Reactive power adjustment device and method based on coordination of flexible DC and high-voltage parallel capacitors

Abstract

The invention relates to a reactive power adjustment device and a method based on match between flexible DC and high-voltage shunt capacitors. Multiple high-voltage shunt capacitor groups and a flexible DC transmission system are connected onto the same AC bus, and a dispatching center calculates reactive power compensation capacity Q according to comparison among the actual voltage level U of the AC bus, the actual reactive power output Q0 of a converter station and standard voltage; whether the reactive power compensation capacity Q is larger than the maximum reactive power compensation capacity Qm of a single high-voltage shunt capacitor group is judged, and if not, the total reactive power for the capacity Qset of the single shunt capacitor group is provided by the flexible DC converter station, or otherwise, the remaining needed reactive power compensation capacity Qvsc2 is provided by the flexible DC converter station. In the case of switching actions, the flexible DC converter station switches all reactive power compensation capacity, the self reactive power output is gradually reduced to Q-(a*Qset) along with switching of the shunt capacitor groups, the over voltage level of a capacitor is reduced significantly, and the active power loss of the device is reduced.

Description

technical field [0001] The invention relates to devices and methods in the field of flexible direct current transmission, in particular to a reactive power adjustment device and method based on the cooperation of flexible direct current and high-voltage parallel capacitors. Background technique [0002] Parallel capacitors are widely used in modern power systems. To improve the power factor of the power grid in the form of parallel capacitor compensation, and strive to achieve local balance of reactive power, reduce line losses, and improve voltage quality, is currently the main technology adopted by power grids in various countries. means. In terms of reactive power balance, high-voltage shunt capacitors play a dominant role, whether for the entire grid or for a local area. Usually, the compensation capacity of the high-voltage shunt capacitors installed in the entire power grid is much larger than the total capacity of the power grid generators. Many substations in my co...

AI Technical Summary

Problems solved by technology

Therefore, the study of the mutual cooperation method between the flexible DC converter and the high-voltage shunt capacitor has important application value for reducing the voltage stress of the equipment and improving the service life, and the flexible DC converter station is matched with the shunt capacitor used on the adjacent AC bus It is not yet mature to complete the switching operation

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