Comparative Static and Dynamic Analysis of Single‐ and Double‐stage Multifunctional 3‐phase Grid‐tied Photovoltaic Systems

This paper presents a comparison analysis involving four multifunctional grid-tied photovoltaic (MPV) systems, divided in single-stage and double-stage architectures. The functionalities can be pointed out as generation/injection of active energy into the utility grid, and active power conditioning including reactive power and load unbalance compensation, as well as load harmonic currents suppression. Thus, beyond the photovoltaic systems' conventional functions, the MPV systems also contribute to improve power quality indicators. Single-phase full-bridge (1-FB) inverters are used to build two grid-tied inverter configurations. In the first, called as MPV-FB, three 1-FB inverters share the same DC-bus, while in the second, named as MPV-3FB, each of the three 1-FB inverters operates with an individual DC-bus. Each inverter configuration integrates the MPV system architectures with single-stage and double-stage, where in the single-stage configuration the photovoltaic array is directly connected to the inverter DC-bus, whereas in the DS one, a step-up DC-DC converter is inserted between the photovoltaic array and the inverter DC-bus. Under several scenarios of operation, the four MPV systems named as MPV-FB-SS, MPV-FB-DS, MPV-3FB-SS and MPV-3FB-DS, are experimentally tested to compare constructive aspects, evaluate static/dynamic performances and power quality issues, as well as capability to operate with photovoltaic array failure.