Abstract: A fault current limiter (FCL) for limiting a fault current in a power line during a fault condition. The FCL includes a magnetic coupling circuit for monitoring current in the power line through magnetic coupling; a sensing circuit for sensing the current in the power line and providing a signal indicative of the sensed current; a control circuit receiving the signal indicative of the sensed current in the power line and determining whether the sensed current indicates that the fault condition exists; and high and low impedance paths that are connected in parallel. The high impedance path includes a discharging impedance circuit for limiting the fault current. The low impedance path includes a reactor circuit and a switching unit having an ON state for conducting current through the low impedance path and an OFF state for conducting current through the high impedance path.

Abstract: A photovoltaic string monitor that provides PV-string level monitoring to detect abnormal operating conditions. The photovoltaic string monitor includes an indicator unit for indicating normal conditions, existing abnormal conditions or past occurrence of abnormal conditions. In one embodiment, the photovoltaic string monitor includes a plurality of lights and an LCD display.

Abstract: A fault current limiter (FCL) for limiting a fault current in a power line during a fault condition. The FCL includes a magnetic coupling circuit for monitoring current in the power line through magnetic coupling; a sensing circuit for sensing the current in the power line and providing a signal indicative of the sensed current; a control circuit receiving the signal indicative of the sensed current in the power line and determining whether the sensed current indicates that the fault condition exists; and high and low impedance paths that are connected in parallel. The high impedance path includes a discharging impedance circuit for limiting the fault current. The low impedance path includes a reactor circuit and a switching unit having an ON state for conducting current through the low impedance path and an OFF state for conducting current through the high impedance path.

Abstract: An integrated magnetic flyback converter includes interleaved phases that can be connected in series for an input stage and in parallel for an output stage. An integrated magnetic core has legs with gaps that may weaken a coupling between a primary and secondary of the associated transformer. The primary and secondary of the transformer may be inversely coupled for each phase. The transformer leg gaps permit each phase to be operated with a duty cycle ratio greater than 50%. The interleaved converter has reduced output current ripple, reduced input component voltage stress, reduced magnetizing inductance, reduced magnetic component physical size and reduced common integrated magnetic core current spikes.

Abstract: An integrated magnetic assembly that allows the primary and secondary windings of a transformer and a separate inductor winding to be integrated on a unitary magnetic structure is disclosed. The unitary magnetic structure includes first, second, and third legs that are physically connected and magnetically coupled. The primary and secondary windings of the transformer can be formed on the third leg of the unitary magnetic structure. Alternatively, the primary and secondary windings can be split between the first and second legs. Thus, the primary winding includes first and second primary windings disposed on the first and second legs and the secondary winding includes first and second secondary windings disposed on the first and second legs. The inductor winding may also be formed either on the third leg or it may split into first and second inductor windings and disposed on the first and second legs. In addition, one or more legs may include an energy storage component such as an air gap.

Abstract: A current-fed DC-DC converter has a topology that improves converter performance and operates an input inductor in continuous conduction mode. The configuration and operation of the converter produces reduced requirements for circuit component ratings and leads to faster transient response time than conventional current-fed DC-DC converters. The converter can operate as an apparent current-fed full bridge converter in one stage, and an apparent current-fed half bridge converter in another stage. The input inductor is configured and operated to release stored energy to the load in conjunction with other energy storage components to provide a continuous output current that significantly reduces output voltage ripple, leading to reduced rating requirements and output components. The converter topology permits a portion of the switching stage to operate with no deadtime to further improve circuit responsiveness and efficiency.

Abstract: An integrated magnetic assembly that allows the primary and secondary windings of a transformer and a separate inductor winding to be integrated on a unitary magnetic structure is disclosed. The unitary magnetic structure includes first, second, and third legs that are physically connected and magnetically coupled. The primary and secondary windings of the transformer can be formed on the third leg of the unitary magnetic structure. Alternatively, the primary and secondary windings can be split between the first and second legs. Thus, the primary winding includes first and second primary windings disposed on the first and second legs and the secondary winding includes first and second secondary windings disposed on the first and second legs. The inductor winding may also be formed either on the third leg or it may split into first and second inductor windings and disposed on the first and second legs. In addition, one or more legs may include an energy storage component such as an air gap.