A new method to compensate current transformer using microprocessors

The authors present a new method to compensate the errors of current transformers by using a microprocessor. The microprocessor is programmed to supply, according to the magnetising curve and the magnetic potential, current which would otherwise come from the primary current. It can thereby effectively reduce current transformer errors. With this method, the effect of compensation is not affected by changes in the primary current or the load. Current transformers for 10 to 220 kV power systems can be improved from the national standard grade 0.5 to 0.1