Cascade STATCOM-based outer loop voltage control method and device

Abstract

The embodiment of the invention discloses a cascade STATCOM-based outer loop voltage control method and device. An outer loop calculation control link of double closed loop compound control for a cascade STATCOM is simplified through removing integral operation links of an interphase voltage-sharing link and an in-phase voltage-sharing link in an outer loop voltage PI control method, and technicalproblems that a proportional-integral controller (PI) controller has inadequate resistance to external disturbance, and the capacitor voltage oscillation phenomenon and system instability are easy tooccur due to the facts that the PI controller is usually adopted for traditional outer loop voltage control and relatively multiple integration links are included, especially a low transient responsespeed of an existing three-phase cascade STATCOM system is caused by the in-phase voltage-sharing link and the interphase voltage-sharing link and does not meet the actual engineering requirements are solved.

Description

technical field [0001] The invention relates to the field of power systems, in particular to an outer loop voltage control method and device based on a chained STATCOM. Background technique [0002] STATCOM, STATic synchronous COMPensator, is a kind of power equipment used in power system for reactive power compensation and comprehensive power quality management. Chained STATCOM means that the main circuit topology of STATCOM adopts single-phase full-bridge circuit (2H bridge) connected in series or in parallel. [0003] With the increasing demand for fast dynamic reactive power compensation, in the field of medium and high voltage power transmission and distribution, the chained STATCOM based on the modular series-parallel structure is characterized by high direct connection voltage, fast response speed, wide compensation range, and excellent transient characteristics. It has been widely used in fields such as wind farms, traditional direct current transmission, and compre...

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Problems solved by technology

[0005] The present invention provides a chain-type STATCOM-based outer-loop voltage control method and device, which are used to solve the problem that the traditional voltage outer-loop control mostly uses a proportional-integral (PI) controller, and there are many integral links, so that the controller is not sensitive to the outside world. Insufficient disturbance resistance, capacitive voltage oscillation and system instability are prone to occur, especially the intra-phase voltage equalization and inter-phase voltage equalization rings, resulting in the slow transient response speed of the existing three-phase chained STATCOM system, which does not conform to actual engineering Asked technical questions

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