A Comparative Study of Different Capacitor Voltage Control Design Strategies for Z-Source Inverter

Abstract

The Z-source inverter (ZSI) is a prominent single-stage power conversion topology compared to traditional voltage source inverter (VSI)/ current source inverter (CSI). It adds the additional buck–boost capability to input voltage with improved reliability. However, the non-minimum phase (NMP) behavior is the major disadvantage of ZSI due to the existence of the right half plane (RHP) zero in the converter transfer functions. The existences of RHP zero destabilize the wideband feedback loops, which imply high gain instability and introduce the constraints on controller design. This paper presents different types of controllers and its design to maintain the required capacitor voltage with better transient response for non-minimum phase ZSI. Different tuning algorithms have been considered for both proportional–integral (PI), and integral–proportional (IP) control schemes. Also, the unified control algorithm has been implemented with both simple boost pulse width modulation (SBPWM) and a modified space vector pulse width modulation (MSVPWM) schemes to obtain the required capacitor voltage. The converter performance is comprehensively analyzed for different controllers and observations are tabulated. The complete analysis has been carried out using the MATLAB/Simulink environment for the proposed models.

KEYWORDS:

• Modified space vector pulse width modulation (MSVPWM)
• PI controller tuning methods
• Shoot through duty ratio (STDR)
• Simple boost control (SBC)
• Unified control
• Z-source inverter (ZSI)

Additional information

Notes on contributors

Kancharana Vinod Kumar

Kancharana Vinod Kumar received the BE degree in electrical and electronics engineering from Anil Neerukonda Institute of Technology and Sciences in 2014. He is pursuing the MTech degree in power and energy systems from National Institute of Technology Karnataka(NITK), Surathkal, India. His research interests include power electronic applications and control systems. Email: [email protected]

Reddiprasad Reddivari

Reddiprasad Reddivari received the BTech degree in electrical and electronics engineering and the MTech degree in power electronics from Jawaharlal Nehru Technological University, Ananthapur, India, in 2011 and 2014, respectively. He is currently working towards the PhD degree in the Department of Electrical and Electronics Engineering, National Institute of Technology Karnataka (NITK), Surathkal, India. His research interests include power electronics applications, impedance source converters, and control systems. Email: [email protected]

Debashisha Jena

Debashisha Jena received his bachelor of electrical engineering degree from University College of Engineering, Burla, India, in 1996, Master’s in electrical engineering in 2004, and PhD degree in control system engineering from the Department of Electrical Engineering, National Institute of Technology, Rourkela, India, 2010. He was awarded a GSEP fellowship in 2008 from Canada for research in control and automation. Currently, he is an assistant professor in the Department of Electrical & Electronics Engineering in the National Institute of Technology Karnataka, Surathkal, Mangalore, India. His research interests include evolutionary computation, system identification, neuro-evolutionary computation, and photovoltaic power conversion systems. Corresponding author. Email: [email protected]