Advanced Flow Control for Supersonic Blowdown Wind Tunnel Using Extended Kalman Filter

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Jiaqi Xi ◽  
Mian Li ◽  
Qiang Zhang ◽  
Zhaoguang Wang
Keyword(s):  
Kalman Filter ◽  
Flow Control ◽  
Extended Kalman Filter ◽  
Control Strategy ◽  
Test Section ◽  
Initial Conditions ◽  
Stagnation Pressure ◽  
Operating Conditions ◽  
Wind Tunnels ◽  
Wide Range

Supersonic blowdown wind tunnels provide controlled test environments for aerodynamic research on scaled models. During the experiments, the stagnation pressure in the test section is required to remain constant. Due to nonlinearity and distributed characteristics of the controlled system, a robust controller with effective flow control algorithms is required for this type of wind tunnels. In this paper, an extended Kalman filter (EKF) based flow control strategy is proposed and implemented. The control strategy is designed based on state estimation of the blowdown process under the EKF structure. One of the distinctive advantages of the proposed approach is its adaptability to a wide range of operating conditions for blowdown wind tunnels. Furthermore, it provides a systematic approach to tune the control parameters to ensure the stability of the controlled air flow. Experiments with different initial conditions and control targets have been conducted to test the applicability and performance of the designed controller. The results demonstrate that the controller and its strategies can effectively control the stagnation pressure in the test section and maintain the target pressure during the stable stage of the blowdown process.

Advanced Flow Control for Supersonic Blowdown Wind Tunnel Using Extended Kalman Filter

2013 ◽  
Author(s):  
Jiaqi Xi ◽  
Qiang Zhang ◽  
Mian Li ◽  
Zhaoguang Wang
Keyword(s):  
Kalman Filter ◽  
Wind Tunnel ◽  
Flow Control ◽  
Extended Kalman Filter ◽  
Control Strategy ◽  
Test Section ◽  
Stagnation Pressure ◽  
Operating Conditions ◽  
Wind Tunnels ◽  
Wide Range

Supersonic wind tunnels provide controlled test environments for aerodynamic research on scaled models. During the experiment, the stagnation pressure in the test section is required to remain constant. Due to the nonlinearity and distributed characteristics of the controlled system, a robust controller with effective flow control algorithms is required, which is then capable of properly working under different operating conditions. In this paper, an Extended Kalman Filter (EKF) based flow control strategy is proposed and implemented in the controller. The control strategy is designed based on the state estimation of a real blowdown wind tunnel, which is carried out under an EKF structure. One of the distinctive advantages of the proposed approach is its adaptability to a wide range of operating conditions for blowdown wind tunnels. Furthermore, it provides a systematic approach to tune the controller parameters to ensure the stability of the controlled air flow. Experiments with different initial conditions and control targets have been conducted to test the applicability and performance of the designed controller. The results demonstrate that the controller and its strategies can effectively control the stagnation pressure in the test section and maintain the target pressure during the stable stage of the blowdown process.

Sensorless finite-state predictive torque control of induction motor fed by four-switch inverter using extended Kalman filter

2018 ◽  
Vol 37 (6) ◽  
pp. 2006-2024 ◽  
Author(s):  
Mohamed Chebaani ◽  
Amar Goléa ◽  
Med Toufik Benchouia ◽  
Noureddine Goléa
Keyword(s):  
Kalman Filter ◽  
Induction Motor ◽  
Extended Kalman Filter ◽  
Direct Torque Control ◽  
Operating Conditions ◽  
Torque Control ◽  
Switching Frequency ◽  
Content Type ◽  
Finite State ◽  
Torque Ripples

Purpose Direct Torque Control (DTC) of induction motor drives is a well-established technique owing to features such as fast dynamic and insensibility to motor parameters. However, conventional DTC scheme, based on comparators and the switching table, suffers from large torque and flux ripples. To improve DTC performance, this study aims to propose and implement a sensorless finite-state predictive torque control using extended Kalman Filter in dSPACE environment. Design/methodology/approach This paper deals with the design of an extended Kalman filter for estimating the state of an induction motor model and for sensorless control of systems using this type of motor as an actuator. A complex-valued model is adopted that simultaneously allows a simpler observability analysis of the system and a more effective state estimation. Findings Simulation and experimental results reveal that the drive system, associated with this technique, can effectively reduce flux and torque ripples with better dynamic and steady state performance. Further, the proposed approach maintains a constant switching frequency. Originality/value The proposed speed observer have been developed and implemented experimentally under different operating conditions such as parameter variation, no-load/load disturbances and speed variations in different speed operation regions.

scholarly journals Estimation of lithium-ion battery state-of-charge using an extended kalman filter

2021 ◽  
Vol 10 (4) ◽  
pp. 1759-1768
Author(s):  
Mouhssine Lagraoui ◽  
Ali Nejmi ◽  
Hassan Rayhane ◽  
Abderrahim Taouni
Keyword(s):  
Kalman Filter ◽  
Lithium Ion Battery ◽  
Extended Kalman Filter ◽  
Lithium Ion ◽  
The State ◽  
Operating Conditions ◽  
State Of Charge ◽  
Ohmic Loss ◽  
Battery Management System ◽  
Transfer Resistance

The main goal of a battery management system (BMS) is to estimate parameters descriptive of the battery pack operating conditions in real-time. One of the most critical aspects of BMS systems is estimating the battery's state of charge (SOC). However, in the case of a lithium-ion battery, it is not easy to provide an accurate estimate of the state of charge. In the present paper we propose a mechanism based on an extended kalman filter (EKF) to improve the state-of-charge estimation accuracy on lithium-ion cells. The paper covers the cell modeling and the system parameters identification requirements, the experimental tests, and results analysis. We first established a mathematical model representing the dynamics of a cell. We adopted a model that comprehends terms that describe the dynamic parameters like SOC, open-circuit voltage, transfer resistance, ohmic loss, diffusion capacitance, and resistance. Then, we performed the appropriate battery discharge tests to identify the parameters of the model. Finally, the EKF filter applied to the cell test data has shown high precision in SOC estimation, even in a noisy system.

scholarly journals Fault Diagnosis of PMSG Stator Inter-Turn Fault Using Extended Kalman Filter and Unscented Kalman Filter

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2972 ◽  
Author(s):  
Waseem El Sayed ◽  
Mostafa Abd El Geliel ◽  
Ahmed Lotfy
Keyword(s):  
Kalman Filter ◽  
Fault Diagnosis ◽  
Extended Kalman Filter ◽  
Continuous Monitoring ◽  
Unscented Kalman Filter ◽  
Fault Tolerant ◽  
Synchronous Generator ◽  
Operating Conditions ◽  
Practical Implementation ◽  
Complete Failure

Since the permeant magnet synchronous generator (PMSG) has many applications in particular safety-critical applications, enhancing PMSG availability has become essential. An effective tool for enhancing PMSG availability and reliability is continuous monitoring and diagnosis of the machine. Therefore, designing a robust fault diagnosis (FD) and fault tolerant system (FTS) of PMSG is essential for such applications. This paper describes an FD method that monitors online stator winding partial inter-turn faults in PMSGs. The fault appears in the direct and quadrature (dq)-frame equations of the machine. The extended Kalman filter (EKF) and unscented Kalman filter (UKF) were used to detect the percentage and the place of the fault. The proposed techniques have been simulated for different fault scenarios using Matlab®/Simulink®. The results of the EKF estimation responses simulation were validated with the practical implementation results of tests that were performed with a prototype PMSG used in the Arab Academy For Science and Technology (AAST) machine lab. The results showed impressive responses with different operating conditions when exposed to different fault states to prevent the development of complete failure.

scholarly journals State-of-Charge Estimation of Lithium-Ion Battery Based on Extended Kalman Filter Algorithm

2020 ◽  
pp. 420-437
Author(s):  
Wu Xiaogang ◽  
Xuefeng Li ◽  
Nikolay I. Shurov ◽  
Alexander A. Shtang ◽  
Michael V. Yaroslavtsev ◽  
...  
Keyword(s):  
Kalman Filter ◽  
Lithium Ion Battery ◽  
Electric Vehicle ◽  
Extended Kalman Filter ◽  
Lithium Ion ◽  
Operating Conditions ◽  
State Of Charge ◽  
Battery Management ◽  
Soc Estimation ◽  
Ternary Polymer

As the core component of electric vehicle, lithium-ion battery needs to adopt effective battery management method to prolong battery life and improve the reliability and safety. The accurate estimation of the battery SOC can be used to prevent the battery over charge and over discharge, reduce damage to the battery and improve battery performance, which plays a vital role in the battery management system. The study of battery SOC estimation mainly focused on the battery model construction and SOC estimation algorithm. Aiming at the problem that the state of charge (SOC) of electric vehicle is difficult to be accurately estimated under complex operating conditions, based on the parameter identification of the equivalent circuit of a ternary polymer lithium-ion battery, an Extended Kalman Filter (EKF) algorithm was used to estimate the SOC of the ternary polymer lithium-ion battery. Simulation and experimental results show that the estimation of SOC can be carried out by using the EKF algorithm under the conditions of China Passenger Car Condition (Chinacar) and new European driving cycle (NEDC) Compared with the coulomb counting method, the average error of SOC estimation can be realized is 1.042% and 1.138% respectively, the maximum error within 4%. Application of this algorithm to achieve SOC estimation has good robustness and convergence

scholarly journals A Novel Solution for the Elimination of Mode Switching in Pump-Controlled Single-Rod Cylinders

Actuators ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 20 ◽  
Author(s):  
Petter H. Gøytil ◽  
Damiano Padovani ◽  
Michael R. Hansen
Keyword(s):  
Control Strategy ◽  
Operating Conditions ◽  
Mode Switching ◽  
Loss Of Control ◽  
Unstable Behavior ◽  
Wide Range ◽  
Stability Issue ◽  
Underlying Mechanisms ◽  
The Stability ◽  
Proper Operation

This paper concerns the stability issue of pump-controlled single-rod cylinders, known as mode switching. First, a review of the topic is provided. Thereafter, the most recently proposed solution for the elimination of mode switching is investigated and shown to result in unstable behavior under certain operating conditions. A theoretical analysis is provided demonstrating the underlying mechanisms of this behavior. Based on the analysis, a novel control strategy is proposed and investigated numerically. Proper operation and stability are demonstrated for a wide range of operating conditions, including situations under which the most recently proposed solution results in unstable behavior and loss of control over the actuator.

Progressive Mesh Densification Method for Numerical Solution of Mixed Elastohydrodynamic Lubrication

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Wei Pu ◽  
Jiaxu Wang ◽  
Dong Zhu
Keyword(s):  
Surface Roughness ◽  
Numerical Solution ◽  
Numerical Solutions ◽  
Initial Conditions ◽  
Solution Process ◽  
Elastohydrodynamic Lubrication ◽  
Operating Conditions ◽  
Machined Surface ◽  
Progressive Mesh ◽  
Wide Range

Numerical solution of mixed elastohydrodynamic lubrication (EHL) is of great importance for the study of lubrication formation and breakdown, as well as surface failures of mechanical components. However, converged and accurate numerical solutions become more difficult, and solution process with a fixed single discretization mesh for the solution domain appears to be quite slow, especially when the lubricant films and surface contacts coexist with real-machined roughness involved. Also, the effect of computational mesh density is found to be more significant if the average film thickness is small. In the present study, a set of sample cases with and without machined surface roughness are analyzed through the progressive mesh densification (PMD) method, and the obtained results are compared with those from the direct iteration method with a single fixed mesh. Besides, more numerical analyses with and without surface roughness in a wide range of operating conditions are conducted to investigate the influence of different compound modes in order to optimize the PMD procedure. In addition, different initial conditions are used to study the effect of initial value on the behaviors of this transient solution. It is observed that, no matter with or without surface roughness considered, the PMD method is stable for transient mixed EHL problems and capable of significantly accelerating the EHL solution process while ensuring numerical accuracy.

A Mathematical Model and Performance Evaluation for a Single-Stage Grid-Connected Photovoltaic (PV) System

2008 ◽  
Vol 9 (6) ◽  
Author(s):  
Prajna Paramita Dash ◽  
Amirnaser Yazdani
Keyword(s):  
Mathematical Model ◽  
Control Strategy ◽  
Voltage Control ◽  
Current Control ◽  
Operating Conditions ◽  
Single Stage ◽  
Control Loop ◽  
Pv System ◽  
Wide Range ◽  
The Impact

This paper proposes a control strategy for important transients of a single-stage, three-phase, PV system that is connected to a distribution network. The proposed control strategy adopts an inner current-control loop and an outer DC-link voltage control loop. The current-control mechanism renders the PV system protected against external faults, enables control of the DC-link voltage and, therefore, controls/maximizes the PV system power output. The paper also proposes a feed-forward compensation strategy for the DC-link voltage control loop to mitigate the impact of the nonlinear characteristic of the PV array on the closed-loop stability, and to permit design and optimization of the DC-link voltage controller for a wide range of operating conditions. A mathematical model and a control design methodology are presented for the PV system, and it is shown that under the proposed control, the PV system fulfills the operational requirements of a grid-connected PV system. The effectiveness of the proposed control strategy and the most important transients of the PV system are evaluated through simulation studies conducted on a detailed switched model of the PV system in the PSCAD/EMTDC software environment.

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