Impact of inverter failure on photovoltaic power generation

After the photovoltaic system is installed, the user is most concerned about the power generation, because it is directly related to the user's return on investment. Among them, the inverter is an important part that cannot be ignored.

The power switching tubes used in the inverters currently on the market include IGBT, MOSFET, etc., which are the most vulnerable components of the inverter. They have three fears: one is overvoltage. A tube with a withstand voltage of 600V will explode in less than 0.1 second if the voltage at both ends exceeds 600V; the second is overcurrent. A tube with a rated current of 50A will explode in less than 0.2 seconds if the current passing through it is greater than 50A; the third is overtemperature. The IGBT junction temperature is generally 150 degrees or 175 degrees, and it is generally controlled below 120 degrees. Heat dissipation design is one of the most critical technologies of the inverter.

When installing the inverter, it is necessary to consider leaving a heat dissipation channel for the inverter. In addition, if the power grid has too high harmonics and too frequent voltage mutations, it will also cause overvoltage damage to the power devices.

The LCD screen of the inverter can display various indicators such as the instantaneous power, power generation, input voltage, etc. of the photovoltaic power station. If it can display the cause of the fault, it will be a very useful component.

Most inverters have displays, but some do not. In addition to the above advantages, LCDs have a fatal flaw - short service life. An average quality LCD will be severely degraded and unusable after working for 30,000-40,000 hours. We calculate based on the inverter working time of 6:00-20:00, and the LCD works 14 hours a day, which is 5,000 hours a year. Assuming the life of the LCD is 40,000 hours, its service life is 8 years.

Nowadays, household inverters generally retain displays, and it is a trend for medium and large power string inverters used in power stations to be without LCD screens.

As an electronic product, photovoltaic inverters have certain limitations in use. Attention should be paid to design and installation. When transporting and installing the inverter, it should be handled with care to avoid loose joints inside. Temperature has a great impact on the life of the main components of the inverter. The inverter should be installed in a ventilated and heat-dissipating place away from direct sunlight. Attention should be paid to matching the components and the inverter. The inverter should not work at full load for a long time. The inverter should not be installed in a power grid environment with too high harmonics. This can significantly reduce the probability of inverter failure and extend its service life.