• Title/Summary/Keyword: Reactive power compensator

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Analysis of Voltage Regulation by DSTATCOM - Using the EMTDC Program

  • Jeon Young-Soo;Kwak No-Hong;Choo Jin-Boo
    • Journal of Power Electronics
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    • v.5 no.4
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    • pp.329-334
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    • 2005
  • The DSTATCOM(Distribution Static Synchronous Compensator) is one of the Custom Power Devices that can regulate voltage. The DSTATCOM operates as a shunt connected static var compensator whose capacitive or inductive output current can be controlled independent of the system voltage. The magnitude of the compensated voltage is limited by characteristics of the system and the load. Compensation capability of the DSTATCOM which can inject 1 MVAR reactive power was simulated by EMTDC under several conditions. This paper analyzes the effect of the DSTATCOM's compensation considering the length and kind of distribution line, the power factor and magnitude of the load, and the duration and magnitude of the voltage variation.

Characteristic Analysis of Static Var Compensator Using Three Phase PWM Cuk AC-AC Converter (3상 PWM Cuk AC-AC 컨버터를 이용한 정지형 무효전력보상기의 특성해석)

  • Choi Nam-Sup
    • Proceedings of the KIPE Conference
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    • 2004.07b
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    • pp.597-600
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    • 2004
  • In this paper, a static var compensator using PWM Cuk AC-AC converter is presented. The PWM Cuk AC-AC converter is modelled by using complex circuit DQ transformation whereby the basic condition to be used as a var compensator is derived and the static characteristic equations such as input current and reactive power is analytically obtained. Finally, the PSIM simulations show the validity of the modelling and analysis.

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A Cascaded D-STATCOM Integrated with a Distribution Transformer for Medium-voltage Reactive Power Compensation

  • Lei, Ertao;Yin, Xianggen;Chen, Yu;Lai, Jinmu
    • Journal of Power Electronics
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    • v.17 no.2
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    • pp.522-532
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    • 2017
  • This paper presents a novel integrated structure for a cascaded distribution static compensator (D-STATCOM) and distribution transformer for medium-voltage reactive power compensation. The cascaded multilevel converter is connected to a system via a group of special designed taps on the primary windings of the Dyn11 connection distribution transformer. The three-phase winding taps are symmetrically arranged and the connection point voltage can be decreased to half of the line-to-line voltage at most. Thus, the voltage stress for the D-STATCOM is reduced and a compromise between the voltage rating and the current rating can be achieved. The spare capacity of the distribution transformer can also be fully used. The working mechanism is explained in detail and a modified control strategy is proposed for reactive power compensation. Finally, both simulation and scaled-down prototype experimental results are provided to verify the feasibility and effectiveness of the proposed connection structure and control strategy.

Modeling and Simulation Reactive Power Compensator using Multi-port Network Algorithm in Electrified Railway (다단자망 알고리즘을 이용한 급전시스템의 무효전력 보상 모델링 및 시뮬레이션)

  • Kim, Joorak
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.5
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    • pp.883-887
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    • 2016
  • The power supply system in Korean electrified railway has adopted AT feeding. If a fault occurs in some substation for any reason, the vicinity substation must feed electric power on the outage substation through catenary. So, the feeding distance grows twice of the normal state at extended feeding condition. If substation's feeding distance is longer than normal condition, the catenary impedance and train to supply electric power from the substation. Therefore, the severe voltage drop can occur and power supply shall be not allowed. This paper presents the model of compensator against voltage drop using multi-port network algorithm. Whole traction power supply system can be analyzed with this model. Computer simulation including this model is performed based on real train schedule and increased schedule in case studies.

A Study on the Parameter Determination of Synchronous Compensator in AC network with HVDC system (HVDC계통에서 동기조상기의 파라미터 선정에 관한 연구)

  • Lee, Seok-Jin;Lee, Heung-Jae
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.8
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    • pp.1353-1359
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    • 2010
  • This paper presents the determination of synchronous compensator(S.C) rating and parameter in Cheju AC network. The role of S.C is to supply Inertia and reactive power to HVDC system which is a kind of a generator without the function of reactive power control and Inertia. Therefore, the parameters of S,C have to be determined by considering HVDC operating characteristics. The background of this paper is the determination of S.C parameters in Cheju AC network in the case of replacing current operating S,C to new S.C type.

Reactive-Power Compensator using Soft-Switching Current-Source Inverter (소프트-스위칭 전류원인버터를 이용한 무효전력보상기)

  • Jeong, Jin-Gyu;Baek, Seung-Taek;Kim, Hui-Jung;Han, Byeong-Mun;Baek, Mun-Hong;Han, Hu-Seok
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.49 no.3
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    • pp.204-210
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    • 2000
  • This paper proposes a new reactive-power compensator composed of a soft-switching current-source inverter. The compensator consists of 3-Phase IGBT bridge, dc reactor, and a resonant circuit. The resonant circuit offers the IGBT bridge to have PWM operation with minimal switching losses. A theoretical analysis and computer simulation with Is-Spice were done to verify the operation of the proposed system. Also a acaled-model of the system was built and tested for verifying the feasibility of proposed system.

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Design of an Asymmetrical Three-phase Inverter for Load Balancing and Power Factor Correction Based on Power Analysis

  • Mokhtari, M.;Golshannavaz, S.;Nazarpour, D.;Aminifar, F.
    • Journal of Electrical Engineering and Technology
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    • v.6 no.3
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    • pp.293-301
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    • 2011
  • This paper presents a novel theoretical method based on power analysis to obtain voltage reference values for an inverter-based compensator. This type of compensator, which is installed in parallel with the load, is usually referred to as the active filter. The proposed method is tailored to design the compensator in such a way that it can simultaneously balance the asymmetric load, as well as correct the power factor of the supply side. For clarity, a static compensator is first considered and a recursive algorithm is utilized to calculate the reactance values. The algorithm is then extended to calculate voltage reference values when the compensator is inverter based. It is evident that the compensator would be asymmetric since the load is unbalanced. The salient feature associated with the proposed method is that the circuit representation of system load is not required and that the load is recognized just by its active and reactive consumptions. Hence, the type and connection of load do not matter. The validity and performance of the new approach are analyzed via a numerical example, and the obtained results are thoroughly discussed.

HVDC System Design for AC Network Reactive Power Control (AC 계통 무효전력 제어를 위한 HVDC 시스템 설계)

  • Choi, Soon-Ho;Choi, Jang-Hum;Kim, Chan-Ki
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.1
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    • pp.8-20
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    • 2013
  • This paper deals with the concept design of HVDC system for controlling AC network reactive power. HVDC system can control active power and reactive power and the control concept of reactive power is similar to SVC(Static Var Compensator). Reactive power is controlled by adjusting firing angle of HVDC system under the condition that AC filters are switched. Reactive power depends on AC voltage condition, considering the steady-state and transient state to maintain the stable operation of AC network in the viewpoint of voltage stability. Therefore, in the design stage of HVDC, the reactive power required in the AC network must be considered. For the calculation of operation angle in HVDC system, the expected reactive power demand and supply status is examined at each AC system bus. The required reactive power affects the determination of the operation angle of HVDC. That is, the range of "control deadband" of operation angle should have the capability supplying the required reactive power. Finally, the reactive power control concepts is applied to 1GW BTB Pyeongtaek-Dangjin HVDC system.

Wind turbine output control using Fuzzy PI controller of Energy storage system (풍력발전시스템의 출력제어를 위한 에너지저장장치의 Fuzzy PI제어기 설계에 관한 연구)

  • Lee, Hee-Tae;Koo, Bon-Gil;Lee, Sang-Hun;Park, June-Ho
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.402-403
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    • 2011
  • This paper presents an active and reactive power compensator for the wind power system with multi-polar synchronous generator. The proposed compensator is composed of a charge/discharge PWM converter and battery. 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 operational feasibility of the proposed model was verified by simulations with PSCAD/EMTDC.

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Static VAR Compensator Using PWM Voltage type Converter (PWM전압형 콘버어터에 의한 정지형 무효전력 보상장치)

  • 정연택;이훈구;황락훈
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.39 no.8
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    • pp.836-846
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    • 1990
  • This paper presents a Static Var Compensator (SVC) system compensating the reactive power for power system, which consists of a voltage type Pulse Width Modulation (PWM) converter and a reactance linking the converter to the source. The system drives the four quadrant modes. The system determines the magnitude of the input voltage, and then compares it with the magnitude of the source voltage by regulating the phase of the SVC about the source. Therefore, the system generates leading compensation currents when the input voltage is larger than the source in magnitude, and lagging compensation currents for smaller input voltage. Reactive power about voluntary load in power system is smoothly compensated by those compensation currents, and also power factor of source is improved. Furthermore, the SVC system using PWM method may improve the source current waveforms by eliminating the 5th and 7th harmonic components from the input voltages.

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