**Harmonic Distortion Caused by Single-Phase Grid-Connected PV Inverter** Harmonic Distortion Caused by Single-Phase Grid-Connected PV Inverter

DOI: 10.5772/intechopen.73030

Yang Du and Dylan Dah-Chuan Lu Yang Du and Dylan Dah-Chuan Lu

Additional information is available at the end of the chapter Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.73030

Abstract

[9] Albadi M, Al Hinai A, Al-Badi A, Al Riyami M, Al Hinai S, Al Abri R. "Measurements and evaluation of harmonics in HV networks—Oman MIS case study". In: the 7th IEEE GCC Conference and Exhibition, Doha, Qatar, 17-20 November 2013. pp. 49-53. DOI:10.1109/

50 Power System Harmonics - Analysis, Effects and Mitigation Solutions for Power Quality Improvement

[10] Al-Badi A, Albadi M, Al-Hinai A. Designing of filter to reduce harmonic in industrial power networks. In: 3rd IEEE International Energy Conference (EnergyCon 2014),

[11] Albadi M, Al Hinai A, Al-Badi A, Al Riyami M, Al Hinai S, Al Abri R. "Measurements and evaluation of flicker in high voltage networks". Renewable Energy and Power Quality

[12] Albadi M, Al Hinai A, Al-Badi A, Al Riyami M, Al Hinai S, Al Abri R. Unbalance in power systems: Case study. In: 2015 IEEE International Conference on Industrial Technology

(ICIT), Seville, Spain, 2015. pp. 1407-1411. DOI: 10.1109/ICIT.2015.7125294

Dubrovnik, Croatia, 13-16 May 2014. DOI: 10.1109/ENERGYCON.2014.6850425

Journal (RE&PQJ). 2014;**12**:1-6. DOI: 10.24084/repqj12.218

IEEEGCC.2013.6705747

Due to the fast growth of photovoltaic (PV) installations, concerns are rising about the harmonic distortion generated from PV inverters. A general model modified from the conventional control structure diagram is introduced to analyze the harmonic generation process. Causes of the current harmonics are summarized, and its relationship with output power levels is analyzed. In particular for two-stage inverter, unlike existing models that assume the direct current (DC)-link voltage is constant, the DC-link voltage ripple is identified as the source of a series of odd harmonics. The inverter is modeled as a time-varying system by considering the DC-link voltage ripple. A closed-form solution is derived to calculate the amplitude of the ripple-caused harmonics. The theoretical derivation and analysis are verified by both simulation and experimental evaluation.

Keywords: DC-link voltage ripple, harmonics, Matlab/Simulink, PV inverter, single phase
