Hierarchical coordination voltage control method and system for hybrid multi-infeed AC/DC hybrid system

Abstract

The invention provides a hierarchical coordination voltage control method and system for a hybrid multi-infeed AC / DC hybrid system. The method comprises the following steps: 1, calculating the track sensitivity of each bus voltage and the voltage sensitivity of each control quantity to a direct-current feed-in bus; 2, judging whether system-level control and converter station-level control are started or not; 3, calculating the reactive power margin of the generator based on the wide-area measurement data, and determining whether the system-level participation coordination control quantity comprises a converter station-level control quantity or not; 4, optimizing and solving a corresponding optimal control sequence of voltage stability coordination control; 5, judging whether the control quantities in the two-stage optimal control sequences of the system and the converter station conflict or not, if yes, selecting the control quantities according to a coordination control rule for application, detecting whether the load bus voltage meets a preset requirement or not after application, and if yes, exiting coordination control; otherwise, repeating the steps 1-5 until the voltage of the load bus meets the preset requirement. And the medium-and-long-term voltage stability of the system can be improved.

Description

technical field [0001] The invention belongs to the field of smart grids, and in particular relates to a method and system for hierarchically coordinated voltage control of a hybrid multi-infeed AC / DC hybrid system. Background technique [0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art. [0003] Due to the reverse distribution of energy centers and loads in my country, conventional direct current has been fully developed due to its advantages of long-distance and large-capacity power transmission. Flexible DC has the characteristics of decoupling regulation of active and reactive power, and no risk of commutation failure. It is suitable for new energy grid connection and interconnection of regional power grids, and has been developed rapidly. With the increase of high-voltage DC lines, flexible DC (VSC-HVDC) and conventional DC (LCC-HVDC) are fed into the same AC busbar ...

AI Technical Summary

Problems solved by technology

This move is not necessarily suitable for medium and long-term voltage problems. Keeping the arc extinguishing angle unchanged ensures the success of conventional DC commutation, but it does not control the entire system voltage optimally.

(2) In the existing medium and long-term voltage instability control scheme, there is a lack of coordinated control between AC and DC systems, and the control characteristics of DC cannot be fully utilized, which reduces the medium and long-term voltage stability of the system

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