摘要:
In a plant for transmitting electric power between two stations (17, 18) through a direct voltage network (16) for High Voltage Direct Current an arrangement (23) is arranged for draining electric power from the direct voltage network. The arrangement has a valve (24) made of bidirectionally controlled thyristors (BCT) with ability to conduct current in both directions therethrough. The plant has also a unit (25) adapted to control the thyristors of the valve so that the current direction between the direct voltage network and the valve is such that electric power is fed from the direct voltage network to an alternating voltage network- connected to the valve independently of the power feeding direction between said two stations (17, 18).
摘要:
A land electrode for a high voltage direct current transmission system including a converter station with a grounding point. The land electrode is connected to the grounding point and includes a plurality of electrode sections. A line electrode includes a part interconnecting two electrode sections. The part of the line electrode exhibits a line resistance. Each electrode section includes at least one electrode element.
摘要:
A return path between a first HVDC station and a second HVDC station. A first electrode is connected to the first station and a second electrode is connected to the second station. The return path includes a first part including a first low resistive zone through the crust of the earth in which the first electrode is embedded. A second part includes the earth mantle. A third part includes a second low resistive zone through the crust of the earth in which the second electrode is embedded.
摘要:
A device in a valve on high voltage potential level and in a high voltage converter station comprises members arranged on high voltage level and adapted to detect parameters of a voltage divider circuit consisting of resistances (24, 25) and capacitors (27, 28) connected in series and across each thyristor of said valve. The capacitors are of self-healing type, in which from the point of time for occurring of a possible fault thereof the capacitance is gradually reduced, and said members are adapted to carry out measurements so as to determine whether the capacitance of the capacitors is changed over the time.
摘要:
A device for supervising the cooling of a cooling system of a valve of a high voltage converter station located on high voltage potential level comprises members (31) located on high voltage potential level and adapted to detect the temperature at cooling blocks (32) of the valve on high voltage potential level and send values so detected to first control units (3) for controlling semiconductor components (4) of the valve. The first control units have means (20) for treating said values detected and the first control units are adapted to send data resulting from said treatment to an arrangement (16) for supervising said valve located on low potential level.
摘要:
A return path between a first HVDC station and a second HVDC station. A first electrode is connected to the first station and a second electrode is connected to the second station. The return path includes a first part including a first low resistive zone through the crust of the earth in which the first electrode is embedded. A second part includes the earth mantle. A third part includes a second low resistive zone through the crust of the earth in which the second electrode is embedded.
摘要:
A HVDC transmission system including at one end of a bipolar HVDC transmission line a converter station for connecting the transmission line to an AC system. The station has two converters and a DC neutral arrangement in common to the converters. The DC neutral arrangement has a separate electrode line connecting member connecting to electrode lines. The electrode lines are dimensioned to be able to at monopolar operation of the converter station transmit substantially full current to an electrode station through the remaining one or ones of the electrode lines at disconnection of an arbitrary of the electrode lines.
摘要:
A land electrode for a high voltage direct current transmission system including a converter station with a grounding point. The land electrode is connected to the grounding point and includes a plurality of electrode sections. Each electrode section includes at least one electrode element.