic (PV) systems to the utility grid. An extended reference signal generation scheme is proposed based on a modified version of the p-q theory using a high selectivity filter (HSF) and power angle control method. The proposed topology provides PV power generation, as well as the function of the UPQC. The shunt active power filter (SAPF) is used to extract the power from the PV power-generating system along with compensating the current harmonics and reactive power. The series active power filter (APF) in the UPQC is used for supplying a part of reactive power required by the load, along with the compensation of the voltage sag/swell, voltage unbalance, and voltage harmonics. This is achieved by controlling the phase angle and magnitude of series injected voltage called the power angle control method. The proposed topology utilizes the renewable energy source with an energy storage unit to meet the dc-link voltage requirement of the shunt and series APF of the UPQC. The shunt inverter control scheme is based on the use of HSF for reference-current generations. In addition, the fuzzy-logic controller is implemented for better current control accuracy of the shunt active filter. The simulation and experimental studies are carried out to validate the effectiveness of the proposed PV-based three-phase, four-wire UPQC.

Preparation of the Face Images in a Video Stream for Recognition and Filtering of Non-Informative Images

There have been specified the principal tasks of the image preparation for the face recognition and criteria of the image quality evaluation. There has been proposed a method of the face tracking in a video stream, a search criterion of the similar images formulated and the current estimators of the contrasting effect and image sharpness analyzed. The method of lighting compensation and the angle control method on the basis of POSIT algorithm have been studied.

S1130103 2次元FEMを利用したねじの回転角法締付けのシミュレーション

Angle control method is one of the basic tightening control methods for bolted joints. The accuracy of the clamp force induced depends basically on the combined stiffness of the bolt/nut assembly and the clamped member which can be determined from the material and the geometry of the bolted joint. However, the preliminary experiment is sometimes required to determine the target angle since the combined stiffness normally represents the non-linear behavior. This study aim to obtain the angle/clamp force relationship by using 2-D FEM. The results suggest that the combined stiffness or the relation between the rotational angle and the clamp force is affected by 3-dimensional factors such as the slippage at the mating threads.

Research on Constant Frequency Electrical Angle Start Method of LCI

Load-commutated inverters (LCIs) are the key starting device of wound-field synchronous motor. By detecting the rotor position and inputting a variable frequent current to the stator windings, the LCI can drive the motor from standstill to a given speed. Thus, rotor position detecting method comes to be the key techniques, but at the ultra-low speed period, the motor’s terminal voltage is too low to accurately sampling and is vulnerable to the interference, which brings risks to the variable frequency driving. In this paper, through analyzing the principles of LCIs and synchronous machine, a constant frequency electrical angle control methods is introduced to solve the difficulty of detecting the rotor position in the low speed period. A 98MW synchronous machine driven with an 18MW LCI are experimented in MATLAB and RTDS systems, the results show that the proposed control strategy can realize soft-start of the wound-field synchronous motor without detecting rotor’s position.

Hardware Implementation of Direct Load Angle Controlled Induction Motor Drive

In this article, a direct load angle (DLA) control method for induction motor drive is proposed to reduce the torque and flux ripple. It is based on control of incremental change in load angle. The torque control is achieved without losing the benefits of conventional direct torque control (DTC) by reference stator flux angle, which is the sum of load angle and rotor flux angle. In this proposed DTC scheme, coordinate transformation is not required in torque control unit and reference voltage sector number and angle are not required in PWM unit, which reduces the control complexity. Proposed DTC control method is applied to two level voltage source inverter fed induction motor drive and hardware results are presented. From the hardware results, it is found that the proposed DTC control scheme impressively reduces the torque and flux ripples when compared with conventional space vector modulation (SVM) DTC.

블라인드연동 LED조명의 조광제어에 따른 재실자의 밝기 변화 인식에 관한 연구

This study has attempted to investigate how subjects perceive changes of brightness and their visual comfort according to daylight responsive LED(Light Emitting Diode) dimming systems in the office with venetian blind. Two studies was conducted. First study is that how subjects perceive changes of brightness and their visual comfort depending on angle control method of the venetian blind while the workplane illuminance level is being maintained through daylight responsive LED dimming system. Second study is that how subjects perceive changes of brightness and their visual comfort depending on the amount of daylight penetrated into the building while the illuminance level is being maintained through daylight responsive LED dimming system. The results of this study could be proposed as basic data in the control of the venetian blind and LED lighting in consideration of their perception on changes of brightness and visual comfort.

Pitch Angle Control and Wind Speed Prediction Method Using Inverse Input-Output Relation of a Wind Generation System

In this paper, a sensorless pitch angle control method for a wind generation system is suggested. One-step-ahead prediction control law is adopted to control the pitch angle of a wind turbine in order for electric output power to track target values. And it is shown that this control scheme using the inverse dynamics of the controlled system enables us to predict current wind speed without an anemometer, to a considerable precision. The inverse input-output of the controlled system is realized by use of an artificial neural network. The proposed control and wind speed prediction method is applied to a Double-Feed Induction Generation system connected to a simple power system through computer simulation to show its effectiveness. The simulation results demonstrate that the suggested method shows better control performances with less control efforts than a conventional Proportional-Integral controller.

Compact Flyeye concentrator with improved irradiance uniformity on solar cell

A Flyeye concentrator with improved irradiance distribution on the solar cell in a concentrator photovoltaic system is proposed. This Flyeye concentrator is composed of four surfaces: a refractive surface, mirror surface, freeform surface, and transmissive surface. Based on the principles of geometrical optics, the contours of the proposed Flyeye concentrator are calculated according to Fermat's principle, the edge-ray principle, and the ray reversibility principle without solving partial differential equations or using an optimization algorithm, therefore a slope angle control method is used to construct the freeform surface. The solid model is established by applying a symmetry of revolution around the opti- cal axis. Additionally, the optical performance for the Flyeye concentrator is simulated and analyzed by Monte-Carlo method. Results show that the Flyeye concentrator optical efficiency of >96.2% is achievable with 1333× concentration ratio and � 1.3 deg acceptance angle, and 1.3 low aspect ratio (average thickness to entry aperture diameter ratio). Moreover, com- paring the Flyeye concentrator specification to that of the Kohler concen- trator and the traditional Fresnel-type concentrator, results indicate that this concentrator has the advantages of improved uniformity, reduced thickness, and increased tolerance to the incident sunlight. © 2013 Society