• Title/Summary/Keyword: Frequency control

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Load Frequency Control of Power System using a Self-tuning Fuzzy PID Controller (자기조정 퍼지 PID제어기를 이용한 전력시스템의 부하주파수 제어)

  • 이준탁
    • Journal of Advanced Marine Engineering and Technology
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    • v.23 no.1
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    • pp.40-46
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    • 1999
  • A self-tuning FPID(Fuzzy Proportional Intergral Derivative) controller fo load frequency control of 2-area power systemis proposed in this paper. The paramters of the proposed self-tuning FPID controller are self-tuned by the proposed fuzzy inference technique. Therefore in this paper the fuzzy inference technique of PID gains using PSGM(Product Sum Gravity Method) is presented and is applied to the load frequency control of 2-area power system. The computer simulation results show that the proposed controller give better more control characteristics than convention-al PID, FLC under load changes.

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Open-Loop Control of Combustion Instability in Hot-Firing Test Using Gaseous Hydrocarbon Fuel (기체 탄화수소 연료 연소시험에서 연소불안정의 개루프 제어)

  • Hwang, Donghyun;Ahn, Kyubok
    • Journal of the Korean Society of Propulsion Engineers
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    • v.22 no.6
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    • pp.28-36
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    • 2018
  • A study was conducted to apply open-loop control to the combustion instability in a dump combustor using gaseous hydrocarbon fuels. Control power and frequency were varied by employing a loudspeaker under combustion conditions with similar characteristic chemistry times of the fuels. In the case of open-loop control where the frequency was identical to the combustion instability frequency, the open-loop control power affected the control performance. Results obtained from conducted open-loop control tests, where the frequency was different from the combustion instability frequency, show that setting the open-loop control frequency similar to the combustion instability frequency is effective.

Power Control Method for FB-SRC IH Cooktop System Considering Limited Switching Frequency Range Condition (가용 동작 주파수 범위를 고려한 FB-SRC 기반 IH 쿡탑 시스템의 전력 제어 방안)

  • Hwang, Yun-Seong;Lee, Joo-Seung;Kang, Seung-Hyun;Kwon, Man-Jae;Jang, Eunsu;Lee, Byoung-Kuk
    • The Transactions of the Korean Institute of Power Electronics
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    • v.27 no.3
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    • pp.256-264
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    • 2022
  • The frequency power control method (FCM) which has a wide operating frequency range is adopted for induction heating (IH) cooktops. When FCM is applied to the full-bridge series resonant converter (FB-SRC) based IH system, high-frequency switching of the inverter is required compared to the half-bridge SRC (HB-SRC)-based IH system. Therefore, the switching loss of the inverter increases, and applying FCM under the condition that the inverter operating frequency range is limited is difficult. Therefore, this paper proposes a control strategy with the phase shift power control method considering that limited frequency conditions are presented. Loss analysis following the control method is performed through simulation and mathematical analysis. In addition, the validity of the proposed control strategy is verified by analyzing the heating performance following the control method through the test results of the 3,200[W] prototype.

The characteristic analyses and output frequency tracking control of a high frequency inverter (고주파 인버터의 특성해석 및 출력주파수 추종제어)

  • 이종무;김영석;조기연
    • 제어로봇시스템학회:학술대회논문집
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    • 1987.10b
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    • pp.597-602
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    • 1987
  • This paper proposes a voltage-fed high frequency resonant inverter having variable voltage variable frequency(VVVF) control function. VVVF control is performed by PWM-TRC method in the boost type chopper and PFM-TRC method in the high frequency resonant inverter. This circuit is suitable for induction heating and melting power supply in industry. The operating characteristics of this inverter are discussed from a theoretical point of view. The results of operating characteristic analyses are given leading to complete designing data.

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Development of the Control System for Fast-Responding Frequency Regulation in Power Systems using Large-Scale Energy Storage Systems

  • Lim, Geon-Pyo;Park, Chan-Wook;Labios, Remund;Yoon, Yong-Beom
    • KEPCO Journal on Electric Power and Energy
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    • v.1 no.1
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    • pp.9-13
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    • 2015
  • Energy storage systems (ESS) can be used to provide frequency regulation services in a power system to replace traditional frequency regulation power plants. Battery ESS, in particular, can provide "fast-responding frequency regulation," wherein the facility can respond immediately and accurately to the frequency regulation signal sent by the system operator. This paper presents the development and the trial run results of a frequency regulation control system that uses large-scale ESS for use in a large power system. The control system was developed initially for the 4 MW ESS demonstration facility in Jocheon Jeju Island, and was further developed for use in the 28 MW ESS facility at the Seo-Anseong substation and the 24 MW ESS facility at the Shin-Yongin substation to provide frequency regulation services within mainland Korea. The ESS facility in Seo-Anseong substation responds to a sudden drop in frequency via governor-free control, while the ESS facility in Shin-Yongin responds via automatic generator control (AGC).

A Study on the Phase Bandwidth Frequency of a Directional Control Valve Based on the Hydraulic Line Pressure (배관 압력을 이용한 방향제어밸브 위상각 대역폭 주파수 측정에 관한 연구)

  • Kim, Sungdong;Lee, Jung-eun;Shin, Daeyoung
    • Journal of Drive and Control
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    • v.15 no.4
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    • pp.1-10
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    • 2018
  • Spool displacement of a direction control valve is the standard signal to measure the bandwidth frequency of the direction control valve. When the spool displacement signal is not available, it is suggested in this study to use the metering hydraulic line as an alternative way to measure - 90 degree phase bandwidth frequency of the hydraulic direction control valve. Dynamics of the hydraulic line is composed of inertia, capacitance, and friction effects. The effect of oil inertia is dominant in common hydraulic line dynamics and the line dynamics is close to a derivative action in a range of high frequency; such as a range of bandwidth frequency of common directional control valves. Phase difference between spool displacement and line load pressure is nearly constant as a valve close to 90 degree. If phase difference is compensated from the phase between valve input and pressure, compensated phase may be almost same as the phase of spool displacement that is a standard signal to measure phase bandwidth frequency of the directional control valve. A series of experiments were conducted to examine the possibility of using line pressure in to measure phase bandwidth frequency of a directional control valve. Phase bandwidth frequency could be measured with relatively high precision based on metering hydraulic line technique and it reveals consistent results even when valve input, oil temperature, and supply pressure change.

Experimental Examination of Multivariable PID Controller Design on Frequency Domain using Liquid Level Process

  • Eguchi, Kazuki;Iwai, Zenta;Mizumoto, Ikuro;Kumon, Makoto
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.786-791
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    • 2005
  • This paper is concerned with the examination and evaluation concerning a tuning method of multivariable PID controllers based on partial model matching on frequency domain proposed by authors from practical view point. In this case, PID controller parameters are determined by minimizing the loss function defined by the difference between frequency response of ideal model transfer function and actual frequency response on several frequency points. The purpose of the paper is to examine and evaluate the performance of the method through actual experiments of MIMO liquid level experimental process control equipment.

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Characteristic comparisons of the constant current LED driver by the ripple of the input voltage (LED 정전류 구동회로의 입력전압 리플 크기에 의한 특성 비교)

  • Park, Chong-Yeun;Jeon, In-Ung;Yoo, Jin-Wan;Choi, Young-Min
    • Journal of Industrial Technology
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    • v.32 no.A
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    • pp.115-118
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    • 2012
  • Recently, there are a lot of papers in order to replace the electrolytic capacitor into the film capacitor in output of PFC(Power Factor Correction). However, the film capacitor, which has capacitance of low values, causes a large ripple voltage in output of PFC. The LED drivers are connected series in the output of PFC and affected by the magnitude of voltage ripple. In this paper, we have compared the fixed frequency method with the variable frequency for the constant-current control and propose the control method to avoid the sub-harmonic oscillation in the variable input voltage. An 80W PFC, using film capacitors instead of electrolytic capacitors, and LED driver has been built and compared the fixed frequency control method with the variable frequency control method.

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Simultaneous Control of Frequency Fluctuation and Battery SOC in a Smart Grid using LFC and EV Controllers based on Optimal MIMO-MPC

  • Pahasa, Jonglak;Ngamroo, Issarachai
    • Journal of Electrical Engineering and Technology
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    • v.12 no.2
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    • pp.601-611
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    • 2017
  • This paper proposes a simultaneous control of frequency deviation and electric vehicles (EVs) battery state of charge (SOC) using load frequency control (LFC) and EV controllers. In order to provide both frequency stabilization and SOC schedule near optimal performance within the whole operating regions, a multiple-input multiple-output model predictive control (MIMO-MPC) is employed for the coordination of LFC and EV controllers. The MIMO-MPC is an effective model-based prediction which calculates future control signals by an optimization of quadratic programming based on the plant model, past manipulate, measured disturbance, and control signals. By optimizing the input and output weights of the MIMO-MPC using particle swarm optimization (PSO), the optimal MIMO-MPC for simultaneous control of the LFC and EVs, is able to stabilize the frequency fluctuation and maintain the desired battery SOC at the certain time, effectively. Simulation study in a two-area interconnected power system with wind farms shows the effectiveness of the proposed MIMO-MPC over the proportional integral (PI) controller and the decentralized vehicle to grid control (DVC) controller.

Demonstration to Operate and Control Frequency Regulation of Power System by 4MW Energy Storage System (4MW 에너지저장장치의 전력계통 주파수 조정 운전제어를 위한 실증)

  • Lim, Geon-Pyo;Han, Hyun-Gyu;Chang, Byung-Hoon;Yang, Seung-Kwon;Yoon, Yong-Beum
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.63 no.3
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    • pp.169-177
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    • 2014
  • Operation and control system has been installed and tested to use energy storage system(ESS) for frequency regulation at 4MW class of ESS demonstration facility installed at Jeju island, Korea in 2013. Simulation tests were performed by programing language C# for power system of Jeju island to develop control algorithm. Site simulation tests were performed in control system itself without connecting power system and energy storage system. Control algorithm was coded, modified and tested to load to controller and communication system and human-machine interface were developed and tested in the process of simulation tests. After similar results to that of simulation tests by programing language were obtained, power system and energy storage system demonstration facility were connected to control system by communication system. Energy storage system for frequency regulation was tested for actual frequency and simulation frequency. The site tests showed the similar results to that of simulation tests and the control systems is possible to be operated for frequency regulation. Faster response of energy storage system for frequency regulation, less costs and less capacity of energy storage systems which cover for frequency regulation of power plants. It is expected that more studies for time-reduction and time-delay elements can make less capacity of energy storage system cover more role of frequency regulation of power plants.