The present invention provides a trip control circuit for a circuit breaker capable of breaking a circuit when a fault current occurs due to a DC current component, as well as an AC current. The trip control circuit comprises a current transformer that has a core allowing a circuit to pass through and a secondary coil for detecting a current flowing on the circuit and providing a current detection signal; an oscillation circuit section that configured to apply an electrical signal to the secondary coil to increase a slope of a hysteresis loop of the current transformer to allow the secondary coil to detect a DC current and an AC current; and a trip determining circuit section that configured to compare a current value indicated by the current detection signal with a predetermined reference current value.

Unique systems, methods, techniques and apparatuses of fault location in DC power distribution systems are disclosed. One exemplary embodiment is a DC power distribution system including a plurality of zones each including a DC power distribution line and a protective device. Each protective device structured to sense one or more electrical characteristics of a line and to controllably open a circuit including the line. At least one intelligent electronic device is structured to determine a line inductance based upon electrical characteristics sensed by one or more of the protective devices and to evaluate a location of the line fault based upon the determined line inductance.

A wireless electric vehicle charging system comprises base-side equipment for generating a magnetic field and vehicle-side equipment for receiving energy via the magnetic field to supply power to a vehicle-driving battery. Monitoring circuitry monitors one or more of voltage, current, or phase associated with the base-side equipment and halts generation of the magnetic field in response to a change in the voltage, current, or phase associated with the operation of the base-side equipment that indicates a fault condition at the vehicle-side equipment, which may include a loss of power or disconnection of a battery. Based on detection of the change, the monitoring circuitry can halt generation of the magnetic field to prevent damage at the vehicle-side equipment.

An apparatus for detecting a defect of an electric power system according to one embodiment of the present disclosure includes a first state signal output unit for outputting a first state signal corresponding to a magnetic force generated at a periphery of a line, a second state signal output unit for outputting a second state signal based on a magnitude of a line current and an increase ratio thereof, and a determination unit for determining whether the electric power system is defective or not based on the first state signal and the second state signal.

A power system comprises a power source, a transmission line coupled to the power source through a circuit breaker, a shunt reactor coupled to the transmission line, and a current transformer connected in series with the shunt reactor. A method for controlling the circuit breaker of the power system comprises processing an output signal of the current transformer to obtain the voltage on the transmission line by determining a time derivative of a current sensed by the current transformer. The method further comprises performing, by at least one control or protection device, a control or protection operation (e.g., auto-reclosing) based on the determined time derivative of the current sensed by the current transformer.

A power system comprises a power source, a transmission line coupled to the power source through a circuit breaker, a shunt reactor coupled to the transmission line, and a current transformer connected in series with the shunt reactor. A method for controlling the circuit breaker of the power system comprises processing an output signal of the current transformer to obtain the voltage on the transmission line by determining a time derivative of a current sensed by the current transformer. The method further comprises performing, by at least one control or protection device, a control or protection operation (e.g., auto-reclosing) based on the determined time derivative of the current sensed by the current transformer.

An electronic circuit for single-event latch-up (SEL) detection and protection of a target integrated circuit (IC) is disclosed. The circuit comprises: a first detector configured for detecting an absolute load current (i) and comparing the absolute load current (i) with a threshold current (i.sub.th); a second detector configured for detecting a rate of change of load current (di/dt) and comparing the rate of change of load current (di/dt) with a threshold current change rate (di/dt).sub.th; and a determination module for triggering a power shut-down to the target IC if the absolute load current (i) exceeds the threshold current (i.sub.th) and/or the rate of change of load current (di/dt) exceeds the threshold current change rate (di/dt).sub.th.

In a circuit breaker arrangement, this disclosure describes a method and circuit design enables a current transformer to be used to detect ground faults in circuit breakers (such as a main-tie-main circuit breakers) that have been designed to receive signals from Rogowski coils.

Power distribution systems and methods are described. In one example, a method of determining by a first circuit protection device in a zone selective interlocking (ZSI) system whether to output a blocking signal to a second circuit protection device in the ZSI system is described. The method includes detecting, by a current rate of change sensor, a rate of change of a current flowing through the first circuit protection device. A trip unit receives a current rate of change signal from the current rate of change sensor. The current rate of change signal is proportional to the detected rate of change of the current flowing through the first circuit protection device. The trip unit determines whether to output the blocking signal to the second circuit protection device based, at least in part, on the current rate of change signal.

Power distribution systems and methods are described. In one example, a method of determining by a first circuit protection device in a zone selective interlocking (ZSI) system whether to output a blocking signal to a second circuit protection device in the ZSI system is described. The method includes detecting, by a current rate of change sensor, a rate of change of a current flowing through the first circuit protection device. A trip unit receives a current rate of change signal from the current rate of change sensor. The current rate of change signal is proportional to the detected rate of change of the current flowing through the first circuit protection device. The trip unit determines whether to output the blocking signal to the second circuit protection device based, at least in part, on the current rate of change signal.