• Journal of Electrical Engineering and Technology
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• 제13권1호
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• pp.270-279
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• 2018

This paper elucidates a hysteresis current controller for enhancing the performance of static synchronous compensator (STATCOM) using cascaded H-bridge multilevel inverter. Due to the rising power demand and growing conventional generation costs a new alternative in renewable energy source is gaining popularity and recognition. A five level single phase cascaded multilevel inverter with two separated dc sources, which is energized by photovoltaic - wind hybrid energy source. The voltages across the each dc source is balanced and standardized by the proposed hysteresis current controller. The performance of STATCOM is analyzed by connecting with grid connected system, under the steady state & dynamic state. To reduce the Total Harmonic Distortion (THD) and to improve the output voltage, closed loop hysteresis current control is achieved using PLL and PI controller. The performance of the proposed system is scrutinized through various simulation results using matlab/simulink and hardware results are also verified with simulation results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1039-1041
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• 1999

Recently Advanced Static Var Compensators(ASVC) or STATic Synchronous COMpesator(STATCOM) has been considered as a next generation reactive power controller. [2] STATCOM is a voltage source inverter(VSI) based static VAr compensator with only small capacitors on the do side. The main function of the STATCOM is to keep the bus voltage magnitude at the desired value. [1] This paper compares the PAM STATCOM with PWM STATCOM. The characteristics and the control method of each model is analyzed. And the simulation of STATCOMs based on the above two methods was presented.

• 전력전자학회논문지
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• 제11권4호
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• pp.293-301
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• 2006

배전급 STATCOM(Distribution-network STATic synchronous COMpensator)에 적용 가능한 공간 벡터 변조 (Space Vector Modulation, SVM) 기법을 이용한 히스테리시스 전류제어기를 제안하였다. 히스테리시스 전류제어기는 빠른 응답 특성, 쉬운 구현, 파라미터 변화에 대한 둔감성 등 많은 장점에도 불구하고 높은 스위칭 주파수와 제한되지 않는 전류 오차 때문에 스위칭 주파수에 영향을 받는 배전급 STATCOM 전류제어기로는 적합하지 않았다. 또한 전압 벡터의 인가방식에서도 뚜렷한 근거가 없어 전류오차가 제한되지 않았다. 이에 본 논문에서는 구역판별기, SVM, 그리고 외부와 내부 히스테리시스 제어기를 이용하여 높은 스위칭 주파수를 저감하고 특정 밴드 내에서 전류 오차를 줄인 개선된 SVM 기반의 히스테리시스 전류제어기를 제안하고 모의실험을 통해 제안한 기법의 유효성을 입증하였다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권8호
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• pp.522-528
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• 2000

In this paper, a static synchronous compensator(STATCOM), which in general compensates reactive power, is proposed in order to balance the unbalanced loads. Reference values for the compensation of the unbalanced loads currents are determined by 3-phase circuit analysis result. Also the STATCOM control unit is designed considering the proposed compensation scheme for the unbalanced loads. As a result, the effectiveness of the STATCOM for balancing the load currents is verified by computer simulations.

• Journal of Electrical Engineering and Technology
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• 제13권1호
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• pp.240-249
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• 2018

Individual DC voltage balance problem is an inherent issue for cascaded H-bridge (CHB) based converter. When the CHB-based static synchronous compensator (STATCOM) is operating at zero current mode, the software-based individual DC voltage balancing control techniques may not work because of the infinitesimal output current. However, the different power losses of each cell would lead to the individual DC voltages unbalance. The uneven power losses on the local supplied cell-controllers (including the control circuit and drive circuit) would especially cause the divergence of individual DC voltages, due to their characteristic as constant power loads. To solve this problem, this paper proposes an adaptive voltage balancing module which is designed in the cell-controller board with small size and low cost circuits. It is controlled to make the power loss of the cell a constant resistance load, thus the DC voltages are balanced in zero current mode. Field test in a 10kV STATCOM confirms the performance of the proposed method.

• 전력전자학회논문지
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• 제19권4호
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• pp.332-341
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• 2014

A cascaded H-bridge multi-level STATCOM(STATic synchronous COMpensator), which is composed of many cell inverters with independent dc-sources, generates inevitably dc-side voltage unbalance among phases when it compensates unbalanced load. It comes from the difference of flowing active power in each phase when this compensator makes negative-sequence current to eliminate the unbalance of source-side current. However, this unbalance can be controlled by injecting zero-sequence current which is decoupled with grid currents, so the compensator can work well during this balancing process. Both a feedback control algorithm, which produces zero-sequence current proportional to dc-side voltage unbalance within each phase, and a feedforward control algorithm, which makes zero-sequence current directly from the compensator's negative-sequence current, were proposed. The dc-side voltage of each phase can be controlled stably by these proposed algorithms in both steady-state and transient, so the compensator can have fast response to satisfy control performance under rapid changing load. These balancing controllers were implemented and verified via simulation and experiment.

• 대한전기학회논문지:전력기술부문A
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• 제48권12호
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• pp.1507-1513
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• 1999

This paper describes simulation and experimental results to analyze the dynamic characteristics of STATCOM, which is connected to the ac system for compensation the power factor and improving the voltage stability. The simulation and experimental results confirm that the scaled model for STATCOM can properly compesate the power factor of the load and regulate the bus voltage at the common connection point.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 추계학술대회 논문집
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• pp.173-174
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• 2014

STATCOM은 전기로와 같은 무효전력 부하원에서 전원 안정화를 목적으로 산업응용분야에 널리 적용되고 있다. 하지만 시스템 비용 절감 등의 이유로 커패시터 뱅크와 함게 운용되는 Hybrid STATCOM의 적용이 요구되어 왔다. 본 논문에서는 포스코ICT에서 개발한 5Mvar Hybrid STATCOM(static synchronous compensator)에 대해 기술하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 전력전자학술대회 논문집
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• pp.524-525
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• 2013

(주)효성에서는 FACTS(Flexible AC Transmission System) 기기 중 하나인 1 MVA STATCOM(Static synchronous Compensator)을 개발하여 제주 행원의 풍력단지에 설치하였으며, 이에 대한 실증운전 및 시험을 완료하였다. STATCOM은 연계된 전력계통의 상황에 맞게 일정전압 제어 및 무효전력 제어모드로 운전되며, 이를 이용하여 계통전압의 안정화에 기여함으로써 전력품질을 향상시키는 역할을 한다. 본 논문에서는 1 MVA STATCOM의 실증운전을 통해 전력품 질향상 사례를 분석하였다.

• Journal of Power Electronics
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• 제13권5호
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• pp.877-883
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• 2013

This paper discussed a transformer-less shunt static synchronous compensator (STATCOM) with consideration of the following aspects: fast compensation of the reactive power, harmonic cancelation and reducing the unbalancing of the 3-phase source side currents. The STATCOM control algorithm is based on the theory of instantaneous reactive power (P-Q theory). A self charging technique is proposed to regulate the dc capacitor voltage at a desired level with the use of a PI controller. In order to regulate the DC link voltage, an off-line Genetic Algorithm (GA) is used to tune the coefficients of the PI controller. This algorithm arranged these coefficients while considering the importance of three factors in the DC link voltage response: overshoot, settling time and rising time. For this investigation, the entire system including the STATCOM, network, harmonics and unbalancing load are simulated in MATLAB/SIMULINK. After that, a 35KVA STATCOM laboratory setup test including two parallel converter modules is designed and the control algorithm is executed on a TMS320F2812 controller platform.