• 제목/요약/키워드: power system state estimation

검색결과 207건 처리시간 0.027초

슬라이딩모드 관측기를 이용한 하이브리드 자동차용 리튬배터리 충전량 예측방법 (State of Charge Estimator using Sliding Mode Observer for Hybrid Electric Vehicle Lithium Battery)

  • 김일송
    • 전력전자학회논문지
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    • 제12권4호
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    • pp.324-331
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    • 2007
  • 본 연구에서는 슬라이딩 모드 관측기를 사용한 리튬 배터리의 충전량 예측방법에 대해서 논의한다. 배터리의 비선형 회로 모델링 기법이 소개되고 슬라이딩 모드 관측기를 사용한 충전량 예측기의 설계 방법이 논의된다. 기존의 복잡한 배터리 모델링 방법 대신, 단순화된 저항-커패시터 모델링 방법이 본 연구에서 사용되었다. 단순화된 모델에 의해 발생되는 오차나 불확실성은 슬라이딩 모드 관측기에 의해 보상되었다. 슬라이딩 모드 관측기의 구조는 단순하지만, 모델링 에러나 외란에 대해서 강인한 특성을 보여준다. 제안된 제어기의 수렴성은 등가제어 방법에 의해서 증명되었다. 제안된 시스템의 성능은 UDDS (Urban Dynamometer Driving Schedule) 시험에 의해서 증명되었다. 시험 결과 제안된 시스템은 실제 주행 환경에서도 우수한 추적 성능을 보여주었다.

Development of a Novel 30 kV Solid-state Switch for Damped Oscillating Voltage Testing System

  • Hou, Zhe;Li, Hongjie;Li, Jing;Ji, Shengchang;Huang, Chenxi
    • Journal of Power Electronics
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    • 제16권2호
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    • pp.786-797
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    • 2016
  • This paper describes the design and development of a novel semiconductor-based solid-state switch for damped oscillating voltage test system. The proposed switch is configured as two identical series-connected switch stacks, each of which comprising 10 series-connected IGBT function units. Each unit consists of one IGBT, a gate driver, and an auxiliary voltage sharing circuit. A single switch stack can block 20 kV-rated high voltage, and two stacks in series are proven applicable to 30 kV-rated high voltage. The turn-on speed of the switch is approximately 250 ns. A flyback topology-based power supply system with a front-end power factor correction is built for the drive circuit by loosely inductively coupling each unit with a ferrite core to the primary side of a power generator to obtain the advantages of galvanic isolation and compact size. After the simulation, measurement, and estimation of the parasitic effect on the gate driver, a prototype is assembled and tested under different operating regimes. Experimental results are presented to demonstrate the performance of the developed prototype.

NFC와 ANN을 이용한 IPMSM 드라이브의 속도 추정 및 제어 (Speed Estimation and Control of IPMSM Drive using NFC and ANN)

  • 이정철;이홍균;정동화
    • 전력전자학회논문지
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    • 제10권3호
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    • pp.282-289
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    • 2005
  • 본 논문에서는 NFC(Neuro-Fuzzy Controller)와 ANN(Artificial Neural network) 제어기를 이용한 IPMSM의 속도 제어 및 추정을 제시한다. PI 제어기에서 나타나는 문제점을 해결하기 위하여 신경회로망과 퍼지제어를 혼합적용한 NFC를 설계한다. 신경회로망의 고도의 적응제어와 퍼지 제어기의 강인성 제어의 장점들을 접목한다. 다음은 ANN을 이용하여 IPMSM 드라이브의 속도 추정기법을 제시한다. 2층 구조를 가진 신경회로망에 BPA(Back Propagation Algorithm)를 적용하여 IPMSM 드라이브의 속도를 추정한다. 추정속도의 타당성을 입증하기 위하여 시스템을 구성하여 제어특성을 분석한다.

전력변환기에 대한 직류링크 커패시터의 고장진단을 위한 간단한 용량 추정 기법 (A Simple Capacitance Estimation Method for Failure Diagnosis of DC Link Electrolytic Capacitor in Power Converters)

  • 손진근;김동준
    • 전기학회논문지P
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    • 제59권4호
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    • pp.378-383
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    • 2010
  • Due to the large capacity and low cost, DC link electrolytic capacitors with of energy storage and voltage regulation are used for almost all types of power converter as the DC/AC inverter or DC/DC converter. Electrolytic capacitor, which is the most of the time affected by the aging effect, plays very important role for the power converter system quality and reliability. Therefore, this paper proposes a simple method to estimate the capacitance variation of an electrolytic capacitor in order to analyze the internal characteristic decrease and worn-out state of an electrolytic capacitor. Simulation results by using capacitor storage energy computation show the validity of the proposed capacitance estimation method.

Study on Advanced Frequency Estimation Technique using Gain Compensation

  • Park, Chul-Won;Shin, Dong-Kwang;Kim, Chul-Hwan;Kim, Hak-Man;Kim, Yoon-Sang
    • Journal of Electrical Engineering and Technology
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    • 제6권4호
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    • pp.439-446
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    • 2011
  • Frequency is an important operating parameter for the protection, control, and stability of a power system. Thus, it must be maintained very close to its nominal frequency. Due to the sudden change in generation and loads or faults in a power system, however, frequency deviates from its nominal value. An accurate monitoring of the power frequency is essential for optimum operation and prevention of wide area blackout. Most conventional frequency estimation schemes are based on the DFT filter. In these schemes, the gain error could cause defects when the frequency deviates from the nominal value. We present an advanced frequency estimation technique using gain compensation to enhance the DFT filter-based technique. The proposed technique can reduce the gain error caused when the frequency deviates from the nominal value. Simulation studies are performed using both the data from EMTP-RV software and the user-defined arbitrary signals to demonstrate the effectiveness of the proposed algorithm. Results show that the proposed algorithm achieves good performance under both steady state tests and dynamic conditions.

우리나라 계통에서의 상태추정 알고리즘 및 향후 개선방향 (State Estimation Algorithm in Korea Power System & Improvement Direction)

  • 전재룡;여현근;송태용
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 제39회 하계학술대회
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    • pp.97-98
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    • 2008
  • 전력계통이 커지고 복잡해짐에 따라 전력계통의 상태를 정확하게 파악하고 안정하게 운영하는데 EMS의 역할이 더욱 커지고 있다. EMS에서 상태추정은 다른 응용프로그램에 대한 기본 자료를 제공하므로 중요하다. 우리나라는 EMS와 MOS를 이용하여 전력계통을 안정하게 운영하고 있다. 본 논문에서는 EMS와 MOS의 상태추정 알고리즘을 소개하고 차이점을 비교하였다. 또한 상태추정 파라미터 운영현황을 분석하여 이를 바탕으로 앞으로의 개선방향을 제시하였다.

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Speed Control for a PMSM Servo System Using Model Reference Adaptive Control and an Extended State Observer

  • Li, Xiaodi;Li, Shihua
    • Journal of Power Electronics
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    • 제14권3호
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    • pp.549-563
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    • 2014
  • In this paper, the speed regulation problem of permanent synchronous motor (PMSM) systems under the vector control framework is studied. A model reference adaptive controller (MRAC) based on the Lyapunov stability theory is first designed. Since the standard MRAC method provides poor disturbance rejection performance in the case of strong disturbances, a composite control method which combines the MRAC method and the disturbance estimation method, called the MRAC+ESO method, is proposed. An extended state observer (ESO) is introduced to estimate the lumped disturbances. The obtained estimated value acts as a feedforward compensation term to the MRAC controller. A stability analysis of the composite control method is given. Simulation and experimental results are presented and compared to show the effectiveness of the proposed control method.

ESTIMATION OF NON-INTEGRAL AND INTEGRAL QUADRATIC FUNCTIONS IN LINEAR STOCHASTIC DIFFERENTIAL SYSTEMS

  • Song, IL Young;Shin, Vladimir;Choi, Won
    • Korean Journal of Mathematics
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    • 제25권1호
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    • pp.45-60
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    • 2017
  • This paper focuses on estimation of an non-integral quadratic function (NIQF) and integral quadratic function (IQF) of a random signal in dynamic system described by a linear stochastic differential equation. The quadratic form of an unobservable signal indicates useful information of a signal for control. The optimal (in mean square sense) and suboptimal estimates of NIQF and IQF represent a function of the Kalman estimate and its error covariance. The proposed estimation algorithms have a closed-form estimation procedure. The obtained estimates are studied in detail, including derivation of the exact formulas and differential equations for mean square errors. The results we demonstrate on practical example of a power of signal, and comparison analysis between optimal and suboptimal estimators is presented.

역기전력 추정 기반 SMPMSM 센서리스 드라이브에서 저항 오차가 대역폭에 미치는 영향 (Influence of Resistance Error to the Bandwidth of Back-EMF Estimation based SMPMSM Sensorless Drives)

  • 김재석;설승기
    • 전력전자학회논문지
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    • 제21권5호
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    • pp.418-426
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    • 2016
  • This paper analyzes the effect of resistance error to the performance of sensorless drive system of surface-mounted permanent magnet synchronous machine (SMPMSM) based on the back-EMF observer. The analysis shows that the bandwidth of the entire sensorless drive system decreased in the low-speed region when using smaller resistance value than the actual one in the back-EMF observer. Even if the back-EMF observer invokes estimation error, the entire sensorless drive system does not make any steady-state position error. These characteristics may have positive effects such as extension of the low speed limit that goes further down in the sensorless drive. The validity of the analysis is verified by the experimental setup comprising the MG set.

히스테리시스 현상을 고려한 확장칼만필터를 이용한 새로운 납축전지의 충전상태 추정방법 (Novel State-of-Charge Estimation Technique of the Lead-acid Battery by Using EKF Considering Hysteresis Phenomenon)

  • 덩반환;최우진
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2013년도 전력전자학술대회 논문집
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    • pp.317-318
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    • 2013
  • State-of-Charge (SOC) is one of the most important indicators for the battery management system. Thus its precise estimation is crucial not only for effectively utilizing the energy but also preventing critical situations from happening to the powertrain of the vehicle. However, lead-acid battery is time-variant and highly nonlinear, and the hysteresis phenomenon causes large errors in estimating SOC. This paper proposes a novel SOC estimation technique for the lead-acid battery by using Extended Kalman Filter (EKF) considering hysteresis effect. The validity of the proposed technique is verified through the experiments.

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