Abstract:
In a method for forecasting shadowing of a photovoltaic (PV) system due to cloud formation or movement, part of the firmament is imaged with fisheye optics onto the input optics of a digital camera. Pixel groups associated with luminous intensity ranges are formed. The spatial arrangement of the groups is analyzed to forecast shadowing of a photovoltaic system. A line extending from the PV system to the sun is formed and is continuously tracked. A reference line located inside a region around the line is formed. Passage of clouds across a reference line is analyzed. The result of the analysis is used to increase the electric power from the PV system to a minimum value through supply of additional backup energy or to reduce the electric power consumption by disconnecting users to ensure that key users do not experience a drop in supplied power below a minimum value.
Abstract:
A mounting support for mounting at least one photovoltaic module having a glass pane on a top side of an, in particular, uneven roof panel includes an elongated strip which can be rolled up and/or unrolled in a roll-up/unroll direction. At least two attachment means for the photovoltaic module are disposed on the strip with a modular dimension. The bottom side of the support is provided in the region of the attachment means with a protruding padding to compensate for uneven roof areas. The top side of the attachment means is provided with a supporting location or surface for edges of the photovoltaic module. The mounting support can be packaged as a roll and attached in a simple and effective manner on uneven and rough roof shingles.
Abstract:
A clamp for attaching rectangular photovoltaic modules on a module rail is constructed so that the upper edge of a first module can be installed at a greater height than the lower edge of a second module. The upper edge of the first module rests on a first supporting surface and the lower edge of the second module rests on a second supporting surface, with the both supporting surfaces disposed on a base and having the same slope. The edges of the modules are affixed on the supporting surfaces by way of a bracket (5). The design of the clamp prevents formation of hollow spaces through which melt water can enter, but from which it cannot drain.
Abstract:
A lightweight support includes a corrugated base body having an elongated rectangular configuration defining an upper longitudinal rim and a lower longitudinal rim. The base body is composed of a first layer made of metal, a second layer which is made of rigid foam and applied onto the first layer, and a third layer which is made of metal and applied onto the second layer. Stabilization rails are attached to the base body in order to maintain integrity of the lightweight support when subject to stress. The stabilization rails can hereby be placed on or at or integrated in the upper and lower longitudinal rims, respectively.
Abstract:
A supporting structure for an open-space photovoltaic system with several ground supports arranged in at least two mutually parallel rows oriented in essentially North-South direction and installed vertically in the ground, with beams supported on free ends of the ground supports located at the same location along a row, and with module rails attached to the beams for attachment of fastening means for photovoltaic modules. The module rails are secured on or between two corresponding adjacent beams in essentially North-South direction. The free ends of the ground supports are positioned at the same height above terrain ground, so that the beams and the module rails extend essentially plane-parallel to the terrain ground. This arrangement reduces material consumption, and only a small surface area of the supporting structure is effectively exposed to wind gusts. Each row of ground supports includes ground supports with both rigid and flexible flexural characteristics.
Abstract:
A photovoltaic system having a plurality of photovoltaic modules producing electric energy and method for operating such photovoltaic system are disclosed. With the method, the photovoltaic modules are connected to a first DC motor having a motor shaft, and a generator shaft of a three-phase generator is coupled to the motor shaft. The three-phase generator can be connected to a power grid. The motor shaft of a second DC motor can be connected to the generator shaft, with only one of the two DC motors being initially driven with the electric energy produced by the photovoltaic modules. The electric energy is subsequently divided among both the first and the second DC motor. This process significantly shortens the startup process of the photovoltaic system compared to conventional systems.
Abstract:
An apparatus and a method for preparing connection of a photovoltaic system (Q1) as a first energy source to a power grid (13) by way of a motor generator set (5, 6, 7) is presented. The DC motor (5) is coupled to a three-phase generator (7) by way of a shaft (6), wherein the three-phase generator (7) can be connected to the power grid (13). It has been observed that connecting this type of apparatus to the small or varying power output of the photovoltaic system (Q1) can be difficult and time-consuming. To enable a clean and quick connection, the DC motor (5) is powered with electric DC current from a second DC current source (Q2), wherein the operation of the three-phase generator (7) is matched to the conditions in the power grid (13) with the help of the second DC current source (Q2), and wherein the photovoltaic system (Q1) is connected to the DC motor (5) and the second DC current source (Q2) is disconnected from the DC motor (5) only after a complete match has been attained. This enables a quick and precise connection of the photovoltaic system (Q1) to the power grid (13) with defined parameters using the three-phase generator (7).
Abstract:
A method and an apparatus for carrying out the method are proposed for identifying defective photovoltaic modules. Two clamp-on ammeters are provided which are connected to a test data acquisition unit for simultaneous measurement of two DC currents. The position of the clamp-on ammeters at the time of the measurement is determined with a position registration means, and measured data and position data are transmitted via an antenna to a data processing center or recorded in a data memory element for further processing.
Abstract:
A base frame for a parking lot roof equipped with photovoltaic modules is proposed, wherein two mirror-symmetrically constructed halves are provided, with each half having an inner arc constructed of three inner struts and an outer arc constructed of three outer struts, which are connected with each other by cross struts. The structure is light-weight and can be easily manufactured.
Abstract:
The photovoltaic system includes a plurality of photovoltaic modules which are connected to form a string or several strings connected in parallel, thereby forming a photovoltaic generator having a positive terminal and negative terminal. A DC constant voltage source connected to the photovoltaic generator to raise the potential of the positive terminal relative to ground potential. This reduces the flow of electrons out of the TCO layer of the modules, thereby reducing or completely eliminating cathode discharges which damage the modules.