Investigation on Amplitude-Domain Modulation for Three-Phase Energy-Stored Quasi-Z Source Inverter

A novel amplitude-domain pulsewidth modulation (AD-PWM) technique for a three-phase energy-stored quasi-Z-source inverter (ES-qZSI) photovoltaic (PV) power system is proposed in this article. The proposed modulation technique performs switching states and shoot-through behavior based on the relationship of size among three-phase voltages, showing the attractiveness of extreme simplicity and low computation. This article further investigates the AD-PWM-based three-phase PV power system. An active power control method is integrated with reactive power compensation for the system in natural coordinate to avoid complicated calculation of trigonometric function. As a result, active power regulation integrated with reactive power compensation is fast and reliable. Compared with the state-of-the-art control schemes for ES-qZSI system utilizing techniques, the proposed control strategy has advantages: 1) the computation is low because there is no shoot-through reference and avoiding complexity vector calculation and 2) there is a reliable capability of ensuring the grid-injected current tracking the grid voltage in phase as the reactive power generated by reactive power equipment is taken into account to control the ES-qZSI's output current. Simulation and experimental results verify the outstanding features of the proposed AD-PWM and active power control strategy integrated with the reactive power compensation technique for a three-phase ES-qZSI PV power system.

Automated summary

This article proposes a novel amplitude-domain pulsewidth modulation (AD-PWM) technique for a three-phase energy-stored quasi-Z-source inverter (ES-qZSI) photovoltaic (PV) power system. The modulation technique performs switching states and shoot-through behavior based on the relationship of size among three-phase voltages, providing simplicity and low computation. The article further investigates the AD-PWM-based three-phase PV power system and integrates an active power control method with reactive power compensation, resulting in fast and reliable active power regulation. The proposed control strategy has advantages over existing schemes, including low computation and the ability to ensure grid-injected current tracking the grid voltage in phase.