• Title/Summary/Keyword: Frequency Regulation

Search Result 637, Processing Time 0.041 seconds

A Study on The Performance Verification and Economic Evaluation of ESS for Frequency Regulation Application (주파수조정용 ESS의 성능검증 및 경제성평가 알고리즘에 관한 연구)

  • Lee, Ju-Gang;Choi, Sung-Sik;Kang, Min-Kwan;Rho, Dae-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.18 no.5
    • /
    • pp.738-744
    • /
    • 2017
  • Recently, the installation of energy storage systems (ESSs) has increased in parallel with the extension of renewable energy resources. However, there has been no concrete analysis ofthe performance verification and economic evaluation of ESSs,which makes it difficult to perform aneffective installation and operation of an ESS. In particular, there are no international technical standards and guidelines on electric ESS for frequency regulation applications. Therefore, acomprehensive study on the power quality, impact on grid, extent of contribution, and cost benefit study of ESS are strongly being required. Under these backgrounds, this paper proposes a performance verification algorithm on ESS for frequency regulation application based on ananalysis of the AGC(Automatic Generation Control) performance verification method of PJM in USA. In addition,this paper proposes an economic evaluation algorithm on a 500 MW installation of ESS for frequency regulation applications using the account settlement of an expensive gas-fired generation plant and coal-fired power generation plant. From the simulation with real ESS operation data and 500 MW installation case, it wasconfirmed that the ESS showssuperior performance toany other conventional generators and provides anannual benefit of 500 MW ESS are between 345~429 billon won.

Analysis for Light Load Regulation of LLC Converter using Bode Plot (보드 선도를 이용한 LLC 컨버터의 경 부하 레귤레이션 특징 분석)

  • Yeon, Cheol-O;Moon, Gun-Woo
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.21 no.6
    • /
    • pp.506-513
    • /
    • 2016
  • In general, LLC converters show great promise in applications that require high efficiency, especially under light load conditions. In particular, LLC converters feature wide gain capability with pulse-frequency modulation and zero voltage switching over entire load conditions. However, output voltage increases in light load conditions. In this study, Bode plot and impedance asymptotes analyses were conducted to obtain insights into the regulation characteristics of LLC converters under light load conditions. To improve the regulation characteristic of LLC converters, a new resonant tank with an additional capacitor is proposed. The design guideline for the proposed LLC converter is determined by the Bode plot and impedance asymptotes analyses. Therefore, the proposed LLC converter achieves the light load regulation while maintaining the advantages of typical LLC converters.

LCD Backlight Inverter Drive IC (액정디스플레이 후광 인버터 구동 IC)

  • Jeong, Dong-Youl;Jang, Cheon-Seob;Lee, Seung-Zoo
    • Proceedings of the KIEE Conference
    • /
    • 2002.07d
    • /
    • pp.2568-2571
    • /
    • 2002
  • A LCD backlight inverter control IC based on the piezoelectric transformer (PZT) for Cold Cathode Fluorescent Lamp (CCFL) lighting is proposed. It is indeed a variable frequency, variable duty (VFVD) controller having dual feedback control loops for achieving both the regulation of lamp current and the maximum efficiency. The PWM controller regulates the lamp current, while the PLL controller tunes the operating frequency to the frequency that the efficiency of the combined LC-PZT resonator becomes maximum. The mixed PLL/PWM control technique lets the backlight inverter operate at the maximum efficiency in spite of the variation of component and environment. The controller features include a protection for an open or broken lamps, and an open lamp regulation.

  • PDF

Load Frequency Control Charateristic of 2-Area Power Systems by Optimal PID Controller (최적PID 제어기에 의한 2지역 전력계통 부하주파수 제어특성에 관한 연구)

  • 정형환;이준탁;안병철;김용필;김해재
    • The Transactions of the Korean Institute of Electrical Engineers
    • /
    • v.43 no.5
    • /
    • pp.703-710
    • /
    • 1994
  • This paper describes for the applicability of optimal PID controller to the load frequency control of 2-area power systems. The proposed optimal PID controllers are designed by the optimization technique of P.I.D's gain coefficients using the relatively ingeneous simplex method, and we have considered the system sensitivity for the optimal gains and the stable effects of systems to speed regulation changes. This PID controller for load frequency control systems with exciter shows better performances and robustness than conventional tie-line bias controller.

  • PDF

Characteristics of Frequency Control by Governor and AGC (AGC와 Governor의 주파수 제어 특성)

  • Choi Seung Ho;Jung Yun Jae;Baeck Wong Ki;Chun Yeong Han
    • Proceedings of the KIEE Conference
    • /
    • summer
    • /
    • pp.60-63
    • /
    • 2004
  • AGC is widely used to regulate the frequency of power systems. It is also used to control the frequency of Korean Power System. Control strategies depends on systems to which it is applied. Korean Power System consists of one control area and it has no tie-line. In this research, we have developed a simulation tool to confirm AGC dynamics. The developed tool has been verified by two-machine three-bus system. Moreover an AGC control strategy has been suggested to avoid contradiction with governor dynamics. Low pass filter with relatively long time constant showed good regulation performance. This simple strategy is expected to be applied to New EMS in KPX to get reasonable AGC regulation performance.

  • PDF

Power Smoothing of a Variable-Speed Wind Turbine Generator Based on the Rotor Speed-Dependent Gain (회전자 속도에 따라 변하는 게인에 기반한 가변속 풍력발전기 출력 평활화)

  • Kim, Yeonhee;Kang, Yong Cheol
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.65 no.4
    • /
    • pp.533-538
    • /
    • 2016
  • In a power grid that has a high penetration of wind power, the highly-fluctuating output power of wind turbine generators (WTGs) adversely impacts the power quality in terms of the system frequency. This paper proposes a power smoothing scheme of a variable-speed WTG that can smooth its fluctuating output power caused by varying wind speeds, thereby improving system frequency regulation. To achieve this, an additional loop relying on the frequency deviation that operates in association with the maximum power point tracking control loop, is proposed; its control gain is modified with the rotor speed. For a low rotor speed, to ensure the stable operation of a WTG, the gain is set to be proportional to the square of the rotor speed. For a high rotor speed, to improve the power smoothing capability, the control gain is set to be proportional to the cube of the rotor speed. The performance of the proposed scheme is investigated under varying wind speeds for the IEEE 14-bus system using an EMTP-RV simulator. The simulation results indicate that the proposed scheme can mitigate the output power fluctuation of WTGs caused by varying wind speeds by adjusting the control gain depending on the rotor speed, thereby supporting system frequency regulation.

The power regulation of a High-Frequency Induction Heating System with time variance load using a neural fuzzy controller (뉴로퍼지 제어기를 이용한 고주파 유도 가열기의 시변부하에 대한 정전력 제어)

  • 장종승;김승철;임영도
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.2 no.2
    • /
    • pp.223-230
    • /
    • 1998
  • This paper describes a phase-shift pulse-width modulation and pulse-frequency modulation series resonant high-frequency inverter using IGBT(Insulated-Gated Bipolar Transistor) for the power control of high-frequency induction heating using neuro-fuzzy, which is practically applied for 20KHz~500KHz induction-heating and melting power supply in industrial fields. The adaptive frequency tracking based phase-shifting PWM(Pulse-Width Modulation) regulation scheme is presented in order to minimize switching losses. The trially-produced breadboards using IGBT are successfully demonstrated and discussed.

  • PDF

A Performance Evaluation of MB-OFDM UWB System Considering the Domestic DAA Regulation (국내 DAA 기술 기준을 고려한 MB-OFDM UWB 성능 평가)

  • Shin, Cheol-Ho;Choi, Sang-Sung
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.19 no.9
    • /
    • pp.1000-1009
    • /
    • 2008
  • The purpose of this paper is to analyze the performance of MB-OFDM UWB system when the interference signal that can be WIMAX signal or 4 G system signal is received by detection limit of -80 dBm/MHz proposed in Korea for DAA(Detect And Avoid) to permit UWB in $3.1{\sim}4.8$ GHz. MB-OFDM UWB system supports two transmission modes; one is TFI(Time frequency Interleaving) mode that transmits OFDM symbols using different carrier frequency from symbol to symbol according to Time Frequency(TF) codes, the other is FFI(Fixed Frequency Interleaving) mode that transmits OFDM symbols using a specific carrier frequency. In this paper, we considered the TX average power and the synchronization structure to reflect the effect of frequency hopping according to TFC. Interference analysis results show that the WiMAX system is fenced thoroughly from UWB interference in domestic DAA regulation, but the performance of MB-OFDM UWB system is degraded seriously by an interference signal with the DAA detection limit even in frequency Hopping mode that can get frequency diversity effect.

The Structural Relationships of Personal and Environmental Factors on Child Aggression: Focusing on Child Negative Emotionality and Emotion Regulation, Mother Rejective Parenting, and Teacher-Child Conflict (유아의 공격성에 대한 개인적 요인과 환경적 요인간의 구조적 관계: 유아의 부정적 정서성과 정서조절, 어머니의 거부적 양육행동, 교사-유아 간 갈등을 중심으로)

  • Lee, Hea Jin;Kim, Sun Hee
    • Korean Journal of Child Studies
    • /
    • v.37 no.4
    • /
    • pp.117-128
    • /
    • 2016
  • Objective: The purpose of this study was to explore the structural relationships of child negative emotionality, mother rejective parenting, teacher-child conflict, and child emotion regulation on child aggression. Methods: The participants in this study were 3- to 5-year-old kindergarten children, their mothers, and their teachers (all of whom lived in Busan). The data were analyzed using PASW Statistics 18.0 and AMOS 21.0. For data analysis, frequency, Cronbach's alphas, Pearson's correlation coefficients, SEM were used. Results: First, mother rejective parenting had an indirect effect on child aggression through child emotion regulation. Second, teacher-child conflict had a direct effect on child aggression and had an indirect effect on child aggression through child emotion regulation. Third, child negative emotionality had an indirect effect on child aggression through mother rejective parenting and teacher-child conflict and child emotion regulation. Conclusion: These finding suggest the importance of mediating effect of mother rejective parenting, teacher-child conflict and child emotion regulation between child negative emotionality and aggression.

A Novel Induction Heating Type Super Heated Vapor Steamer using Dual Mode Phase Shifted PWM Soft Switching High Frequency Inverter

  • Sugimura, Hisayuki;Eid, Ahmad;Lee, Hyun-Woo;Nakaoka, Mutsuo
    • Proceedings of the KIPE Conference
    • /
    • 2005.07a
    • /
    • pp.774-777
    • /
    • 2005
  • In this paper, a constant frequency phase shifting PWM controlled voltage source full bridge-type series load resonant high-frequency inverter using the IGBT power modules is presented for innovative consumer electromagnetic induction heating applications such as a hot water producer, steamer and super heated steamer. The full bridge arm side link passive quasi-resonant capacitor snubbers in parallel with the each power semiconductor device and high frequency AC load side linked active edge inductive snubber-assisted series load resonant tank soft switching inverter with a constant frequency phase shifted PWM control scheme is discussed and evaluated on the basis of the simulation and experimental results. It is proved from a practical point of view that the series load resonant and edge resonant hybrid high-frequency soft switching PWM inverter topology, what is called class DE type. including the variable-power variable-frequency(VPVF) regulation function can expand zero voltage soft switching commutation range even under low output power setting ranges, which is more suitable and acceptable for induction heated dual packs fluid heater developed newly for consumer power utilizations. Furthermore, even in the lower output power regulation mode of this high-frequency load resonant tank high frequency inverter circuit it is verified that this inverter can achieve ZVS with the aid of the single auxiliary inductor snubber.

  • PDF