Lead compensator-based voltage control of quasi Z-source inverter for grid integration of photovoltaic system

Abstract

This paper proposes lead compensator-based voltage control of a 3-phase quasi Z-source inverter (q-ZSI) integrating a solar PV system with the grid. Shoot-through control is incorporated in voltage-oriented control for regulating the dc-link voltage of q-ZSI. The lead compensator, which provides robust performance by shifting the pole pair to the right hand of the s-plane to ensure system stability, helps to determine the shoot-through duty ratio. The lead compensator is designed based on the bode diagram for the transfer function of the capacitor voltage to shoot-through duty ratio with unity feedback gain. Additionally, using a lead compensator also results in simpler tuning requirements. The performance of 3-phase q-ZSI-based grid-tied PV with lead compensator-based dc-link voltage control is analysed under different operating conditions. The analysis reveals IEEE-1547 compliant operation with only active power being injected into the grid and dc-link voltage regulation.

KEYWORDS:

• Grid integration
• lead compensator
• photovoltaic (PV) system
• quasi z-source inverter
• renewable energy
• voltage source inverter

Disclosure statement

No potential conflict of interest was reported by the author(s).