Patents by Inventor Dragan Maksimovic

Dragan Maksimovic 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).

  • Patent number: 11864357
    Abstract: A double-sided cold plate includes a manifold comprising openings extending from a first surface of the manifold through the manifold to a second surface of the manifold forming recesses within the manifold and an inlet channel and an outlet channel fluidly coupled to the recesses within the manifold, a plurality of first heat sinks coupled to the first surface of the manifold enclosing the openings on the first surface, and a plurality of second heat sinks positioned adjacent each other along a length of the manifold and coupled to the second surface of the manifold, enclosing the openings on the second surface, a width of the plurality of second heat sinks is greater than a width of the manifold thereby forming an overhanging portion on each lengthwise side of the manifold, the overhanging portion configured to mechanically support a plurality of electrical components positioned around a perimeter of the manifold.
    Type: Grant
    Filed: May 25, 2021
    Date of Patent: January 2, 2024
    Assignees: Toyota Motor Engineering and Manufacturing North America, Inc., University of Colorado Boulder
    Inventors: Feng Zhou, Yuqing Zhou, Ercan Mehmet Dede, Robert Erickson, Dragan Maksimovic, Vivek Sankaranarayanan, Yucheng Gao
  • Patent number: 11735782
    Abstract: An apparatus for voltage sharing of series connected battery modules in a DC microgrid includes a battery management system and a battery module controller that generates, for an mth of N converters connected together to a DC microbus, a droop current ?d,m that includes a converter voltage error signal {tilde over (v)}err,m multiplied by a droop multiplier gd(i). Each converter is a DC/DC converter connected between a battery module, with one or more battery cells, and the DC microbus. The mth converter uses the droop current ?d,m, a common current reference ?all of a battery pack that includes the battery modules and an input current ?m to the mth converter to control switching of the mth converter. The common current reference ?all is from the battery management system. The voltage error signal {tilde over (v)}err,m is based on an output voltage {tilde over (v)}o,m of the mth converter and an average converter output voltage {tilde over (v)}avgeodcmastereodcmastereodcmaster.
    Type: Grant
    Filed: June 17, 2021
    Date of Patent: August 22, 2023
    Assignee: Utah State University
    Inventors: Mohamed Ahmed Kamel Ahmed, Regan Zane, Dragan Maksimovic
  • Patent number: 11621633
    Abstract: Transformerless stacked active bridge (TSAB) direct current (DC)-to-DC power converters designed based on parent switched capacitor (SC) converter topologies. The TSAB DC-to-DC power converter includes the SC converter. The SC converter includes a plurality of switches and a plurality of capacitors. Each capacitor of the plurality of capacitors is electrically coupled to at least one of the plurality of switches. The plurality of capacitors includes tree capacitors, and link capacitors forming a loop with at least one of the tree capacitors. The TSAB DC-to-DC power converter includes at least one inductor electrically coupled in series to at least one of the link capacitors. The TSAB DC-to-DC power converters provide high efficiency bi-directional operation without requiring isolation transformers.
    Type: Grant
    Filed: March 16, 2021
    Date of Patent: April 4, 2023
    Assignee: The Regents of the University of Colorado
    Inventors: Jianglin Zhu, Dragan Maksimovic
  • Patent number: 11596088
    Abstract: A cold plate having a manifold includes a recess extending from a first side to a second side of the manifold, where the recess includes openings to the recess positioned lengthwise along the first side and a single opening to the recess on the second side, an inlet and an outlet fluidly coupled to the recess, a plurality of plates fastened to the first side enclosing the openings, a heat sink fastened to the second side enclosing the single opening on the second side, and a plurality of fluid cores one of each positioned between each of the plurality of plates and the heat sink. The plurality of fluid cores include a flow distribution insert, a first plate fin positioned between the flow distribution insert and the heat sink fastened to the second side, and a second plate fin positioned between the flow distribution insert and the heat sink.
    Type: Grant
    Filed: January 29, 2021
    Date of Patent: February 28, 2023
    Assignees: TOYOTA MOTOR ENGINEERING & MANUFACTURING NORTH AMERICA, INC., UNIVERSITY OF COLORADO BOULDER
    Inventors: Feng Zhou, Ercan Mehmet Dede, Hiroshi Ukegawa, Robert Erickson, Dragan Maksimovic, Vivek Sankaranarayanan, Yucheng Gao
  • Patent number: 11545297
    Abstract: Embodiments of the disclosure relate to apparatuses for enhanced thermal management of an inductor assembly using functionally-graded thermal vias for heat flow control in the windings of the inductor. In one embodiment, a PCB for an inductor assembly includes a top surface and a bottom surface. Two or more electrically-conductive layers are embedded within the PCB and stacked vertically between the top surface and the bottom surface. The two or more electrically-conductive layers are electrically connected to form an inductor winding. A plurality of thermal vias thermally connects each of the two or more electrically-conductive layers to a cold plate thermally connected to the bottom surface. A number of thermal vias thermally connecting each electrically-conductive layer to the cold plate is directly proportional to a predetermined rate of heat dissipation from the electrically-conductive layer.
    Type: Grant
    Filed: November 22, 2019
    Date of Patent: January 3, 2023
    Assignees: TOYOTA MOTOR ENGINEERING & MANUFACTURING NORTH AMERICA, INC., UNIVERSITY OF COLORADO BOULDER
    Inventors: Ercan Dede, Yucheng Gao, Vivek Sankaranarayanan, Aritra Ghosh, Robert Erickson, Dragan Maksimovic
  • Publication number: 20220399153
    Abstract: Various embodiments of the present disclosure relate to power conversion using a planar transformer assembly that provides medium-voltage isolation at high frequencies. A planar transformer comprises primary and secondary planar windings configured to generate an isolated output. Each primary and secondary winding is interleaved on layers of a printed circuit board using one or more vias within the layers of the printed circuit board. The planar transformer also comprises a magnetic core and a field-shaping apparatus coupled with the printed circuit board. The field-shaping apparatus is configured to shape an electric field generated by the windings. The primary windings can be coupled to a DC source via switching devices while the secondary windings can be coupled via switching devices to one or more DC ports followed by AC inverters configured to generate three single-phase AC outputs for medium voltage applications.
    Type: Application
    Filed: June 14, 2022
    Publication date: December 15, 2022
    Inventors: Satyaki Mukherjee, Branko Majmunovic, Dragan Maksimovic, Brian B. Johnson
  • Publication number: 20220393589
    Abstract: A voltage converter comprises a drive control circuit configured to generate switch control signals and a feedback circuit. The feedback circuit comprises a proportional control and a gain controller. The feedback circuit is configured to receive a sensed output voltage based on an output DC voltage, receive a voltage reference, obtain an input voltage value based on an input DC voltage, and generate an error signal based on a comparison of the sensed output voltage with the voltage reference. The feedback circuit is further configured to obtain a proportional gain value based on the voltage reference and the input voltage value and to generate a proportional value based on the proportional gain value and the error signal.
    Type: Application
    Filed: June 3, 2022
    Publication date: December 8, 2022
    Inventors: Dragan Maksimovic, Faleh Alskran, V. Inder Kumar, Chandan Suthar
  • Publication number: 20220393485
    Abstract: An apparatus includes a battery pack with N battery bricks, each with a DC output voltage. The output of each brick is connected in series providing a bus voltage. Each brick includes battery power modules (“BPMs”) connected in parallel and each connected to a battery cell. Each BPM charges/discharges the connected battery cell. Each brick has a battery brick controller that provides a control signal to each brick's BPMs. A control signal of a BPM is derived from a BPM error signal that includes a battery cell current of the battery cell of BPM subtracted from a summation of an average current signal, a local droop current and a balancing current. The balancing current is based on a current SOC of the battery cell connected to the BPM and a desired SOC for the battery cell connected to the BPM. A BMS derives the balancing current for the BPMs.
    Type: Application
    Filed: November 18, 2021
    Publication date: December 8, 2022
    Applicants: Utah State University, University of Colorado Boulder
    Inventors: Mohamed Ahmed Kamel Ahmed, Regan A. Zane, Dragan Maksimovic
  • Publication number: 20220386509
    Abstract: A double-sided cold plate includes a manifold comprising openings extending from a first surface of the manifold through the manifold to a second surface of the manifold forming recesses within the manifold and an inlet channel and an outlet channel fluidly coupled to the recesses within the manifold, a plurality of first heat sinks coupled to the first surface of the manifold enclosing the openings on the first surface, and a plurality of second heat sinks positioned adjacent each other along a length of the manifold and coupled to the second surface of the manifold, enclosing the openings on the second surface, a width of the plurality of second heat sinks is greater than a width of the manifold thereby forming an overhanging portion on each lengthwise side of the manifold, the overhanging portion configured to mechanically support a plurality of electrical components positioned around a perimeter of the manifold.
    Type: Application
    Filed: May 25, 2021
    Publication date: December 1, 2022
    Applicants: TOYOTA MOTOR ENGINEERING & MANUFACTURING NORTH AMERICA, INC., University of Colorado Boulder
    Inventors: Feng Zhou, Yuqing Zhou, Ercan Mehmet Dede, Robert Erickson, Dragan Maksimovic, Vivek Sankaranarayanan, Yucheng Gao
  • Publication number: 20220248560
    Abstract: A cold plate having a manifold includes a recess extending from a first side to a second side of the manifold, where the recess includes openings to the recess positioned lengthwise along the first side and a single opening to the recess on the second side, an inlet and an outlet fluidly coupled to the recess, a plurality of plates fastened to the first side enclosing the openings, a heat sink fastened to the second side enclosing the single opening on the second side, and a plurality of fluid cores one of each positioned between each of the plurality of plates and the heat sink. The plurality of fluid cores include a flow distribution insert, a first plate fin positioned between the flow distribution insert and the heat sink fastened to the second side, and a second plate fin positioned between the flow distribution insert and the heat sink.
    Type: Application
    Filed: January 29, 2021
    Publication date: August 4, 2022
    Applicants: Toyota Motor Engineering & Manufacturing North America, Inc., University of Colorado Boulder
    Inventors: Feng Zhou, Ercan Mehmet Dede, Hiroshi Ukegawa, Robert Erickson, Dragan Maksimovic, Vivek Sankaranarayanan, Yucheng Gao
  • Publication number: 20210399352
    Abstract: An apparatus for voltage sharing of series connected battery modules in a DC microgrid includes a battery management system and a battery module controller that generates, for an mth of N converters connected together to a DC microbus, a droop current ?d,m that includes a converter voltage error signal {tilde over (v)}err,m multiplied by a droop multiplier gd(i). Each converter is a DC/DC converter connected between a battery module, with one or more battery cells, and the DC microbus. The mth converter uses the droop current ?d,m, a common current reference ?all of a battery pack that includes the battery modules and an input current ?m to the mth converter to control switching of the mth converter. The common current reference ?all is from the battery management system. The voltage error signal {tilde over (v)}err,m is based on an output voltage {tilde over (v)}o,m of the mth converter and an average converter output voltage {tilde over (v)}avgeodcmastereodcmastereodcmaster.
    Type: Application
    Filed: June 17, 2021
    Publication date: December 23, 2021
    Applicants: Utah State University, University of Colorado Boulder
    Inventors: Mohamed Ahmed Kamel Ahmed, Regan Zane, Dragan Maksimovic
  • Publication number: 20210288581
    Abstract: Transformerless stacked active bridge (TSAB) direct current (DC)-to-DC power converters designed based on parent switched capacitor (SC) converter topologies. The TSAB DC-to-DC power converter includes the SC converter. The SC converter includes a plurality of switches and a plurality of capacitors. Each capacitor of the plurality of capacitors is electrically coupled to at least one of the plurality of switches. The plurality of capacitors includes tree capacitors, and link capacitors forming a loop with at least one of the tree capacitors. The TSAB DC-to-DC power converter includes at least one inductor electrically coupled in series to at least one of the link capacitors. The TSAB DC-to-DC power converters provide high efficiency bi-directional operation without requiring isolation transformers.
    Type: Application
    Filed: March 16, 2021
    Publication date: September 16, 2021
    Inventors: Jianglin Zhu, Dragan Maksimovic
  • Publication number: 20210184578
    Abstract: A bidirectional composite converter is provided. The bidirectional composite converter can be used with power electronics, such as but not limited to electric vehicles and other applications. In some implementations, for example, the composite converter may be used in a powertrain of an electric vehicle to couple batteries to a high voltage bus of the vehicle to provide power to the motors and to one or more integrated charging ports (e.g., ac grid wired connections or a wireless charging port) for extremely fast charging. In various implementations, the bidirectional converter architecture may comprise one or more dc transformer modules (DCX's) arranged with output port(s) coupled in series at an output port of the composite converter.
    Type: Application
    Filed: August 16, 2019
    Publication date: June 17, 2021
    Inventors: Robert ERICKSON, Dragan MAKSIMOVIC, Vivek SANKARANARAYANAN, Aritra GHOSH, Yucheng GAO
  • Publication number: 20210159007
    Abstract: Embodiments of the disclosure relate to apparatuses for enhanced thermal management of a planar inductor assembly. In one embodiment, a cooling package for an inductor assembly includes a cold plate and a heat-spreading bracket mechanically coupled to the cold plate at a first end of the heat-spreading bracket. The cold plate has a slotted recess for mounting a first inductor core along a first end thereof. The heat-spreading bracket is configured to apply a clamping force to a second inductor core at a second end opposite to the first end of the heat-spreading bracket.
    Type: Application
    Filed: November 22, 2019
    Publication date: May 27, 2021
    Applicants: Toyota Motor Engineering & Manufacturing North America, Inc., University of Colorado Boulder
    Inventors: Ercan M. DEDE, Tsuyoshi NOMURA, Robert ERICKSON, Dragan MAKSIMOVIC, Vivek SANKARANARAYANAN, Yucheng GAO, Aritra GHOSH
  • Publication number: 20200388432
    Abstract: Embodiments of the disclosure relate to apparatuses for enhanced thermal management of an inductor assembly using functionally-graded thermal vias for heat flow control in the windings of the inductor. In one embodiment, a PCB for an inductor assembly includes a top surface and a bottom surface. Two or more electrically-conductive layers are embedded within the PCB and stacked vertically between the top surface and the bottom surface. The two or more electrically-conductive layers are electrically connected to form an inductor winding. A plurality of thermal vias thermally connects each of the two or more electrically-conductive layers to a cold plate thermally connected to the bottom surface. A number of thermal vias thermally connecting each electrically-conductive layer to the cold plate is directly proportional to a predetermined rate of heat dissipation from the electrically-conductive layer.
    Type: Application
    Filed: November 22, 2019
    Publication date: December 10, 2020
    Applicants: Toyota Motor Engineering & Manufacturing North America, Inc., University of Colorado Boulder
    Inventors: Ercan DEDE, Yucheng GAO, Vivek SANKARANARAYANAN, Aritra GHOSH, Robert ERICKSON, Dragan MAKSIMOVIC
  • Patent number: 10855203
    Abstract: A cascaded architecture composed of interconnected blocks that are each designed to process constant power and eliminate bulk energy storage are provided. Further, local controls within each block natively achieve both block- and system-level aims, making the system modular and scalable. Further methods of providing power conversion using such interconnected clocks are also provided.
    Type: Grant
    Filed: May 2, 2019
    Date of Patent: December 1, 2020
    Assignees: The Regents of the University of Colorado, a body corporate, Alliance for Sustainable Energy, LLC
    Inventors: Dragan Maksimovic, Prasanta Achanta, Brian B. Johnson, Miguel Rodriguez, Vahan Gevorgian
  • Publication number: 20200067423
    Abstract: A cascaded architecture composed of interconnected blocks that are each designed to process constant power and eliminate bulk energy storage are provided. Further, local controls within each block natively achieve both block- and system-level aims, making the system modular and scalable. Further methods of providing power conversion using such interconnected clocks are also provided.
    Type: Application
    Filed: May 2, 2019
    Publication date: February 27, 2020
    Inventors: Dragan Maksimovic, Prasanta Achanta, Brian B. Johnson, Miguel Rodriguez, Vahan Gevorgian
  • Patent number: 10554164
    Abstract: In some aspects, an electric vehicle power system may comprise two or more electrically connected power modules connected to a system communication bus. Each power module may comprise a rechargeable battery electrically connected to a DC bus, an inverter circuit electrically connected to the DC bus, and at least one of a single-phase rectifier circuit electrically connected to the DC bus or a multi-phase rectifier circuit electrically connected to the DC bus. A local controller configured to send control signals may be connected to the rechargeable battery, the inverter circuit, and the at least one of the single-phase rectifier circuit or the multi-phase rectifier circuit. The single-phase rectifier circuit may be configured to convert a single-phase AC power signal into the DC voltage of the DC bus. The multi-phase rectifier circuit may be configured to convert a multi-phase AC power signal into the DC voltage of the DC bus.
    Type: Grant
    Filed: November 1, 2016
    Date of Patent: February 4, 2020
    Assignee: SUNGROW POWER SUPPLY CO., LTD.
    Inventors: Milan Ilic, Dragan Maksimovic, Mika Nuotio
  • Patent number: 10536068
    Abstract: A systematic procedure for the synthesis of hybrid feedforward control architectures for pulse-width modulated (PWM) switching converters is provided. In this hybrid feedforward control architecture selected converter variables are sensed and utilized in a particular way based on the converter open-loop characteristics to determine the duty-cycle needed to achieve a control objective. Compared to standard feedback control techniques, advantages can include simpler controller implementation, more convenient sensing, and improved static and dynamic regulation. An example systematic procedure for developing hybrid feedforward controllers is illustrated by first considering a previously known example of hybrid feedforward control: hybrid feedforward control of a boost power factor correction (PFC) rectifier operating in discontinuous conduction mode (DCM).
    Type: Grant
    Filed: June 26, 2017
    Date of Patent: January 14, 2020
    Assignee: The Regents of the University of Colorado, a body corporate
    Inventors: Usama Anwar, Khurram K. Afridi, Dragan Maksimovic
  • Patent number: 10461633
    Abstract: One aspect of the invention provides a DC-to-DC driver including: a converter including an output configured to drive a load with an output current; and a feedback controller coupled to the converter. The feedback controller includes: a pulse-width modulator configured to output a first pulse-width modulated signal to the converter; a first switching mechanism coupled to the pulse-width modulator; a compensator having an output coupled to the first switching mechanism, the compensator configured to generate a first duty cycle control signal based on a comparison of the output current and a first reference voltage; and a sampler having an input coupled to the output of the compensator and an output coupled to the switching mechanism, the sampler configured to generate a second duty cycle control signal based on the first duty cycle control signal.
    Type: Grant
    Filed: July 5, 2018
    Date of Patent: October 29, 2019
    Assignee: The Regents of the University of Colorado, a Body Corporate
    Inventors: Alihossein Sepahvand, Dragan Maksimovic, Khurram Afridi