3레벨 NPC타입 태양광 PCS에서의 누설전류 저감기법

다국어 초록 (Multilingual Abstract)

In this paper, Reduction method of leakage current in 3-level photovoltaic PCS(Power Conditioning System) is proposed and verified by simulation and experiment. Leakage current generation is analyzed through an equivalent model of the common mode voltage considering a significant parasitic capacitance existing between the photovoltaic array and ground, and combined two methods to reduce the leakage current, which are a new PWM method and leakage current bypass path with a damping network, are proposed. In the first, the leakage current is reduced significantly by a PWM method using two carriers with 180 degree- phase difference without losing the voltage utilization rate. In the second, the leakage current is further reduced by adding a bypass path from LCL filter to the mid-point of DC link with a damping network. The combined two methods is verified by simulations and experiments. The proposed method using the PWM method is verified to reduce the leakage current by 73% compared to the conventional SVPWM, and the bypass circuit with the damping network further reduces the leakage current by 93 %, respectively.

목차 (Table of Contents)

• 제 1 장 서론 1
• 1.1 연구배경 1
• 1.2 연구목적 2
• 1.3 논문개요 4
• 제 2 장 3상 3레벨 NPC 타입에서의 공통전압 및 누설전류 5
• 2.1 3상태양광 PCS 5
• 2.1.1 3레벨 인버터 구성 6
• 2.1.2 3레벨 NPC 타입 인버터 동작원리 8
• 2.2 공통모드 전압 및 누설전류 12
• 2.2.1 등가모델을 이용한 공통모드전압과 누설전류 해석 13
• 제 3 장 누설전류 저감기법 15
• 3.1 PWM을 이용한 누설전류 저감기법 15
• 3.1.1 3상 3레벨 SVPWM 15
• 3.1.2 누설전류 저감을 위한 SVPWM 기법 18
• 3.2 토폴로지를 이용한 누설전류 저감기법 26
• 제 4 장 시뮬레이션 및 실험결과 30
• 4.1 3상 3레벨 NPC 타입 인버터 실험 시스템 30
• 4.1.1 제어보드 31
• 4.1.2 게이트보드 32
• 4.1.3 센서보드 33
• 4.2 PWM을 이용한 누설전류 저감기법 시뮬레이션 및 실험결과 35
• 4.2.1 시뮬레이션 35
• 4.2.2 실험 44
• 4.3 토폴로지 이용한 누설전류 저감기법 시뮬레이션 및 실험결과 47
• 4.3.1 시뮬레이션 47
• 4.3.2 실험 51
• 제 5장 결론 53
• 참고문헌 54
• Abstract 57