Tajikistan Micro Grid-connected Inverter

A high-level block diagram of a grid-connected solar microinverter system is shown in Figure 4. The term, “microinverter”, refers to a solar PV system comprised of a single low-power inverter module for each PV panel.

The term, “microinverter”, refers to a solar PV system comprised of a single low-power inverter module for each PV panel. These systems are becoming more and more popular as they reduce overall installation costs, improve safety and better maximize the solar energy harvest. Other advantages of a solar microinverter system include:

The Solar Microinverter Reference Design is a single stage, grid-connected, solar PV microinverter. This means that the DC power from the solar panel is converted directly to a rectified AC signal. This con-version is done by an interleaved flyback converter.

When the grid is removed, the microinverter will see the local load. In the event that the local load resonates near the operating frequency before the grid was removed, the microinverter will see a small change in active and reactive power, and will not be able to detect that the grid has shut down.

There are two main requirements for solar inverter systems: harvest available energy from the PV panel and inject a sinusoidal current into the grid in phase with the grid voltage. In order to harvest the energy out of the PV panel, a Maximum Power Point Tracking (MPPT) algorithm is required.

Islanding is the continued operation of the inverter when the grid has been removed intentionally, by acci-dent or by damage. In other words, if the grid has been removed from the microinverter, then the microinverter should stop supplying power to the grid. All anti-islanding methods can be categorized as being passive or active.