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US 4,723,188 AGranted
Permanent magnet surge arrestor for DC power converter
AssigneeGeneral Electric Company
InventorWilliam McMurray
Life of this patent
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AssigneeGeneral Electric Company
InventorWilliam McMurray
Estimating the term…
An improved surge current limiting method and apparatus is provided for an inverter circuit. The inverter includes electronic switching devices serially connected between relatively positive and negative voltage buses and alternately conductive for providing alternating current paths through a load connected to a terminal intermediate the two switching devices. An inductor connected in series with the switching devices is provided with a permanent magnet core which is magnetically polarized in a direction such that current through the inductor attempts to reverse the magnetic polarity of the permanent magnet. The inductor is sized such that normal current through the inductor is not appreciably attenuated by the inductance. Under fault current conditions, the magnetic field generated by the higher currents through the inductor is opposed by the magnetic field of the permanent magnet so as to provide a substantial current limiting effect. The permanent magnet current limiting inductor may be used in various locations in an inverter circuit and may be applied to either single phase or multi-phase inverters.
An inverter with surge current limiting, comprising:
In a voltage conversion system for providing an alternating current output, the system including at least two controllable switching devices and circuit means coupling said switching devices serially between relatively positive and negative voltage buses, the devices being alternately conducting for producing the alternating current output at an intermediate connection, said circuit means including apparatus for limiting fault currents, said apparatus comprising at least one inductor having a permanent magnet core, said inductor being serially connected in a fault current path and being poled such that current through said inductor creates a magnetic field opposite in polarity to the field of said core.
In a voltage conversion system for regulating current to a load, the system including at least one controllable switching device and circuit means for coupling said switching device in series with the load between relatively positive and negative voltage buses, the switching device being gated between conductive and nonconductive states for regulating load current, said circuit means including apparatus for limiting fault currents, said apparatus comprising at least one inductor having a permanent magnet core, said inductor being connected in a fault current path and being poled such that current through said inductor creates a magnetic field opposite in polarity to the magnetic field of said core.
Dependencies are inferred from the claim text.