What Are the Factors That Affect Solar Inverter Lifespan?
The solar inverter, as the core of the power generation system, directly affects the operation of the entire power station, and its service life has become a major concern for everyone. What are the factors that directly affect the service life of solar inverters?
Solar inverters theoretically belong to switching power supplies, so their components can mostly be divided into resistors, capacitors, diodes, power devices (IGBT or MOS tubes), inductors and transformers, current sensors, ICs, optocouplers, relays, etc. Resistors, surface-mount capacitors, and ceramic capacitors can usually last for more than 20 years. Inductors and transformers, as long as they do not exceed the ambient temperature of the raw materials used in their design, can theoretically operate for a long time without being ineffective. Small-power diodes and transistor bases can run for more than 100,000 hours. The mechanical life of relays is usually more than one million times, and the electrical life exceeds 10,000 times. Power devices IGBT or MOS is usually not considered in terms of their service life as long as they meet the design specifications.
Component life is the basic element that ensures the service life of the inverter, but the quality design is the core element that ensures the service life of the inverter. What design elements will seriously affect the service life of solar inverters and be difficult to detect in the short term?
The ambient temperature is one of the main factors that directly affect the service life of the inverter, especially for components such as electrolytic capacitors and optocouplers. For every 10°C increase in temperature, the service life of the electrolytic capacitor is reduced by half. High temperatures can also accelerate the light loss of optocouplers. However, IGBT drives usually use optocouplers, so ineffective optocouplers can cause IGBT damage.
Relays have a lifespan of one million times when switching zero current, but their lifespan is almost exponentially reduced with the increase of current during switching. Accurate software control is the main factor that ensures the relay life when switching in the zero-current direction.
The environment for solar inverters is usually harsh, with many influencing factors such as poor grid quality and large local inductive loads. If the protection function and EMC design of the inverter are not good enough, it is very likely to be affected externally. Once the IGBT drive is affected, it is easy to cause false triggering and machine failure.
Although some solar inverters can reach an IP65 protection level and can be installed indoors and outdoors, the installation environment still has a relatively large impact on the service life of the inverter. If the solar inverter is installed in an environment where there is strong sunlight, high humidity, and high acidity and alkalinity, it will reduce the service life of the inverter. At the same time, it is easy to cause inverter overheating and load shedding in the environment of direct sunlight, thus directly affecting power generation. Therefore, choosing a suitable installation environment is also a main factor that ensures the service life of the solar inverter.