What Is A Micro Inverter?

What is a Microinverter?

PV microinverters generally refer to inverters in PV power generation systems with a power of less than 4000 watts and with module-level MPPT, the full name is micro PV grid-connected inverter.

Working principle of micro inverter:

1.DC input: the dc energy generated by the photovoltaic panels is transmitted to the microinverter through a cable.

2.Maximum Power Point Tracking (MPPT): Microinverters usually contain a maximum power point tracker, which monitors the output voltage and current of the PV panels to ensure that the maximum possible power is extracted from the PV panels.

3.Inverting: The microinverter converts DC power into AC power. In this process, it needs to adjust the output voltage and frequency to match the standard voltage and frequency of the home or commercial grid.

4.Synchronisation and grid connection: The microinverter must ensure that the AC power generated is synchronised with the grid and automatically stops working for safety in the event of unstable grid voltage or power failure.

In contrast to the traditional centralised inverter, the microinverter inverts each module. The advantage is that each module can be independently controlled by MPPT, which can significantly improve the overall efficiency, and also avoid the DC high voltage, poor weak light effect, and barrel effect that centralised inverters have.

The combination of micro-inverter and communication function can be used to monitor the status of each module and detect the module that is faulty. When one of the panels does not work well in a PV power plant applying micro-inverters, only that one will be affected. All other photovoltaic panels will be operating at their optimal working condition, making the overall system more efficient and generating more power.

According to the grid connection method, there are grid-connected microinverters and off-grid microinverters.

According to the output voltage, there are single-phase microinverse and three-phase microinverse.

Advantages of microinverters:

1.Safety

Traditional centralised inverters or string inverters usually have DC voltages of hundreds or thousands of volts, which are easy to catch fire and not easy to extinguish after fire. Micro inverter only tens of volts of DC voltage, all in parallel, to minimise the potential safety hazards.

2.Intelligent

Component-level monitoring, you can see the working status of each component in the ECU.

3.High efficiency, more power generation

Component-level MPPT, no barrel effect, reducing the impact of shading on power generation;

Good low light effect, because the starting voltage is low, only 20V, and it can work when the light is weak.

4.Long life

Usually the design life of micro inverse is 12-25 years.

5.Convenient and beautiful

There is no need to build a special power distribution room, the micro-reverse can be installed directly behind the module or on the stand, because it is a parallel structure, later increase the scale can be installed directly, without changing the previous configuration.