A self-excited starting system and method for a static synchronous series compensator

Abstract

The invention relates to a self-excitation starting system and a self-excitation starting method for a static synchronous series compensator. The system comprises a first circuit breaker which is mounted on an alternating-current bus of an external alternating-current system, a winding on one side of a transformer is parallelly connected to two sides of the first circuit breaker through an alternating-current side switch, and a winding on the other side of the transformer is parallelly connected to two sides of a bypass thyristor. The bypass thyristor is parallelly connected to two sides of a second circuit breaker which is connected with a filter, and the filter is connected with a series converter which is connected with a controller. According to the technical scheme, a cascaded H-Bridge multi-level structure based SSSC (static synchronous series compensator) system mathematic model is derived, single-phase phase-locked loops and novel two-stage direct-current voltage stabilizing strategies are designed, and a starting process of the static synchronous series compensator meets system requirements on stability and quickness in starting.

Description

technical field [0001] The invention relates to the technical field of flexible AC power transmission, in particular to a self-excited starting system and method for a static synchronous series compensator. Background technique [0002] In recent years, the rapid development of my country's economy, the rapid growth of electricity load, and the increasingly complex grid structure have brought about problems such as uneven distribution of power flows, limited transmission capacity, and reduced power quality. The introduction of the Static Synchronous Series Compensator (SSSC) in the new FACTS device improves the controllability of the power flow and voltage of the system on the basis of ensuring the transmission capacity. At this time, the multiple structure has the disadvantages of bulky size, difficult design and high cost, and this structure is often not considered in engineering. The cascaded multi-level structure is easy to package and modularize, and is arranged on the...

AI Technical Summary

Problems solved by technology

[0003] At this stage, some static synchronous series compensators are started by separate excitation methods that rely on external power sources; some are combined with parallel equipment, and the startup of the series part can rely on the startup method of capacitor power supply on the parallel side; some directly provide external voltage sources on the DC side , ignoring the self-starting method; some start-up directly depends on the AC line difference, consider a single H-bridge module, ignore the cascade voltage equalization problem, and its self-excited start-up depends on the AC line, the reaction speed and starting voltage are limited

These start-up schemes have the disadvantages of large investment, inapplicability to engineering practice, and limitations in control strategy and compensation capacity

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