摘要:
A plant for transmitting electric power through HVDC comprises two converter stations interconnected by a bipolar direct voltage network and each connected to an alternating voltage network. Each converter station has a Voltage Source Converter with switching cells each including at least one energy storing capacitor. The Voltage Source Converters are configured to utilize a direct voltage having a higher magnitude for a first of the poles than for a second thereof with respect to ground.
摘要:
An apparatus for tapping electric energy from an HVDC power transmission system includes at least one voltage source converter. The apparatus includes an intermediate ac network containing the voltage source converter, and a switching arrangement for disconnecting the intermediate ac network in dependence on the transmission direction of the HVDC power transmission system.
摘要:
A modular HVDC converter system including a high voltage direct current network, and at least two DC/AC converters being connected in series to the HVDC network. Each of the DC/AC converters is arranged to provide AC to a separate AC load.
摘要:
A device for supervising different positions of a valve of a high voltage converter station located on a high voltage potential level comprises members arranged on a high voltage potential level and adapted to detect function parameters of the valve on a high voltage potential level and send values detected thereby to first control units for controlling the semiconductor components of the valve. The first control units have devices for processing the detected values and the first control units are adapted to utilize light conductors running back therefrom to a valve control unit for sending data resulting from the processing to an arrangement for supervising the valve located on a low potential level.
摘要:
A plant for transmitting electric power is provided. The plant has a direct voltage network connected to at least one alternating voltage network through a station. The station transmits electric power between the direct voltage network and the alternative voltage network and has at least one converter for converting direct voltage to alternating voltage and for converting alternating voltage to direct voltage. The plant comprises a DC/DC converter connected between the poles of the direct voltage network. The DC/DC converter is adapted to create a higher voltage between the poles on the station remote side of the DC/DC converter than on the station near side.
摘要:
In a thyristor valve having a plurality of series-connected thyristors, each thyristor has an individual recovery protection device arranged in its entirety at the potential of the thyristor. For each thyristor, the protection device comprises a voltage-sensing member whch indicates the point of time when the thyristor takes up reverse blocking voltage. A time-determining member defines a certain time interval, counting from said point of time. Control members are arranged to deliver a control pulse for firing the thyristor if the off-state voltage of the thyristor during the time interval exceeds a predetermined value.
摘要:
A semiconductor power module includes at least two sub modules. The sub modules include at least one respective transistor having a collector, an emitter, and a gate. The module includes a connection arrangement having a collector terminal unit for connecting the collectors of the at least two sub modules collectively to external circuit components, at least two emitter terminal units for connecting the respective emitters of the at least two sub modules individually to external circuit components, and at least two gate terminal units for connecting the respective gates of the at least two sub modules individually to external circuit components.
摘要:
A rail structure related to a track of a system adapted for electrically driving a vehicle along a roadway. The vehicle is provided with a current collector which is displaceable up and down and sideways in relation to the direction of transportation, in order to be brought into mechanical and electrical contact with elongated tracks positioned below the roadway and comprising a conductor adapted to be supplied with current and put under voltage. The rail structure comprises one or more tracks oriented parallel with external wall sections made of metal, and a partition separating the external wall sections and comprising an intermediate wall made of an electrically conductive material. Conductors are arranged in a lower portion of the tracks, respectively. The tracks comprise electrically insulating layers applied to surface portions facing each other of said wall sections and the partition, the insulating layers being coordinated with the lower portions and intended to support the conductors.
摘要:
A plant for transmitting electric power includes a direct voltage network (100) and at least one three-phase alternating voltage network (101) connected thereto through a station (102). This station includes a Voltage Source Converter (103). A unit (104) is configured to control the converter according to a PWM pattern for generating an alternating voltage having a third harmonic voltage part added to a fundamental voltage part. No transformer is arranged between phase outputs (106) of the converter and the alternating voltage network (101). An arrangement (107) is configured to block the third harmonic voltage part and prevent it from reaching the alternating voltage network.
摘要:
An apparatus for protecting equipment connected to a high voltage direct current line comprises a current valve having at least one semiconductor device and a rectifying member connected in anti-parallel therewith. A surge arrester is configured to connect said current valve to said line, and a control unit is configured to control the current valve to conduct for draining current from the line to ground.