Designing a Quasi-Z-Source Inverter with Energy Storage to Improve Grid Power Quality

ABSTRACT

Photovoltaic (PV) systems are made of different components and, if not the most, one of the most important components is PV inverter. In the past few years, using quasi-Z-source inverters (QZSI) has become more and more popular. However, the mentioned inverters have critical issues when the direction and intensity of sunlight changes during the day. Therefore, in this article, a new QZSI, which reduces input current ripples, relative amplitude of harmonics produced, and improving the output voltage waveform, delivered to the network is introduced. In the topology of the proposed converter, two batteries are placed in parallel to capacitors in the circuit. The batteries will lessen current ripples caused by changes occurred in light intensity and its direction. Moreover, a modified active/reactive power control is presented and applied in proposed QZSI (PQZSI) to control the real and reactive output power of the PV, separately. Based on mathematical modeling, the PQZSI reduces both inductor current ripples and total harmonic distortion of output voltage which simulations, performed by Matlab/Simulink^®, are presented to verify the proposed concept.

KEYWORDS:

• Quasi-Z-source inverters
• PV system
• Power quality
• Active/reactive power control

Additional information

Notes on contributors

S. Honarbari

S Honarbari received his BSc degree in electrical engineering from Azad University, Damavand, Iran in 2014 and MSc degree in electrical engineering power electronics from Azad University, Roodehen, Iran in 2018. Currently, he is a lecturer with Islamic Azad University, and working at the Power Electronic Lab, Azad University, and Tehran, Iran. His interest areas include power electronic, renewable energy, photovoltaics, power quality. Email: [email protected]

M. Alizadeh Bidgoli

M Alizadeh Bidgoli received his the BSc, MSc and PhD degrees in electrical engineering and power systems from K N Toosi University, Tehran, Iran, in 2007, 2009, and 2015, respectively. Currently he is assistant professor with the Department of Electrical Engineering, Islamic Azad University, and Tehran, Iran. His interest areas include nonlinear control, renewable energy systems, microgrid, power system dynamic, electric machines drive, power quality.