Evaluating wavelet decomposition techniques in protective relays under continuous run-time simulated operation

• With the modern technology of power generation and the rapid increase in renewable energy sources, fundamental frequency and harmonics have had a major effect on the power system network. As a result, continuous monitoring and protection are needed to ensure a healthy system through digital measurements and waveform frequency analysis. • In this work, the run-time testing model designed for protective frequency relays is presented using the decomposition algorithm of Wavelet transform mathematical tools. With simulator works, run-time simulated scenarios in electrical power systems are modeled by MAT. • LAB/Simulink, incorporating frequency faults that may occur in the network. • With Wavelet’s ability to analyze time-varying (non-stationary) signals, it is used in three types of testing: 1. Run-time Simulink operation. 2. Run-time Simulink and function operation. 3. Run-time sampling time operation for over and under frequency relay performance. • The results are presented and discussed in terms of: 1. System complexity. 2. Run real-time simulation. 3. Run-time capability. 4. Data sampling. 5. Decision time. 6. Performance. As modern power systems continue to evolve with the integration of advanced technologies and a growing share of renewable energy sources, maintaining grid stability has become increasingly challenging. Variations in the fundamental frequency and the presence of harmonics can significantly affect the performance of electrical networks. To ensure a stable and reliable grid, continuous monitoring and protection are essential through digital measurements and frequency analysis. This study introduces a run-time testing model for protective frequency relays, utilizing the Wavelet transform as a signal decomposition. Known for its ability to analyze non-stationary signals, the Wavelet transform is applied in three testing configurations: run-time Simulink operation, a combination of Simulink and function-based testing, and run-time sampling for assessing over- and under-frequency relay performance. The model's effectiveness is evaluated based on several key factors, including system complexity, run time responsiveness, data sampling resolution, reaction time, and overall performance. Unlike traditional methods, this approach supports real-time signal decomposition, effective noise filtering, and accurate detection of transient faults. As a result, it delivers more reliable, responsive, and practical protection under the dynamic conditions of modern power grids.