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.

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 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 negative sequence voltage (NSV) protection system is provided that can be added to existing equipment or included as a standalone device for detecting GFOV in electrical configurations connecting distributed energy resources to utility grids. The NSV protection system can be implemented at the low side of a distribution transformer of a typical distribution circuit or in a control system of inverter-based energy resources connected to a distribution feeder. The NSV protection system includes a passive monitoring system that outputs a trip signal when a potential GFOV is detected to occur. The trip signal can then be relayed to open the circuit breakers of a distribution circuit or to cause an inverter-based energy resource to trip offline.

An AC-DC power supply receives input AC power and outputs DC power. The converter includes a high power factor bridge rectifier, a barrier circuit with resistor(s) and capacitor(s), and a step-down switching DC-DC converter to step-down a first DC voltage to a second, lower, DC voltage for output. Additionally, fault-protection is provided by redundancy in diodes on diode legs of a bridge rectifier and capacitor(s) of a filter circuit thereof, and a fault-protection circuit to sense current from a step-down switching DC-DC converter, a first voltage from the step-down switching DC-DC converter, and/or a second voltage at an output of the step-down switching DC-DC converter, and open the circuit on a fault.

Systems and methods provide an alternative high voltage cutoff technique for disconnecting a high voltage battery from an electrical network of a vehicle in the event of a fault condition. Embodiments include a vehicle system comprising an electrical bus and a battery module coupled to the electrical bus via a contactor and a disconnector. The vehicle system further includes a controller configured to switch the contactor to an open state, upon receiving a fault condition signal, and if the contactor failed to open, activating the disconnector to break electrical connection between the battery module and the electrical bus. In some embodiments, the fault condition signal is generated upon detecting a vehicular impact. In some embodiments, the disconnector is a pyrotechnic device powered by a vehicle battery included in the vehicle system.

A leakage current interruption device comprises: the leakage current interruption device in which it is coupled electrically between the power switch and the load: the first and second input stages coupled with a side of the power source; the first and second output stages coupled with a side of the load; the first and second switching members for turning on and off respectively the electrical connection between the first and second input stages and the first and second output stages; a switching driving member in which it is coupled between the first and second input stages and generates and outputs a switching driving signal to turn on or off the first and second switching members according to the on or off signals of the power switch.

The present invention discloses a short-circuit-protection electronic switch serial connect to the load, which is applied to the load control in a DC or AC power supply occasion. With load over-current and short-circuit-protection function, it is characterized in that the primary switch component is a part of the cut-off-type positive feedback protective trigger circuit, the primary switch component and the positive feedback gate element form a cut-off-type positive feedback protective trigger circuit. It can be widely applied to directly turn-on and turn-off control of all kinds of serial connection AC or DC load devices phase angle control and PWM control fields.

The present invention discloses a short-circuit-protection electronic switch serial connect to the load, which is applied to the load control in a DC or AC power supply occasion. With load over-current and short-circuit-protection function, it is characterized in that the primary switch component is a part of the cut-off-type positive feedback protective trigger circuit, the primary switch component and the positive feedback gate element form a cut-off-type positive feedback protective trigger circuit. It can be widely applied to directly turn-on and turn-off control of all kinds of serial connection AC or DC load devices phase angle control and PWM control fields.

A power converting device includes a DC-DC converting circuit, a DC-AC converting circuit, and an insulation detecting circuit. The DC-DC converting circuit is configured to convert a DC input voltage to a DC bus voltage. The DC-AC converting circuit is electrically coupled to the DC-DC converting circuit and configured to convert the DC bus voltage to an AC voltage. The insulation detecting circuit is electrically coupled between the DC-DC converting circuit and the DC-AC converting circuit. The insulation detecting circuit is configured to detect a ground impedance value of the power converting device according to the DC bus voltage.