An electrical link (8) between a DC high-voltage power source (2) and a user apparatus (5) including: an electrical conductor (4) surrounded by an insulating cover (4a), and an electrical protection device (3) that includes a conductive sleeve (7) arranged around the insulating cover (4a), a current generator (10) connected to a current injection point (30) of the conductive sleeve (7), a circuit breaker (9) arranged on the conductor and configured to cut off a current transiting through the conductor (4), and a detection module (11) connected to a current tap-off point (31) of the conductive sleeve (7) and to the circuit breaker (9) and configured to detect a current leak out of the conductor (4) and command the circuit breaker (9).

An electrical link (290) configured to link a DC high-voltage power source (270) to a user apparatus (250), and includes an electrical conductor (240) surrounded by an insulating cover and an electrical protection device (200) including: a conductive sleeve (280) arranged around the insulating cover, a biasing module (245) configured to voltage-bias the conductive sleeve (280), a circuit breaker (210) arranged on the conductor (240) and configured to cut off a current transiting through the conductor (240), and a detection module (220) connected to the conductive sleeve (280) and configured to detect a current leak out of the conductor (240) and to command the circuit breaker (210) on the basis of the detection. The invention also relates to a method for the secure supply of electric power.

An electrical link (290) configured to link a DC high-voltage power source (270) to a user apparatus (250), and includes an electrical conductor (240) surrounded by an insulating cover and an electrical protection device (200) including: a conductive sleeve (280) arranged around the insulating cover, a biasing module (245) configured to voltage-bias the conductive sleeve (280), a circuit breaker (210) arranged on the conductor (240) and configured to cut off a current transiting through the conductor (240), and a detection module (220) connected to the conductive sleeve (280) and configured to detect a current leak out of the conductor (240) and to command the circuit breaker (210) on the basis of the detection. The invention also relates to a method for the secure supply of electric power.

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.

An electrical link including a protective sheath surrounding at least two conductors each covered by an insulating jacket and an electrical protection system includes: a conductive sheath on each of the insulating jackets, a circuit breaker for each conductor; a direct current generator generating a direct current to be successively applied to each conductive sheath; and a leakage current detection circuit for each conductive sheath; a sequencer successively supplying the direct current to each conductive sheath; the detection circuit measures a current in each conductive sheath and compares a voltage proportional to the current to a first and second ranges of values, the detection circuit activating the circuit breaker if: the voltage is outside of the first range of values while the current generator generates a non-zero current; or the voltage is outside of the second range of values.

An electrical link including a protective sheath surrounding at least two conductors each covered by an insulating jacket and an electrical protection system includes: a conductive sheath on each of the insulating jackets, a circuit breaker for each conductor; a direct current generator generating a direct current to be successively applied to each conductive sheath; and a leakage current detection circuit for each conductive sheath; a sequencer successively supplying the direct current to each conductive sheath; the detection circuit measures a current in each conductive sheath and compares a voltage proportional to the current to a first and second ranges of values, the detection circuit activating the circuit breaker if: the voltage is outside of the first range of values while the current generator generates a non-zero current; or the voltage is outside of the second range of values.

An intelligent leakage current detection and interruption device for a power cord, including a switch module for controlling electrical connection of two power lines between input and output ends; a leakage current detection module, including two leakage current detection lines and a signal feedback line, one end of the parallelly coupled two leakage current detection lines being coupled via the signal feedback line to a point between the two power lines, for respectively detecting a leakage current on the two power lines; a detection monitoring module, coupled to the leakage current detection module, for detecting open circuit conditions in the two leakage current detection lines; and a drive module, coupled to the switch module, the leakage current detection module and the detection monitoring module, for driving the switch module to disconnect power to the output end in response to any detected leakage current or open circuit condition.

A method detects a high-impedance ground fault in an electrical energy supply network with a grounded neutral point. A test signal is fed via a detection device into the energy supply network, the test signal has a frequency which differs from the network frequency of the energy supply network. To enable a reliable detection, with low equipment costs, of high-impedance ground faults in energy supply networks with a grounded neutral point, a three-phase test signal is fed into the phase conductors of the energy supply network as the test signal. A measuring signal which indicates the residual voltage of the test signal is generated with the detection device. The residual voltage is compared with a threshold value using a test device of the detection device, and the presence of a high-impedance ground fault is detected if the residual voltage exceeds the threshold value.

A method detects a high-impedance ground fault in an electrical energy supply network with a grounded neutral point. A test signal is fed via a detection device into the energy supply network, the test signal has a frequency which differs from the network frequency of the energy supply network. To enable a reliable detection, with low equipment costs, of high-impedance ground faults in energy supply networks with a grounded neutral point, a three-phase test signal is fed into the phase conductors of the energy supply network as the test signal. A measuring signal which indicates the residual voltage of the test signal is generated with the detection device. The residual voltage is compared with a threshold value using a test device of the detection device, and the presence of a high-impedance ground fault is detected if the residual voltage exceeds the threshold value.