The use of amorphous alloys to protect electrical networks from high-frequency overvoltages

To protect substation equipment from high-frequency overvoltages, it is necessary not only to reduce the amplitude of the input pulse, but also to dampen it. The most promising way to do this is to use a frequency-dependent device (CHZ), the resistance and inductance of which grow with increasing frequency of the input signal and which is connected to the substation in series. At industrial frequencies, this device conducts lossless operating currents, at high frequencies, for example, during lightning pulses, the resistance of the device increases sharply due to an abnormal skin effect. A tape made of an amorphous 5BDSR alloy is used as a conductive layer in the CZU developed in 2014. The relative magnetic permeability of this tape is 50,000, which turned out to be insufficient for effective protection of substation equipment. The development of new devices having a different form of the control unit itself or its conductors also proved unable to provide effective protection of substation equipment. A new approach or new materials are needed to increase the effectiveness of the protective properties of the frequency- dependent devices being developed.