Maximum power extraction for wind turbines through a novel yaw control solution using predicted wind directions

Song, Dongran,Yang, Jian,Fan, Xinyu,Liu, Yao,Liu, Anfeng,Chen, Guo,Joo, Young Hoon Elsevier 2018 Energy conversion and management Vol.157 No.-

<P><B>Abstract</B></P> <P>For modern horizontal axis wind turbines (WTs), a yaw drive mechanism is utilized to adjust the nacelle position to face the wind direction. Depending on historical signals from wind direction sensors, conventional yaw control methods could not provide sufficient performance in tracking winds, and thus result in a reduction of wind power extraction. This issue needs to be tackled using advanced control solutions. Taking advantage of predicted wind directions, a novel control solution is proposed in this study. Specifically, the proposed solution refers to a novel control structure that consists of a wind direction predictive model and a novel yaw control method. Under the proposed control structure, a hybrid autoregressive integrated moving average method-based Kalman filter (ARIMA-KF) model is used to predict the wind direction, and two novel yaw control methods are proposed: one created by using the predicted wind direction as the tracking reference, and the other based on a model predictive control (MPC) using a finite control set. To demonstrate the feasibility and the superiority of the proposed solution, two novel yaw controllers are developed and tested through some simulation tests using industrial data. Their performance is compared to the one of two industrial yaw controllers. Comparison results show that the two novel yaw controllers are capable of reducing yaw error, and thus increase wind power extraction for the WTs. Meanwhile, it is noticeable that the MPC-based controller has an advantage in the aspect of reducing yaw actuator usage.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel yaw control solution using predicted wind direction is proposed. </LI> <LI> An ARIMA-KF based model is used to predict the wind direction. </LI> <LI> One novel yaw control method uses the predicted wind direction as the tracking reference. </LI> <LI> The other one is based on a model predictive control using a finite control set. </LI> <LI> The novel yaw control solution extracts 1% more wind power. </LI> </UL> </P>

A Cyber Security Enhancement Method for Non-direct CDAs

In Hyo Lee 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1

Nuclear Safety and Security Commission (NSSC) and KINAC review a Cyber Security Plan (CSP) by「ACT ON PHYSICAL PROTECTION AND RADIOLOGICAL EMERGENCY」. The CSP contains cyber security implementation plans for the licensee’s nuclear power plant, and it shall meet the requirements of KINAC/RS-015, a regulatory standard. The KINAC/RS-015 provides more detailed information on the legal requirements, so if licensees implement cyber security under the approved CSP, they can meet the law. To protect nuclear facilities from cyber-attacks, licensees should identify their essential digital assets, so-called “Critical Digital Assets” (CDAs). Then, they apply cyber security controls (countermeasures for cyber-attacks) on CDAs consisting of technical, operational, and management security controls. However, it is hard to apply cyber security controls on CDAs because of the large amounts of CDAs and security controls in contrast to the shortage of human resources. So, licensees in the USA developed a methodology to solve this problem and documented it by NEI 13-10, and US NRC endorsed this document. The main idea of this methodology is, by classifying CDAs according to their importance, applying small amounts of security controls on less important CDAs, so-called non-direct CDAs. In the case of non-direct CDAs, only basic cyber security controls are applied, that is, baseline cyber security controls. The baseline cyber security controls are a minimum set of cyber security controls; they consist of control a) from control g) a total of 7 controls. Although non-direct CDAs are less critical than other CDAs (direct CDAs), they are still essential to protect them from cyber-attacks. This paper aims to suggest a cyber security enhancement method for non-direct CDAs by analyzing the baseline cyber security controls. In this paper, baseline cyber security controls were analyzed respectively and relatively and then concluded how to apply small amounts of cyber security controls on non-direct CDAs rather than direct CDAs without scarifying cyber security.

유도전동기 드라이브의 고성능 제어를 위한 새로운 퍼지제어기

정동화,이정철,이홍균 한국산업안전학회 2002 한국안전학회지 Vol.17 No.4

This paper is presented new fuzzy controller for high performance of induction motor drive. New fuzzy controller took out appropriate amounts of accumulated control input according to fuzzily described situations in addition to the incremental control input calculated by conventional direct fuzzy controller. The structures of the proposed controller was motivated by the problems of direct fuzzy controller. The direct controller was given generally inevitable overshoot when one tries to reduce rise time of response. The undesirable characteristics of the direct fuzzy controller are caused by integrating operation of the controller, even though the integrator itself is introduced to overcome steady state error in response. The proposed controller clear out fuzzily integrated quantities according to the situation. This paper attempts to provide a thorough comparative insight into the behavior of induction motor drive with direct and new fuzzy speed controller. The validity of the comparative results is confirmed by the simulation results for induction motor drive system.

IPMSM 드라이브의 고성능 제어를 위한 새로운 퍼지제어기

이정철,이홍균,김종관,정동화 대한전자공학회 2003 電子工學會論文誌-SC (System and control) Vol.40 No.3

종래 직접 퍼지제어기에서는 누적 오차의 발생과 제어입력의 누적으로 인한 과도응답의 성능을 악화시킬 수 있으며 이러한 단점의 보완은 제어입력만으로 결정하기 어렵다. 본 논문에서는 이러한 문제점을 해결하기위해 과도상태에서 나타나는 오버슈트와 상승시간을 고려하기 위해 퍼지제어기를 이용한 재설정 변화분을 설정하며 이를 직접 퍼지제어기에 추가하여 병렬형태로 구성된 새로운 퍼지제어기를 구성한다. 본 논문에서 제시한 새로운 퍼지제어기를 IPMSM 드라이브에 적용하여 새로운 퍼지제어기가 직접 퍼지제어기와 비교하여 응답성능이 우수함을 제시하고 그 타당성을 입증한다. This paper is proposed new fuzzy controller for high performance of interior permanent magnet synchronous motor(IPMSM) drive. New fuzzy controller take out appropriate amounts of accumulated control input according to fuzzily described situations in addition to the incremental control input calculated by conventional direct fuzzy controller The structures of the proposed controller is motivated by the problems of direct fuzzy controller. The direct controller generally give inevitable overshoot when one tries to reduce rise time of response especially when a system of order higher than one is under consideration. The undesirable characteristics of the direct fuzzy controller are caused by integrating operation of the controller, even though the Integrator itself is introduced to overcome steady state error in response. Proposed controller fuzzily clear out integrated quantities acrording to situation. This paper attempts to provide a thorough comparative insight into the behavior of IPMSM drive with direct and new fuzzy speed controller. The validity of new fuzzy speed controller is confirmed by response results for IPMSM drive system.

Modified Direct Torque Control using Algorithm Control of Stator Flux Estimation and Space Vector Modulation Based on Fuzzy Logic Control for Achieving High Performance from Induction Motors

Hassan Farhan Rashag,S. P. Koh,Ahmed N. Abdalla,Nadia M. L. Tan,K. H. Chong 전력전자학회 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.3

Direct torque control based on space vector modulation (SVM-DTC) protects the DTC transient merits. Furthermore, it creates better quality steady-state performance in a wide speed range. The modified method of DTC using SVM improves the electrical magnitudes of asynchronous machines, such as minimizing the stator current distortions, the stator flux with electromagnetic torque without ripple, the fast response of the rotor speed, and the constant switching frequency. In this paper, the proposed method is based on two new control strategies for direct torque control with space vector modulation. First, fuzzy logic control is used instead of the PI torque and a PI flux controller to minimizing the torque error and to achieve a constant switching frequency. The voltages in the direct and quadratic reference frame (Vd ,Vq) d q are achieved by fuzzy logic control. In this scheme, the switching capability of the inverter is fully utilized, which improves the system performance. Second, the close loop of stator flux estimation based on the voltage model and a low pass filter is used to counteract the drawbacks in the open loop of the stator flux such as the problems saturation and dc drift. The response of this new control strategy is compared with DTC-SVM. The experimental and simulation results demonstrate that the proposed control topology outperforms the conventional DTC-SVM in terms of system robustness and eliminating the bad outcome of dc-offset.

Feedback control strategies for active control of noise inside a 3-D vibro-acoustic cavity

Ashok K. Bagha,Subodh V. Modak 국제구조공학회 2017 Smart Structures and Systems, An International Jou Vol.20 No.3

This paper presents and compares three feedback control strategies for active control of noise inside a 3-D vibro-acoustic cavity. These are a) control strategy based on direct output feedback (DOFB) b) control strategy based on linear quadratic regulator (LQR) to reduce structural vibrations and c) LQR control strategy with a weighting scheme based on structural-acoustic coupling coefficients. The first two strategies are indirect control strategies in which noise reduction is achieved through active vibration control (AVC), termed as AVC-DOFB and AVC-LQR respectively. The third direct strategy is based on active structural-acoustic control (ASAC). This strategy is an LQR based optimal control strategy in which the coupling between the various structural and the acoustic modes is used to design the controller. The strategy is termed as ASAC-LQR. A numerical model of a 3-D rectangular box cavity with a flexible plate (glued with piezoelectric patches) and with other five surfaces treated rigid is developed using finite element (FE) method. A single pair of collocated piezoelectric patches is used for sensing the vibrations and applying control forces on the structure. A comparison of frequency response function (FRF) of structural nodal acceleration, acoustic nodal pressure, and piezoelectric actuation voltage is carried out. It is found that the AVC-DOFB control strategy gives equal importance to all the modes. The AVC-LQR control strategy tries to consume the control effort to damp all the structural modes. It is seen that the ASAC-LQR control strategy utilizes the control effort more intelligently by adding higher damping to those structural modes that matter more for reducing the interior noise.

Direct Roll Moment Control for Electric Vehicles Based on Roll Angle Observer and Lateral Tire Force Control

K. Nam,S. Oh,H. Fujimoto,Y. Hori 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5

This paper presents roll stability control methodology for future personal electric vehicles with 4 wheel steering system and lateral force sensors. Direct roll moment control is realized by 4 wheel steering control based on lateral tire force control. In this paper, the lateral tire force, obtained from novel lateral force sensors, was utilized to estimate a roll angle and to control the vehicle roll motion. In order to estimate roll angle, a linear observer was proposed and implemented in an experimental electric vehicle. The effectiveness of a proposed roll angle observer was verified through field tests. By using an estimated roll angle, a direct roll moment controller for roll stability was designed based on general two-degree-of?freedom (2-DOF) control methodology. Effectiveness of a proposed roll stability control method was verified through computer simulation using CarSim software.

Torque Control Strategy for High Performance SR Drive

Jin-Woo Ahn 대한전기학회 2008 Journal of Electrical Engineering & Technology Vol.3 No.4

This paper attempts to summarize torque control strategy for high performance SR drive. There are primarily two strategies for torque control. One method is direct torque control, which uses the simple control scheme and hysteresis controller to reduce the torque ripple. Another method is indirect torque control, which uses the complicated algorithms or simple distribution function to distribute each phase torque and obtain current command. The current controller is used to control phase torque by a given current command. In order to compare these two strategies of torque control, five torque control methods are introduced. The advantages and disadvantages of each method are presented. At last, they are verified by some simulations and experimental results.

Energy Model Based Direct Torque Control of Induction Motor Using IP Controllers

Mannan, Mohammad Abdul,Murata, Toshiaki,Tamura, Junji Journal of International Conference on Electrical 2012 Journal of international Conference on Electrical Vol.1 No.4

This paper deals with direct torque control of an induction motor (IM) with constant switching frequency. The desired torque is obtained from the speed controller which is designed using the IP controller. Decoupling control of torque and flux is developed based on the energy model of IM using the IP controller strategies. The desired d-axis and q-axis stator voltage components are obtained from the designed controller, which decouples torque and flux. The constant switching frequency can be applied using space-vector pulse width modulation, since the desired stator voltage can be known from the decoupling torque and flux controllers. In order to achieve stable operation of the proposed IP controllers, the gains of the controllers are chosen by setting the poles in negative (left) half of s-plane and by choosing the rising time for the response of the step function. The proposed controller was verified in simulations using Matlab/Simulink and results have proven excellent performance. It was found that the proposed IP controllers can provide excellent performance to track the desired torque and speed and to reject the disturbance of load.

Modified Direct Torque Control using Algorithm Control of Stator Flux Estimation and Space Vector Modulation Based on Fuzzy Logic Control for Achieving High Performance from Induction Motors

Rashag, Hassan Farhan,Koh, S.P.,Abdalla, Ahmed N.,Tan, Nadia M.L.,Chong, K.H. The Korean Institute of Power Electronics 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.3

Direct torque control based on space vector modulation (SVM-DTC) protects the DTC transient merits. Furthermore, it creates better quality steady-state performance in a wide speed range. The modified method of DTC using SVM improves the electrical magnitudes of asynchronous machines, such as minimizing the stator current distortions, the stator flux with electromagnetic torque without ripple, the fast response of the rotor speed, and the constant switching frequency. In this paper, the proposed method is based on two new control strategies for direct torque control with space vector modulation. First, fuzzy logic control is used instead of the PI torque and a PI flux controller to minimizing the torque error and to achieve a constant switching frequency. The voltages in the direct and quadratic reference frame ($V_d$, $V_q$) are achieved by fuzzy logic control. In this scheme, the switching capability of the inverter is fully utilized, which improves the system performance. Second, the close loop of stator flux estimation based on the voltage model and a low pass filter is used to counteract the drawbacks in the open loop of the stator flux such as the problems saturation and dc drift. The response of this new control strategy is compared with DTC-SVM. The experimental and simulation results demonstrate that the proposed control topology outperforms the conventional DTC-SVM in terms of system robustness and eliminating the bad outcome of dc-offset.