• Journal of Power Electronics
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• 제16권6호
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• pp.2129-2138
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• 2016

The full-bridge inverter, widely used for single-phase photovoltaic grid-connected applications, presents a leakage current issue. Therefore, an AC bypass branch is introduced to overcome this challenge. Nevertheless, existing modulation strategies entail drawbacks that should be addressed. One is the zero-crossing distortion (ZCD) of the AC current caused by neglecting the AC filter inductor voltage. Another is that the system cannot deliver reactive power because the AC bypass branch switches at the power frequency. To address these problems, this work proposes an optimized hybrid modulation strategy. To reduce ZCD, the phase angle of the inverter output voltage reference is shifted, thereby compensating for the neglected leading angle. To generate the reactive power, the interval of the negative power output is calculated using the power factor. In addition, the freewheeling switch is kept on when power is flowing into the grid and commutates at a high frequency when power is fed back to the DC side. In this manner, the dead-time insertion in the high-frequency switching area is minimized. Finally, the performances of the proposed modulation strategy and traditional strategies are compared on a universal prototype inverter. Experimental results validate the theoretical analysis.

• 한국전자통신학회논문지
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• 제14권4호
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• pp.685-692
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• 2019

본 논문은 태양광발전소의 최적 발전효율에 기여하는 패널 각도조절의 연관성을 연구하고자 설비구성이 동일한 2개의 발전단지를 대상으로 1개소는 정해진 각도로 분기별 각도변화를 주었고 1개소는 그대로 유지하여 8개월 간의 총발전량을 비교하여 고정형 태양광발전소 발전량과 고정가변형 태양광발전소의 발전효율 차이를 확인하고자 한다. 고정형 태양광발전소와 고정가변형 태양광발전소의 발전량 차이를 분석하여 발전 효율성을 높일 수 있는 운영 방법을 제안한다.