Reliability and accelerated life tests of the AC module mounted OKE4 inverter

The quality, reliability and expected lifetime of the AC module inverter OKE4 is discussed. Performance with respect to harmonics, power factor and efficiency, based on laboratory and field tests meets existing standards, both in Europe and the USA. The OKE4 will also meet the Dutch national safety standard. The expected lifetime of AC module inverters is generally questioned as these will be mounted on the back side of the modules, while the cell temperature of thermally isolated PV modules can easily reach 80/spl deg/C. In order to estimate the lifetime, accelerated life tests are currently being executed. To perform these tests, special equipment was developed and the inverter was modified.