The primary purpose of a reliable electrical power system is to continuously provide consumers with high-quality services. In addition, this system should be able to limit and minimize the duration of outages under abnormal conditions. Voltage dips, power losses, and electrical surges may occur, however, because it is impractical and impossible to avoid the effects of physical accidents, natural risks, device malfunctions, etc. Protective relaying schemes are a pessimistic method of detecting unacceptable conditions, such as failures, and automatically maintaining the stability of power systems by swiftly disconnecting the damaged portion from the remainder of the electrical networks. This research seeks to model, simulate and develop a multifunction digital relay for protection against over and under voltage, over current, and over and under frequency using MATLAB/SIMULINK. Next, the paper will discuss digital protection techniques for multifunction relays in these settings. In addition, an analysis will be carried out during voltage, current, and frequency fluctuations. The system will be built using Arduino Mega 2560 microcontrollers. Finally, we designed a relay for comparison that protects against imbalanced voltage and reverse power via DQ transformation. The concept of relay cascading is also included in this study.