An overcurrent protection device is to be provided between a power supply and a load circuit including an electric load and an electric wire electrically connected with each other, and includes a switching element, a current detector, a characteristic estimation portion, and a controller. The switching element switches flowing and interrupting of a load current that flows from the power supply to the electric load. The current detector detects the load current. The characteristic estimation portion estimates a thermal characteristic of the electric wire based on the load current detected by the current detector. The controller outputs an overcurrent protection signal for interrupting the load current so as to protect the load circuit from an overcurrent to the switching element based on the thermal characteristic estimated by the characteristic estimation portion and the load current detected by the current detector.

A leakage current detection and interruption (LCDI) device for power cord, and power connector and appliance employing the same. The LCDI device includes a switch module coupled on the power supply lines to control electrical connection between input and output ends of the device; a leakage current detection module including a leakage current detection line, for detecting a leakage current on the power supply lines and outputting a leakage current fault signal accordingly; a drive module, for driving the switch module to disconnect the electrical connection in response to the leakage current fault signal and/or an open circuit fault signal, the open circuit fault signal representing an open circuit condition of the leakage current detection line; and a test module including a test switch, coupled to the leakage current detection module, where the leakage current detection module outputs the leakage current fault signal when the test switch is closed.

The wide application of power electronic components in power systems with renewable energy sources has changed the fault characteristics of conventional power systems, resulting in the performance degradation of conventional protections. To solve these problems, a novel principle of pilot protection based on structural similarity and square error criteria is provided. The structural similarity criterion utilizes the difference of fault characteristics between renewable sources and synchronous generators to identify internal faults, and the square error criterion is used to solve abnormal calculation of the conventional similarity based protection. Compared with conventional differential protections, the disclosed protection shows excellent performance in speed and reliability during various faults.

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 includes an electrical protection device. The electrical link, for linking an AC high-voltage generator to a user apparatus, includes an electrical conductor surrounded by a first inner insulating envelope. An electrical protection device includes a conductive sheath around the inner insulating envelope. A fixed DC current generator is connected to a current injection point of the conductive sheath. A circuit breaker that can be activated is on the electrical conductor and configured to break the electrical link when it is activated. A detection module is connected to a current tap-off point of the conductive sheath and to the circuit breaker, the detection module being configured to detect a break in the conductive sheath, a current leak out of the electrical conductor or a current leak out of the sheath and to activate the circuit breaker.

Circuits, methods, and apparatus that may provide power supply voltages in a safe and reliable manner that meets safety and regulatory concerns and does not exceed physical limitations of cables and other circuits and components used to provide the power supply voltages. One example may provide a cable having a sufficient number of conductors to provide power without exceeding a maximum current density for the conductors. Another example may provide a cable having more than the sufficient number of conductors in order to provide an amount of redundancy. Current sense circuits may be included for one or more conductors. When an excess current is sensed, a power source in the power supply may be shut down, the power source may be disconnected from one or more conductors, or both events may occur.

An intelligent leakage current detection and interruption device for a power cord, including a switch module configured to control electrical connection of first and second power lines between input and output ends; a leakage current detection module, including first and second leakage current detection lines coupled in series, configured to detect a leakage current on the first and second power lines, respectively; a detection monitoring module, coupled in series to the first and second leakage current detection lines and to the first and second power lines, configured to detect an open circuit condition in the first or second leakage current detection line; and a drive module, coupled to the switch module, the leakage current detection module and the detection monitoring module, configured to drive the switch module to cut off power to the output end in response to any detected leakage current or open circuit condition.

A surge protector for providing electricity to an electronic device. The surge protector including a housing defining a module slot and including a module connector positioned within the module slot and a module insertable into the module slot and including at least one connector port and a housing connector. The housing connector can be operably connectable to the module connector when the module is inserted into the module slot. The cable can be connected to the module and housing such that the module can be positioned at a location remote from the housing.

A power cord leakage current detection and protection device, including: a switch unit controlling an electrical connection between input and output ends of the device, a switch drive module, and a leakage current detection circuit which includes a leakage current detection line for detecting a leakage current on a power supply line. The switch drive module includes a semiconductor device assembly, and a solenoid assembly coupled between a power supply line and the semiconductor device assembly. The solenoid assembly includes multiple coils with their current paths coupled in parallel; the semiconductor device assembly includes multiple semiconductor devices with their current paths coupled in parallel. When at least one coil is not an open-circuit and at least one semiconductor device is not an open-circuit, the switch drive module controls the switch unit based on a leakage current signal detected by the leakage current detection circuit to disconnect the power supply.

An electric wire protection device includes a voltage adjusting unit that adjusts voltage of a power source side and supplies the resulting voltage to a load, and a controller that includes a calculation unit configured to compute temperature information of an electric wire connecting the power source and the load from a value of an electric current flowing through the voltage adjusting unit, and that is configured to make the voltage adjusting unit into a shutoff state of shutting off the power source and the load on the basis of the temperature information.