An electrical connector testing system can include a first connector end and a controller coupled to first connector end. The system can also include an electrical load coupled to the first connector end, where the electrical load includes an electrical cable and a second connector end coupled to an end of the electrical cable. The controller can determine whether an adverse electrical condition exists with respect to the electrical load before allowing power to flow between the first connector end and the second connector end.

The invention relates to an electric circuit arrangement and a method for coupling an insulation monitoring device to an ungrounded power supply system via a coupling impedance, which is realized to be operant for each active conductor of the power supply system and which is formed as an ohmic resistance circuit, the ohmic resistance circuit having a settable resistance value which is changeable and a switching-off function for decoupling the insulation monitoring device from the network and being realized as a bidirectional cascade comprising a series circuit of two transistors provided in a mirror-inverted manner, each having a diode connected in parallel, a controlled change in resistance of the transistors for setting the changeable resistance value being effected by a control circuit and the switching-off function for decoupling from the grid being realized by setting a maximum resistance value.

An arrangement for injection-based ground fault protection handling including a number of stator windings of an electric machine that are connected to a neutral point, a first transformer including at least one primary winding connected to at least one measurement point of the stator windings and at least one secondary winding for measuring an electrical quantity of the machine at the measurement point. There is also a second transformer having a primary winding connected between the neutral point and a ground potential and a secondary winding for connection to a signal generation and detection unit in order to inject a signal into the neutral point and receive a response. The impedance of the second transformer is in the range of the impedance of the machine.

An arrangement for injection-based ground fault protection handling including a number of stator windings of an electric machine that are connected to a neutral point, a first transformer including at least one primary winding connected to at least one measurement point of the stator windings and at least one secondary winding for measuring an electrical quantity of the machine at the measurement point. There is also a second transformer having a primary winding connected between the neutral point and a ground potential and a secondary winding for connection to a signal generation and detection unit in order to inject a signal into the neutral point and receive a response. The impedance of the second transformer is in the range of the impedance of the machine.

A system for locating a ground fault in an HRG power distribution system includes an HRG pulsing system having a ground fault sensor to detect a ground fault, a pulsing contactor to introduce a pulsing current into the power distribution system, and a controller to control the pulsing contactor to introduce the pulsing current into the power distribution system in response to a ground fault detection by the ground fault sensor. Current sensors in the power distribution system monitor three-phase current signals on conductors of the power distribution system, with the current sensors positioned on distribution networks in the power distribution system and at a protection device included on each respective distribution network. A processor associated with each protection device and operably connected to the current sensors thereat receives signals from the current sensors for identifying a location of a ground fault in the power distribution system.

A system for locating a ground fault in an HRG power distribution system includes an HRG pulsing system having a ground fault sensor to detect a ground fault, a pulsing contactor to introduce a pulsing current into the power distribution system, and a controller to control the pulsing contactor to introduce the pulsing current into the power distribution system in response to a ground fault detection by the ground fault sensor. Current sensors in the power distribution system monitor three-phase current signals on conductors of the power distribution system, with the current sensors positioned on distribution networks in the power distribution system and at a protection device included on each respective distribution network. A processor associated with each protection device and operably connected to the current sensors thereat receives signals from the current sensors for identifying a location of a ground fault in the power distribution system.

A method monitors an energy transmission device, in particular an energy transmission line or an energy distribution network, via which electric current is transmitted at a predefined network frequency. An electrical measurement signal having at least one non-network frequency, i.e. a frequency which differs from the network frequency, or a non-network frequency band, is fed into the energy transmission device at a predefined position thereon. An electrical measured quantity related to the non-network frequency or the non-network frequency band is measured at the predefined position or a different position on the energy transmission device with the formation of at least one measured value or frequency-band-related measured value characteristic. A fault signal is generated if the measured value, the frequency-band-related measured value characteristic, a comparative value or comparative value characteristic formed with the measured value or the measured value characteristic indicates a fault in the energy transmission device.

A method monitors an energy transmission device, in particular an energy transmission line or an energy distribution network, via which electric current is transmitted at a predefined network frequency. An electrical measurement signal having at least one non-network frequency, i.e. a frequency which differs from the network frequency, or a non-network frequency band, is fed into the energy transmission device at a predefined position thereon. An electrical measured quantity related to the non-network frequency or the non-network frequency band is measured at the predefined position or a different position on the energy transmission device with the formation of at least one measured value or frequency-band-related measured value characteristic. A fault signal is generated if the measured value, the frequency-band-related measured value characteristic, a comparative value or comparative value characteristic formed with the measured value or the measured value characteristic indicates a fault in the energy transmission device.

A circuit for alternating current and direct current leakage detection. The circuit can achieve multiple functions such as direct current leakage detection, alternating current leakage detection, and leakage sampling link self-check. The circuit mainly comprises: an LDO module for converting an externally input power supply voltage into a voltage required for leakage detection; a frequency divider module for performing frequency division on a high-frequency clock signal; a logic control module for driving an MOS transistor and controlling the switching of different working modes; an MOS transistor driving module for driving an external leakage detection coil; a leakage detection coil for inducing alternating current and direct current leakage signals and a leakage self-check signal; a sampling resistor for converting the current signal flowing through the leakage detection coil into a voltage signal; a PGA module for amplifying a sampling signal; a gain control module for controlling a PGA amplification factor; an ADC module for performing digital-to-analog conversion of the signals; a DSP module for processing the alternating current and direct current leakage signals and the leakage self-check signal; and a current limiting module for limiting a loop current.

An earth leakage detecting device comprises following elements. A first end of coupling capacitor is connected to a current path of power storage connected to load in a state of being insulated from a ground. Voltage output unit generates a periodic voltage that changes periodically, and applies the periodic voltage to a second end of coupling capacitor via impedance element. Voltage measurer measures a voltage at a connection point between coupling capacitor and impedance element. Earth leakage determiner determines presence or absence of an earth leakage between the current path of power storage and the ground on the basis of the measured voltage. Voltage output unit has a preparation period for constantly outputting a potential between a high-side potential and a low-side potential of the periodic voltage before a measurement period for outputting the periodic voltage.