Ultrahigh-voltage direct-current transmission project converter transformer alternating-current loop system on-site inspection method

Abstract

Disclosed is an ultrahigh-voltage direct-current (DC) transmission project converter transformer alternating-current (AC) loop system on-site inspection method. The method is implemented on a converter transformer after installation and commissioning test, and a converter valve is installed and is always in a locked state. An AC 500kV GIS is removed temporarily to a drainage line of the converter transformer, a test converter transformer T is connected, a test voltage is applied to the AC network side of the converter transformer through the converter transformer T, the valve-side windings of a Y / Y converter transformer and a Y / Delta converter transformer are grounded, and whether there is a loop defect from the primary wiring to the secondary loop of the converter transformer is judged by detecting the amplitudes and phases of the primary test current, primary test voltage, secondary current and secondary voltage. The design, construction and commissioning quality of a converter transformer AC loop system can be detected comprehensively, and the level of safe and stable operation of DC transmission can be improved.

Description

technical field [0001] The invention relates to the technical field of ultra-high voltage direct current transmission. Background technique [0002] In the ultra-high voltage direct current transmission system, the converter transformer and the converter valve together realize the mutual conversion between alternating current and direct current, which is the core equipment in the ultra-high voltage direct current transmission system. The basis for the safe and stable operation of the DC transmission system, the correctness of the design and construction of the AC circuit will directly determine the stability and safety of the DC transmission. [0003] First of all, the converter transformer is located at the core of the mutual conversion of AC and DC voltages. There are not only the first bushing and the last bushing, but also the star-shaped connection head bushing and the end bushing on the valve side, and the angular connection first bushing on the valve side. End bushin...

AI Technical Summary

Problems solved by technology

One-time installation and wiring is complicated, and its correctness lacks effective verification

[0006] Based on the core position and importance of the converter transformer in the HVDC transmission system, coupled with the complexity of the primary and secondary installation and wiring of the AC loop system, only according to the existing technology and based on personal experience, through the loop wiring check, local Tests and other methods have made it difficult to find defects such as open circuit of AC circuit, short circuit of voltage circuit, reversed polarity, wrong transformation ratio, wrong bus, etc., which may lead to interruption or delay of the operation of the converter transformer during the process of putting into operation, and even equipment failure. damage or system failure

Images