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.

The application relates to a method and system for a pilot directional protection of LCC-HVDC lines based on virtual grounding resistance The method comprises: Obtaining a conduction state information of a converter and characteristic parameters of a converter circuit within one commutation period after a fault occurs; according to the conduction state information and characteristic parameters, determining characteristic frequency of the circuit; according to the characteristic frequency and characteristic parameters, determining a virtual grounding resistance; according to the virtual grounding resistance, determining fault areas.

The application relates to a method and system for a pilot directional protection of LCC-HVDC lines based on virtual grounding resistance The method comprises: Obtaining a conduction state information of a converter and characteristic parameters of a converter circuit within one commutation period after a fault occurs; according to the conduction state information and characteristic parameters, determining characteristic frequency of the circuit; according to the characteristic frequency and characteristic parameters, determining a virtual grounding resistance; according to the virtual grounding resistance, determining fault areas.

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.

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).

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 apparatus and method for selecting a ground capacitor that is connected between a ground of a circuit board included in a battery pack and a vehicle chassis. The apparatus includes a checking module configured to check a ground location on the circuit board; a selecting module configured to select a reference location on the circuit board, based on the ground location checked by the checking module; a calculating module configured to calculate a distance from the reference location selected by the selecting module to a nearest ground location as a reference distance; a computing module configured to compute a reference frequency by using the reference distance calculated by the calculating module; and a choosing module configured to choose a recommended capacitor, based on the reference frequency computed by the computing module.

An apparatus and method for selecting a ground capacitor that is connected between a ground of a circuit board included in a battery pack and a vehicle chassis. The apparatus includes a checking module configured to check a ground location on the circuit board; a selecting module configured to select a reference location on the circuit board, based on the ground location checked by the checking module; a calculating module configured to calculate a distance from the reference location selected by the selecting module to a nearest ground location as a reference distance; a computing module configured to compute a reference frequency by using the reference distance calculated by the calculating module; and a choosing module configured to choose a recommended capacitor, based on the reference frequency computed by the computing module.

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 converter system includes a plurality of converters, a sampling circuit, and a control circuit. The plurality of converters are connected in parallel. Each converter includes a detection circuit which includes a first switch and at least two resistors. The first switch is connected in parallel with one of the at least two resistors. The control circuit control the sampling circuit to collect a first voltage and a second voltage, where the first voltage is a voltage that is between a second bus and a ground cable and that is collected by the sampling circuit when first switches in detection circuits of a first quantity are in a turn-on state, the second voltage is a voltage that is between the second bus and the ground cable and that is collected by the sampling circuit when first switches in detection circuits of a second quantity are in a turn-on state.