How Does a Grid Tie Inverter Work?

The grid-connected inverter is a special kind of inverter, a grid-tie inverter is a solar inverter that works without batteries.

In addition to converting DC to AC, its output AC can also be synchronized with the frequency and phase of the mains, so the output AC can be returned to the mains. Grid-tie inverters are often used in applications where some DC voltage source, such as solar panels or small wind turbines, is connected to the grid.

What is the principle of grid inverter?

Inverters convert DC power to AC power for transmission back to the grid. The frequency of the output voltage of the grid-connected inverter should be the same as the frequency of the grid (50 or 60Hz), which is generally realized by the internal oscillator, and the output voltage should also be limited not to exceed the grid voltage. 

The power factor of a modern high-quality grid-connected inverter is 1, that is, its output voltage is in the same phase as the current, and the phase difference with the grid voltage is within 1 degree. There is a microprocessor in the inverter, which can sense the AC waveform of the grid, and generate voltage to feed back to the grid according to this waveform. However, the power sent back to the grid requires a certain proportion of reactive power so that the power of the nearby grid is within the allowable range. 

Otherwise, if a regional grid has a high proportion of renewable energy, its voltage may rise too high during times of high power output (such as midday).

If the grid fails, the grid-connected inverter needs to be disconnected from the grid quickly. This is a regulation of the National Electric Code (NEC) in the United States to ensure that grid-connected inverters will not supply power to the grid when the grid is out of power, and workers who repair the grid will not be electrocuted.

When properly configured, grid-tie inverters can allow a home to run on its own alternative energy source (such as solar or wind power) without complicated wiring and batteries. If the alternative energy source is insufficient, the insufficient part is still powered by the grid.

What is the difference between MPPT solar inverter and hybrid solar inverter?

1. Hybrid Solar Inverter
Hybrid solar inverter refers to grid-connected and off-grid solar inverter in one machine, there is also a solar charge controller inside solar hybrid parallel and off-grid inverter. This parallel off-grid inverter can use both off-grid and grid-connected types.

2. Hybrid mppt solar inverter
Hybrid mppt solar inverters can be configured with batteries for energy storage. In this solar power generation system, solar energy can be used to charge the battery and supply power to the load. When there is excess solar energy, the energy can be fed to the grid to generate income.