基于三次谐波的电机保护

Protector of Transformer Air Cooled Motor Based on Third Harmonic

针对电力变压器风机电机保护要求高的特点,提出了一种利用三次谐波的35kV变电所主变风冷系统的电机保护装置,给出了该保护装置的基本原理,包括三次谐波的获取方法,相位比较器的结构、原理等.实际测试波形表明了所提方案的可行性,同时实际运行表明该装置具有一定的实用性和可靠性.

To meet the needs of power transformer blower fan motor strict protecting demands in the substation, the motor protection based on third harmonic for 35kV substation main transformer air cooled system is introduced in this paper. It presents the principles that include the gain method for third harmonic, structure and principle of phase comparator. The practical test waves indicate that the scheme is feasible. It is proved through practice more than one year that the protector is of good practicability and reliability.