Table 8 Comparison between existing and proposed protection techniques.
From: Adaptive non unit traveling wave protection algorithm for multi terminal HVDC grids
Reference | Signal processing technique | Fault detection criterion | Tested grid system | Fault detection time | Fault resistance | Sampling rate |
|---|---|---|---|---|---|---|
S Transform | Gaussian | Meshed seven terminal grid | 1.3 ms | 2 Ω to 14 Ω | 10 kHz | |
Hilbert Huang | Instantaneous energy density level | Meshed seven terminal grid | 2 ms | 50 Ω | 10 kHz | |
Discrete Wavelet | Backward & Forward TW ratio | Three terminal grid system | 3ms | 300Ω | 10 kHz | |
Modal Domain analysis | Line mode reactor voltage | Meshed four terminal grid | 1.1 ms | 200Ω | 100 kHz | |
Hilbert Huang | Average frequency | Meshed four terminal grid | 4 ms | 1Ω | 25 kHz | |
Discrete Wavelet | Wavelet energy | Three terminal star-connected grid | 3 ms | 50Ω | 50 kHz | |
Fast Fourier Transform | TW frequency spectral ratio | CIGRE grid model | 0.5 ms | 200Ω | 2 MHz | |
Proposed technique | Daubechies wavelets transform | Energy of wavelet coefficients | Four terminals with five cables meshed grid | 1 ms | 500Ω | 50 kHz |
