Numerical relay development environment

Advancements in application of digital signal processors in measurement and protection relaying schemes has evolved from many decades. New adaptive techniques are being developed for better power system protection. These techniques need to be tested on numerical relay test bench to analyze its accuracy and reliability under real time power system transient behavior. This paper presents generic numerical relay development environment comprising of newly developed relay and computer based hardware-in-the-loop test bench setup. The hardware is designed to accept data in IEEE COMTRADE format. Different power system operating conditions are simulated in MiPower software package and injected to the relay using National Instrument's NI 9263 converter modules and LabVIEW software package. Relaying scheme performance is analyzed in computer by event capture capability of the relay and serial communication with computer. Percentage bias generator differential scheme is implemented and tested in the setup. Results show stable and accurate performance of the hardware.