Patents by Inventor Shashank Krishnamurthy

Shashank Krishnamurthy 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: 10308480
    Abstract: An embedded power module includes a substrate, first and second semiconducting dies, first and second gates, and first and second vias. The first semiconducting die is embedded in the substrate and spaced between opposite first and second surfaces of the substrate. The second semiconducting die is embedded in the substrate, is spaced between the first and second surfaces, and is spaced from the first semiconducting die. The first gate is located on the first surface. The second gate is located on the second surface. The first via is electrically engaged to the first gate and the second semiconducting die, and the second via is electrically engaged to the second gate and the first semiconducting die.
    Type: Grant
    Filed: July 8, 2016
    Date of Patent: June 4, 2019
    Assignee: OTIS ELEVATOR COMPANY
    Inventor: Shashank Krishnamurthy
  • Publication number: 20190097551
    Abstract: A system includes a converter operatively connected to an alternating current (AC) power source and a direct current (DC) bus, an inverter operatively connected to a motor and the DC bus, and a controller. The converter includes a first plurality of switching devices in selective communication with each phase of the AC power source and the DC bus. The inverter includes a second plurality of switching devices in selective communication with each phase of the motor and the DC bus. The controller is operable to command dropping of a brake through a passive delay circuit responsive to an emergency stop condition for a load driven by the motor and reduce a voltage on the DC bus by dropping at least one phase of the AC power source and/or using a dynamic braking resistor prior to the brake physically dropping.
    Type: Application
    Filed: September 28, 2017
    Publication date: March 28, 2019
    Inventors: Prasanna Nagarajan, Shashank Krishnamurthy, Konda Reddy Chevva
  • Patent number: 10221038
    Abstract: A control system (48) having a motor (28) is disclosed. The control system (48) may include a converter (32) operatively connected to a power source (36), an inverter (34) operatively connected to the motor (28), and a controller (50) operatively connected to the converter (32) or inverter (34). The controller (50) may be configured to receive control command signals, receive state feedback signals, and generate duty cycle signals for upper and lower arms of each phase (40) of the motor (28) based at least in part on the control command signals and state feedback signals. The duty cycle signals may minimize neutral point current in the converter (32) or inverter (34).
    Type: Grant
    Filed: December 18, 2013
    Date of Patent: March 5, 2019
    Assignee: OTIS ELEVATOR COMPANY
    Inventors: Ismail Agirman, Yang Wang, Shashank Krishnamurthy
  • Publication number: 20180334356
    Abstract: An elevator power distribution system includes an elevator car (114; 214; 314; 414; 514) configured to travel in a lane (113, 115, 117; 213; 313, 315, 317; 413, 415, 417; 513, 515, 517) of an elevator shaft (111) and a linear propulsion system configured to impart force to the elevator car. The linear propulsion system includes a first portion (216), mounted in the lane and a second portion (218) mounted to the elevator car configured to coact with the first portion (216) to impart movement to the elevator car.
    Type: Application
    Filed: January 19, 2016
    Publication date: November 22, 2018
    Inventors: Shashank Krishnamurthy, Daryl J. Marvin, Luis Arnedo
  • Publication number: 20180257907
    Abstract: A system including a drive portion, and an external computing device in communication with the drive portion, wherein the external computing device is configured to receive operational data from the drive portion, determine operational parameters based at least in part on the operational data, determine whether the operational parameters are valid, and automatically transmit commands to the drive portion if the operational parameters are valid.
    Type: Application
    Filed: December 17, 2015
    Publication date: September 13, 2018
    Inventors: Yang WANG, HanJong KIM, Christopher S. CZERWINSKI, Edward PIEDRA, Shashank KRISHNAMURTHY, Draguna VRABIE, Rui HUANG
  • Publication number: 20180234031
    Abstract: A method of configuring a power conversion cell for a distributed power system according to an example of the present disclosure includes: importing one or more software modules onto a controller of a conversion device configured to control power conversion with one or more of the modules selected based on one or more of a load or source device, and the results of a software simulation.
    Type: Application
    Filed: October 2, 2015
    Publication date: August 16, 2018
    Inventors: Luis Arnedo, Shashank Krishnamurthy, Vladimir Blasko
  • Publication number: 20180186595
    Abstract: An elevator system includes a first elevator car (28) constructed and arranged to move in a first lane (30, 32, 34) and a first propulsion system (40) constructed and arranged to propel the first elevator. An electronic processor of the elevator system is configured to selectively control power delivered to the first propulsion system (40). The electronic processor includes a software-based power estimator configured to receive a first weight signal and a nm trajectory signal for calculating a power estimate and comparing the power estimate to a maximum power allowance. The electronic processor is configured to output an automated command signal if the power estimate exceeds the maximum power allowance.
    Type: Application
    Filed: August 24, 2016
    Publication date: July 5, 2018
    Inventors: Shashank Krishnamurthy, Jose Miguel Pasini, David Ginsberg, Arthur Hsu
  • Patent number: 10008917
    Abstract: A regenerative drive device and a method for configuring the DC link of a regenerative drive device are disclosed. The multilevel regenerative drive device may include an inverter having a plurality of power components and a converter having a plurality of power components. The multilevel regenerative drive device may also include a direct current (DC) link bridging the inverter and the converter, the DC link including a capacitor, an inverter neutral point, and a converter neutral point independent of the inverter neutral point. Alternatively, the inverter neutral point and the converter neutral point may be connected.
    Type: Grant
    Filed: December 18, 2013
    Date of Patent: June 26, 2018
    Assignee: OTIS ELEVATOR COMPANY
    Inventors: Ismail Agirman, Steven M. Millett, Shashank Krishnamurthy, Yang Wang
  • Patent number: 9998031
    Abstract: A neutral point clamped, multilevel level converter includes a DC voltage link; a first capacitor coupling one side of the DC link to a neutral point; a second capacitor coupling another side of the DC link to the neutral point; a plurality of phase legs, each phase leg including switches, each phase leg coupled to an AC node; a current sensor associated with each AC node; and a controller generating a PWM signal to control the switches, the controller generating a current zero sequence component in response to current sensed at each of the current sensors, the controller adjusting a modulation index signal in response to the current zero sequence component to produce the PWM signal.
    Type: Grant
    Filed: August 29, 2017
    Date of Patent: June 12, 2018
    Assignee: OTIS ELEVATOR COMPANY
    Inventors: Luis Arnedo, Marinko Kovacic, Yang Wang, Shashank Krishnamurthy
  • Publication number: 20180022576
    Abstract: A drive and motor system and method for a six phase machine with negligible common-mode voltage is provided. The six-phase machine includes six phase windings divided into at least two windings groups configured to generate a zero common-mode pulse width modulation. The drive and motor system and method can also include at least one direct current source and a six phase inverter switching between positive and negative power of the at least one direct current source.
    Type: Application
    Filed: February 3, 2016
    Publication date: January 25, 2018
    Inventors: Dong Jiang, Shashank Krishnamurthy, Daryl J. Marvin
  • Publication number: 20180016115
    Abstract: An elevator system with an elevator car 14, a linear propulsion system to impart force to the elevator car in a hoistway 11, a hoistway communication network 106, 206, a local communication network 110, 210, 310 and motion controls. One of the motion controls proximate to 61 operable to command at least one drive 42A-42F via the local communication network. The at least one drive is coupled to one or more motor segments 22 of the linear propulsion system. The elevator system further includes a controller 46 operable to command the primary control via the hoistway communication network to reposition the elevator car within the hoistway. The designation of the primary control transitions between the motion controls as the elevator car moves in the hoistway.
    Type: Application
    Filed: February 4, 2016
    Publication date: January 18, 2018
    Inventors: David Ginsberg, Dang V. Nguyen, Shashank Krishnamurthy
  • Publication number: 20180009630
    Abstract: An elevator car travels in a lane (113, 115, 117) of an elevator shaft (111). A linear propulsion system imparts force to the car (214). The system includes a first part (116) mounted in the lane of the shaft and a second part (118) mounted to the elevator car configured to co-act with the first part to impart movement to the car. Car state sensors (360a-c) are disposed in the lane and determine a state space vector of the car within the lane. A sensed element (364) on the car is sensed by the plurality of car state sensors when the car is in proximity to the respective car state sensor. A control system (225) applies an electrical current to at least one of the first part and the second part and the plurality of car state sensors communicate with the control system and the linear propulsion system to provide state space vector data.
    Type: Application
    Filed: February 3, 2016
    Publication date: January 11, 2018
    Inventors: Peter DEPAOLA, JR., Richard N. FARGO, David GINSBERG, Dang V. NGUYEN, Shashank KRISHNAMURTHY
  • Publication number: 20180009637
    Abstract: An embedded power module includes a substrate, first and second semiconducting dies, first and second gates, and first and second vias. The first semiconducting die is embedded in the substrate and spaced between opposite first and second surfaces of the substrate. The second semiconducting die is embedded in the substrate, is spaced between the first and second surfaces, and is spaced from the first semiconducting die. The first gate is located on the first surface. The second gate is located on the second surface. The first via is electrically engaged to the first gate and the second semiconducting die, and the second via is electrically engaged to the second gate and the first semiconducting die.
    Type: Application
    Filed: July 8, 2016
    Publication date: January 11, 2018
    Inventor: Shashank Krishnamurthy
  • Publication number: 20180009631
    Abstract: A ropeless elevator system 10 includes a lane 13, 15, 17. One or more cars 20 are arranged in the lane. At least one linear motor 38, 40 is arranged along one of the lane and the one or more cars, and a magnet 50, 60 is arranged along the other of the lane and the one or more cars. The at least one magnet is responsive to the at least one linear motor. A linear motor controller 70 is operatively connected to the at least one linear motor, and a lane controller 80 is operatively connected to the linear motor controller. A back electro-motive force (EMF) module 84 is operatively connected to at least one of the linear motor controller and the lane controller. The lane controller being configured and disposed to control stopping one of the one or more cars based on a back EMF signal from the at least one linear motor determined by the EMF module.
    Type: Application
    Filed: February 4, 2016
    Publication date: January 11, 2018
    Inventors: Shashank Krishnamurthy, Vladimir Blasko, Enrico Manes
  • Publication number: 20170355555
    Abstract: A method of operating an elevator system for a learn run sequence including the steps of moving, using a linear propulsion system, an elevator car through a lane of an elevator shaft at a selected velocity; detecting, using a sensor system, the location of the elevator car when it moves through the lane; controlling, using a control system, the elevator car, the control system being in operable communication with the elevator car, the linear propulsion system, and the sensor system; and determining, using the control system, a location of each of the car state sensors relative to each other within the lane in response to at least one of a travel time of the elevator car, a velocity of the elevator car, a position of the elevator car, and a height of the elevator car.
    Type: Application
    Filed: June 12, 2017
    Publication date: December 14, 2017
    Inventors: David Ginsberg, Shashank Krishnamurthy, Lei Xing, Penghe Geng, Ankit Anand Gupta, Yogesh Parmod Jadhav, Basavanagouda Goudra, Pramod Mandikal Gurukumar
  • Publication number: 20170359000
    Abstract: A neutral point clamped, multilevel level converter includes a DC voltage link; a first capacitor coupling one side of the DC link to a neutral point; a second capacitor coupling another side of the DC link to the neutral point; a plurality of phase legs, each phase leg including switches, each phase leg coupled to an AC node; a current sensor associated with each AC node; and a controller generating a PWM signal to control the switches, the controller generating a current zero sequence component in response to current sensed at each of the current sensors, the controller adjusting a modulation index signal in response to the current zero sequence component to produce the PWM signal.
    Type: Application
    Filed: August 29, 2017
    Publication date: December 14, 2017
    Inventors: Luis Arnedo, Marinko Kovacic, Yang Wang, Shashank Krishnamurthy
  • Publication number: 20170317607
    Abstract: A three-level converter includes a first converter leg having first switches connected across a positive DC node and a negative DC node, a second converter leg having second switches connected across the positive DC node and the negative DC node, and a third converter leg having third switches connected across the positive DC node the negative DC node. The converter includes a battery connected between the positive DC node and the negative DC node, and center-connected to a ground node having a ground potential. Each of the first, second, and third converter legs is connected to the ground node.
    Type: Application
    Filed: October 21, 2015
    Publication date: November 2, 2017
    Inventors: Ismail Agirman, Steven M. Millett, Daryl J. Marvin, Shashank Krishnamurthy
  • Publication number: 20170297860
    Abstract: An elevator system and/or method executed by an elevator controller for detecting a fault within the elevator system. The elevator controller utilizes the fault to disable a drive control portion of the elevator controller and activate a drive u-stop control portion of the elevator controller. The drive u-stop control portion of the elevator controller generates a signal based on at least one of a speed estimation, a velocity profile, and feedforward information. The elevator controller applies the signal to an inverter connected to the elevator controller to execute the urgent stop of an elevator car of the elevator system.
    Type: Application
    Filed: April 15, 2016
    Publication date: October 19, 2017
    Inventors: SHASHANK KRISHNAMURTHY, DARYL J. MARVIN
  • Publication number: 20170294397
    Abstract: A die and substrate assembly is disclosed for a die with electronic circuitry and a substrate. A sintered bonding layer of sintered metal is disposed between the die and the substrate. The sintered bonding layer includes a plurality of zones having different sintered metal densities. The plurality of zones are distributed along one or more horizontal axes of the sintered bonding layer, along one or more vertical axes of the sintered bonding layer or along both one or more horizontal and one or more vertical axes of the sintered bonding layer.
    Type: Application
    Filed: April 8, 2016
    Publication date: October 12, 2017
    Inventors: Paul F. Croteau, Sergei F. Burlatsky, Shashank Krishnamurthy
  • Patent number: 9755546
    Abstract: A neutral point clamped, multilevel level converter includes a DC voltage link; a first capacitor coupling one side of the DC link to a neutral point; a second capacitor coupling another side of the DC link to the neutral point; a plurality of phase legs, each phase leg including switches, each phase leg coupled to an AC node; a current sensor associated with each AC node; and a controller generating a PWM signal to control the switches, the controller generating a current zero sequence component in response to current sensed at each of the current sensors, the controller adjusting a modulation index signal in response to the current zero sequence component to produce the PWM signal.
    Type: Grant
    Filed: November 21, 2012
    Date of Patent: September 5, 2017
    Assignee: OTIS ELECATOR COMPANY
    Inventors: Luis Arnedo, Marinko Kovacic, Yang Wang, Shashank Krishnamurthy