Through an example of a main transformer switch-in with load during the reverse transmission of a 750 kV power plan,the paper introduces the basic principle of transformer switch-in with load.EMTPE program that is use...Through an example of a main transformer switch-in with load during the reverse transmission of a 750 kV power plan,the paper introduces the basic principle of transformer switch-in with load.EMTPE program that is used to establish a calculation model,at the same time mainly considers the excitation characteristics of the transformer,the transient model of the circuit breaker,and the model of high voltage transformer,and calculated the inrush current with transformer switch-in with load in this plan.During system debugging in the plan,the two sets of main transformers passed the closing and opening test,and the data of inrush current in the test are recorded and analyzed.The simulation calculation and measured data show that the results are consistent.The simulation calculation also shows that it is not recommended to perform on-load closing of the transformer except for special circumstances,because of the influence of hysteresis characteristic when the transformer was switched in with load or the terminal voltage of the transformer resumed normal level from a low one after an external near-end fault was cleared,which various transformer differential protection using the characteristics of inrush to implement block scheme may mal-operate.展开更多
某核电厂主变压器采用中性点经过气体绝缘封闭母线(GIB)直接接地的方式,由于GIB外壳接地方式不明确,存在GIB外壳和接地体环流过大的现象,严重威胁着变压器的安全可靠运行。为研究接地体数量和接地位置对GIB外壳环流大小及分布的影响,使...某核电厂主变压器采用中性点经过气体绝缘封闭母线(GIB)直接接地的方式,由于GIB外壳接地方式不明确,存在GIB外壳和接地体环流过大的现象,严重威胁着变压器的安全可靠运行。为研究接地体数量和接地位置对GIB外壳环流大小及分布的影响,使用电磁暂态仿真软件EMTP搭建500k V GIB环流仿真模型,分析了稳态运行时GIB外壳不同接地组合对感应环流大小及分布的影响。研究表明,GIB外壳一点接地时,流过GIB外壳和接地线上的感应环流最小,此研究对同类型设备的接地方式选择有一定的指导作用。展开更多
文摘Through an example of a main transformer switch-in with load during the reverse transmission of a 750 kV power plan,the paper introduces the basic principle of transformer switch-in with load.EMTPE program that is used to establish a calculation model,at the same time mainly considers the excitation characteristics of the transformer,the transient model of the circuit breaker,and the model of high voltage transformer,and calculated the inrush current with transformer switch-in with load in this plan.During system debugging in the plan,the two sets of main transformers passed the closing and opening test,and the data of inrush current in the test are recorded and analyzed.The simulation calculation and measured data show that the results are consistent.The simulation calculation also shows that it is not recommended to perform on-load closing of the transformer except for special circumstances,because of the influence of hysteresis characteristic when the transformer was switched in with load or the terminal voltage of the transformer resumed normal level from a low one after an external near-end fault was cleared,which various transformer differential protection using the characteristics of inrush to implement block scheme may mal-operate.
文摘某核电厂主变压器采用中性点经过气体绝缘封闭母线(GIB)直接接地的方式,由于GIB外壳接地方式不明确,存在GIB外壳和接地体环流过大的现象,严重威胁着变压器的安全可靠运行。为研究接地体数量和接地位置对GIB外壳环流大小及分布的影响,使用电磁暂态仿真软件EMTP搭建500k V GIB环流仿真模型,分析了稳态运行时GIB外壳不同接地组合对感应环流大小及分布的影响。研究表明,GIB外壳一点接地时,流过GIB外壳和接地线上的感应环流最小,此研究对同类型设备的接地方式选择有一定的指导作用。
