The split core current transformer is suitable for current measurement and microcomputer protection of power supply equipment which is below 35KV and 10KV in the AC power system. The current transformer has the characteristics of small size, light weight, openability, and easy installation. As an important electrical component in the low-voltage power distribution system, AKH 0.66's role in the transformation of the power grid is becoming more and more obvious, and it has been widely used in measurement, metering, relay protection, system monitoring, grounding protection and various power system analysis.