What are the factors that affect the life of inverter?

Inverter belongs to switching power supply in a broad sense, so its components can be basically divided into resistors, capacitors, diodes, power devices (IGBT or MOS tubes), inductors and transformers, current sensors, IC, optocouplers, relays and so on.

The service life of resistors, patch capacitors and ceramic capacitors can generally reach more than 20 years. When designing inductors and transformers, it is theoretically believed that they can work for a long time without failure as long as the temperature of their materials is not exceeded. Low-power diodes and triodes can basically work for more than 654.38+ 10,000 hours; The mechanical life of relay is generally above 6.5438+0.0000 times, and the electrical life is above 6.5438+0.00000 times. As long as the power device IGBT or MOS meets the design specifications, the service life is generally not considered. Fans and fuses are vulnerable parts, which will not affect the life of the inverter. If it is broken, it only needs to be replaced in time. The service life of thin film capacitors is over 65,438+million hours, and that of electrolytic capacitors is generally 2,000-3,000 h at 105℃, and only 5,000-6,000 h, but the service life of electrolytic capacitors doubles with the decrease of temperature. Therefore, in the inverter, the biggest short board of the device is the life of the electrolytic capacitor.

2. Design factors

The life of devices is the basic factor to ensure the life of inverters, but excellent design is the core factor to ensure the life of inverters. So which design factors will seriously affect the life of the inverter and are difficult to detect in a short time?

Temperature is one of the important factors that affect the life of inverter, especially electrolytic capacitors, optocouplers and other components. When the temperature rises by 65438 00℃, the life of electrolytic capacitor will be reduced by half. If the temperature is too high, the optical attenuation of the optical coupler will also be accelerated. However, IGBT is usually driven by optocoupler, so the failure of optocoupler will lead to IGBT damage.

When the relay is switched at zero current, its service life reaches 6.5438 0 million times. However, with the increase of current during switching, its service life decreases almost exponentially. Accurate software control makes relay switch at zero current angle, which is the key factor to ensure its service life.

The working environment of inverter is generally harsh, and there are many interference factors, such as poor power grid quality and large local inductive load. If the inverter protection function and EMC design are not good, it will be vulnerable to external interference. Once the IGBT power is disturbed, it will easily lead to its misleading and explosion.

3. Comprehensive factors

Although this series of inverters are IP65 protection grade and can be installed indoors and outdoors, the installation environment has a great influence on the life of inverters. If the inverter is installed in an environment with direct sunlight, high humidity and high pH value, the life of the inverter will be shortened, and it will easily lead to over-temperature and load reduction of the inverter in the exposed environment, thus affecting power generation. Therefore, choosing a suitable installation environment is also a key factor to ensure the life of the inverter.

Summary: Although there are many factors that affect the life of the inverter, as long as the components are selected correctly and designed well, the inverter can run stably for at least 10 years, so it is recommended to choose the first-line brand inverter at home and abroad to escort your power station.