Abstract: Nuisance tripping is reduced in a power protection and distribution system including an upstream circuit breaker, a power distribution bus, and one or more downstream circuit breakers. A signal indicative of a current or pending downstream circuit breaker tripping action, such as a Zone Selective Interlocking (ZSI) signal, normally used to delay tripping of the upstream breaker, is used to suppress an optical flash detection system from tripping the upstream breaker in response to an optical flash resulting from the tripping of the downstream breaker. In this way, nuisance tripping of the upstream breaker is avoided when the downstream breaker trips (and the ZSI function is preserved).

Abstract: In a power protection and distribution assembly a trip system monitors electrical current and sends a current status signal to an arc flash protection system indicating whether current characteristic of an arc event is detected. The arc flash protection system evaluates this current status signal along with a light status signal indicating whether light characteristic of an arc event has been detected. Based on this evaluation, the arc flash protection system sends a control signal to the trip system for controlling the trip system to trip a breaker. The systems each include a full-duplex signaling module for sending the signals between the systems over a pair of conductors. Each signaling module sends one of the signals by modulating the magnitude of a current through or a voltage across the conductors, and receives the other signal by demodulating the magnitude of the current through or the voltage across the conductors, as distinctively modulated by the other signaling module.

Abstract: In a power protection and distribution assembly a trip system monitors electrical current and sends a current status signal to an arc flash protection system indicating whether current characteristic of an arc event is detected. The arc flash protection system evaluates this current status signal along with a light status signal indicating whether light characteristic of an arc event has been detected. Based on this evaluation, the arc flash protection system sends a control signal to the trip system for controlling the trip system to trip a breaker. The systems each include a full-duplex signaling module for sending the signals between the systems over a pair of conductors. Each signaling module sends one of the signals by modulating the magnitude of a current through or a voltage across the conductors, and receives the other signal by demodulating the magnitude of the current through or the voltage across the conductors, as distinctively modulated by the other signaling module.

Abstract: Nuisance tripping is reduced in a power protection and distribution system including an upstream circuit breaker, a power distribution bus, and one or more downstream circuit breakers. A signal indicative of a current or pending downstream circuit breaker tripping action, such as a Zone Selective Interlocking (ZSI) signal, normally used to delay tripping of the upstream breaker, is used to suppress an optical flash detection system from tripping the upstream breaker in response to an optical flash resulting from the tripping of the downstream breaker. In this way, nuisance tripping of the upstream breaker is avoided when the downstream breaker trips (and the ZSI function is preserved).

Abstract: A power inverter comprises a push-pull inverter circuit that includes a transformer having a primary winding coupled to a DC bus and a secondary winding coupled to an AC bus, main power switches coupling each end of the primary winding to a DC return, and one or more supplemental power switches coupling at least one end of the primary winding to a snubber bus. The supplemental switch at a given end of the primary winding forms a buck-mode converter in combination with the primary winding and the associated free-wheeling diode at that end of the primary winding, and can be controlled by a switching controller to effect energy transfer between the snubber bus and DC bus. The switching controller can be configured to control power flow between the DC, AC, and snubber buses by controlling the common-mode and differential-mode voltages of the primary winding via main/supplemental power switch control.