# US 10,873,265 B2 · Bidirectional three-phase direct current (DC)/DC converters > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,873,265 B2 - Document ID: US10873265B2 - Status: Granted - Kind: B2 - Application number: 16/289,322 - Filed: 2019-02-28 - Published: 2019-12-12 - Granted: 2020-12-22 - Earliest claimed: 2018-06-12 - Assignees: Virginia Tech Intellectual Properties, Inc. - Applicants: Virginia Tech Intellectual Properties, Inc - Inventors: Hao Xue; Bin Li; Qiang Li; Fred C. Lee - Web page: https://patentgrep.com/patent/US10873265B2 ## CPC - H02M 3/33584: {Bidirectional converters} - H02M 7/219: in a bridge configuration - H02M 1/0058: {by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero (using an auxiliary actively switched resonant commutation circuit connected to an intermediate DC voltage or between two push-pull branches of an inverter bridge H02M7/4811; in resonant inverters H02M7/4815; in inverters operating from a resonant DC source H02M7/4826)} - Y02B 70/10: Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes - 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) - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract A bidirectional three-phase direct current (DC)/DC converter and method are disclosed. The converter comprises a primary side comprising a DC bus having a positive side and a negative side, a first set of rectifiers connected between the positive side and the negative side of the DC bus, a first set of M resonant tanks connected to a respective rectifier of the first set of rectifiers and a first set of M transformers. Each transformer is connected to a respective resonant tank. Each resonant tank comprises a resonant capacitor and a resonant inductor. The secondary side of the converter is fully symmetrical to the primary side of the converter to ensure that the conversion gain in the forward and reverse directions is the same. ## Claims ### Claim 1 A bidirectional three-phase direct current (DC)/DC converter comprising: a primary side comprising: a first DC bus having a positive side and a negative side; a first set of M rectifiers connected between the positive side and the negative side of the first DC bus, where M is a positive integer that is greater than or equal to three; a first set of M resonant tanks, each resonant tank connected to a respective rectifier of the first set of rectifiers, each resonant tank comprising a resonant capacitor and a resonant inductor; and M transformers, each transformer having a primary side and a secondary side, each resonant tank of the first set of M resonant tanks being connected to the primary side of a respective transformer; and a secondary side comprising: a second DC bus having a positive side and a negative side; a second set of M rectifiers connected between the positive side and the negative side of the second DC bus; and a second set of M resonant tanks, each resonant tank of the second set of M resonant tanks being connected to a respective rectifier of the second set of rectifiers, each resonant tank of the second set of M resonant tanks comprising a resonant capacitor and a resonant inductor, each resonant tank of the second set of M resonant tanks being connected to the secondary side of a respective transformer, wherein a gain in a forward direction of DC/DC conversion is substantially equal to a gain in a reverse direction of DC/DC conversion. ### Claim 2 (depends on 1) The bidirectional three-phase DC/DC converter of claim 1, wherein each rectifier of the first set of rectifiers is a half bridge rectifier. ### Claim 3 (depends on 2) The bidirectional three-phase DC/DC converter of claim 2, wherein each rectifier of the second set of rectifiers is a half bridge rectifier. ### Claim 4 (depends on 3) The bidirectional three-phase DC/DC converter of claim 3, wherein the resonant capacitors of the first set of M resonant tanks are delta-connected. ### Claim 5 (depends on 4) The bidirectional three-phase DC/DC converter of claim 4, wherein the resonant capacitors of the second set of M resonant tanks are delta-connected. ### Claim 6 (depends on 5) The bidirectional three-phase DC/DC converter of claim 5, wherein the resonant inductors of the first set of M resonant tanks are in series with the respective primary sides of the transformers. ### Claim 7 (depends on 6) The bidirectional three-phase DC/DC converter of claim 6, wherein the primary sides of the transformers are Y-connected. ### Claim 8 (depends on 7) The bidirectional three-phase DC/DC converter of claim 7, wherein the resonant inductors of the second set of M resonant tanks are in series with the respective primary sides of the transformers. ### Claim 9 (depends on 8) The bidirectional three-phase DC/DC converter of claim 8, wherein the secondary sides of the transformers are Y-connected. ### Claim 10 (depends on 9) The bidirectional three-phase DC/DC converter of claim 9, wherein the resonant inductors of the first and second sets of M resonant inductors and the transformers are integrated into a single magnetic core. ### Claim 11 (depends on 3) The bidirectional three-phase DC/DC converter of claim 3, wherein each half bridge rectifier comprises first and second switches in parallel with first and second diodes, respectively, each resonant tank of the first set of M resonant tanks being connected to the respective rectifier of the first set of M half bridge rectifiers at a node in between the first and second switches. ### Claim 12 (depends on 3) The bidirectional three-phase DC/DC converter of claim 3, wherein the resonant capacitors of the first and second sets of M resonant tanks have capacitance values that are substantially equal. ### Claim 13 (depends on 3) The bidirectional three-phase DC/DC converter of claim 3, wherein the resonant capacitors of the first set of M resonant tanks have capacitance values that are unequal to the capacitance values of the resonant capacitors of the second set of M resonant tanks. ### Claim 14 (depends on 3) The bidirectional three-phase DC/DC converter of claim 3, wherein the resonant inductors of the first and second sets of M resonant tanks have inductance values that are substantially equal. ### Claim 15 (depends on 3) The bidirectional three-phase DC/DC converter of claim 3, wherein the resonant inductors of the first set of M resonant tanks have inductance values that are unequal to the inductance values of the resonant inductors of the second set of M resonant tanks. ### Claim 16 (depends on 3) The bidirectional three-phase DC/DC converter of claim 3, wherein the primary and secondary sides of the transformers have equal turns ratios. ### Claim 17 (depends on 3) The bidirectional three-phase DC/DC converter of claim 3, wherein the primary and secondary sides of the transformers have unequal turns ratios. ### Claim 18 A bidirectional three-phase direct current (DC)/DC converter comprising: a primary side comprising: a first DC bus having a positive side and a negative side; a first set of half bridge rectifiers connected between the positive side and the negative side of the first DC bus, where M is a positive integer that is greater than or equal to three; a first set of M resonant tanks, each resonant tank of the first set of M resonant tanks being connected to a respective half bridge rectifier of the first set of M half bridge rectifiers, each resonant tank comprising a resonant capacitor and a resonant inductor, the resonant capacitors being delta-connected; and M transformers, each transformer having a primary side that is connected to a respective resonant tank of the first set of M resonant tanks, the primary sides of the transformers being Y-connected; and a secondary side comprising: a second DC bus having a positive side and a negative side; a second set of half bridge rectifiers connected between the positive side and the negative side of the second DC bus; and a second set of M resonant tanks, each resonant tank of the second set of M resonant tanks being connected to a respective half bridge rectifier of the second set of M half bridge rectifiers, each resonant tank of the second set of M resonant tanks comprising a resonant capacitor and a resonant inductor, the resonant capacitors of the second set of M resonant tanks being delta-connected, each transformer having a secondary side that is connected to a respective resonant tank of the second set of M resonant tanks, the secondary sides of the transformers being Y-connected, wherein a gain in a forward direction of DC/DC conversion is substantially equal to a gain in a reverse direction of DC/DC conversion.