The decoupler utilizes solid-state technology with a non-metallic housing, capable of controlling the impact of AC stray currents or lightning currents on buried pipelines, thereby extending the pipeline's service life. Simultaneously, it prevents the hazards of stray currents accumulating on the pipeline to human safety and interference with communication lines.
As a DC isolation and AC coupling device, the BX-SSD/EX-100 is used to prevent cathodic protection currents from reaching a predetermined threshold voltage while also conducting induced AC currents. When the voltage attempts to exceed the threshold, the SSD immediately switches to short-circuit mode to provide overvoltage protection. Once the overvoltage subsides, it automatically reverts to DC isolation mode. This operational cycle can occur countless times, typically triggered by AC fault currents or lightning currents. The standard threshold voltage for the SSD is -2V/+2V. The threshold voltage can be an absolute value voltage or a peak voltage, at which switching occurs, representing the sum of the DC and AC peak voltages across the isolator. This ensures a very low clamping voltage across the SSD terminals.

Applications of Solid-State Decouplers
Decoupling of pipeline potential gradient mats (grounding mats)
Overvoltage protection for equipment against AC faults, lightning, and switching transients (e.g., insulated joints, insulated flanges)
For safety, decoupling between different metals that may become AC-coupled under certain conditions
AC grounding and direct isolation of electrical equipment in cathodic protection systems
To reduce locations with AC-induced voltages

The solid-state decoupler is an AC interference protection product with the function of "blocking DC and passing AC," featuring high steady-state AC interference current, fault current, lightning surge conduction capability, and extremely low DC leakage levels. This product can be installed at parallel or crossing points of pipelines with high-voltage transmission lines or electrified railways, as well as at centralized grounding locations such as stations and valve chambers, providing AC interference, fault current, and lightning surge protection for metal pipelines while preventing the loss of cathodic protection current.

As a DC isolation and AC conduction device, it blocks the conduction of DC currents within a certain voltage range, such as -2 to +2V or -3 to +1V, while providing a low-impedance path for AC currents. When the voltage between the two terminals of the solid-state decoupler exceeds the DC conduction threshold, it enters a low-impedance DC conduction mode. When the voltage between the terminals drops below the DC conduction threshold, it resumes high impedance to DC currents, cutting off the DC current.