Development of DSP based high speed numerical distance relay and its evaluation using hardware in loop power system simulator

Numerical distance relays are used for the protection of long transmission lines. These relays require specialized hardware for high speed signal acquisition and computation of relaying quantities. The digital signal controller (DSC) and the data converters used in the relay have a major influence on the performance of the relay. In order to achieve high reliability and to reduce the size of the relay, it is desirable to use minimum hardware components. The newly arrived DSC and special range of data converters are offering optimal hardware solutions. This paper presents design and developments of distance relay hardware based on DSC TMS320F28335 and ADS8556 a simultaneous sampling type analog to digital converter (ADC), both from Texas Instruments. The distance relay designed using above hardware is evaluated through hardware in the loop (HIL) experimental setup. The fault transient signals are obtained from EMTDC/PSCAD considering a typical 220KV transmission line and these signals in turn are injected to the proposed relay through Doble F6150 power system simulator to perform elaborate dynamic tests.