Patents by Inventor Alireza Nami
Alireza Nami has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11757368Abstract: A transformer arrangement is provided. The transformer arrangement includes a transformer with a primary and a secondary winding and a chain link of switching blocks connected in series between one of the windings and a load, where the switching blocks comprise a first set of voltage contribution blocks and a second set of circuit breaker blocks, where the first set of voltage contribution blocks is configured to adjust a voltage output by the transformer with an offset voltage and the second set of circuit breaker blocks is configured to interrupt a current running through the chain link.Type: GrantFiled: December 18, 2020Date of Patent: September 12, 2023Assignee: HITACHI ENERGY SWITZERLAND AGInventors: Roberto Alves, Nan Chen, Frans Dijkhuizen, Jan Svensson, Alireza Nami
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Patent number: 11694840Abstract: Provided is a transformer arrangement wherein active and/or reactive power can be injected in an alternating current link using a current regulator and a voltage regulator portion, wherein at least one winding with which the current regulator is connected in parallel is at least one tertiary winding, and wherein the current regulator includes a number of current regulator sections, each connected to a corresponding voltage regular section of a voltage regulator portion via a corresponding dc link.Type: GrantFiled: December 18, 2020Date of Patent: July 4, 2023Assignee: Hitachi Energy Switzerland AGInventors: Roberto Alves, Nan Chen, Frans Dijkhuizen, Jan Svensson, Alireza Nami
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Publication number: 20230020854Abstract: An inductive power device with variable active winding size, comprises first circuitry, multiple winding segments and switching circuitry operable to connect selectable combinations of the winding segments serially to the first circuitry via taps. At least two of the winding segments are of unequal size, wherein said at least two winding segments are provided as sequential portions of a total winding magnetically coupled to an opposite winding, wherein the winding segments have uniform polarity with respect to said magnetic coupling. The switching circuitry comprises an arrangement of semiconductor switches which are operable to include or exclude each winding segment independently. In an embodiment, the arrangement of switches comprises at least one half-bridge structure.Type: ApplicationFiled: December 15, 2020Publication date: January 19, 2023Applicant: Hitachi Energy Switzerland AGInventors: Nan CHEN, Yuhei OKAZAKI, Roberto ALVES, Alireza NAMI
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Publication number: 20220407429Abstract: A transformer arrangement is provided. The transformer arrangement includes a transformer with a primary and a secondary winding and a chain link of switching blocks connected in series between one of the windings and a load, where the switching blocks comprise a first set of voltage contribution blocks and a second set of circuit breaker blocks, where the first set of voltage contribution blocks is configured to adjust a voltage output by the transformer with an offset voltage and the second set of circuit breaker blocks is configured to interrupt a current running through the chain link.Type: ApplicationFiled: December 18, 2020Publication date: December 22, 2022Applicant: Hitachi Energy Switzerland AGInventors: Roberto ALVES, Nan CHEN, Frans DIJKHUIZEN, Jan SVENSSON, Alireza NAMI
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Publication number: 20220344093Abstract: Provided is a transformer arrangement wherein active and/or reactive power can be injected in an alternating current link using a current regulator and a voltage regulator portion, wherein at least one winding with which the current regulator is connected in parallel is at least one tertiary winding, and wherein the current regulator includes a number of current regulator sections, each connected to a corresponding voltage regular section of a voltage regulator portion via a corresponding dc link.Type: ApplicationFiled: December 18, 2020Publication date: October 27, 2022Applicant: Hitachi Energy Switzerland AGInventors: Roberto ALVES, Nan CHEN, Frans Dijkhuizen, Jan Svensson, Alireza NAMI
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Patent number: 11424679Abstract: The present disclosure relates to a converter cell (4) for an MMC. The cell comprises a primary energy storage (Cm), an inductor (Lf), and a secondary energy storage (Cf); and first and second converter valves (T1, T2). The secondary energy storage (Cf) is connected in series with the first converter valve (T1), and together with said first converter valve in parallel with the inductor (Lf), and the primary energy storage (Cm) is connected in series with the second converter valve (T2), and together with said second converter valve (T2) in parallel with the inductor (Lf).Type: GrantFiled: February 27, 2019Date of Patent: August 23, 2022Assignee: HITACHI ENERGY SWITZERLAND AGInventors: Aravind Mohanaveeramani, Jan Svensson, Lennart Harnefors, Alireza Nami
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Patent number: 11418127Abstract: The present disclosure relates to a converter cell (4) for a power converter. The cell comprises a plurality of semiconductor devices (T) forming a half-bridge or full-bridge topology in the cell. The cell also comprises an energy storage (5) connected across the at least one switch leg (6). The cell also comprises a crowbar leg (7) connected across the at least one switch leg, comprising a plurality of series connected semiconductor crowbar switches (C) arranged to short-circuit the energy storage (5). The cell also comprises first and second AC terminals (A, B), wherein at least one of said AC terminals is connected to one of the at least one switch leg, between two of the plurality of series connected semiconductor devices of said switch leg, and connected to the crowbar leg, between two of the plurality of series connected crowbar switches of said crowbar leg.Type: GrantFiled: February 28, 2019Date of Patent: August 16, 2022Assignee: Hitachi Energy Switzerland AGInventors: Aravind Mohanaveeramani, Jan Svensson, Alireza Nami
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Publication number: 20220085731Abstract: The present disclosure relates to a converter cell (4) for a power converter. The cell comprises a plurality of semiconductor devices (T) forming a half-bridge or full-bridge topology in the cell. The cell also comprises an energy storage (5) connected across the at least one switch leg (6). The cell also comprises a crowbar leg (7) connected across the at least one switch leg, comprising a plurality of series connected semiconductor crowbar switches (C) arranged to short-circuit the energy storage (5). The cell also comprises first and second AC terminals (A, B), wherein at least one of said AC terminals is connected to one of the at least one switch leg, between two of the plurality of series connected semiconductor devices of said switch leg, and connected to the crowbar leg, between two of the plurality of series connected crowbar switches of said crowbar leg.Type: ApplicationFiled: February 28, 2019Publication date: March 17, 2022Inventors: Aravind Mohanaveeramani, Jan Svensson, Alireza Nami
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Publication number: 20220045610Abstract: The present disclosure relates to a converter cell (4) for an MMC. The cell comprises a primary energy storage (Cm), an inductor (Lf), and a secondary energy storage (Cf); and first and second converter valves (T1, T2). The secondary energy storage (Cf) is connected in series with the first converter valve (T1), and together with said first converter valve in parallel with the inductor (Lf), and the primary energy storage (Cm) is connected in series with the second converter valve (T2), and together with said second converter valve (T2) in parallel with the inductor (Lf).Type: ApplicationFiled: February 27, 2019Publication date: February 10, 2022Inventors: Aravind Mohanaveeramani, Jan Svensson, Lennart Harnefors, Alireza Nami
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Publication number: 20200106384Abstract: An inverter arrangement based on photovoltaic elements includes at least two strings including switching elements, which strings are connected to at least two AC terminals, where at least one of the strings is a string of submodules, each submodule including at least two switching elements and an energy storage element, having DC terminals and being configured to make a voltage contribution to the forming of an AC voltage on an AC terminal, and a number of input stages each including at least one energy delivery element, where at least some of the energy delivery elements are photovoltaic elements, each input stage being connected to DC terminals of a corresponding for delivering power to or from at least one AC terminal when the corresponding submodule contributes to the forming of the AC voltage on the AC terminal.Type: ApplicationFiled: October 1, 2019Publication date: April 2, 2020Inventors: Cicero Postiglione, Frans Dijkhuizen, Jan Svensson, Alireza Nami, Francisco Canales
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Patent number: 10530272Abstract: A voltage source converter includes a number of converter modules, one for each of a number of phases, connected in-series between two DC terminals. Each converter module includes an upper director valve in series with a lower director valve, where a junction between the two provides a primary AC terminal, an upper wayshaper section, a common waveshaper block and a lower waveshaper section in parallel with the valves, where the upper and lower waveshaper sections include multilevel cells and the common waveshaper block include at least one common waveshaper connected between the upper and lower waveshaper sections, a first switching element connected between a secondary AC terminal and the upper waveshaper section and a second switching element connected between the secondary AC terminal and the lower waveshaper section.Type: GrantFiled: December 21, 2016Date of Patent: January 7, 2020Assignee: ABB SCHWEIZ AGInventors: Praveen Kumar Barupati, Hongbo Jiang, Alireza Nami, Sasitharan Subramanian, Vishal Vekhande
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Publication number: 20190348925Abstract: A voltage source converter includes a number of converter modules, one for each of a number of phases, connected in-series between two DC terminals. Each converter module includes an upper director valve in series with a lower director valve, where a junction between the two provides a primary AC terminal, an upper waveshaper section, a common waveshaper block and a lower waveshaper section in parallel with the valves, where the upper and lower waveshaper sections include multilevel cells and the common waveshaper block include at least one common waveshaper connected between the upper and lower waveshaper sections, a first switching element connected between a secondary AC terminal and the upper waveshaper section and a second switching element connected between the secondary AC terminal and the lower waveshaper section.Type: ApplicationFiled: December 21, 2016Publication date: November 14, 2019Applicant: ABB SCHWEIZ AGInventors: Praveen Kumar BARUPATI, Hongbo JIANG, Alireza NAMI, Sasitharan SUBRAMANIAN, Vishal VEKHANDE
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Patent number: 10256745Abstract: A multilevel converter converting between AC and DC includes a phase leg having a first and a second phase arm, the first phase arm being connected between a first pole having a first potential and a first AC terminal and the second phase arm being connected between the first AC terminal and a second potential, where the phase arms include half-bridge and full-bridge cells, where each cell includes at least one energy storage element for providing the voltage contribution and cell switching units with cell switches and anti-parallel diodes for controlling the voltage contribution, where the full-bridge cells include a bypass switch controllable to bypass the corresponding energy storage element, and when a phase-to-ground fault occurs the cell switches are blocked and the bypass switches activated with a delay in relation to the blocking.Type: GrantFiled: November 25, 2014Date of Patent: April 9, 2019Assignee: ABB SCHWEIZ AGInventors: Alireza Nami, Jiaqi Liang, Frans Dijkhuizen, Liwei Wang
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Publication number: 20180212533Abstract: A multilevel converter converting between AC and DC includes a phase leg having a first and a second phase arm, the first phase arm being connected between a first pole having a first potential and a first AC terminal and the second phase arm being connected between the first AC terminal and a second potential, where the phase arms include half-bridge and full-bridge cells, where each cell includes at least one energy storage element for providing the voltage contribution and cell switching units with cell switches and anti-parallel diodes for controlling the voltage contribution, where the full-bridge cells include a bypass switch controllable to bypass the corresponding energy storage element, and when a phase-to-ground fault occurs the cell switches are blocked and the bypass switches activated with a delay in relation to the blocking.Type: ApplicationFiled: November 25, 2014Publication date: July 26, 2018Applicant: ABB SCHWEIZ AGInventors: Alireza NAMI, Jiaqi LIANG, Frans DIJKHUIZEN, Liwei WANG
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Patent number: 9991713Abstract: An energy storage system (ESS) for an electrical system includes an energy storage, and a converter interface arranged for connecting the energy storage to the electrical system. The converter interface includes a modular multilevel converter in which each phase leg includes a plurality of series connected cells of which at least one is a half-bridge cell and at least one is a full-bridge cell.Type: GrantFiled: February 19, 2014Date of Patent: June 5, 2018Assignee: ABB SCHWEIZ ABInventors: Tomas Tengner, Christopher Townsend, Hector Zelaya de la Parra, Alireza Nami
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Patent number: 9929634Abstract: A switching cell for a chain link includes a first side including a first terminal and a second terminal, a second side including a third terminal and a fourth terminal, a first switching unit, a second switching unit, and a first and a second capacitor unit. The first terminal is connected to the second terminal via the first capacitor unit. The first capacitor unit has its positive side facing the first terminal. The third terminal is connected to the fourth terminal via the second capacitor unit. The second capacitor has its positive side facing the fourth terminal. The second terminal is connected to the fourth terminal via the second switching unit. The switching cell also includes a third capacitor unit, and the first terminal is connected to the third terminal via a first series connection including the first switching unit and the third capacitor unit. The third capacitor unit has its positive side facing the third terminal. A switching module includes at least one such switching cell.Type: GrantFiled: August 8, 2014Date of Patent: March 27, 2018Assignee: ABB SCHWEIZ AGInventors: Alireza Nami, Christopher Townsend
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Patent number: 9876358Abstract: A converter arrangement and a method of controlling a three-phase converter arrangement connected to a transmission grid are provided. The converter arrangement includes three phase legs and an energy transfer circuit. The method includes providing a varying respective output phase voltage to the transmission grid by selecting energy storage elements of both the phase legs and the energy transfer circuit and connecting the selected energy storage elements to the transmission grid output. The method further includes selecting energy storage elements for performing a transfer of energy between the energy storage elements during the control period.Type: GrantFiled: June 7, 2013Date of Patent: January 23, 2018Assignee: ABB SCHWEIZ AGInventors: Frans Dijkhuizen, Alireza Nami, Hector Zelaya De La Parra, Christopher Townsend
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Publication number: 20170237330Abstract: A switching cell for a chain link includes a first side including a first terminal and a second terminal, a second side including a third terminal and a fourth terminal, a first switching unit, a second switching unit, and a first and a second capacitor unit. The first terminal is connected to the second terminal via the first capacitor unit. The first capacitor unit has its positive side facing the first terminal. The third terminal is connected to the fourth terminal via the second capacitor unit. The second capacitor has its positive side facing the fourth terminal. The second terminal is connected to the fourth terminal via the second switching unit. The switching cell also includes a third capacitor unit, and the first terminal is connected to the third terminal via a first series connection including the first switching unit and the third capacitor unit. The third capacitor unit has its positive side facing the third terminal. A switching module includes at least one such switching cell.Type: ApplicationFiled: August 8, 2014Publication date: August 17, 2017Applicant: ABB Schweiz AGInventors: Alireza NAMI, Christopher TOWNSEND
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Patent number: 9716425Abstract: A multilevel converter converting between AC and DC includes a phase arm with a number of cells between a DC pole and an AC terminal, the cells include at least one hybrid full bridge cell including a first cell connection terminal for coupling to the DC pole, a second cell connection terminal for coupling to the AC terminal, an energy storage element having a positive and a negative end, a first group of series connected semiconducting units in parallel with the energy storage element, where a junction between these forms one cell connection terminal, and a second group of series connected semiconducting units in parallel with the energy storage element and including a third semiconducting unit and a fourth semiconducting unit consisting of a number of unidirectional conducting elements including at least one unidirectional conducting element, where a junction between these forms a further cell connection terminal.Type: GrantFiled: January 21, 2013Date of Patent: July 25, 2017Assignee: ABB SCHWEIZ AGInventors: Alireza Nami, Liwei Wang
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Publication number: 20170170658Abstract: An energy storage system (ESS) for an electrical system includes an energy storage, and a converter interface arranged for connecting the energy storage to the electrical system. The converter interface includes a modular multilevel converter in which each phase leg includes a plurality of series connected cells of which at least one is a half-bridge cell and at least one is a full-bridge cell.Type: ApplicationFiled: February 19, 2014Publication date: June 15, 2017Applicant: ABB SCHWEIZ AGInventors: Tomas TENGNER, Christopher TOWNSEND, Hector ZELAYA DE LA PARRA, Alireza NAMI