The following steps are performed in order to test a tap changer (20) of a transformer (5; 6) which tap changer is designed to change a transmission ratio of the transformer (5; 6): generating a test signal which is supplied to a winding (1-3; 10) of the transformer (5; 6) and to the tap changer (20). Repeatedly actuating the tap changer (20) in order to change the transmission ratio with each actuation. Determining a curve of an electrical measurement variable (I; I.sub.1; I.sub.2) of the transformer (5; 6) over time (t) respectively during the step of actuating the tap changer (20) depending on the test signal. automatically illustrating the curves (41, 42) in a temporally-superimposed manner.

An apparatus having a conducting probe configured to couple with an electrical conductor of an electrical terminal. The apparatus has a sensor in contact with the conducting probe. The apparatus has a controller electrically coupled to the sensor, where the controller is configured to monitor the sensor values, and when the sensor values comply with a monitoring rule associated with a hazardous condition, the controller is configured to initiate an action to mitigate the hazardous condition.

A distributed test method applicable to a system-level test of intelligent high voltage equipment. The method includes: firstly, carrying out unified modeling on test equipment behaviors according to test requirements, and generating a general test case for ensuring accuracy and coordination of test behaviors and test time sequences under various work conditions; then, extracting, according to a feature element of role defining, sequence states of same roles from the general test case, and recombining the sequence states according to an execution sequence so as to form test sub-cases of the roles; finally, executing, by each piece of test equipment, corresponding test sub-cases to achieve cooperative linkage by means of information interaction, so as to accomplish entire process simulation of the test conditions.

An apparatus having a conducting probe configured to couple with an electrical conductor of an electrical terminal. The apparatus has a sensor in contact with the conducting probe. The apparatus has a controller electrically coupled to the sensor, where the controller is configured to monitor the sensor values, and when the sensor values comply with a monitoring rule associated with a hazardous condition, the controller is configured to initiate an action to mitigate the hazardous condition.

A gas density relay check device and a check method thereof are provided. In check, a temperature adjusting mechanism and a gas density relay are relatively set. Temperature rise and fall of a temperature compensation element of the gas density relay is adjusted through the temperature adjusting mechanism, then the gas density relay is enabled to have a contact signal action. A gas density value is obtained according to the pressure value and the temperature value in the contact action. A contact signal operating value of the gas density relay is detected to check on the contact signal operating value of the gas density relay. The gas density relay check device of the present disclosure is capable of accurately checking gas density relays, and is particularly applicable to a gas density relay without a three-way valve, and check can be achieved without disassembling the gas density relay.

A solid state switch power emulator circuit, the circuit including a high voltage section including a high voltage power supply (HVPS); a high voltage capacitor (HVC) electronically connected to the HVPS in parallel; a high voltage switch (HVS) electronically connected to the HVC and the HVPS in series; and a high voltage load (HVL) electronically connected to the HVS in series; a low voltage section including a low voltage power supply (LVPS); a low voltage capacitor (LVC) electronically connected to the LVPS in parallel; a low voltage switch (LVS) electronically connected to the LVPS and the LVC in series; a low voltage load (LVL) electronically connected to the LVS in series; and a high voltage diode (HVD) electronically connected to the LVL in series, wherein voltage levels associated with the low voltage section are less than voltage levels associated with the high voltage section.

A method of connecting electrical substation wiring in an electrical substation provides pre-bundled yard cables configured to connect between field devices in the substation and a yard interface connection cabinet. The yard interface connection cabinet has an outside plug bulkhead plate that is accessible from outside of a control house that houses the yard interface connection cabinet. The outside plug bulkhead plate has a plurality of connectors configured to mate with the yard cables. The yard interface connection cabinet further has internal wires extending from an inside plug bulkhead plate and terminating at a terminal block. The connections and wires in the yard interface connection cabinet are tested with the yard cables before installation of the yard interface connection cabinet and yard cables in the substation. The yard cables are connected between the field devices and the outside plug bulkhead plate from outside of the control house.

The application provides an electrical system with online sampling and check function and its check method for high-voltage and medium-voltage electrical equipment, including electrical equipment, gas density relay, gas density sensor, temperature regulation mechanism, online check contact signal sampling unit and intelligent control unit. The temperature rise and fall of the temperature compensation element of the gas density relay is regulated through the temperature regulation mechanism to enable the contact action of the gas density relay of electrical equipment. The contact action is transmitted to the intelligent control unit through the online check contact signal sampling unit. The intelligent control unit detects the alarm and/or blocking contact signal operating value and/or return value according to the density value of the contact action; the check of the gas density relay can be completed without maintenance personnel on site, which greatly improves the reliability of the power grid and the work efficiency, and reduces the O&M cost. At the same time, it also realizes the mutual self-inspection between gas density relay and gas density sensor, and further realizes the maintenance-free.

The application provides an electrical system with online sampling and check function and its check method for high-voltage and medium-voltage electrical equipment, including electrical equipment, gas density relay, gas density sensor, valve, pressure regulating mechanism, online check contact signal sampling unit and intelligent control unit. The pressure is increased or decreased by the pressure regulating mechanism to enable the contact action of the gas density relay of electrical equipment. The contact action is transmitted to the intelligent control unit through the online check contact signal sampling unit. The intelligent control unit detects the alarm and/or blocking contact signal operating value and/or return value according to the density value of the contact action; the check of the gas density relay can be completed without maintenance personnel on site, which greatly improves the reliability of the power grid and the work efficiency, and reduces the O&M cost. At the same time, it also realizes the mutual self-inspection between gas density relay and gas density sensor, and further realizes the maintenance-free.

A detection system for detecting an electrical discharge in an electrical apparatus includes a first sensing device that senses an acoustic wave and an electromagnetic wave and generates a first combined signal. A signal processing device processes the first combined signal and determines the occurrence and properties of an electrical discharge.