The invention belongs to the technical field of
direct current monitoring, and discloses a TMR-based open-close type
direct current leakage current detection device, which comprises a
magnetic core, one or more pairs of TMR sensors, a
secondary side feedback coil and a main
control circuit, and is characterized in that the
magnetic core is provided with air gaps which are oppositely arranged; the TMR sensors are symmetrically arranged in the air gap; the
secondary side feedback coil is wound on the surface of the
magnetic core and forms closed-
loop control with the main
control circuit; the main
control circuit comprises an acquisition feedback circuit, a
secondary side detection circuit and a main control
chip, the acquisition feedback circuit acquires signals of the TMR sensor under the control of the main control
chip, generates feedback current and inputs the feedback current to the secondary side feedback coil, and the secondary side detection circuit is connected between the secondary side feedback coil and the main control
chip. And the main control chip collects the secondary side
voltage of the secondary side detection circuit and calculates to obtain the
direct current leakage current. According to the invention, direct current leakage current detection with high sensitivity, low drift and strong anti-interference capability is realized under the open-close structure, and the requirements of a modern
electric power system on continuity, safety and
maintainability are met.