# US 9,438,099 B2 · Harmonic displacement reduction > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,438,099 B2 - Document ID: US9438099B2 - Status: Granted - Kind: B2 - Application number: 14/527,309 - Filed: 2014-10-29 - Published: 2015-07-09 - Granted: 2016-09-06 - Earliest claimed: 2014-01-09 - Applicants: Fred O. Barthold - Inventors: Fred O. Barthold - Web page: https://patentgrep.com/patent/US9438099B2 ## CPC - H02M 1/12: Arrangements for reducing harmonics from AC input or output - H02M 3/335: using semiconductor devices only - 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 Reducing voltage excursions in a circuit comprises: performing resonant commutation, including transferring, via a first set of one or more diodes, energy stored by a set of one or more parasitic inductances to a set of one or more capacitors; and performing recovery-to-load, including discharging energy stored in the set of one or more capacitors via a second set of one or more diodes, through the set of one or more parasitic inductances to a load of the circuit. ## Claims ### Claim 1 A method of reducing voltage excursions in a circuit comprising a converter portion and a harmonic displacement reduction (HDR) portion, the method comprising: performing resonant commutation to transfer, via a first set of one or more diodes included in the HDR portion, energy stored by a set of one or more parasitic inductances included in the converter portion to a set of one or more capacitors included in the HDR portion, including: causing a current to flow through at least some of the set of one or more parasitic inductances included in the converter portion; and stopping the current from flowing through the at least some of the set of one or more parasitic inductances included in the converter portion and redirecting the current to flow through at least some of the first set of one or more diodes included in the HDR portion to charge the set of one or more capacitors included in the HDR portion; and performing recovery-to-load, including: discharging the charged set of one or more capacitors via a second set of one or more diodes, thereby causing a current to flow through the second set of one or more diodes and energy to be inductively transferred to a load of the circuit. ### Claim 2 (depends on 1) The method of claim 1, wherein the resonant commutation is performed in a first state, and the recovery-to-load is performed in a second state. ### Claim 3 (depends on 1) The method of claim 1, further comprising performing DC-DC power conversion. ### Claim 4 (depends on 1) The method of claim 1, wherein the energy is stored by the set of one or more parasitic inductances while a first switch in the converter portion is on and a second switch in the converter portion is off. ### Claim 5 (depends on 1) The method of claim 1, wherein performing resonant commutation includes switching a first switch in the converter portion from on to off while keeping a second switch in the converter portion off. ### Claim 6 (depends on 5) The method of claim 5, wherein switching the first switch from on to off causes a current to cease flowing through the switch and to be commutated through a diode to charge a capacitor. ### Claim 7 (depends on 5) The method of claim 5, wherein performing recovery-to-load includes switching the second switch on while keeping the first switch off. ### Claim 8 A harmonic displacement reduction (HDR) circuit comprising: a set of one or more capacitors; a first set of one or more diodes coupled to the set of one or more capacitors, and a second set of one or more diodes coupled to a source; wherein: each of the set of one or more capacitors has a first lead that is coupled to one or more corresponding leads of one or more diodes in the first set of one or more diodes, and a second lead that is configured to be coupled to a corresponding lead of a corresponding switch included in a second circuit; each of the first set of one or more diodes has a first lead that is coupled to a corresponding lead of a corresponding one of the set of one or more capacitors, and a second lead that is coupled to a corresponding lead of another one of the first set of one or more diodes; each of the second set of one or more diodes has at least one lead that is coupled to a corresponding lead of a source of the second circuit and wherein the first set of one or more diodes, the set of one or more capacitors, and the second set of one or more diodes are configured to: perform resonant commutation to transfer, via the first set of one or more diodes, energy stored by a set of one or more parasitic inductances to the set of one or more capacitors, the set of one or more parasitic inductances being included in the second circuit, and to perform the resonant commutation including to: cause a current to flow through at least some of the set of one or more parasitic inductances included in the second circuit; and stop the current from flowing through the at least some of the set of one or more parasitic inductances included in the second circuit and redirect the current to flow through at least some of the first set of one or more diodes to charge the set of one or more capacitors; and perform recovery-to-load, including to: discharge the charged set of one or more capacitors via the second set of one or more diodes, thereby causing a current to flow through the second set of one or more diodes and energy to be inductively transferred to a load of the second circuit. ### Claim 9 (depends on 8) The circuit of claim 8, wherein the set of one or more parasitic inductances comprises an interstitial parasitic inductance of magnetic windings of an inductor. ### Claim 10 (depends on 8) The circuit of claim 8, wherein the set of one or more capacitors include C0G dielectric. ### Claim 11 A power converter circuit, comprising: a converter portion comprising a set of one or more parasitic inductances and a source; and a harmonic displacement reduction (HDR) portion coupled to the converter portion, the HDR portion comprising a first set of one or more diodes, a second set of one or more diodes, and a set of one or more capacitors, wherein: each of the set of one or more capacitors has a first lead that is coupled to one or more corresponding leads of one or more diodes in the first set of one or more diodes, and a second lead that is configured to be coupled to a corresponding lead of a corresponding switch included in a second circuit; each of the first set of one or more diodes has a first lead that is coupled to a corresponding lead of a corresponding one of the set of one or more capacitors, and a second lead that is coupled to a corresponding lead of another one of the first set of one or more diodes; each of the second set of one or more diodes has at least one lead that is coupled to a corresponding lead of a source of the second circuit and wherein the HDR portion is configured to: perform resonant commutation to transfer, via the first set of one or more diodes, energy stored by the set of one or more parasitic inductances to the set of one or more capacitors, including to: cause a current to flow through at least some of the set of one or more parasitic inductances included in the converter portion; and stop the current from flowing through the at least some of the set of one or more parasitic inductances and redirect the current to flow through at least some of the first set of one or more diodes to charge the set of one or more capacitors; and perform recovery-to-load, including to: discharge the charged set of one or more capacitors via the second set of one or more diodes, thereby causing a current to flow through the second set of one or more diodes and energy to be inductively transferred to a load of the power converter circuit. ### Claim 12 (depends on 11) The power converter circuit of claim 11, wherein the converter portion is a DC-DC converter. ### Claim 13 (depends on 11) The power converter circuit of claim 11, wherein the converter portion is an isolated, multi-phase boost derived DC-DC converter. ### Claim 14 (depends on 11) The power converter circuit of claim 11, wherein the energy is stored by the set of one or more parasitic inductances while a first switch in the converter portion is on and a second switch in the converter portion is off. ### Claim 15 (depends on 11) The power converter circuit of claim 11, wherein the converter portion further comprises a first switch and a second switch, and wherein the HDR portion's performance of resonant commutation includes switching the first switch from on to off while keeping the second switch off. ### Claim 16 (depends on 15) The power converter circuit of claim 15, wherein the switching the first switch from on to off causes a current to cease flowing through the switch and to be commutated through a diode to charge a capacitor. ### Claim 17 (depends on 15) The power converter circuit of claim 15, wherein the HDR portion's performance of recovery-to-load includes switching the second switch on while keeping the first switch off.