Impact analysis of tap switch out of step for converter transformer

3rd International Conference on Advances in Energy, Environment and Chemical Engineering

能源学;生态环境科学;化学工业

Hong-Yue, Zhang^1 ; Zhen-Hua, Zhang^1 ; Zhang-Xue, Xiong^1 ; Gao-Wang, Y.U.^1

XJ Group Limited by Share Ltd, Xuchang

461000, China^1

关键词: Converter station;    Converter transformers;    Differential protection;    Economic operations;    Harmonic components;    Normal operations;    Over-excitation protection;    Quality of power supply;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/69/1/012200/pdf
DOI  :  10.1088/1755-1315/69/1/012200

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

AC transformer load regulation is mainly used to adjust the load side voltage level, improve the quality of power supply, the voltage range is relatively narrow. In DC system, converter transformer is the core equipment of AC and DC power converter and inverter. converter transformer tap adjustment can maintain the normal operation of the converter in small angle range control, the absorption of reactive power, economic operation, valve less stress, valve damping circuit loss, AC / DC harmonic component is also smaller. In this way, the tap switch action is more frequent, and a large range of the tap switch adjustment is required. Converter transformer with a more load voltage regulation switch, the voltage regulation range of the switch is generally 20∼30%, the adjustment of each file is 1%∼2%. Recently it is often found that the tap switch of Converter Transformers is out of step in Converter station. In this paper, it is analyzed in detail the impact of tap switch out of step for differential protection, overexcitation protection and zero sequence over current protection. Analysis results show that: the tap switch out of step has no effect on the differential protection and the overexcitation protection including the tap switch. But the tap switch out of step has effect on zero sequence overcurrent protection of out of step star-angle converter transformer. The zero sequence overcurrent protection will trip when the tap switch out of step is greater than 3 for out of step star-angle converter transformer.