FPAA-based MHO distance relay considering CVT transient supervision

Present-day numerical relays provide remarkable capabilities such as monitoring, recording and communication. These capabilities are considered as secondary priority whereas speed and reliability are the two most important characteristics of a protective relay. Even though present-day numerical relays have provided considerable capabilities and advantages, they have not improved speed of operation in comparison to their solid-state counterparts. The idea of applying mixed signals processing using advanced analogue and digital technology in several applications has started. Use of advanced programmable analogue technology, which is known as field programmable analogue arrays (FPAAs), seems to have the potential to be used in protective relays. Hybrid hardware using both digital signal processor (DSP) and FPAAs is proposed to implement mho distance relay considering capacitor voltage transformer (CVT) transient supervision for low and high system impedance ratio (SIR) systems. Test results are reported and compared with a commercial relay test results.