中文摘要：

换流变压器是高压直流输电系统的核心设备,其损耗将会对直流输电系统的稳定性产生影响,因而备受关注。因此,首先探究了换流变压器空负载损耗的影响因素,并利用Matlab软件的Simulink平台进行了仿真分析。仿真结果表明：对于换流变压器的空载损耗,谐波次数和谐波电压畸变率的增加使得空载损耗下降,但下降幅度较小,其中5、7次谐波对空载损耗的影响最大;对于换流变压器的负载损耗,谐波次数和谐波电流畸变率的增加使得负载损耗增加,幅度较大,且谐波次数和畸变率对负载损耗的影响远大于空载损耗。然后,提出了适用于换流变压器现场测量的含附加电阻的换流变压器谐波等值电路,利用谐波损耗新模型与常规谐波等效电路对换流变压器谐波损耗进行计算,并将计算结果与IEC方法的计算结果进行对比,对比结果验证了新模型的合理性。根据本文提出的方法,可以对换流变压器损耗现场测试结果进行校正,因此对换流变压器的现场试验具有重要的工程意义。

英文摘要：

The loss of convert transformer, as a core device of high voltage direct current（HVDC）, has some effects on the stability of HVDC transmission system. Consequently, we researched the no-load loss and its influential factors on converter transformer, and simulated the loss by using the Simulink platform of Matlab. The simulation results show that, for the converter transformer no-load loss, when the harmonic frequency and harmonic voltage distortion rate increase, the no-load loss slightly decreases, and the fifth and the seventh harmonics have the most remarkable impact; for the converter transformer load loss, when the harmonic frequency and harmonic current distortion rate increase, the load loss remarkably increases, and the harmonic frequency and harmonic distortion rate have greater impact to the load loss than to the no-load loss. Moreover, we put forward the converter transformer harmonic equivalent circuit containing additional resistance which is suitable for converter transformer on-site measurement, adopted a new harmonic loss model and the conventional harmonic equivalent circuit to calculate the converter transformer harmonic loss, and compared the results with those by the IEC method.It is verified the new model of harmonic loss is reasonable. According to the proposed method, the results of the loss of the converter transformer on-site testing can be corrected, so it has important engineering significance to the converter transformer on-site testing.