变压器式可控电抗器(CRT)各绕组的电流与其各个控制绕组晶闸管的触发次序及触发角大小关系密切.在根据各个控制绕组触发角的大小规定触发次序后,采用分段线性化的方法,建立了用自、互电感表示的电路方程,通过求解电路方程,得出所有绕组电流瞬时值在任意时段上的矩阵表达式.通过傅里叶分解求得所有绕组基波电流的傅里叶系数与各个控制绕组晶闸管触发角之间的非线性函数关系式的矩阵形式,进而得到其基波电流有效值.分析和算例结果说明,所给出的CRT绕组电流计算公式适用于CRT的所有工作方式;控制绕组逐级短路的工作方式只是一个特例.
The current of CRT (Controllable Reactor of Transformer type) winding is closely related to me switching sequence and firing angle of its controlling thyristor. The thyristor switching sequence is determined according to the thyristor firing angles and the circuit equations expressed with self-inductance and mutual-inductance are established by the subsection linearization method,which are solved to obtain the matrix expression of instantaneous winding currents for an arbitrary period. Fourier decomposition is applied to obtain the matrix forms of nonlinear function relationships between the Fourier coefficients of fundamental winding current and the thyristor firing angle and then the RMS of fundamental winding current. The results of analysis and case study indicate that,the given formulas for CRT winding current calculation can be applied to all CRT working modes while the working mode of sequential control winding short-circuit is merely a special case.