A fault protection arrangement. The fault protection arrangement may include a neutral grounding resistor including a first non-ground end, connected to a neutralizing point, and a second non-ground end. The fault protection arrangement may include a neutral grounding resistance monitor assembly, directly coupled to the second non-ground end of the neutral grounding resistor. The neutral grounding resistance monitor assembly may include comprising a signal source coupled to the neutralizing-point; a first current sense circuit coupled between the signal source and the neutralizing-point; a first voltage sense circuit coupled between the signal source and the neutralizing-point; a second current sense circuit, comprising a current sensor, coupled between the second non-ground end of the neutral grounding resistor and a protective earth connection.

A method for obtaining a contact resistance of a planar device includes: obtaining a contact resistance of a planar device by using a potential measurement method, in the measurement of the surface potential distribution, the planar device is in a state of current flowing, a certain voltage drop is formed at a junction area of the device; extracting the voltage drop measured through the Kelvin microscope by using a linear fitting method; and dividing the measured voltage drop by the current flowing through the device, thereby accurately calculating the magnitude of the contact resistance at the junction area of the planar device. With the present invention, the contact resistance of the planar device can be precisely measured, which is suitable for the contact resistance measurement experiments of devices such as thin film transistors and diodes. The invention has the advantages of reasonable theory, accurate result, simple and easy operation, and is favorable for optimizing the device performance and establishing a complete electrical model of the device.

A test method and device for a contact resistor are provided, configured to test a contact resistor of a metal-oxide-semiconductor (MOS) transistor. The method includes: a resistance value per area and a temperature coefficient of resistance of the contact resistor are acquired; and a target resistance value of the contact resistor is determined according to the resistance value per area, the temperature coefficient of resistance, and an area of the contact resistor.

An evaluation jig comprises a pair of female terminals connectable to a pair of male terminals of a charging connector, and an adjustment member that can adjust contact resistance of the female terminal and the male terminal. The female terminal is reducible in diameter. The adjustment member can apply an external force to the female terminal to reduce the female terminal in diameter.

An evaluation method is a method for evaluating a charging connector in coolability by connecting an evaluation jig to the charging connector, the charging connector including a pair of male terminals coolable with a coolant, the evaluation jig including a pair of female terminals, the pair of female terminals being connected to the pair of male terminals in evaluating the charging connector in coolability. The method comprises: connecting the pair of female terminals to the pair of male terminals; adjusting a connection state between the male terminal and the female terminal such that contact resistance between the terminals is 0.06 mΩ or more and 0.15 mΩ or less; and after the adjusting, evaluating the coolability depending on whether the male and female terminals have a temperature of 90° C. or lower when a charging current of 400 A is supplied to the terminals for 30 minutes.

A method of measuring contact resistance at an interface for superconducting circuits is provided. The method includes using a chain structure of superconductors to measure a contact resistance at a contact between contacting superconductor. The method further includes eliminating ohmic resistance from wire lengths in the chain structure by operating below the lowest superconducting transition temperature of all the superconductors in the chain structure. The measurement is dominated by contact resistances of the contacts between contacting superconductors in the chain.

Provided are a method, apparatus and system for measuring a resistance parameter of a grounding system, and a monitoring network. The method comprises: inputting a driving current into a plurality of sections of a grounding system path (S602), wherein the grounding system path comprises at least a grounded apparatus, a grounding body, and a downlead connecting the grounded apparatus and the grounding body; measuring response voltages generated by the plurality of sections, and acquiring a response current flowing through the downlead (S604); and determining a resistance parameter of the grounding system path according to the driving current, the response voltages and the response current (S606).

An evaluation jig comprises a female terminal connectable to a male terminal of a charging connector. The female terminal includes a plurality of contact pieces and a support portion. Each contact piece has a flexible piece, and a contact portion protruding toward the center axis from an inner surface of the flexible piece. The flexible piece forms a portion of a cylinder having the center axis. The flexible piece has a length equal to or larger than twice an outer diameter of the cylinder in a direction parallel to the center axis. The flexible piece is elastically deformable so that the flexible piece has a distal end portion to be displaceable in a radial direction of the cylinder relative to a proximal end portion of the flexible piece. The contact portion has a shape curved so as to protrude inward in the radial direction.

The evaluation jig comprises a pair of female terminals connectable to a pair of male terminals of a charging connector and an adjustment member capable of adjusting contact resistance of the female terminal and the male terminal. The female terminal is reducible in diameter. The adjustment member includes an annular band attached to an outer peripheral surface of the female terminal and formed in an annulus surrounding the female terminal, a metal band attached to an outer peripheral surface of the annular band and capable of applying external force to the female terminal to reduce the female terminal in diameter, and an adjustment unit capable of adjusting the external force applied by the metal band to the female terminal. The annular band is made of an electrically and thermally insulating material.

An evaluation method is a method for evaluating a charging connector in coolability by connecting an evaluation jig to the charging connector, the charging connector including a pair of male terminals coolable with a coolant, the evaluation jig including a pair of female terminals, the pair of female terminals being connected to the pair of male terminals in evaluating the charging connector in coolability. The method comprises: connecting the pair of female terminals to the pair of male terminals; adjusting a connection state between the male terminal and the female terminal such that contact resistance between the terminals is 0.06 mΩ or more and 0.15 mΩ or less; and after the adjusting, evaluating the coolability depending on whether the male and female terminals have a temperature of 90° C. or lower when a charging current of 400 A is supplied to the terminals for 30 minutes.