• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.1
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• pp.115-126
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• 2023

Due to the fluctuating random and periodical nature of renewable energy generation power quality disturbances occurred more frequently in power generation transformation transmission and distribution. Various power quality disturbances may lead to equipment damage or even power outages. Therefore it is essential to detect and classify different power quality disturbances in real time automatically. The traditional PQD identification method consists of three steps: feature extraction feature selection and classification. However, the handcrafted features are imprecise in the feature selection stage, resulting in low classification accuracy. This paper proposes a deep neural architecture based on Convolution Neural Network and Long Short Term Memory combining the time and frequency domain features to recognize 16 types of Power Quality signals. The frequency-domain data were obtained from the Fast Fourier Transform which could efficiently extract the frequency-domain features. The performance in synthetic data and real 6kV power system data indicate that our proposed method generalizes well compared with other deep learning methods.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.34-35
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• 2013

최근 신재생 에너지원의 증가와 더불어 전력 산업 전반의 요구에 대해 에너지 저장시스템(ESS, Energy Storage System)에 대한 필요성이 높아지고 있다. 전력 수요의 급격한 증가는 전력계통의 교란이 증가하게 되어 전력품질의 문제를 야기 시키고, 이에 따라 송배전 설비의 증설에 교구 커지고 있는 상황이다. 이에 대한 적절한 대안으로 배터리를 이용한 에너지 저장 시스템(BESS, Battery Energy Storage System)이 대두되고 있는 상황이며, 특히 계통연계형 PCS에 BESS를 적용시킬시에 능동적인 부하 평준화 기능을 통해 송배전 설비투자 지연의 목적을 달성할 수 있는 장점을 가진다. 따라서 본 논문에서는 BESS기능을 겸비한 PCS 시스템 구성을 제안하고, 이에 대하여 기술한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6A
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• pp.556-562
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• 2006

In this paper, macro diversity coding methods are proposed to efficiently transmit broadcast packet data over mobile cellular networks based on OFDM. In the method, cells are divided into multiple cell groups which transmit one of two orthogonal branches in a transmit diversity code. Furthermore, a coded packet is partitioned into the subblocks for which different cell group combinations are assigned to transmit two different branches. The methods extend the cell coverage at the same transmit power due to the transmit diversity of each symbol and coding diversity obtained through different fading statistics over the subblocks.

• Journal of the Korean Society for Railway
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• v.18 no.4
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• pp.325-334
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• 2015

This paper deals with a control method for a hybrid energy storage system (ESS) with a battery and super capacitor for grid-connected operation. To improve the grid regulation and to minimize the depth of discharge of the battery, control algorithms for the hybrid ESS are proposed. A p-q control with predictive current control is used for the inverters for the super-capacitor and the battery. To verify the effectiveness of the proposed control method, simulation studies using the PSIM and RTDS are carried out for the actual grid model.