Patents by Inventor Niannian CAI

Niannian CAI 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: 11735913
    Abstract: An autonomous real-time remedial action scheme (RAS) control system may receive electrical measurements of a power system. The RAS control system may determine active power and reactive power of each bus in the power system based on the received electrical measurements. The RAS control system may dynamically determine whether to shed one or more loads, generators, or both in the power system by optimizing an objective function to maintain maximum critical load and maximum critical generation in the electrical system based on the active and reactive power of each bus in the power system and the generation of each generator in the power system. The RAS control system may send a command to trip at least one breaker to cause the at least one breaker to shed the one or more loads, generators, or both. The RAS control system may send a command to runback one or more generators.
    Type: Grant
    Filed: May 25, 2021
    Date of Patent: August 22, 2023
    Assignee: Schweitzer Engineering Laboratories, Inc.
    Inventors: Niannian Cai, Abdel Rahman Khatib
  • Patent number: 11588333
    Abstract: A microgrid power flow monitoring and control system is described herein. The control system may determine active and reactive power sharing shortage on the electric power delivery system. The control system may utilize the control strategies of generation units, such as ISO control, droop control and constant power control to estimate power flow within a microgrid or other isolated system. A control strategy of one or more generators may be modified based on the determined power flow.
    Type: Grant
    Filed: May 9, 2022
    Date of Patent: February 21, 2023
    Assignee: Schweitzer Engineering Laboratories, Inc.
    Inventors: Abdel Rahman Khatib, Niannian Cai
  • Publication number: 20220393468
    Abstract: An autonomous real-time remedial action scheme (RAS) control system may receive electrical measurements of a power system. The RAS control system may determine active power and reactive power of each bus in the power system based on the received electrical measurements. The RAS control system may dynamically determine whether to shed one or more loads, generators, or both in the power system by optimizing an objective function to maintain maximum critical load and maximum critical generation in the electrical system based on the active and reactive power of each bus in the power system and the generation of each generator in the power system. The RAS control system may send a command to trip at least one breaker to cause the at least one breaker to shed the one or more loads, generators, or both. The RAS control system may send a command to runback one or more generators.
    Type: Application
    Filed: May 25, 2021
    Publication date: December 8, 2022
    Applicant: Schweitzer Engineering Laboratories, Inc.
    Inventors: Niannian Cai, Abdel Rahman Khatib
  • Publication number: 20220271530
    Abstract: A microgrid power flow monitoring and control system is described herein. The control system may determine active and reactive power sharing shortage on the electric power delivery system. The control system may utilize the control strategies of generation units, such as ISO control, droop control and constant power control to estimate power flow within a microgrid or other isolated system. A control strategy of one or more generators may be modified based on the determined power flow.
    Type: Application
    Filed: May 9, 2022
    Publication date: August 25, 2022
    Applicant: Schweitzer Engineering Laboratories, Inc.
    Inventors: Abdel Rahman Khatib, Niannian Cai
  • Patent number: 11368048
    Abstract: A microgrid power flow monitoring and control system is described herein. The control system may determine active and reactive power sharing shortage on the electric power delivery system. The control system may utilize the control strategies of generation units, such as ISO control, droop control and constant power control to estimate power flow within a microgrid or other isolated system. A control strategy of one or more generators may be modified based on the determined power flow.
    Type: Grant
    Filed: July 24, 2020
    Date of Patent: June 21, 2022
    Assignee: Schweitzer Engineering Laboratories, Inc.
    Inventors: Abdel Rahman Khatib, Niannian Cai
  • Patent number: 11177657
    Abstract: A power system simulator may calculate mechanical power of at least one generator at a second time in a simulated power system based at least in part on electrical power of the at least one generator at a first time. The power system simulator may calculate system frequency at second time based on system dynamic model that models the electrical power and the mechanical power of the simulated power system, frequency and voltage characteristics in the simulated power system, and inertia of the at least one generator. The power system simulator may provide simulated power system measurements based on the active power values to a power system controller to allow testing of the power system controller.
    Type: Grant
    Filed: September 25, 2020
    Date of Patent: November 16, 2021
    Assignee: Schweitzer Engineering Laboratories, Inc.
    Inventors: Abdel Rahman Khatib, Niannian Cai
  • Patent number: 11038352
    Abstract: Systems and methods described herein may be used to search for a minimum load overshed in a power system. For example, a control system includes memory and a processor operatively coupled to the memory. The processor may obtain an amount of power consumed by each load in a total set of loads in a microgrid. The processor may detect a difference between the amount of power generated and the amount of power consumed. The processor may select a subset of loads to shed from the total set of loads by searching a tree of potential load shed amounts to substantially balance the amount of power generated with the amount of power consumed. The processor may send one or more signals to one or more electronic devices to cause the selected subset of loads to be shed.
    Type: Grant
    Filed: November 26, 2019
    Date of Patent: June 15, 2021
    Assignee: Schweitzer Engineering Laboratories, Inc.
    Inventors: Abdel Rahman Khatib, Niannian Cai
  • Publication number: 20210159700
    Abstract: Systems and methods described herein may be used to search for a minimum load overshed in a power system. For example, a control system includes memory and a processor operatively coupled to the memory. The processor may obtain an amount of power consumed by each load in a total set of loads in a microgrid. The processor may detect a difference between the amount of power generated and the amount of power consumed. The processor may select a subset of loads to shed from the total set of loads by searching a tree of potential load shed amounts to substantially balance the amount of power generated with the amount of power consumed. The processor may send one or more signals to one or more electronic devices to cause the selected subset of loads to be shed.
    Type: Application
    Filed: November 26, 2019
    Publication date: May 27, 2021
    Applicant: Schweitzer Engineering Laboratories, Inc.
    Inventors: Abdel Rahman Khatib, Niannian Cai
  • Patent number: 11009931
    Abstract: The present disclosure relates to systems and methods of predicting voltages for various contingencies. For example, a monitoring system may include a processor that acquires at least one contingency of an electric power delivery system. The processor may acquire an expected control action based on the at least one contingency from controllers/IEDs. The processor may predict a voltage of at least one bus of the electric power delivery system by simulating the change in the state of the electric power delivery system caused by the expected control action. The processor may determine that the voltage of the at least one bus is predicted to violate one or more operational settings of the electric power delivery system if the at least one contingency were to occur. The processor may provide an indication that the voltage violates the one or more operational settings on a display of the electronic device.
    Type: Grant
    Filed: February 25, 2019
    Date of Patent: May 18, 2021
    Assignee: Schweitzer Engineering Laboratories, Inc.
    Inventors: Abdel Rahman Khatib, Niannian Cai
  • Patent number: 10992134
    Abstract: The present disclosure relates to shedding loads based on perturbation of active power and perturbation of reactive power. For instance, a method includes receiving electrical measurements of a power system. The method includes detecting a contingency in the power system. The method includes determining perturbation of the active power and perturbation of reactive power in the power system based on the electrical measurements. The method includes shedding one or more loads of the power system due to the contingency based on the perturbation of the active power and the perturbation of reactive power.
    Type: Grant
    Filed: May 10, 2019
    Date of Patent: April 27, 2021
    Assignee: Schweitzer Engineering Laboratories, Inc.
    Inventors: Niannian Cai, Abdel Rahman Khatib, Niraj Kiritkumar Shah
  • Patent number: 10931109
    Abstract: The present disclosure relates to a computationally efficient technique for determining loads to shed based on both active and reactive power. For example, a monitoring and control system may receive electrical measurements of a power system. The monitoring and control system may determine an active power and a reactive power of each bus in the power system based on the received electrical measurements. The monitoring and control system may send a command to trip at least one breaker to cause the at least one breaker to shed a load based at least in part on both the active power and the reactive power consumed by each bus in the power system.
    Type: Grant
    Filed: January 10, 2019
    Date of Patent: February 23, 2021
    Assignee: Schweitzer Engineering Laboratories, Inc.
    Inventors: Niannian Cai, Abdel Rahman Khatib, Niraj Kiritkumar Shah
  • Publication number: 20200356128
    Abstract: The present disclosure relates to shedding loads based on perturbation of active power and perturbation of reactive power. For instance, a method includes receiving electrical measurements of a power system. The method includes detecting a contingency in the power system. The method includes determining perturbation of the active power and perturbation of reactive power in the power system based on the electrical measurements. The method includes shedding one or more loads of the power system due to the contingency based on the perturbation of the active power and the perturbation of reactive power.
    Type: Application
    Filed: May 10, 2019
    Publication date: November 12, 2020
    Applicant: Schweitzer Engineering Laboratories, Inc.
    Inventors: Niannian Cai, Abdel Rahman Khatib, Niraj Kiritkumar Shah
  • Publication number: 20200358310
    Abstract: A microgrid power flow monitoring and control system is described herein. The control system may determine active and reactive power sharing shortage on the electric power delivery system. The control system may utilize the control strategies of generation units, such as ISO control, droop control and constant power control to estimate power flow within a microgrid or other isolated system. A control strategy of one or more generators may be modified based on the determined power flow.
    Type: Application
    Filed: July 24, 2020
    Publication date: November 12, 2020
    Applicant: Schweitzer Engineering Laboratories, Inc.
    Inventors: Abdel Rahman Khatib, Niannian Cai
  • Patent number: 10763695
    Abstract: A microgrid power flow monitoring and control system is described herein. The control system may determine active and reactive power sharing shortage on the electric power delivery system. The control system may utilize the control strategies of generation units, such as ISO control, droop control and constant power control to estimate power flow within a microgrid or other isolated system. A control strategy of one or more generators may be modified based on the determined power flow.
    Type: Grant
    Filed: July 7, 2017
    Date of Patent: September 1, 2020
    Assignee: Schweitzer Engineering Laboratories, Inc.
    Inventors: Abdel Rahman Khatib, Niannian Cai
  • Publication number: 20200227915
    Abstract: The present disclosure relates to a computationally efficient technique for determining loads to shed based on both active and reactive power. For example, a monitoring and control system may receive electrical measurements of a power system. The monitoring and control system may determine an active power and a reactive power of each bus in the power system based on the received electrical measurements. The monitoring and control system may send a command to trip at least one breaker to cause the at least one breaker to shed a load based at least in part on both the active power and the reactive power consumed by each bus in the power system.
    Type: Application
    Filed: January 10, 2019
    Publication date: July 16, 2020
    Applicant: Schweitzer Engineering Laboratories, Inc.
    Inventors: Niannian Cai, Abdel Rahman Khatib, Niraj Kiritkumar Shah
  • Publication number: 20200026337
    Abstract: The present disclosure relates to systems and methods of predicting voltages for various contingencies. For example, a monitoring system may include a processor that acquires at least one contingency of an electric power delivery system. The processor may acquire an expected control action based on the at least one contingency from controllers/IEDs. The processor may predict a voltage of at least one bus of the electric power delivery system by simulating the change in the state of the electric power delivery system caused by the expected control action. The processor may determine that the voltage of the at least one bus is predicted to violate one or more operational settings of the electric power delivery system if the at least one contingency were to occur. The processor may provide an indication that the voltage violates the one or more operational settings on a display of the electronic device.
    Type: Application
    Filed: February 25, 2019
    Publication date: January 23, 2020
    Applicant: Schweitzer Engineering Laboratories, Inc.
    Inventors: Abdel Rahman Khatib, Niannian Cai
  • Patent number: 10097000
    Abstract: The analysis tool employs a computer-implemented algorithm that uses homotopy-based approaches to map the solution from the exit point to the controlling unstable equilibrium point (UEP). The computational time is reduced significantly by using an approximate exit point rather than computing an accurate exit point as it is required in finding the controlling UEPs using traditional transient stability direct methods. In addition, this method eliminates the necessity of computing the minimum gradient point (MGP) which is a key element in using Newton methods. These properties provide an advantage to homotopy-based approaches over traditional iterative methods in terms of both speed of computation and reliability of finding solutions.
    Type: Grant
    Filed: August 11, 2015
    Date of Patent: October 9, 2018
    Assignee: Board of Trustees of Michigan State University
    Inventors: Joydeep Mitra, Mohammed Ben-Idris, Niannian Cai
  • Publication number: 20180034317
    Abstract: A microgrid power flow monitoring and control system is described herein. The control system may determine active and reactive power sharing shortage on the electric power delivery system. The control system may utilize the control strategies of generation units, such as ISO control, droop control and constant power control to estimate power flow within a microgrid or other isolated system. A control strategy of one or more generators may be modified based on the determined power flow.
    Type: Application
    Filed: July 7, 2017
    Publication date: February 1, 2018
    Applicant: Schweitzer Engineering Laboratories, Inc.
    Inventors: Abdel Rahman Khatib, Niannian Cai
  • Publication number: 20160041232
    Abstract: The analysis tool employs a computer-implemented algorithm that uses homotopy-based approaches to map the solution from the exit point to the controlling unstable equilibrium point (UEP). The computational time is reduced significantly by using an approximate exit point rather than computing an accurate exit point as it is required in finding the controlling UEPs using traditional transient stability direct methods. In addition, this method eliminates the necessity of computing the minimum gradient point (MGP) which is a key element in using Newton methods. These properties provide an advantage to homotopy-based approaches over traditional iterative methods in terms of both speed of computation and reliability of finding solutions.
    Type: Application
    Filed: August 11, 2015
    Publication date: February 11, 2016
    Applicant: Board of Trustees of Michigan State University
    Inventors: Joydeep MITRA, Mohammed BEN-IDRIS, Niannian CAI