温度及直流偏磁对换流变压器铁心磁性能及磁场问题影响的研究

Research of effect of temperature and DC bias on magnetic performance and magnetic field of iron core of converter transformer

测量了30ZH120电工钢片在不同直流偏磁及温度条件下磁特性,经过迭代计算得到了考虑偏置磁通后的B-H曲线。基于一台产品级750kV换流变压器(哈密-郑州特高压直流输变电工程),仿真计算了不同直流偏磁及温度条件下换流变压器磁场分布和空载电流,结果表明:直流偏磁和工作温度影响电工钢片和换流变压器铁心线性区和非线性区,随着温度及直流偏磁的增加,换流变压器铁心磁通密度和空载电流增加,因此,在设计中应该考虑温度及直流偏磁的影响。

The magnetic properties of 30ZH120 electrical silicon sheet under different DC bias and temperature conditions were measured,and the B-H curve considering the bias flux is obtained by iterative calculation.Then,the magnetic field distribution and excitation current characteristics of one product grade 750kV converter transformer(Hami-Zhengzhou UHV DC Transmission and Transformation Project)under different DC bias and temperature conditions are simulated.The results show that,DC bias and working temperature affect the linear and nonlinear regions of the electrical steel sheet and converter transformers.The magnetic flux density and no-load current of converter transformer will increse with increase of temperature and DC bias.Therefore,the effect of temperature and DC bias should be considered in the transformer design.