Abstract: The invention relates to a holding system (1) for mounting a photovoltaic module (6) to a base (8) by means of ground supports (2, 2a, 44, 44a) which comprise a bearing head (4, 4a, 50, 50a), a ground support body (22) and a bearing surface (28, 48) on the bottom side which counteracts a penetration of the ground supports into the base (8), wherein the ground supports (2, 2a, 46, 46a) comprise on their head side a bearing plate (14, 14?, 14a, 14a?, 54, 54?, 54a, 54a?) that is disposed at a slanted angle (?) in relation to the base (8), and wherein the ground supports (2, 2a, 46, 46a) are provided and prepared such that, in the mounted state, the bearing plates (14, 14?, 14a, 14a?, 54, 54?, 54a, 54a?) of a ground support pair (2, 2a, 46, 46a) are spaced apart from each other vertically in relation to the base (8) and from each other horizontally in adjustment to the photovoltaic module (6) and that they are aligned with each other at least in essence.

Abstract: The disclosure relates to a method for operating a photovoltaic system for feeding a medium-voltage grid, wherein the photovoltaic system has a photovoltaic generator including a plurality of photovoltaic modules, at least one inverter and at least one medium-voltage transformer. The medium-voltage transformer is connected on the primary side directly to a low-voltage AC output of the inverter, the inverter is connected to the photovoltaic generator via a DC input, and the inverter permits reverse currents from the low-voltage AC output to the DC input. The method is characterized by the fact that in the event that there is insufficient generation of electric power for the feed by the photovoltaic modules, the inverter remains connected on the AC side to the medium-voltage grid via the medium-voltage transformer, and remains connected on the DC side to the photovoltaic generator.

Abstract: A method for checking the operation of a photovoltaic module of a photovoltaic power station. The module has a positive terminal, a negative terminal and a number of solar cells, in particular thin-layer solar cells. An electric field emitted by the photovoltaic module as a result of solar radiation is measured at an exposed measurement location during the operation of the power station and the electrical voltage present between the positive terminal and the negative terminal is determined from the measured electric field. A corresponding measuring instrument has a sensor to be placed near the photovoltaic module so as to measure the electric field strength. A rod or wand may be used to position the sensor, or a robot may be configured for automatic travel on the photovoltaic module.

Abstract: A photovoltaic system has a plurality of subsystems, each with a photovoltaic generator and an associated inverter. The inverter has a control element for setting the maximum power point of its subsystem. A battery is connectible in parallel with the photovoltaic generator. The inverters are connectible to a power grid, which is operated by a utility operator. When a control device receives an emergency signal from the utility operator indicating impending instability of the grid, the following is initiated: If the battery voltage is above the current voltage as set by the MPP control element, the battery is immediately connected to the input of the inverter while the generator remains connected to the inverter. If the battery voltage is below the current voltage the battery connection is delayed until the MPP control element has adjusted the voltage. Then the voltage is further lowered to generate a discharge current from the battery.

Abstract: A method for operating a photovoltaic system provides, with the turning off of the otherwise adjusted regulation to the maximum power point MPP, to make a selective mismatching at the inverter, in order to cause a battery current, which is added to the system current. As a result, an additional energy source to maintain a minimum feed power is achieved during a rapidly changing cloud pattern.

Abstract: A housing having three side walls and a cover is provided, wherein an opening for introducing a pipe is formed in one of the side walls. The side walls are arranged in a U-shape, with the opening being provided in the side wall forming the first side thereof, and with a pipe section that aligns with the opening being connectable to the second side forming the opposite side wall thereof. The cross-section of the pipe section, in particular its diameter, is larger or smaller than the cross-section of the pipe. As a result, the pipe and the pipe section can be slid one inside the other.

Abstract: During operation of at least one power generator (EE) in a power supply network, a reactive power transfer between the two upper voltage levels (1, 2) is sensed at a first transformer (T1) connecting these levels, and the voltage at a first network connection point (5) at the lowest voltage level (3) is ascertained. The amount of a reactive power demand served by the power generator (EE) is calculated as a function of the ascertained voltage value in order to maintain the voltage ascertained at the lowest voltage level (3) within a predefinable voltage range, wherein a means (WR) of the power generator (EE) is activated for a reactive power draw or a reactive power delivery, based on the calculated reactive power demand.

Abstract: A photovoltaic generator is provided that has at least one string of multiple series-connected photovoltaic modules, each of which has a plurality of series-connected photovoltaic cells. One quarter to one half of all photovoltaic modules of the at least one string can be short-circuited by means of a switch. Activation of the switch takes place when a predefined voltage value across the string is exceeded. The shorting switch is only present in some of the arrays making up the photovoltaic generator, which reduces cabling costs. Because of the parallel connection of the arrays, the voltage of the arrays without shorting switches is drawn down to a lower voltage that is safe for the inverter.

Abstract: A photovoltaic system having a photovoltaic generator, whose strings with series-connected photovoltaic modules have a positive pole and a negative pole, and with an inverter whose DC input is connected to the two poles. The voltage of the positive pole and/or of the negative pole is measured with respect to ground, and a first switching element located between the positive pole and the DC input of the inverter and/or a second switching element located between the negative pole and the DC input of the inverter is opened, while a third switching element located between the positive pole and the negative pole is closed, when the voltage of the positive pole or of the negative pole exceeds a predefined first or second limit value.

Abstract: A photovoltaic system comprises a plurality of photovoltaic modules which are electrically connected to a string or to multiple parallel-connected strings and form a PV generator. The first string end forms the negative pole of the photovoltaic generator, and the second string end forms the positive pole. A voltage reduction device is provided with the aid of which the potential of the negative pole is lowered to ground. Advantages with regard to the insulation class of the connecting cable used are also provided.

Abstract: A method and a device for carrying out the method are disclosed in order to aid in the search for faulty photovoltaic modules. In a photovoltaic system comprising multiple PV units electrically connected in parallel, each PV unit is assigned its own fixed current sensor. Furthermore, each PV unit can be removed from the parallel circuit by a switching device.

Abstract: A measuring method for determining an output drop of a PV unit is provided. The PV unit is arranged within a photovoltaic system comprising a plurality of electrically parallel-connected PV units. Each PV unit can be removed from the parallel circuit by a switching device. Further, a total current measuring device for measuring the total current through all PV units of the parallel circuit is provided. The defective PV unit is determined in an evaluation unit by the connection and disconnection of a disconnect switch.

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 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: 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: A method for operating a photovoltaic system with a plurality of photovoltaic modules and with a DC motor connected to the photovoltaic modules is proposed. The motor shaft of the DC motor is coupled to a generator shaft of a three-phase generator, wherein the three-phase generator can be connected to a power grid. The motor shaft of a second DC motor can also be connected with the generator shaft, and the electric energy produced by the photovoltaic modules is initially only used for driving a single DC motor and is during the subsequent operation divided between those DC motors. A battery is provided which can be connected with the second DC motor instead of the PV system by changing the excitation of the second DC motor such that it's motor voltage corresponds to the open-circuit voltage of the battery.

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.

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.

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.