# US 12,003,182 B2 · DC-to-DC converter having a secondary resonant circuit capacitor, and method for operating a DC-to-DC converter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,003,182 B2 - Document ID: US12003182B2 - Status: Granted - Kind: B2 - Application number: 17/439,698 - Filed: 2020-02-17 - Published: 2022-05-26 - Granted: 2024-06-04 - Earliest claimed: 2019-03-21 - Assignees: Siemens Energy Global GmbH & Co. KG - Applicants: Siemens Energy Global GmbH & Co. KG - Inventors: Michael Finkenzeller; Mirjam Mantel; Monika Poebl - Web page: https://patentgrep.com/patent/US12003182B2 ## CPC - H02M 3/33584: {Bidirectional converters} - 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)} - H02M 3/01: {Resonant DC/DC converters} - H02M 3/33573: {Full-bridge at primary side of an isolation transformer} - H02M 7/4815: {Resonant converters (H02M7/4811 and H02M7/4826 take precedence)} - 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 DC-to-DC converter includes a primary side of a transformer element of the DC-to-DC converter and a secondary side of the transformer element, the primary side having a first rectifier circuit and a primary-side resonant circuit and the secondary side having a second rectifier circuit and a secondary-side stored energy source, the transformer element being arranged between the primary side and the secondary side in order to transfer electrical energy, the secondary side having a secondary resonant circuit capacitor. ## Claims ### Claim 1 A DC-DC voltage converter comprising: a primary side of a transformer element of the DC-DC voltage converter, and a secondary side of the transformer element, wherein a primary-side number of windings of the transformer element is designed to not be equal to a secondary-side number of windings of the transformer element, wherein the primary side has a first rectifier circuit and a primary-side resonant circuit and the secondary side has a second rectifier circuit and a secondary-side energy store, wherein the primary-side resonant circuit comprises a primary-side resonant circuit capacitor having a first capacitor value, a series primary inductance for leakage, and a parallel inductance, wherein the transformer element is arranged between the primary side and the secondary side in order to transmit electrical energy, wherein the secondary side energy store comprises a secondary-side resonant circuit capacitor, having a second capacitor value, and a series secondary inductance for leakage, the second capacitor value formed as a product of the first capacitor value and a quotient of the series primary inductance for leakage and the series secondary inductance for leakage, and wherein the series primary inductance for leakage and the parallel inductance for ZVS operation are integrated in the transformer element close to no-load operation, such that an inductor combination is formed. ### Claim 2 (depends on 1) The DC-DC voltage converter as claimed in claim 1, wherein the second rectifier circuit is designed as an electrical full bridge. ### Claim 3 (depends on 1) The DC-DC voltage converter as claimed in claim 1, wherein at least the secondary-side resonant circuit capacitor is designed as a series capacitor. ### Claim 4 (depends on 1) The DC-DC voltage converter as claimed in claim 1, wherein at least the secondary-side resonant circuit capacitor is designed as a parallel capacitor. ### Claim 5 (depends on 1) The DC-DC voltage converter as claimed in claim 1, wherein a series inductance is connected in addition to the secondary-side resonant circuit capacitor. ### Claim 6 A method for operating a DC-DC voltage converter having a primary side of a transformer element of the DC-DC voltage converter and having a secondary side of the transformer element, wherein the primary side is provided with a first rectifier circuit and a primary-side resonant circuit and the secondary side is provided with a second rectifier circuit and a secondary-side energy store, and wherein electrical energy is transmitted between the primary side and the secondary side, the method comprising: bidirectionally transmitting electrical energy from the primary side to the secondary side or from the secondary side to the primary side by means of a secondary-side resonant circuit capacitor, wherein a primary-side number of windings of the transformer element is designed to not be equal to a secondary-side number of windings of the transformer element, wherein the primary-side resonant circuit comprises a primary-side resonant circuit capacitor having a first capacitor value, a series primary inductance for leakage and a parallel inductance, wherein the secondary-side resonant circuit capacitor has a second capacitor value formed as a product of the first capacitor value and a quotient of the series primary inductance for leakage and a series secondary inductance for leakage, and integrating the series primary inductance for leakage and a parallel inductance for ZVS operation in the transformer element close to no-load operation, such that an inductor combination is formed.