• Title/Summary/Keyword: state parameter

Search Result 1,831, Processing Time 0.035 seconds

Identification of Parameter Errors in Electric Power Systems by WLAV State Estimation (WLAV 상태추정에 의한 전력계통 파라미터 에러 추정에 관한 연구)

  • Kim, Hong-Rae;Gwon, Hyeong-Seok;Kim, Dong-Jun
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • v.49 no.9
    • /
    • pp.451-458
    • /
    • 2000
  • This paper addresses the issues of the parameter error detection and identification in electric power systems. In this paper, the parameter error identification and estimation is carried out as part of the state estimation. A two stage estimation procedure is used to detect and identify the parameter errors. The suspected parameters are identified by the WLAV state estimator as the first stage. A new WLAV state estimator adding the suspected system parameters in the state vector is used to estimate the exact value of parameter errors. Supporting examples are given by using IEEE 14 bus system.

  • PDF

On-line System Identification using State Observer

  • Park, Duck-Gee;Hong, Suk-Kyo
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2005.06a
    • /
    • pp.2538-2541
    • /
    • 2005
  • This paper deals one of the methods of system identification, especially on-line system identification in time-domain. The algorithm in this study needs all states of the system as well input to it for system identification. In this reason, Kalman filter is used for state estimation. But in order to implement a state estimator, the fact that a system model must be known is logical contradiction. To overcome this, state estimation and system parameter estimation are performed simultaneously in one sample. And the result of the system parameter estimation is used as basis to state estimation in next sample. On-line system identification comes, in every sample by performing both processes of state estimation and parameter estimation that are related mutually and recursively. This paper demonstrates the validity of proposed algorithm through an example of an unstable inverted pendulum system. This algorithm can be useful for on-line system identification of a system that has fewer number of measurable output than system order or number of states.

  • PDF

ESTIMATION OF THE SINGULAR COEFFICIENT IN THE STEADY STATE DIFFUSION EQUATION

  • Cho, Chung-Ki
    • Journal of applied mathematics & informatics
    • /
    • v.10 no.1_2
    • /
    • pp.309-323
    • /
    • 2002
  • This paper studies the parameter estimation problem for a steady state flow in an inhomogeneous medium. Our approximation scheme could be used when the diffusion coefficient is singular. The function space parameter estimation convergence(FSPEC) is considered and numerical simulations are performed.

Sensorless IPMSM Drives based on Extended Nonlinear State Observer with Parameter Inaccuracy Compensation

  • Mao, Yongle;Liu, Guiying;Chen, Yangsheng
    • Journal of international Conference on Electrical Machines and Systems
    • /
    • v.3 no.3
    • /
    • pp.289-297
    • /
    • 2014
  • This paper proposed a novel high performance sensorless control scheme for IPMSM based on an extended nonlinear state observer. The gain-matrix of the observer has been derived by using state linearization method. Steady state errors in estimated rotor position and speed due to parameter inaccuracy have been analyzed, and an equivalent flux error is defined to represent the overall effect of parameter errors contributing to the wrong convergence of the estimated rotor speed as well as rotor position. Then, an online compensation strategy was proposed to limit the estimation errors in rotor position and speed. The effectiveness of the extended nonlinear state observer is validated through simulation and experimental test.

Real-Time Identification and Estimation of Transformer Tap Ratios Containing Errors

  • Kim, Hongrae;Kwon, Hyung-Seok
    • KIEE International Transactions on Power Engineering
    • /
    • v.2A no.3
    • /
    • pp.109-113
    • /
    • 2002
  • This paper addresses the issue of parameter error identification and estimation in electric power systems. Parameter error identification and estimation is carried out as a part of the state estimation. A two stage estimation procedure is used to detect and identify parameter errors. Suspected parameters are identified by the WLAV state estimator in the first stage. A new WLAV state estimator adding suspected system parameters in the state vector is used to estimate the exact values of parameters. Supporting examples are given by using the IEEE 14 bus system.

Torque Ripple Minimization of PMSM Using Parameter Optimization Based Iterative Learning Control

  • Xia, Changliang;Deng, Weitao;Shi, Tingna;Yan, Yan
    • Journal of Electrical Engineering and Technology
    • /
    • v.11 no.2
    • /
    • pp.425-436
    • /
    • 2016
  • In this paper, a parameter optimization based iterative learning control strategy is presented for permanent magnet synchronous motor control. This paper analyzes the mechanism of iterative learning control suppressing PMSM torque ripple and discusses the impact of controller parameters on steady-state and dynamic performance of the system. Based on the analysis, an optimization problem is constructed, and the expression of the optimal controller parameter is obtained to adjust the controller parameter online. Experimental research is carried out on a 5.2kW PMSM. The results show that the parameter optimization based iterative learning control proposed in this paper achieves lower torque ripple during steady-state operation and short regulating time of dynamic response, thus satisfying the demands for both steady state and dynamic performance of the speed regulating system.

Mixed $H_2/H_{\infty}$ Control of Two-wheel Mobile Robot

  • Roh, Chi-Won;Lee, Ja-Sung;Lee, Kwang-Won
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2003.10a
    • /
    • pp.438-443
    • /
    • 2003
  • In this paper, we propose a control algorithm for two-wheel mobile robot that can move the rider to his or her command and autonomously keep its balance. The control algorithm is based on a mixed $H_2/H_{\infty}$ control scheme. In this control problem the main issue is to move the rider while keeping its balance in the presence of disturbances and parameter uncertainties. The disturbance force caused by uneven road surfaces and the uncertainty due to different rider's heights are considered. To this end we first consider a state feedback controller as a basic framework. Secondly, we obtain the state feedback gain $K_2$ minimizing the $H_2$ norm and the state feedback gain $K_{\infty}$ minimizing the $H_{\infty}$ norm over the whole range of parameter uncertainty. Finally, we select mixed $H_2$/$H_{\infty}$ state feedback controller K as the geometric mean of $K_2$ and $K_{\infty}$. Simulation results show that the mixed $H_2/H_{\infty}$ state feedback controller combines the effects of the optimal $H_2$ state feedback controller and robust $H_{\infty}$ controller state feedback controller efficiently in the presence of disturbance and parameter uncertainty.

  • PDF

An Algorithm for Transformer Tap Estimation by WLAV State Estimator (가중최소절대값을 이용한 변압기 텝 추정 알고리즘)

  • Kim, Hong-Rae;Kwon, Hyung-Seok
    • Proceedings of the KIEE Conference
    • /
    • 1999.11b
    • /
    • pp.279-281
    • /
    • 1999
  • This paper addresses the issues of the parameter error detection and identification in power system. The parameter error identification is carried out as part of the state estimation procedure. The weighted least absolute value(WLAV) estimation method is used for this procedure. The standard formulation of the state estimation problem is modified to include the effects of the parameter errors as well. A two step procedure for the detection and identification of faulted parameters is proposed. Supporting examples are given using IEEE 14 bus system.

  • PDF

Robust H\ulcorner Control for Delayed System with Time-Varying Norm-Bounded Parameter Uncertainty

  • Kim, Jong-Hae;Jeung, Eun-Tae;Park, Hong-Bea
    • Journal of Electrical Engineering and information Science
    • /
    • v.1 no.2
    • /
    • pp.33-38
    • /
    • 1996
  • In this paper, we present a robust H\ulcorner control design method for parameter uncertain systems that have delay in both state and control input. Through a certain algebraic Riccati inequality approach, a state feedback controller is obtained. The proposed state feedback controller stabilizes parameter uncertain delay systems and guarantees disturbance attenuation within a prescribed level. An illustrative example is given to demonstrate the results of the proposed method.

  • PDF

The Research on the Modeling and Parameter Optimization of the EV Battery (전기자동차 배터리 모델링 및 파라미터 최적화 기법 연구)

  • Kim, Il-Song
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.25 no.3
    • /
    • pp.227-234
    • /
    • 2020
  • This paper presents the methods for the modeling and parameter optimization of the electric vehicle battery. The state variables of the battery are defined, and the test methods for battery parameters are presented. The state-space equation, which consists of four state variables, and the output equation, which is a combination of to-be-determined parameters, are shown. The parameter optimization method is the key point of this study. The least square of the modeling error can be used as an initial value of the multivariable function. It is equivalent to find the minimum value of the error function to obtain optimal parameters from multivariable function. The SIMULINK model is presented, and the 10-hour full operational range test results are shown to verify the performance of the model. The modeling error for 25 degrees is approximately 1% for full operational ranges. The comments to enhance modeling accuracy are shown in the conclusion.