# US 2024/0204501 A1 · Ac busbar for current sharing between parallelly connected semiconductor switching pairs > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2024/0204501 A1 - Document ID: US20240204501A1 - Status: Published application - Kind: A1 - Application number: 18/067,152 - Filed: 2022-12-16 - Published: 2024-06-20 - Earliest claimed: 2022-12-16 - Assignees: BAE Systems Controls Inc. - Applicants: BAE Systems Controls Inc. - Inventors: Robert J. Vovos; Arthur P. Lyons; Stephen L. Homan - Web page: https://patentgrep.com/patent/US20240204501A1 ## CPC - H02G 5/02: Open installations - H02M 7/003: {Constructional details, e.g. physical layout, assembly, wiring or busbar connections} - H02G: INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) ## Abstract An AC busbar for connecting at least three phases from a semiconductor switching unit to a load is provided. The AC busbar parallelly connects the at least three phases and provides current balancing. The AC busbar has a terminal-side conductor mechanically connectable to each AC terminal of the semiconductor switching unit and a load-side conductor positioned between the terminal-side conductor and the load. A distance between the terminal-side conductor and the load-side conductor is such that a difference in an inductance between a connection point for a respective AC terminal of each phase and a common point on a middle of the load-side conductor is less than a predetermined percentage with respect to an average of the respective inductances. ## Claims ### Claim 1 An AC busbar configured to connect at least three phases from a semiconductor switching unit to a load, each phase having an AC terminal, wherein the at least three phases are connected in parallel by the AC busbar, the AC busbar comprising: a terminal-side conductor mechanically connectable to each AC terminal of the semiconductor switching unit; a load-side conductor positioned between the terminal-side conductor and the load, the load-side conductor being parallel to the terminal-side conductor; two connecting conductors connecting the terminal-side conductor and the load-side conductor; and a conductor orthogonally projecting from the load-side conductor, the orthogonally projecting conductor configured to be connected with the load, the orthogonally projecting conductor is centered on the load-side conductor, wherein a distance between the terminal-side conductor and the load-side conductor is such that a difference in an inductance between a connection point for a respective AC terminal of each phase and a common point on a middle of the load-side conductor is less than a predetermined percentage with respect to an average of the respective inductances. ### Claim 2 (depends on 1) The AC busbar of claim 1, wherein the predetermined percentage is about 10%. ### Claim 3 (depends on 1) The AC busbar of claim 1, wherein the terminal-side conductor, the load-side conductor and the two connecting conductors form a rectangular shape. ### Claim 4 (depends on 1) The AC busbar of claim 1, wherein each connecting conductor is configured and dimensioned to be surrounded by a current sensor. ### Claim 5 (depends on 1) The AC busbar of claim 1, wherein each connecting conductor is configured for substantially a same current. ### Claim 6 (depends on 1) The AC busbar of claim 1, wherein a cross-sectional area of each connecting conductor is configured for at least 450 A. ### Claim 7 (depends on 1) The AC busbar of claim 1, wherein there are three-phases and three AC terminals, one per phase and wherein the terminal-side conductor has three corresponding openings to mount the AC busbar to the three AC terminals. ### Claim 8 (depends on 7) The AC busbar of claim 7, wherein a distance AC current travels from a connection point for the central terminal of the three-phases along the AC busbar to the common point is asymmetric with a distance AC current travels from the connection point for the end terminals of the three-phases of the semiconductor switching unit to the common point. ### Claim 9 (depends on 1) The AC busbar of claim 1, wherein the orthogonally projecting conductor is configured and dimensioned for a current of at least 900 A. ### Claim 10 (depends on 7) The AC busbar of claim 7, wherein the orthogonally projecting conductor is aligned with the connection point for the central terminal of the three-phases. ### Claim 11 (depends on 1) The AC busbar of claim 1, wherein a distance between the terminal-side conductor and the load-side conductor is greater than about 25 mm and less than about 40 mm. ### Claim 12 (depends on 1) The AC busbar of claim 1, wherein the terminal-side conductor, the two connecting conductors, the load-side conductor and the conductor orthogonally projecting from the load-side conductor are continuous and formed from a single conductor. ### Claim 13 (depends on 1) The AC busbar of claim 1, wherein the terminal-side conductor and the two connecting conductors is formed from a single conductor. ### Claim 14 (depends on 1) The AC busbar of claim 1, wherein the inductance difference between the respective connection points and the common point is less than about 2 nH. ### Claim 15 (depends on 14) The AC busbar of claim 14, wherein the current difference between the terminals is less than about 5% for a current of about 1000 hz. ### Claim 16 An AC busbar configured to connect at least three phases from a semiconductor switching unit to a load, each phase having an AC terminal, wherein the at least three phases are connected in parallel by the AC busbar, the AC busbar comprising: a terminal-side conductor mechanically connectable to each AC terminal of the semiconductor switching unit; a load-side conductor positioned between the terminal-side conductor and the load; two connecting conductors connecting the terminal-side conductor and the load-side conductor; and a conductor orthogonally projecting from the load-side conductor, the orthogonally projecting conductor configured to be connected with the load, the orthogonally projecting conductor is centered on the load-side conductor, wherein a distance between the terminal-side conductor and the load-side conductor is such that a difference in an inductance between a connection point for a respective AC terminal of each phase and a common point on a middle of the load-side conductor is less than a predetermined percentage with respect to an average of the respective inductances.