Abstract: A photovoltaic power plant (25, 32, 33, 34, 35) comprising one or more photovoltaic devices (27), each device comprising at least two terminals (30, 31) wherein one or more of the terminals (30, 31) is connected to a switch (12, 13) which is in turn connected to a point (10, 15, 16) held at a voltage relative to ground (11) and at least one switch (12, 13) is controlled in response to one or more parameters, and a method of controlling such a power plant (25, 32, 33, 34, 35).

Abstract: In large PV power plants, grounding of individual PV modules may lead to problems. The present invention overcomes such problems. The basis for the invention is a PV power plant comprising one or more PV generators, each comprising a PV string and an inverter with a DC input and an AC output. The PV string comprises at least one PV module and is electrically connected to the DC input of the inverter. The inverter comprises means for controlling the DC potential at the DC input depending on the DC potential at the AC output. The AC outputs of the inverters are coupled in parallel. The novel feature of the invention is that the PV power plant further comprises an offset voltage source, which controls the DC potential at the AC outputs. Thereby, the DC potential at the DC input will be indirectly controlled, and it is thus possible to ensure that the potentials with respect to ground at the terminals of the PV modules are all non-negative or all non-positive without grounding the PV modules.

Abstract: A photovoltaic power plant (25, 32, 33, 34, 35) comprising one or more photovoltaic devices (27), each device comprising at least two terminals (30, 31) wherein one or more of the terminals (30, 31) is connected to a switch (12, 13) which is in turn connected to a point (10, 15, 16) held at a voltage relative to ground (11) and at least one switch (12, 13) is controlled in response to one or more parameters, and a method of controlling such a power plant (25, 32, 33, 34, 35).

Abstract: The invention relates to an arrangement having at least one electric potential-varying device for varying the electric potential of at least one electrical device with respect to earth potential, and a plant room facility. In the operating state, the electric potential-varying device is disposed in the plant room facility.

Abstract: In large PV power plants, grounding of individual PV modules may lead to problems. The present invention overcomes such problems. The basis for the invention is a PV power plant comprising one or more PV generators, each comprising a PV string and an inverter with a DC input and an AC output. The PV string comprises at least one PV module and is electrically connected to the DC input of the inverter. The inverter comprises means for controlling the DC potential at the DC input depending on the DC potential at the AC output. The AC outputs of the inverters are coupled in parallel. The novel feature of the invention is that the PV power plant further comprises an offset voltage source, which controls the DC potential at the AC outputs. Thereby, the DC potential at the DC input will be indirectly controlled, and it is thus possible to ensure that the potentials with respect to ground at the terminals of the PV modules are all non-negative or all non-positive without grounding the PV modules.

Abstract: The invention relates to a method for determining the type of connection of at least two electric devices (5) whereby each device comprises a similar connector arrangement. The aim of the invention is to increase the reliability during the starting up process and during the operation of a system which comprises several electric units (5). According to the invention, a first device (5) modifies the voltage on the connector arrangement (11) and the modified voltage is determined as a first voltage, such that a second device (5) determines a second voltage on at least the connector arrangement (11) and determines whether an electric connection exists or not between the connector arrangements (11) of the devices (5) by comparing the determined comparison of the voltages.

Abstract: The invention relates to a method for determining the type of connection of at least two electric devices (5) whereby each device comprises a similar connector arrangement. The aim of the invention is to increase the reliability during the starting up process and during the operation of a system which comprises several electric units (5). According to the invention, a first device (5) modifies the voltage on the connector arrangement (11) and the modified voltage is determined as a first voltage, such that a second device (5) determines a second voltage on at least the connector arrangement (11) and determines whether an electric connection exists or not between the connector arrangements (11) of the devices (5) by comparing the determined comparison of the voltages.

Abstract: The invention relates to a method for determining the type of connection of at least two electric devices (5) whereby each device comprises a similar connector arrangement. The aim of the invention is to increase the reliability during the starting up process and during the operation of a system which comprises several electric units (5). According to the invention, a first device (5) modifies the voltage on the connector arrangement (11) and the modified voltage is determined as a first voltage, such that a second device (5) determines a second voltage on at least the connector arrangement (11) and determines whether an electric connection exists or not between the connector arrangements (11) of the devices (5) by comparing the determined comparison of the voltages.

Abstract: An apparatus for cooling carcass parts (1) comprises at least one cooling element (8, 9) with a flexible cooling surface (14) for abutment with a carcass part (1); a form-stable shell (15); and a cavity (17) behind the flexible cooling surface (14), through which cavity refrigerant can flow from an inlet to an outlet. The apparatus also comprises a moving device (13) for moving the cooling element (9) for abutment of the cooling surface (14) with the carcass part (1).

Abstract: A power converter for converting energy from a green power unit as e.g. a solar cell into energy fed into the commercial grid is described. The object is to provide a versatile modularized power converter with eased access to control of the power switches. Another object is to improve the electrical efficiency. This is achieved by using an independent controller on a DC/DC module and an independent controller on a DC/AC module, whereby the the two independent controllers communicate with each other and the outside world by means of a communication bus. Further, the DC/DC module of the power converter comprises a transformer which transfers energy from the DC/DC module to the DC/AC module. This design enables independent control of the modules and eases controllability of the power switches in order to suppress retroaction from pulsations generated on the mains when supplying energy to a single phase grid. Hereby the electrical efficiency of the power converter is increased.

Abstract: For independent load sharing of current harmonics between parallel inverter units (1a, 1b, 1c) in an AC power system without intra-unit control signal communication, where each inverter unit is connected to a common load (8) through a separate impedance (7a, 7b , 7c), amplitude and phase of a selected current harmonic is determined for each unit by processing of a current value M measured in a power output line (51a, 51b, 51c) from the unit before the separate impedance and is compared with amplitude and phase of a feed-back voltage or current (V) from the power output line to produce an error signal, which is used for determination of a control signal component for the selected harmonic for incorporation into a control signal input to control means for controlling the content of said harmonic in the voltage and/or current supplied by the inverter unit (1a, 1b, 1c) to the common load (8).

Abstract: For independent load sharing of current harmonics between parallel inverter units (1a, 1b, 1c) in an AC power system without intra-unit control signal communication, where each inverter unit is connected to a common load (8) through a separate impedance (7a, 7b, 7c), amplitude and phase of a selected current harmonic is determined for each unit by processing of a current value M measured in a power output line (51a, 51b, 51c) from the unit before the separate impedance and is compared with amplitude and phase of a feed-back voltage or current (V) from the power output line to produce an error signal, which is used for determination of a control signal component for the selected harmonic for incorporation into a control signal input to control means for controlling the content of said harmonic in the voltage and/or current supplied by the inverter unit (1a, 1b, 1c) to the common load (8).

Abstract: A method of heat treatment of products advanced through a chamber by circulation through the chamber of hot, humid air that is evacuated, is supplied with humidity and heat and then blown back to the chamber, includes the step of supplying heat and humidity to the air by atomization into the circulating air of excess water of a temperature higher than that intended in the chamber. An apparatus for carrying out the method includes a chamber comprising one or more subunits, through which subunit(s) the products to be thermally treated are passed, a fan which on its draught side is connected with the subunit for exhaustion of the humid air and on its delivery side with a flow passage for blowback of the humid air to the subunit, and a water atomizer for water of a higher temperature than that desired in the scalding chamber. The method provides for obtaining a stable heat treatment at varying load and actions of heat and cold.

Abstract: In large PV power plants, grounding of individual PV modules may lead to problems. The present invention overcomes such problems. The basis for the invention is a PV power plant comprising one or more PV generators, each comprising a PV string and an inverter with a DC input and an AC output. The PV string comprises at least one PV module and is electrically connected to the DC input of the inverter. The inverter comprises means for controlling the DC potential at the DC input depending on the DC potential at the AC output. The AC outputs of the inverters are coupled in parallel. The novel feature of the invention is that the PV power plant further comprises an offset voltage source, which controls the DC potential at the AC outputs. Thereby, the DC potential at the DC input will be indirectly controlled, and it is thus possible to ensure that the potentials with respect to ground at the terminals of the PV modules are all non-negative or all non-positive without grounding the PV modules.