电力变压器偏磁试验电源研制

Design of Power Supply for Testing on Power Transformer of DC Bias

分析了电力变压器磁化产生的原因、现象和危害,阐述了对变压器在带电状态下的磁化现象进行研究的必要性;提出一种新的测试电路连接方式,试验电源可避免直接承受高压,同时能向变压器注入连续可调的直流电流;通过分析磁化后励磁电流和磁通的关系,说明磁化现象产生的原因;通过建立等效电路,并结合磁化电流谐波组成,分析了回路中的电流成分,从而明确了试验电源的工作要求;介绍了直流电源的结构,说明了蓄电池、电感、电容、控制电路、保护电路的设计原则;最后利用220 V变压器进行试验,验证了电源的效果。

The paper briefly introduces magnetic saturation of transformer about cause,phenomenon and damage for power transformer and the importance of studying of such characteristics,and proposes a topology of testing power transformer＇s magnetic saturation,in which a DC power source can inject DC current into transformer and avoid en-during high voltage.By analyzing relationship between magnetic current and magnetic flux,the causes are made clear for magnetic phenomenon.The main components and harmonics of current in circuit are researched so the request for DC source can be known.The structure of power supply and the design rule of battery,inductance,capacitor,control circuit and protection are introduced.Finally,the effect of power supply is testified by use of AC220 V transformers.