AC Power Distribution System with Transient Suppression and Harmonic Attenuation

Abstract

An AC power distribution unit for coupling AC power having a fundamental frequency to a plurality of electrical loads has an enclosure. A power input feed is retained by the enclosure for coupling to a source of the AC power. A plurality of power output feeds is retained by the enclosure for coupling to the plurality of electrical loads. A harmonic mitigation module is retained in the enclosure and is connected in series between the power input feed and the plurality of power output feeds. The harmonic mitigation module bilaterally reduces harmonic current distortion above a predetermined frequency between the power input feed and the plurality of power output feeds.

1 . An AC power distribution unit for coupling AC power having a fundamental frequency to a plurality of electrical loads, comprising:
 a wall-mounted enclosure;   a power input feed in said enclosure for coupling to a source of said AC power;   a plurality of power output feeds in said enclosure for coupling to said plurality of electrical loads; and   a harmonic mitigation module retained in said enclosure and connected in series between said power input feed and said plurality of power output feeds, said harmonic mitigation module bilaterally reducing harmonic current distortion with respect to said plurality of electrical loads above a predetermined frequency between said power input feed and said plurality of power output feeds while harmonic current is distortion at said predetermined odd harmonic is substantially unreduced.   
   
   
       2 . The unit of  claim 1  wherein said predetermined frequency is comprised of a third harmonic of said fundamental frequency. 
   
   
       3 . The unit of  claim 1  further comprising:
 a surge suppression device mounted within said enclosure and coupled to said power output feeds for operating with said electrical loads.   
   
   
       4 . The unit of  claim 1  in a panelboard configuration further comprising:
 a plurality of overcurrent protection elements mounted within said enclosure, each overcurrent protection element providing a respective power output feed.   
   
   
       5 . The unit of  claim 1  wherein said predetermined frequency is comprised of a third harmonic of said fundamental frequency, and wherein said unit further comprises:
 an isolating transformer mounted within said enclosure and coupled between said power input feed and said plurality of power output feeds, wherein said isolating transformer substantially reduces said third harmonic.   
   
   
       6 . The unit of  claim 1  in a point-of-use configuration further comprising:
 a plurality of receptacles supported on said enclosure and connected to respective power output feeds.   
   
   
       7 . The unit of  claim 6  further comprising:
 an isolating transformer mounted within said enclosure and coupled between said power input feed and said plurality of power output feeds, wherein said isolating transformer is selected from the group comprising a K-rated type transformer, and isolation type transformer, a zig-zag type transformer, and a ferroresonant voltage regulator type transformer.   
   
   
       8 . The unit of  claim 6  further comprising:
 a surge suppression device mounted within said enclosure and coupled to said power output feeds for operating with said electrical loads.   
   
   
       9 . The unit of  claim 1  wherein said harmonic mitigation module comprises a line reactor. 
   
   
       10 . The unit of  claim 1  wherein said harmonic mitigation module comprises a lowpass filter. 
   
   
       11 . The unit of  claim 1  wherein said harmonic mitigation module comprises a choke filter. 
   
   
       12 . An electrical panelboard for supplying AC power having a fundamental frequency from an input power feed to electrical loads on a plurality of branch circuits, said panelboard comprising:
 a wall-mount enclosure;   a phase bus in said enclosure;   a plurality of circuit breakers in said enclosure connected to said phase bus and having an output terminal for coupling to a respective branch circuit;   a TVSS module in said enclosure coupled with said branch circuits for lo suppressing transient voltages and surges to said branch circuits; and   a harmonic mitigation module in said enclosure coupled with said branch circuits for bilaterally reducing harmonic current distortion with respect to said electrical loads above a predetermined frequency while harmonic current distortion at said predetermined odd harmonic is substantially unreduced.   
   
   
       13 . The electrical panelboard of  claim 12  wherein said wall-mount enclosure is adapted for flush mounting between standard wall studs. 
   
   
       14 . The electrical panelboard of  claim 12  wherein said wall-mount enclosure is adapted for surface mounting.