• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.1
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• pp.102-107
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• 2005

This paper describes a new voltage sag-swell generator for the test of custom power devices such as UPS, DVR, DSTATCOM, SSTS, etc. Voltage sag, swell, outage, and unbalance generation mechanism and the operating principle are described for the proposed scheme. The usefulness of the scheme is proved through simulations and experiments. The proposed scheme has good features of simple structure, high reliability, wide range of sag and swell variation, and easy control. Especially, the scheme can provide a cost-effective implementation of a power quality disturbance generator. Therefore, it is expected that the scheme will contribute to the self implementation of the system with low cost in laboratory.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.466-467
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• 2010

Researches about DSTATCOM are mainly divided two parts, one is the calculation of the load-side average active power and dc-link capacitor average voltage, the other part is the current control. This paper proposes a calculation of dc-link capacitor average voltage using improved method instead of conventional method using LPF (low pass filter). Through the theoretical analysis and simulation under unbalance loads and non-linear load, the proposed method is verified.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.468-469
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• 2010

DSTATCOM(Distribution STATic COMpensator) is one of the custom power devices, and protects a distribution line from unbalanced and harmonic current caused by non-linear and unbalanced loads. Conventional researches use a LPF(Low Pass Filter) to eliminate ripple component at the calculation of compensation current. This paper proposes a calculation of compensation current using phase shift that can be a counterproposal of conventional methods using LPF.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.193-196
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• 2003

This paper describes a new Sag-Swell generator for the test of custom power devices such as UPS, DYR, DSTATCOM, 5575, etc. The proposed science has good features of simple structure, high reliability, wide range of Sag and Swell variation, and easy control. Outage, harmonic distortion, notches, and voltage unbalance also can be generated. The operation principle of the proposed scheme is described and verified through simulations.

• Journal of Electrical Engineering and Technology
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• v.6 no.6
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• pp.769-775
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• 2011

Custom power devices such as dynamic voltage restorer (DVR) and DSTATCOM are used to improve the power quality in distribution systems. These devices require real power to compensate the deep voltage sag during sufficient time. An interline DVR (IDVR) consists of several DVRs in different feeders. In this paper, a neural network is proposed to control the IDVR performance to achieve optimal mitigation of voltage sags, swell, and unbalance, as well as improvement of dynamic performance. Three multilayer perceptron neural networks are used to identify and regulate the dynamics of the voltage on sensitive load. A backpropagation algorithm trains this type of network. The proposed controller provides optimal mitigation of voltage dynamic. Simulation is carried out by MATLAB/Simulink, demonstrating that the proposed controller has fast response with lower total harmonic distortion.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.69-71
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• 2008

Recently, the interest on power quality has been hot issue because the equipments cause voltage disturbance and become more sensitive to the voltage disturbance. The DVR(Dynamic Voltage Restorer) is one of the Custom Power Device that can compensate the voltage. DVR operates as a series connected compensator whose output voltage can be controlled system voltage. And the magnitude of compensation voltage is limited by the characteristics of system and load. Compensation capability of DVR was simulated by EMTDC under several condition. This paper analyzed effect of DVR's compensation at power quality test center which has SSFG(Sag, swell, and Flicker Generator, CPDs(SSTS, DVR, DSTATCOM), and loads.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.3-5
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• 2003

본 논문은 DVR과 DSTATCOM 같은 수 MVA급 용량의 CPD (Custom Power Device)를 평가하기 위한 Sag 및 Swell 전압 발생 장치에 사용될 두 가지 형태의 새로운 회로 방식에 관한 것이다. 제안된 Sag 및 Swell 전압 발생 장치는 계통선로에 직렬로 연결된 직렬 변압기를 통해 다양한 형태로 전압을 발생 시킬 수 있으며, 전격회로는 Solid-State Switched Tap Changer와 AC-Chopper 두 가지 방식을 이용하고 있다. 본 논문에서는 제안된 각각의 방식에 대한 고조파 분석을 하였고, 또한 시뮬레이션을 통해서 제안된 Sag 및 Swell 전압 발생장치를 통해서 원하는 형태의 전압을 얻을 수 있음을 확인하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.1
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• pp.41-47
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• 2012

This paper proposes a calculation of compensation current using phase shift to eliminate ripple components of instantaneous active power under unbalanced or non-linear loads condition. The proposed phase shift method instead of existing method(LPF; Low Pass Filter) to remove ripple components and this proposed method improves performances of transient and steady state response. To compare proposed method with existing method, experiments have been done for calculating an average active power at load side. Their results show that transient response and steady state response of proposed method is improved.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.514-517
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• 2004

This paper describes a new 3 phase Sag-Swell generator for the test of custom power devices such as UPS, DVR, DSTATCOM, SSTS, etc. The proposed scheme has good features of simple structure, high reliability wide range of sag and swell variation, It can also generate voltage outage. The control scheme for the generation is simple. The operation principle of the proposed scheme is described and verified through simulations.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.5
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• pp.463-470
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• 2006

This paper deals with a new 3-phase power quality disturbance generator. The proposed generator can provide phase jump as well as voltage sag, swell, outage, unbalance, and over and under voltage. The operating principle of the generator is described in each mode of disturbance. The magnitude of the phase jump is analysed and it is found that the magnitude is the function of the turn-ratios of the transformers consisting the generator. The scheme has simple structure compared with the conventional one, and the major components of the proposed scheme are SCR thyristor and transformer, which guarantees high reliability and cost-effective implementation of the generator. Furthermore, high efficiency can be obtained because there is no PWM switching of the semiconductor devices, and it is easy to control the system. Simulations are carried out to confirm the operation in each disturbance mode, and experiments has been done with 5kVA power rating. The usefulness of the proposed scheme is verified through simulation and experimental results. It is expected that the scheme can be applied to the performance test of the custom power devices such as UPS, DVR, DSTATCOM, and SSTS with cost-effective system.