| 摘要 |
An inverter includes a first switch to disconnect an output of the inverter from any device connected thereto, a second switch to disconnect and connect an input of the inverter from direct current fed to the inverter, and a discharge device to discharge any residual charge on a large capacitor. The inverter further includes a voltage sensor to measure input DC voltage to the inverter, a current sensor to measure input DC current to the inverter and a data recorder to provide a current voltage trace to provide a current-voltage curve tracer to provide current-voltage properties of the solar array to which the inverter is attached. The inverter is capable of reproducibly operating at the same point on a module IV curve for a given set of temperature and irradiance conditions. By coupling a temperature sensor to the inverter, photovoltaic module temperature can be measured and combined with the data from the input DC current and voltage sensors and information on the photovoltaic module operating characteristics to compute solar plane-of-array irradiance. Also described is a method for ascertaining photovoltaic module temperature by combining irradiance data, input DC current and voltage measurements and the knowledge that the inverter is operating at a known point on an IV curve. The inverter also includes AC current and voltage sensors for computing inverter output total harmonic distortion.
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