# US 8,787,049 B2 · Control method for converting power, and electronic power converter adapted to carry out said method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,787,049 B2 - Document ID: US8787049B2 - Status: Granted - Kind: B2 - Application number: 13/291,589 - Filed: 2011-11-08 - Published: 2012-05-10 - Granted: 2014-07-22 - Earliest claimed: 2010-11-08 - Assignees: Ingeteam Power Technology, S.A. - Applicants: Francisco Javier Chivite Zabalza; Miguel Angel Rodriguez Vidal; Danel Madariaga Zubimendi; Pedro Izurza Moreno; Gorka Calvo Olalla - Inventors: Francisco Javier Chivite Zabalza; Miguel Angel Rodriguez Vidal; Danel Madariaga Zubimendi; Pedro Izurza Moreno; Gorka Calvo Olalla - Web page: https://patentgrep.com/patent/US8787049B2 ## CPC - H02M 7/49: Combination of the output voltage waveforms of a plurality of converters - H02J 3/01: Arrangements for reducing harmonics or ripples - H02M 1/009: {having two or more independently controlled outputs (for DC-DC converter with intermediate AC H02M3/33561)} - H02M 7/487: Neutral point clamped inverters - 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) - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY ## Abstract A control method and apparatus are provided to convert a DC voltage into alternating voltage. The apparatus includes a first inverter and a second inverter to generate a first alternating voltage and a second alternating voltage, respectively. Also included is an interphase transformer to combine these alternating voltages in parallel to obtain a first resulting alternating voltage. The apparatus also includes a third inverter and a fourth inverter to generate a third and fourth alternating voltage, respectively. These are combined to form a second resulting alternating voltage. The second resulting alternating voltage is displaced in phase approximately 180° in relation to the first resulting alternating voltage. ## Claims ### Claim 1 A control method for converting power, the method comprising: converting a DC voltage into a first alternating voltage waveform using a first multi-level inverter; converting the DC voltage into a second alternating voltage waveform using a second multi-level inverter; combining the first alternative voltage waveform and the second alternating voltage waveform in parallel to obtain a first resulting alternating voltage waveform; converting the DC voltage into a third alternating voltage waveform using a third multi-level inverter; converting the DC voltage into a fourth alternating voltage waveform using a fourth multi-level inverter; combining the third alternative voltage waveform and the fourth alternating voltage waveform in parallel to obtain a second resulting alternating voltage waveform, wherein the second resulting alternating voltage waveform (AC34) is displaced in phase by approximately 180° in relation to the first resulting alternating voltage waveform and the common-mode voltages are eliminated from at least one of the alternating voltage waveforms or resulting alternating voltage waveforms. ### Claim 2 (depends on 1) The method according to claim 1, wherein the first, second, third and fourth alternating voltage waveforms that are combined in parallel with each other to obtain the corresponding first and second resulting alternating voltage waveforms comprise different instantaneous values. ### Claim 3 (depends on 2) The method according to claim 2, wherein in order to convert a DC voltage into an alternating voltage for obtaining the alternating voltage waveforms, the multi-level inverters use a PWM modulation with modulating signals in the multi-level inverters displaced in phase in respect to each other, and triangular carrier signals that are in phase. ### Claim 4 (depends on 2) The method according to claim 2, wherein in order to convert the DC voltage into the alternating voltage for obtaining the alternating voltage waveforms, the multi-level inverters use a PWM modulation with modulating signals in the multi-level inverters in phase, and triangular carrier signals that are equal but displaced in phase in relation to each other. ### Claim 5 (depends on 2) The method according to claim 2, wherein in order to convert the DC voltage into the alternating voltage for obtaining the alternating voltage waveforms, the multi-level inverters use a PWM modulation with modulating signals in the multi-level inverters displaced in phase a certain angle in relation to each other, and triangular carrier signals that are equal but displaced in phase in relation to each other. ### Claim 6 (depends on 2) The method according to claim 2, wherein in order to convert the DC voltage into the alternating voltage for obtaining the first and second alternating voltage waveforms a selective harmonic elimination or mitigation modulation is used. ### Claim 7 (depends on 2) The method according to claim 2, wherein the common-mode voltages are eliminated from at least one of the first and second alternating voltage waveforms and the first resulting waveform; and/or one of the third and fourth alternating voltage waveforms or the second resulting alternating waveform. ### Claim 8 (depends on 2) The method according to claim 2, wherein the common-mode voltages are eliminated from the alternating voltage waveforms once said alternating voltage waveforms have been combined. ### Claim 9 (depends on 2) The method according to claim 2, wherein the common-mode voltages are eliminated from the alternating voltage waveforms once said alternating voltage waveforms have been combined. ### Claim 10 (depends on 1) The method according to claim 1, wherein the common-mode voltages are eliminated from at least one of the first and second alternating voltage waveforms and the first resulting waveform; and/or one of the third and fourth alternating voltage waveforms or the second resulting alternating waveform. ### Claim 11 (depends on 1) The method according to claim 1, wherein the common-mode voltages are eliminated from the alternating voltage waveforms once said alternating voltage waveforms have been combined. ### Claim 12 (depends on 1) The method according to claim 1, wherein the common-mode voltage is eliminated from each alternating voltage waveform, said alternating voltage waves subsequently being combined with each other. ### Claim 13 An electronic power converter, comprising a block of inverters that comprises at least two multi-level inverters to convert a DC voltage into an alternating voltage to obtain at least two alternating voltage waveforms; a combining unit that combines in parallel both alternating voltage waves to obtain a first resulting alternating voltage waveform; a second block of inverters that comprises at least two additional multi-level inverters to convert the DC voltage into an alternating voltage to obtain at least two second alternating voltage waveforms; a second combining unit to combine in parallel both of the second alternating voltage waveforms to obtain a second resulting alternating voltage waveform displaced in phase by approximately 180° with the first resulting alternating voltage waveform; and a filter to eliminate the common-mode voltages from the alternating voltage waveforms and the resulting alternating voltage waveforms. ### Claim 14 (depends on 13) The converter according to claim 13, wherein each combining unit comprises an interphase transformer. ### Claim 15 (depends on 13) The converter according to claim 13, wherein the filter comprises a zero-sequence blocking transformer. ### Claim 16 (depends on 13) The converter according to claim 13, wherein the filter eliminates the common-mode voltages from each alternating voltage waveform. ### Claim 17 (depends on 13) The converter according to claim 13, wherein the inverters are three-level inverters. ### Claim 18 (depends on 13) The converter according to claim 13, further comprising a second filter to eliminate the common-mode voltages from the first resulting alternating voltage waveform, and third filter to eliminate the common-mode voltages from the second resulting alternating voltage waveform. ### Claim 19 (depends on 18) The converter according to claim 18, wherein the inverters are three-level inverters. ### Claim 20 (depends on 18) The converter according to claim 18, wherein each combining unit comprises an interphase transformer. ### Claim 21 (depends on 18) The converter according to claim 18, wherein the filter comprises a zero-sequence blocking transformer.