The DC leakage current sensor is a measurement module that utilizes the fluxgate principle to convert measured DC current into a proportional DC current or voltage signal output. The primary and secondary sides are highly insulated. It typically outputs standard signals such as DCDC 4-20mA, DC 0-5V, and DC 0-10V, which can be collected by various devices like PLCs, RTUs, and DAS cards. It is suitable for various current monitoring applications.
The working principle of the DC leakage current sensor employs magnetic modulation (also known as a flux gate) technology. An internal square wave oscillator generates a compensating current to balance the primary current, achieving magnetic field equilibrium. At this point, the output value VM is accurate, reflecting the primary current, and is primarily used for detecting small DC currents and differential currents.
Leakage current sensors are installed around the positive and negative output lines of a DC circuit. During operation, the equipment detects signals from individual branches in real time. When the branch insulation is normal, the currents passing through the sensors are of equal magnitude and opposite in direction, resulting in a zero output signal. When a branch is grounded, the leakage current sensor detects differential current, and the sensor output is not zero. Therefore, by detecting the output signals of individual branch sensors, the grounded branch in the DC system can be determined. This principle offers high selectivity precision and is not affected by the distribution capacitance of the lines.
