A system is provided that includes a power transmitter configured to provide power to a current loop, a power receiver configured to receive the power from the current loop. The power receiver is configured to, on a periodic basis, disconnect from the current loop to stop pulling power from the current loop for a period of time to enable a safety check to be performed by the power transmitter. The power transmitter is configured to: monitor current on the current loop; determine whether a current level on the current loop passes the safety check within a predetermined time interval since a determination that the current level was not within a safe range; and control connectivity of the power to the current loop depending on whether the safety check has or has not passed within the predetermined time interval.

An object is to provide a DC power supply connector that can suppress occurrence of an arc discharge at DC power off with a small-scale configuration without reducing power efficiency during DC power supply and can reduce heat generation.

The connector includes, on at least any of a positive-electrode-side electrode side and a negative-electrode-side electrode side, a movable contact piece (20c) that touches a first contact (25) in a state where a terminal (11) on a power receiving side has been inserted and to touch a second contact (24) in a state where the terminal has not been inserted, and a current limiting circuit (30) including a switching element (T1). The current limiting circuit (30) does not flow a current to the switching element (T1) in the case where the movable contact piece (20c) is touching the first contact (25), and flows a current to the terminal (11) through the movable contact piece (20c) until the movable contact piece (20c) is linked to the second contact (24) after separation from the first contact (25), and gradually decreases the flowing current.

An object is to provide a DC power supply connector that can suppress occurrence of an arc discharge at DC power off with a small-scale configuration without reducing power efficiency during DC power supply and can reduce heat generation.

The connector includes, on at least any of a positive-electrode-side electrode side and a negative-electrode-side electrode side, a movable contact piece (20c) that touches a first contact (25) in a state where a terminal (11) on a power receiving side has been inserted and to touch a second contact (24) in a state where the terminal has not been inserted, and a current limiting circuit (30) including a switching element (T1). The current limiting circuit (30) does not flow a current to the switching element (T1) in the case where the movable contact piece (20c) is touching the first contact (25), and flows a current to the terminal (11) through the movable contact piece (20c) until the movable contact piece (20c) is linked to the second contact (24) after separation from the first contact (25), and gradually decreases the flowing current.

A vehicle power supply device converts power from high voltage to low voltage by selectively connecting a predetermined power storage element group to a low voltage electric load from a high voltage power supply formed by connecting power storage elements in series. A leakage current from the high voltage power supply is measured during the dead time period when the power storage element group is not connected to the low voltage electric load. When the value exceeds a predetermined value, the connection between the power storage element group and the low-voltage electric load is interrupted, so that electric shock is prevented.

A method for discharging a vehicle high-voltage electrical system, which is galvanically isolated from a ground potential, in the presence of a residual current makes provision for the following step: determining whether a residual current flows between a first HV potential of the vehicle high-voltage electrical system and the ground potential or a residual current flows between a second HV potential of the vehicle high-voltage electrical system and the ground potential. The method furthermore makes provision to discharge only that Cy capacitance which exists between the ground potential and that HV potential from which or to which the residual current flows. The discharging is triggered by determining the existence of a residual current. Furthermore, an on-board vehicle electrical system and an insulation monitoring device which are designed for performing the method are described. In addition, a corresponding charging-station high-voltage electrical system is described.

A detector is provided that generates a leakage signal corresponding to a current imbalance between a line conductor and a neutral conductor for a load, and selectively injects a test signal into the neutral conductor. A frequency of the test signal substantially corresponds to a utility frequency. The detector measures a first value of the leakage signal, determines if the first value is less than first threshold value, and begins injection of the test signal into the neutral conductor in response to determining that the that first value is less than the first threshold value. In response to injecting the test signal, the detector measures a second value of the signal, determines if the second value is greater than a second threshold value, and disconnects the line conductor from the load in response to determining that the second value is greater than the second threshold value.

A protection device for an electric DC grid includes a first protection circuit part including a series circuit consisting of a first discharge resistor and a first protection switch between a positive potential line and a reference potential line and a second protection circuit part including a series circuit consisting of a second discharge resistor and a second protection switch between a negative potential line and the reference potential line. The first and second protection switches can be actuated to close if a first and/or second voltage measuring device ascertains that a specified voltage value has been undershot and/or exceeded or the first and/or second protection switch can be actuated to close in an event of a fault current measured by a fault-current measuring device.

A fault managed power system (FMPS) and method monitors and detects fault currents in PoE, PFC, and other cables that indicate likely human contact with cable conductors. The level of current detected through the human body combined with a fast response time limits the energy to prevent a person from experiencing ventricular fibrillation, resulting in a so-called touch-safe level. For overload and short-circuit fault protection, the system automatically and immediately removes power from the cables. This limits the amount of energy provided into the fault, thereby maintaining touch-safe operation and also preventing electrical fires and system component protection. The system/method can accomplish this even at voltage levels considerably higher than existing touch-safe standards, for example, Class 2 (below 50 Vac) power supplies. Such a system/method allows the amount of power in applications like PoE and PFC to be safely increased to levels much greater than the current maximum (100 W).

A fault managed power system (FMPS) and method monitors and detects fault currents in PoE, PFC, and other cables that indicate likely human contact with cable conductors. The level of current detected through the human body combined with a fast response time limits the energy to prevent a person from experiencing ventricular fibrillation, resulting in a so-called touch-safe level. For overload and short-circuit fault protection, the system automatically and immediately removes power from the cables. This limits the amount of energy provided into the fault, thereby maintaining touch-safe operation and also preventing electrical fires and system component protection. The system/method can accomplish this even at voltage levels considerably higher than existing touch-safe standards, for example, Class 2 (below 50 Vac) power supplies. Such a system/method allows the amount of power in applications like PoE and PFC to be safely increased to levels much greater than the current maximum (100 W).

An electrical installation includes: a switchgear cabinet; a protective switch arranged in the switchgear cabinet; at least one optical triggering device which is operatively connected to the protective switch and for triggering or switching off the protective switch upon optical detection of an arc; a detection device for detecting an access or an access request to a secured area of the electrical installation by detecting a presence of the at least one optical triggering device in a danger area of the electrical installation; and an electronic circuit which is connected to the detection device and allows, and otherwise prevents, a triggering or switching off of the protective switch by the at least one optical triggering device upon detection of the access or the access request, when the at least one optical triggering device is present in the danger area.