A direct current transmission system and its backup reactive power control device

Abstract

A direct current transmission system and a backup reactive control device thereof, the backup reactive control device comprising a reactive control unit and a measurement and control unit. The measurement and control unit is connected to the reactive control unit, is provided with an interface used for detecting the voltage of an alternating current busbar, the on / off state of each alternating current filter, and the voltage and current of the direct current transmission system, and transmitting detected information to the reactive control unit; the reactive control unit is connected to a control interface of the alternating current filter and a station control host, and connected to an interface for acquiring the working state of the station control host; and the reactive control unit is used for transmitting a control command to the control interface of the alternating current filter according to the working state of the station control host, busbar voltage information received from the measurement and control unit and a current power level value. The system may be controlled to exchange reactive power without communicating with a pole control unit. The voltage of the alternating current busbar may be kept stable, and the problem of being able to control the stability of the direct current transmission system when two reactive control hosts are both unavailable is solved.

Description

technical field [0001] The invention belongs to the technical field of reactive power compensation control of a direct current transmission system, and in particular relates to a direct current transmission system and a backup reactive power control device thereof. Background technique [0002] With the continuous operation of DC UHV / EHV projects, the stable operation of the UHV DC transmission system is becoming more and more important to the stable operation of the entire power grid system, which requires the control system to have higher reliability. [0003] At present, there are two main methods of reactive power control in the UHV control system: [0004] The first is the independent configuration of the reactive power control device, that is, the reactive power compensation of the DC system is carried out by using an independently configured reactive power control device; the advantage of this method is that the structure is clear and the control is simple. Whether t...

AI Technical Summary

Problems solved by technology

[0004] The first is the independent configuration of the reactive power control device, that is, the reactive power compensation of the DC system is performed by using an independently configured reactive power control device; the advantage of this method is that the structure is clear and the control is simple. Whether the backup strategy is complete will directly affect the temperature operation of the system;

[0005] The second is to set the reactive power control device in the extreme control system, that is, to issue reactive power control commands through the extreme control system, such as figure 1 As shown; the advantage of this method is that it can avoid the situation that the whole station filter / capacitor cannot be controlled when the bipolar control layer exits, and reduces the risk of system outage when the bipolar layer control exits. The disadvantage is that the design of the system interface is complicated , the control logic is complicated, and the reliability is poor. Once the extreme control layer fails, reactive power compensation cannot be performed

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