Abstract:
The invention relates to a photovoltaic system for generating an output voltage which is essentially uninfluenced by varying irradiation, the photovoltaic system comprising a photovoltaic source (1) having an input terminal (2) and an output terminal (3). The photovoltaic system is characterized in that the photovoltaic system comprises a voltage adding arrangement (4) comprising a first input terminal (5) and an output terminal (6), the voltage adding arrangement (4) is connected in series with the photovoltaic source (1), and in that a first route (7) comprising a voltage source (9) and a second route (8) constituting a voltage source bypass extend between said first input terminal (5) and said output terminal (6) of the voltage adding arrangement (4), said first and second routes being alternately activateable.
Abstract:
It is presented a power converter for transferring power between a first high voltage DC connection being a voltage stiff DC connection, a second high voltage DC connection being a current stiff DC connection and a high voltage AC connection. The power converter comprises a power converter assembly comprising: a first voltage source converter, a first current source converter, and a second voltage source converter, connected serially in the mentioned order between a positive terminal and a negative terminal of the first high voltage DC connection; and a plurality of transformers connected on one side to the high voltage AC connection and on a second side to respective AC sides of converters. The positive terminal of the second high voltage DC connection is connected on to a point between the first current source converter and the first voltage source converter, and the negative terminal of the second high voltage DC connection is connected to a point between the first current source converter and the second voltage source converter.
Abstract:
It is presented a DC/DC/AC power converter. The power converter comprises a power converter assembly comprising: a first voltage source converter and a second voltage source converter connected serially between a positive terminal and a negative terminal of the first high voltage DC connection, wherein respective AC sides of the voltage source converters are connected to a common AC bus; a DC blocking device between the AC side of at all but one of the voltage source converters and the AC bus; and a phase shift device between the AC side of the second voltage source converter and the AC side of the first voltage source converter. The terminals of the second high voltage DC connection are connected on either side of the second voltage source converter; and the AC connection is connected to the AC bus.
Abstract:
An electric power plant comprises a solar energy park (10), a DC line (12) connecting the park to a DC/AC converter (13) and an alternating voltage network (15) connected to the latter. An energy storing assembly (16) is connected to the DC line (12) in parallel with the solar energy park (10). An arrangement (18) collects information about operation parameters of the plant and a control unit (19) controls flow of electric power within the plant based on information from this arrangement.
Abstract:
The invention relates to a photovoltaic system for generating an output voltage which is essentially uninfluenced by varying irradiation, the photovoltaic system comprising at least one photovoltaic unit (1) comp- rising two photovoltaic sources (2, 2'), each comprising an input terminal (3, 3') and an output terminal (4, 4'). The invention is characterized in that the photovoltaic unit (1) comprises two voltage adding arrangements (5, 5'), each having a first route (13) comprising a voltage source (15) and a second route (14) constituting a voltage source bypass, the first voltage adding arrangement (5) is connected in series with the first photovoltaic source (2) and the second voltage adding arrangement (5') is connected in series with the second photovoltaic source (2'), and a switch (12) is arranged between an input terminal (3) of the first photovoltaic source (2) and an output terminal (4') of the second photovoltaic source (2'), and in addition the input terminals (8, 10) of the photovoltaic unit (1) constituting the external interface of the photovoltaic system are interconnected and the output terminals (9, 11) of the photovoltaic unit (1) constituting the external interface of the photovoltaic system are interconnected.
Abstract:
The invention relates to a photovoltaic system for generating an output voltage which is essentially uninfluenced by varying irradiation, the photovoltaic system comprising at least one photovoltaic unit (1) comp- rising two photovoltaic sources (2, 2'), each comprising an input terminal (3, 3') and an output terminal (4, 4'). The invention is characterized in that the photovoltaic unit (1) comprises two voltage adding arrangements (5, 5'), each having a first route (13) comprising a voltage source (15) and a second route (14) constituting a voltage source bypass, the first voltage adding arrangement (5) is connected in series with the first photovoltaic source (2) and the second voltage adding arrangement (5') is connected in series with the second photovoltaic source (2'), and a switch (12) is arranged between an input terminal (3) of the first photovoltaic source (2) and an output terminal (4') of the second photovoltaic source (2'), and in addition the input terminals (8, 10) of the photovoltaic unit (1) constituting the external interface of the photovoltaic system are interconnected and the output terminals (9, 11) of the photovoltaic unit (1) constituting the external interface of the photovoltaic system are interconnected.
Abstract:
It is presented a power converter for converting power between a first high voltage direct current, DC, connection, a second high voltage DC connection and a high voltage alternating current, AC, connection. The power converter comprises: a first phase arrangement comprising a first converter arm, a second converter arm, a third converter arm, a fourth converter arm, a fifth converter arm and a sixth converter arm. The first, second third and fourth converter arms are serially connected in the mentioned order between two terminals of the first high voltage DC connection. The high voltage AC connection is connected between the second converter arm and the third converter arm.
Abstract:
It is presented a high voltage DC/DC converter for converting between a first DC connection and a second DC connection. The high voltage DC/DC converter comprises: a first set of DC terminals; a second set of DC terminals); a multiphase transformer device comprising a plurality of primary windings and a corresponding plurality of secondary windings; a first converter arranged to convert DC to AC, comprising a plurality of phase legs serially connected between the first set of DC terminals, wherein each phase leg is connected to an AC connection of a respective primary winding; and a second converter arranged to convert AC from the secondary windings to DC on the second set of DC terminals.
Abstract:
An electric plant with a capacity to charge electric batteries is a plant for transmitting electric power comprising a Voltage Source Converter (1), an alternating voltage network (14) connecting an alternating voltage side of the converter and a direct voltage part (7) connected to the direct voltage side of the converter. The converter (1) has a series connection of switching cells (8) having each at least one energy storing capacitor. Electric batteries may be connected in parallel with said capacitor, and the charging state thereof may be influenced by controlling the switching cells of the Voltage Source Converter through a control arrangement (15).
Abstract:
An arrangement for protecting a solid-state dc-breaker during a fault condition causing a voltage transient across the dc-breaker, wherein the arrangement comprises a first and a second varistor arranged in parallel with the dc-breaker, the first varistor is adapted to minimise the voltage transient created across the dc-breaker and the second varistor is adapted to minimise a leakage current through the arrangement when the dc-breaker has been turned off, and the arrangement comprises a switch arrangement configured to connect and disconnect the first or second varistor such that the first varistor is connected at least during the voltage transient and the second varistor is connected at least when the voltage across the dc-breaker has decreased below a threshold value.