Abstract: A temperature-controlled solar power inverter is described herein. The solar power inverter includes multiple components (for example, a power transistor, a control board, or a heat sink). The temperature of a component may rise due to heat generated by the component or heat absorbed from other components. The solar power inverter also includes a temperature sensor configured to measure a temperature at a location proximate to the component and a cooling device configured to cool the component. The solar power inverter also includes a controller coupled to the temperature sensor and the cooling device. The controller is programmed to receive the temperature from the temperature sensor and control the cooling device based upon the temperature and a temperature setpoint of the component. The temperature setpoint is based upon 1) a component initial temperature, 2) a temperature excursion limit of the component, and 3) an absolute temperature limit of the component.

Abstract: A system and method for operating a photovoltaic element at or near a maximum power point. A maximum power point tracker changes a voltage or current set point of a photovoltaic element in sequential discrete steps, measuring an output power at each step after a predetermined settling time. A slope of a power-voltage curve is then estimated and the slope is corrected for irradiance changes. Finally, an operating voltage or current of the photovoltaic element is adjusted based on the slope of the power-voltage curve and other factors, causing the photovoltaic element to operate at or near its maximum power.

Abstract: A cabinet for a solar power inverter is described. A solar power inverter receives DC current from a solar panel and transforms the DC current into AC current. To cool the inverter equipment, an air inlet receives ambient air drawn into the cabinet by an air pressurizer. The ambient air is urged into a pressurized air plenum, from which two ports channel the air into at least two air paths to flow over the equipment in the cabinet. The equipment in the cabinet is arranged such that the air passes over more heat-sensitive equipment before reaching less heat-sensitive equipment. The equipment in the cabinet can be separated by grounded, metal walls to contain and diminish electromagnetic interference. The equipment may be accessed from a single, front side of the cabinet.

Abstract: A system and method for operating a photovoltaic element at or near a maximum power point. A maximum power point tracker changes a voltage or current set point of a photovoltaic element in sequential discrete steps, measuring an output power at each step after a predetermined settling time. A slope of a power-voltage curve is then estimated and the slope is corrected for irradiance changes. Finally, an operating voltage or current of the photovoltaic element is adjusted based on the slope of the power-voltage curve and other factors, causing the photovoltaic element to operate at or near its maximum power.

Abstract: A solar power forecasting system can provide forecasts of solar power output by photovoltaic plants over multiple time frames. A first time frame may be several hours from the time of the forecast, which can allow utility personnel sufficient time to make decisions to counteract a forecasted shortfall in solar power output. For example, the utility personnel can decide to increase power production and/or to purchase additional power to make up for any forecasted shortfall in solar power output. A second time frame can be several minutes from the time of the forecast, which can allow for operations to mitigate effects of a forecasted shortfall in solar power output. Such mitigation operations can include directing an energy management system to shed noncritical loads and/or ramping down the power produced by the photovoltaic plants at a rate that is acceptable to the utility to which the photovoltaic plants provide power.

Abstract: A solar power forecasting system can provide forecasts of solar power output by photovoltaic plants over multiple time frames. A first time frame may be several hours from the time of the forecast, which can allow utility personnel sufficient time to make decisions to counteract a forecasted shortfall in solar power output. For example, the utility personnel can decide to increase power production and/or to purchase additional power to make up for any forecasted shortfall in solar power output. A second time frame can be several minutes from the time of the forecast, which can allow for operations to mitigate effects of a forecasted shortfall in solar power output. Such mitigation operations can include directing an energy management system to shed noncritical loads and/or ramping down the power produced by the photovoltaic plants at a rate that is acceptable to the utility to which the photovoltaic plants provide power.

Abstract: A system and method for operating a photovoltaic element at or near a maximum power point. A maximum power point tracker changes a voltage or current set point of a photovoltaic element in sequential discrete steps, measuring an output power at each step after a predetermined settling time. A slope of a power-voltage curve is then estimated and the slope is corrected for irradiance changes. Finally, an operating voltage or current of the photovoltaic element is adjusted based on the slope of the power-voltage curve and other factors, causing the photovoltaic element to operate at or near its maximum power.

Abstract: A temperature-controlled solar power inverter is described herein. The solar power inverter includes multiple components (for example, a power transistor, a control board, or a heat sink). The temperature of a component may rise due to heat generated by the component or heat absorbed from other components. The solar power inverter also includes a temperature sensor configured to measure a temperature at a location proximate to the component and a cooling device configured to cool the component. The solar power inverter also includes a controller coupled to the temperature sensor and the cooling device. The controller is programmed to receive the temperature from the temperature sensor and control the cooling device based upon the temperature and a temperature setpoint of the component. The temperature setpoint is based upon 1) a component initial temperature, 2) a temperature excursion limit of the component, and 3) an absolute temperature limit of the component.

Abstract: A cabinet for a solar power inverter is described. A solar power inverter receives DC current from a solar panel and transforms the DC current into AC current. To cool the inverter equipment, an air inlet receives ambient air drawn into the cabinet by an air pressurizer. The ambient air is urged into a pressurized air plenum, from which two ports channel the air into at least two air paths to flow over the equipment in the cabinet. The equipment in the cabinet is arranged such that the air passes over more heat-sensitive equipment before reaching less heat-sensitive equipment. The equipment in the cabinet can be separated by grounded, metal walls to contain and diminish electromagnetic interference. The equipment may be accessed from a single, front side of the cabinet.

Abstract: A system and method for operating a photovoltaic element at or near a maximum power point. A maximum power point tracker changes a voltage or current set point of a photovoltaic element in sequential discrete steps, measuring an output power at each step after a predetermined settling time. A slope of a power-voltage curve is then estimated and the slope is corrected for irradiance changes. Finally, an operating voltage or current of the photovoltaic element is adjusted based on the slope of the power-voltage curve and other factors, causing the photovoltaic element to operate at or near its maximum power.

Abstract: A method and apparatus uses photoluminescence to identify defects in one or more specified material layers of a sample. One or more filtering elements are used to filter out predetermined wavelengths of return light emitted from a sample. The predetermined wavelengths are selected such that only return light emitted from one or more specified material layers of the sample is detected. Additionally or alternatively, the wavelength of incident light directed into the sample may be selected to penetrate the sample to a given depth, or to excite only one or more selected material layers in the sample. Accordingly, defect data characteristic of primarily only the one or more specified material layers is generated.

Abstract: A method for using photoluminescence to identify defects in a sub-surface region of a sample includes performing a first probe of the sample. A first data set, based on the first probe, is produced indicating defects located primarily in a surface layer of the sample. A second data set, based on a second probe, is produced indicating defects located in both the surface layer and a sub-surface region of the sample. The first data set is subtracted from the second data set to produce a third data set indicating defects located primarily in the sub-surface region of the sample. The first data set may optionally be normalized relative to the second data set before performing the subtraction. The first and second probes may advantageously be performed using a first laser and a second laser, respectively, having different wavelengths from each other.