Design standards for grid-connected inverters for communication base stations

Grid-connected PV inverters have traditionally been thought as active power sources with an emphasis on maximizing power extraction from the PV modules. While maximizing power transfer remains a top priority, utility grid stability is now widely acknowledged to benefit from several auxiliary services that grid-connected PV inverters may offer.

It covers grid integration standards for renewable energy, such as interconnection requirements and related grid compliance tests. It also includes standards or documents sharing best practices for planning, modeling, forecasting, assessment, control and protection, scheduling and dispatching of renewables, with a grid level perspective.

We propose a passivity-based control strategy to enhance the stability and dynamic performance of grid-forming multi-inverter power stations and address these challenges. The inner loop designed from the perspective of energy reshaping, ensures the stability of the inverter's output.

This work provides a feasible solution for enhancing inverter stability in power stations, contributing to the reliable integration of renewable energy. Existing grid-connected inverters encounter stability issues when facing nonlinear changes in the grid, and current solutions struggle to manage complex grid environments effectively.

In Ref., the current needs in modern Grid codes of different nations are compared, debated, and assessed to satisfy the significant photovoltaic power plant integration. Usually, standards allows the use of devices for system protection from dangerous conditions, such as unwanted islanding.

In the grid-connected inverter, the associated well-known variations can be classified in the unknown changing loads, distribution network uncertainties, and variations on the demanded reactive and active powers of the connected grid.