In this thesis , the author analyses the deficiency in detecting and controlling function of the computer detecting and controlling system utilized in present transforming station . the strategy of design of software on operation and direction of 5 00kv transformer station is presented . it points out that we can deduce the mathematic analytical formula using the current , voltage and power of two terminals of transmission line as input . on this basis , we do realtime calculation of 500kv transmission line ' s parameter . we can also deduce the linear analytical formula of three - winding autotransformer ' s resistence using its current , voltage and power as input . the corresponding software is programmed on this basis 论文提出以输电线路本端和对端电流、电压、功率作为输入量,导出了超高压长线的波阻抗和传播常数的数学解析式,在此基础上进行了500kv输电线路实时参数计算;提出以三绕组自耦变压器的电流、电压、功率为输入量,导出了自耦变压器绕组的电阻、电抗的线性解析式并进而对变压器的实时参数进行计算;在此基础上编制了相应的软件。