Comparison of the Performance of Four Direct Current Decouplers

The performances of four direct current (DC) decouplers were investigated by the combination of experimental measurements and field tests. In order to evaluate the DC threshold voltage, DC leakage and alternating current (AC) impedance, DC volt-ampere curve and AC volt-ampere curve of the four DC decouplers were measured. The results were confirmed by field tests. Besides, the effects of DC decoupler on the AC mitigation efficiency of ground-bed and on the cathodic protection potential of buried pipeline were discussed.