How Long Is the Lifespan of a PV Inverter?

Photovoltaic inverters are composed of structural parts, circuit boards, power devices (IGBT or MOS tubes), capacitors, inductors and transformers, current sensors, liquid crystal displays and fans. The service life of a photovoltaic inverter follows the "cask principle", that is, its service life is determined by the device with the shortest service life.

In photovoltaic inverters, the short board of life is electrolytic capacitors. There is electrolyte in the electrolytic capacitor. Over time, the electrolyte may evaporate and dry out, resulting in an increase in the equivalent series impedance of the electrolytic capacitor. Under the same current, a higher ESR will cause the capacitor to heat up, thereby It further aggravating the evaporation of the electrolyte, forming a vicious cycle that eventually leads to device failure.

The life of the power device is the basis of the life of the photovoltaic inverter, so what other factors will affect the life of the inverter?

1. Temperature. For every 10°C increase in temperature, the life of the electrolytic capacitor is reduced by half, and the high temperature will also accelerate the optical decay of the optocoupler, and the failure of the optocoupler will cause damage to the IGBT.

2. The inverter's own protection function and EMC. Poor inverter protection function and EMC design will easily be interfered by the outside world. If the IGBT drive interferes, it will easily lead to its misdirection and cause the machine to explode.

3. Installation environment. Photovoltaic inverters installed in an environment with direct sunlight, humidity, and acid/alkali pH will shorten their lifespan.

As long as the components are selected correctly and the design is good, the photovoltaic inverter can run stably for at least 10 years.