METHOD AND APPARATUS FOR CONTROLLING HYBRID DIRECT-CURRENT TRANSMISSION SYSTEM

    公开(公告)号:EP3407455A1

    公开(公告)日:2018-11-28

    申请号:EP17762406.1

    申请日:2017-01-19

    IPC分类号: H02J3/36

    CPC分类号: H02J3/36 Y02E60/60

    摘要: A method and apparatus for controlling a hybrid direct-current (DC) transmission system. The method comprises: adjusting the total number of inserted sub-modules of a modular multi-level converter and the polarity of an output level of the inserted sub-modules in real time, according to a DC voltage of a rectifier station at other end; or adjusting the total number of inserted sub-modules of a modular multi-level converter and the polarity of an output level of the inserted sub-modules in real time, according to the magnitude of a DC current or DC power; or adjusting the total number of inserted sub-modules of a modular multi-level converter and the polarity of an output level of the inserted sub-modules in real time, according to both the magnitude of the DC current and the DC voltage of the rectifier station at the other end. The method can effectively control the DC voltage and the direct current of a hybrid DC transmission system, avoiding the power transmitting breakdown.

    METHOD AND APPARATUS FOR HANDLING DIRECT-CURRENT SIDE LINE FAULT OF VOLTAGE SOURCE CONVERTER

    公开(公告)号:EP4290721A1

    公开(公告)日:2023-12-13

    申请号:EP22749146.1

    申请日:2022-01-29

    IPC分类号: H02H7/26 H02J3/36

    摘要: The invention provide a method and device for handling a DC-side line fault of a voltage source converter, wherein the voltage source converter is arranged at a rectifier end or an inverter end of any DC pole of a DC transmission system, and the rectifier end and the inverter end are connected through a DC line. The fault handling method comprises: acquiring a normal value of a DC voltage reference value of the voltage source converter; setting a DC current limiting target value of the voltage source converter; acquiring a DC current limiting control output value based on a DC current measured value and the DC current limiting target value; setting a DC voltage reference value of the voltage source converter based on the normal value of the DC voltage reference value and the DC current limiting control output value; setting the DC current limiting target value to be zero when a DC side line fault is detected; and rising the DC voltage reference value of the voltage source converter in response to end of de-ionization, and changing the DC current limit target value of the voltage source converter.

    METHOD AND APPARATUS FOR SUPPRESSING IMPACT OF COMPENSATOR ON LINE DISTANCE PROTECTION

    公开(公告)号:EP3618212A1

    公开(公告)日:2020-03-04

    申请号:EP18806444.8

    申请日:2018-05-22

    IPC分类号: H02H7/26

    摘要: A method and apparatus for suppressing the impact of a compensator on line distance protection is provided, wherein the method comprises: obtaining a first current of a line connected to a compensator or series converters in the compensator, and a first voltage of a bus connected to the compensator or the line connected to the compensator; exiting the series converters and series transformers if the first current is greater than a preset current threshold and a duration is greater than a first preset time threshold; exiting the series converters and the series transformers if the first voltage is less than or equal to a preset voltage threshold and duration is greater than a second preset time threshold set the output voltage of the series converters to zero, and if a second current of an element corresponding to the first current meets conditions which the first current needs to meet; and otherwise, canceling the setting of the output voltage of the series converters to zero and obtaining a first current if a second voltage of the line corresponding to the first voltage is greater than the preset voltage threshold and the duration is greater than a third preset time threshold.

    VOLTAGE AND CURRENT CONTROL METHOD AND DEVICE FOR DIRECT-CURRENT POWER TRANSMISSION SYSTEM

    公开(公告)号:EP3681006A1

    公开(公告)日:2020-07-15

    申请号:EP18885604.1

    申请日:2018-11-28

    IPC分类号: H02J3/36

    摘要: Disclosed in the present invention is a voltage and current control method for a direct-current transmission system. The method comprises: calculating a DC voltage reference value of a voltage source converter of a DC voltage control end, on the basis whether a direct-current voltage end of a direct-current pole of a direct-current transmission system substantially controls a direct-current voltage; using 1/2 of the calculated direct-current voltage reference value of the voltage source converter as a bridge arm voltage direct-current bias, calculating a difference between the direct-current voltage reference value of the voltage source converter and a measured direct-current voltage value, and inputting the difference into a direct-current voltage control outer loop of the voltage source converter to perform closed-loop control, so as to control the direct-current voltage or the direct current of the direct-current pole. Correspondingly, also provided is a voltage and current control device for the direct-current transmission system. By the means of the present invention, the direct-current voltage and the direct current of the direct-current transmission system provided with the voltage source converter can be effectively controlled.

    METHOD AND SYSTEM FOR FAULT POSITIONING AND RECOVERY OF VOLTAGE SOURCE CONVERTER

    公开(公告)号:EP3419138A1

    公开(公告)日:2018-12-26

    申请号:EP17792434.7

    申请日:2017-04-25

    IPC分类号: H02J3/36 H02H7/26 H02H3/06

    摘要: The present invention relates to a method and system for fault positioning and recovery of a voltage source converter. The method comprises: locking a converter station when it is detected that an alternating-current voltage contains a zero sequence voltage or a direct-current voltage contains an unbalanced voltage; positioning a fault by continuing to detect the zero sequence voltage of an alternating-current side of the converter; and recovering the operation of each station after the fault is positioned. The method for fault positioning and recovery is simple and practical, has high reliability and can effectively detect the problems that each station contains a zero sequence voltage of an alternating-current side and cannot easily position a fault caused due to the fact that the zero sequence voltage of the alternating-current side is transmitted by a voltage source converter to an opposite-side alternating-current system; meanwhile, by means of the recovery method, a non-faulty converter station can get rid of the influences of a faulty converter station for rapid recovery, rapid recovery based on a voltage source converter station system is implemented, and the application of a transformerless wiring method in the voltage source converter can be promoted, thereby finally achieving that the occupied space of a converter station is reduced, losses are reduced, and manufacture costs are reduced.