变压器式可控电抗器CRT(Controliable Reactor of Transformer Type)应用于牵引供电系统中进行无功补偿时会向牵引网流入谐波电流,其大小与CRT各个控制绕组的触发角密切相关.在定义了触发角向量、触发次序及多绕组调节模式等概念的基础上,采用分段线性化方法,得出多绕组调节模式下CRT工作绕组电流在任意时段的瞬时表达式的计算公式;利用傅里叶级数分析方法求得工作绕组电流各次谐波分量傅里叶系数与触发角向量之间的函数关系式,进而得到各次谐波分量有效值的计算公式.分析和算例结果说明,本文得出的多绕组调节模式下CRT谐波电流计算公式是正确的,并更具一般性.本文工作拓展了CRT谐波电流的分析办法,为CRT谐波优化等控制策略的设计奠定了理论基础.
Harmonic current will flow into traction network when controllable reactor of transformer type (CRT) is applied to compensating reactive power for traction power system, the size of which is closely related to the triggered angle of each thyristor connected with control winding of CRT. Based on the definition of the vector of triggered angles, switching sequence and multi-winding regulating mode, the instantaneous expression of working winding current during arbitrary period in the multi-winding regulating mode was obtained by means of the method of subsection linearization. The analysis method of Fourier series was used to acquire the matrix form of function relationships between Fourier coefficients of harmonic components of working winding current and the vector of triggered angles, based on which, the formula for calculating the RMS of each harmonic component was acquired. The results of the analyses and examples showed the correctness of the proposed formulas for calculating the harmonic currents of CRT in multi-winding regulating mode in this paper, which can be used in more general cases. This paper expands the analysis methods of harmonic currents for CRT, and lays a theoretical foundation for the design of control strategies of CRT such as harmonic optimization.