• Title/Summary/Keyword: Reactive power compensator

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A Sensorless Control of IPMSM using the Adaptive Back-EMF Estimator and Improved Instantaneous Reactive Power Compensator (적응 역기전력 추정기와 개선된 순시 무효전력 보상기를 이용한 돌극형 영구자석 전동기의 센서리스 제어)

  • Lee, Joonmin;Hong, Joo-Hoon;Kim, Young-Seok
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.5
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    • pp.794-803
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    • 2016
  • This paper propose a sensorless control system of IPMSM with a adaptive back-EMF estimator and improved instantaneous reactive power compensator. A saliency-based back-EMF is estimated by using the adaptive algorithm. The estimated back-EMF is inputted to the phase locked loop(PLL) and the improved instantaneous reactive power(IRP) compensator for estimating the position/speed of the rotor and compensating the error components between the estimated and the actual position, respectively. The stability of the proposed system is achieved through Popov's hyper stability criteria. The validity of proposed algorithm is verified by the simulations and experiments.

Reactive Power Compensator for Pulsed Power Electric Network of International Thermonuclear Experimental Reactor (국제 열핵융합실험로 펄스전원계통의 무효전력보상기 검증)

  • Jo, Hyunsik;Jo, Jongmin;Cha, Hanju
    • The Transactions of the Korean Institute of Power Electronics
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    • v.20 no.3
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    • pp.290-295
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    • 2015
  • Analysis and verification of reactive power compensator (RPC) for ITER pulsed power electric network (PPEN) are described in this paper. The RPC system is rated for a nominal power of 250 Mvar necessary to comply with the allowable reactive power limit value from the grid 200 Mvar. This system is currently under construction and is based on static var compensation technology with a thyristor-controlled reactor and a harmonic filter. The RPC minimizes reactive power from grid using prediction of reactive power consumption of AC-DC converters. The feasibility of the reactive power compensation was verified by assembling a real controller and implementing ITER PPEN in the real time digital simulator for the hardware-in-loop facility. When maximum reactive power is reached, grid voltage is stabilized and maximum reactive power decreased from 120 Mvar to 40 Mvar via the reactive power prediction method.

Operational Analysis of Energy Storage System to Improve Performance of Wind Power System with Induction Generator (농형유도 풍력발전기의 성능개선을 위한 에너지저장장치의 동작특성 분석)

  • Lee, Ji-Heon;Shim, Myong-Bo;Lee, Hye-Yeon;Han, Byung-Moon;Yang, Seung-Chul
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.6
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    • pp.1138-1145
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    • 2009
  • This paper presents an active and reactive power compensator for the wind power system with squirrel-cage induction generator. The output power of a wind power system changes irregularly according to the variation of wind speed. The developed system is able to continuously compensate the active and reactive power. The 3-phase inverter operates for the compensation of reactive power, while the DC/DC converter with super-capacitors operates for the compensation of active power. The operational feasibility of the proposed model was verified by simulations with PSCAD/EMTDC and the feasibility of hardware implementation was confirmed by experimental works with a scaled hardware model. The proposed compensator can be expected that developed system may be used to compensated the abrupt power variation due to sudden change of wind speed or sudden power-drop by tower effect. It can be also applied for the distributed generation and the Micro-Grid.

Comparative Study of the Behavior of a Wind Farm Integrating Three Different FACTS Devices

  • Sarrias, Raul;Gonzalez, Carlos;Fernandez, Luis M.;Garcia, Carlos Andres;Jurado, Francisco
    • Journal of Electrical Engineering and Technology
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    • v.9 no.4
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    • pp.1258-1268
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    • 2014
  • Improving grid connection of wind farms is a relevant issue to be addressed, especially for fixed-speed wind turbines. Certain elements, such as FACTS (Flexible AC Transmission Systems), are able to perform voltage and reactive power regulation in order to support voltage stability of wind farms, and compensate reactive power consumption from the grid. Several devices are grouped under the name of FACTS, which embrace different technologies and operating principles. Here, three of them are evaluated and compared, namely STATCOM (Static Synchronous Compensator), SVC (Static Var Compensator) and SSSC (Static Synchronous Series Compensator). They have been modeled in MATLAB/Simulink, and simulated under various scenarios, regarding both normal operation and grid fault conditions. Their response is studied together with the case when no FACTS are implemented. Results show that SSSC improves the voltage stability of the wind farm, whereas STATCOM and SVC provide additional reactive power.

The Comparison of Operating Characteristics of SVC and STATCOM for Compensating the Reactive Power in the Jeju Power System (제주계통의 무효전력보상을 위한 SVC와 STATCOM의 운전특성 비교)

  • LEE, SEUNGMIN;Kim, Eel-Hwan;Kim, Ho Min;Oh, Sung-Bo;LEE, DOHEON
    • Journal of the Korean Solar Energy Society
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    • v.35 no.3
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    • pp.49-56
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    • 2015
  • This paper presents a comparative operating characteristics of static var compensator(SVC) and static synchronous compensator(STATCOM) for compensating the reactive power in the Jeju power system. There are two kinds of reactive power compensating systems, which are active and passive system in the applications of the line commutated converter type high voltage direct current (LCC-HVDC). In the Jeju power system, two STATCOMs as active compensating system have been operating. Even though STATCOM has good performance compared with SVC, economical efficiency of former system is not good to the latter system. So, it is necessary to examine the performance and economical efficiency depend on the intention before appling the system. To compare the operating characteristics of two systems in the Jeju power system, simulations have been carried out for case studies that both of the HVDC system have transient state by using PSCAD/EMTDC program.

The Vibration Suppression using Reactive Power Compensator for Speed Control of Parallel Connected Dual Fan Motors fed by a Single Inverter (단일 인버터 기반 에어컨용 실외기 팬 모터 병렬운전에서의 무효전력보상기를 이용한 맥동저감 기법)

  • Yun, Chul;Kwon, Woo-Hyen;Cho, Nae-Soo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.12
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    • pp.2008-2013
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    • 2016
  • This paper proposes analysis and suppression method for reactive power vibration of the slave motor caused by back-EMF mismatch between the master and the slave motor and stator resistance during middle-low speed operation. The master and slave motors are parallel connected dual SPMSMs(Surface mounted Permanent Magnet Synchronous Motors) fed by a single inverter. To suppress vibration of reactive power, RPC(Reactive Power Compensator) proposed in this paper analyzes flux-axis current vibration of the slave motor that occurs in middle-low speed operation using a mathematical model of the fan motor. And RPC adds vibration components detected from flux-axis current of the slave motor to flux-axis current of the master motor. The results of experiment conducted verify the efficacy of the proposed method.

Reduction of Harmonics and Compensation of Reactive Power about Wind Power Generation System Connected to Grid (계통 연계형 풍력발전 시스템의 고조파 저감 및 무효전력 보상)

  • Kim, Yeong-Min;Hwang, Jong-Sun;Kim, Jong-Man;Park, Hyun-Chul;Song, Seung-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.1093-1096
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    • 2002
  • In this paper, a novel multi voltage inverter system is proposed for reductions of harmonics, which can compensate reactive power. At first, we remove capacitor at input side for reactive power compensation. Secondly, by adding DC voltage to the filter capacitor, it can control power factors as lead-phase according to alterations of loads at power reception. Thirdly, if winding and single phase-bridge inverter(auxiliary circuit) is installed to DC power for reduction of harmonic, waveform of output voltages become to 36-steps. Thus, SVC(static var compensator) systems which can reduce harmonics are designed.

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SVC coupled UPQC for reactive power compensation capacity increase and DC link voltage reduction (무효전력 보상 용량 증대 및 DC 링크 전압 저감을 위한 SVC 결합형 UPQC)

  • Pyo, Soo-Han;Park, Jang-Hyun;Oh, Jeong-Sik;Park, Tae-Sik
    • Journal of IKEEE
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    • v.23 no.1
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    • pp.99-106
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    • 2019
  • This paper propose a new form of UPQC (Unified Power Quality Compensator) to compensate the current and voltage quality problems of nonlinear loads. The conventional UPQC system consists of a series inverter, a parallel inverter, and a common DC link. A new type of UPQC proposed is a parallel compensator with SVC (Static Var Compensator) added to compensate for the wide compensation range and low DC link voltage. The parallel inverter compensates the reactive power generated by the nonlinear load, and the series inverter compensates the sag and swell generated at the power supply side.

Speed Sensorless Control for Interior Permanent Magnet Synchronous Motor based on an Instantaneous Reactive Power and a Fuzzy PI Compensator (순시무효전력과 퍼이 이득 보상기를 이용한 IPMSM의 속도 센서리스 제어)

  • Kang, Hyoung-Seok;Shin, Jae-Hwa;You, Wan-Sik;Kang, Min-Hyoung;Kim, Young-Seok
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.173-174
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    • 2007
  • In this paper, a new speed sensorless control based on an instantaneous reactive power and a fuzzy PI compensator are proposed for the interior permanent magnet synchronous motor (IPMSM) drives. The conventional fixed gain PI and PID controllers are very sensitive to step change of command speed, parameter variations and load disturbance. Also, to the estimated speeds are compensated by using an instantaneous reactive power in synchronously rotating reference frame. In a fuzzy compensator, the system control parameters are adjusted by a fuzzy rule based system, which is a logical model of the human behavior for process control. The effectiveness of algorithm is confirmed by the experiments.

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Design of Robust Current Controller Using GA for Three Level 24-Pulse VSC Based STATCOM

  • Janaki, M.;Thirumalaivasan, R.;Prabhu, Nagesh
    • Journal of Power Electronics
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    • v.11 no.3
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    • pp.375-380
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    • 2011
  • A STATic synchronous COMpensator (STATCOM) is a shunt connected voltage source converter (VSC) based FACTS controller using Gate Turn Off (GTO) power semiconductor devices employed for reactive power control. The operation principal is similar to that of a synchronous condenser. A typical application of a STATCOM is voltage regulation at the midpoint of a long transmission line for the enhancement of power transfer capability and/or reactive power control at the load centre. This paper presents the modeling of STATCOM with twenty four pulse three level VSC and Type-1 controller to regulate the reactive current or the bus voltage. The performance is evaluated by transient simulation. It is observed that, the STATCOM shows excellent transient response to step change in the reactive current reference. While the eigenvalue analysis is based on D-Q model, the transient simulation is based on both D-Q and 3 phase models of STATCOM (which considers switching action of VSC).