Development of medium-voltage distribution relay with precision current measurement and multi-lingual capability

The performance and functions provided within digital protection relays are progressing every year. This trend is clearly apparent within the field of distribution relays. As an example, in order to make global applications possible within the same model, relays are now designed to cover various ratings. However, we have to consider local de facto standards in order that the product be accepted in the wide variety of markets found in various countries. This paper describes a distribution relay that has been developed (type; GRE110M within GRE-series relays for medium-voltage protection) with some features of the development that are of particular interest, including a precision current measurement function and multi-lingual capability.