摘要:
The present invention relates to an AC/DC converter station for interconnection of a DC transmission line and an AC network, the AC/DC converter station including an AC/DC converter and a control system configured to control the AC/DC converter. The AC/DC converter station comprises a capacitor connected in series between the AC/DC converter and the AC network, and a voltage measurement device arranged to measure the voltage across the capacitor. The AC/DC converter further comprises a control system connected to the voltage measurement device and arranged to receive, from the voltage measurement device, a signal indicative of a measured voltage. The control system is arranged to perform the control of the AC/DC converter in dependence of the signal received from the voltage measurement device. The invention further relates to a method of operating an AC/DC converter station.
摘要:
A Voltage Source Converter having at least one phase leg connected to opposite poles of a direct voltage side of the converter and comprising a series connection of switching cells has an arrangement configured to apply a pressure to opposite ends of stacks of semiconductor assemblies for pressing the assemblies towards each other so as to obtain electric contact between semiconductor assemblies in said stack while ensuring that the semiconductor assemblies of a first path of each switching cell of the converter go into a permanently closed circuit state in case of a failure of the respective switching cell. A second path of each switching cell has means configured to keep said second path including an energy storing capacitor non-conducting upon occurrence of a said failure.
摘要:
An apparatus for controlling the electric power transmission in a high voltage direct current, HVDC, power transmission system includes at least one HVDC transmission line for carrying direct current, DC. The apparatus includes a first converter for converting alternating current, AC, to direct current and/or direct current to alternating current, and a second converter for converting direct current to alternating current and/or alternating current to direct current, each of the first and second converters having an AC side for output and/or input of alternating current and a DC side for output and/or input of direct current. The first converter is connectable via its DC side to the HVDC transmission line, the AC side of the second converter is connected to the AC side of the first converter, and the second converter is connectable via its DC side to a DC source. The apparatus is adapted to control the direct current of the HVDC transmission line by introducing a DC voltage in series with the HVDC transmission line. A HVDC power transmission system includes the above-mentioned apparatus.
摘要:
The present invention relates to an AC/DC converter comprising at least two phase legs connected in series between first and second DC connection terminals of the AC/DC converter, wherein each phase leg comprises: an AC connection having first and second terminals arranged to connect the phase leg to a phase of an AC system; a phase branch comprising at least one converter cell and having first and second branch end terminals; and a capacitor. The capacitor is connected the between the first branch end terminal and the first AC connection terminal, so that the capacitor forms a DC blocking capacitor. The second AC terminal is connected to the second branch end terminal. The series connection of the phase legs between first and second DC connection terminal is such that a first series connection point in a phase leg is located between the first branch end terminal and the capacitor, while a second series connection point is located between the second branch end terminal and the second AC connection. The invention further relates to a method of operating such AC/DC converter.
摘要:
A method, voltage source converter and computer program product for limiting the current in a DC power transmission system are disclosed. The voltage source converter has an AC side and a DC side and a fault current path between these sides. It furthermore includes a control unit and at least one switching unit of a first type provided in the fault current path and that includes a primary switching element together with an anti-parallel secondary controllable rectifying element. Based on a fault being detected in the DC power system when the primary switching elements of the converter are blocked, the control unit changes the control of the controllable rectifying element from acting as a non-controllable rectifying to acting as a controllable rectifying element.
摘要:
The present invention relates to an AC/DC converter comprising at least two phase legs connected in series between first and second DC connection terminals of the AC/DC converter, wherein each phase leg comprises: an AC connection having first and second terminals arranged to connect the phase leg to a phase of an AC system; a phase branch comprising at least one converter cell and having first and second branch end terminals; and a capacitor. The capacitor is connected the between the first branch end terminal and the first AC connection terminal, so that the capacitor forms a DC blocking capacitor. The second AC terminal is connected to the second branch end terminal. The series connection of the phase legs between first and second DC connection terminal is such that a first series connection point in a phase leg is located between the first branch end terminal and the capacitor, while a second series connection point is located between the second branch end terminal and the second AC connection. The invention further relates to a method of operating such AC/DC converter.
摘要:
A Voltage Source Converter having at least one phase leg connected to opposite poles of a direct voltage side of the converter and including a series connection of switching cells has an arrangement configured to apply a pressure to opposite ends of stacks of semiconductor assemblies for pressing the assemblies towards each other so as to obtain electric contact between semiconductor assemblies in the stack while ensuring that the semiconductor assemblies of a first path of each switching cell of the converter go into a permanently closed circuit state in case of a failure of the respective switching cell. A second path of each switching cell has a member configured to keep the second path including an energy storing capacitor non-conducting upon occurrence of the failure.
摘要:
The present invention relates to an AC/DC converter station for interconnection of a DC transmission line and an AC network, the AC/DC converter station including an AC/DC converter and a control system configured to control the AC/DC converter. The AC/DC converter station comprises a capacitor connected in series between the AC/DC converter and the AC network, and a voltage measurement device arranged to measure the voltage across the capacitor. The AC/DC converter further comprises a control system connected to the voltage measurement device and arranged to receive, from the voltage measurement device, a signal indicative of a measured voltage. The control system is arranged to perform the control of the AC/DC converter in dependence of the signal received from the voltage measurement device. The invention further relates to a method of operating an AC/DC converter station.
摘要:
A method, voltage source converter and computer program product for limiting the current in a DC power transmission system are disclosed. The voltage source converter has an AC side and a DC side and a fault current path between these sides. It furthermore includes a control unit and at least one switching unit of a first type provided in the fault current path and that includes a primary switching element together with an anti-parallel secondary controllable rectifying element. Based on a fault being detected in the DC power system when the primary switching elements of the converter are blocked, the control unit changes the control of the controllable rectifying element from acting as a non-controllable rectifying to acting as a controllable rectifying element.