Patents Assigned to Northern Power Systems, Inc.
  • Patent number: 10224831
    Abstract: Feedback-type control systems for power converters that assist the power converters in staying within operational limited during disturbances. In some embodiments, each control system includes an impedance current regulator controlled as a function of an error between a measured feedback voltage signal representing the output of the power converter and an active feedforward voltage signal. In some multiphase embodiments, the impedance current regulator includes a gain that is adjusted as a function of the level of phase imbalance among the multiple phases. In some multiphase embodiments, a total current limit is determined as a function of the level of phase imbalance among the multiple phases. Corresponding feedback control methods and software, as well as power converter systems and AC network systems incorporating such feedback control systems, are also disclosed.
    Type: Grant
    Filed: January 22, 2018
    Date of Patent: March 5, 2019
    Assignee: Northern Power Systems, Inc.
    Inventors: Hector H. Hurtado, Stephen P. Hoskins, Jeffrey K. Petter
  • Patent number: 9515529
    Abstract: An apparatus and method for the installation and removal of permanent magnets in a permanent magnet electromechanical machine, for example a wind turbine power unit generator. A magnet holder is mounted on a magnet carrying structure such as a rotor. Permanent magnets may be inserted into and removed from the magnet holder after the electromechanical machine is assembled. The magnet holders define passages for airflow between the inside top and magnet surface. In this manner, permanent magnets may be installed on the magnet carrying structure and provided with additional cooling via said passages. Further, the holders may be configured to secure the magnets by an interference fit, without using bolts or adhesives, to facilitate both assembly and removal for maintenance and repair.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: December 6, 2016
    Assignee: Northern Power Systems, Inc.
    Inventors: Jonathan A. Lynch, Mark S. Piercey, Peter P. Mongeau
  • Patent number: 9467072
    Abstract: A power converter module for use alone or with other modules in a multiphase power converter. The power converter module has an enclosure that surrounds internal components to prevent radiation of electromagnetic energy, which internal components also limit conduction of electromagnetic energy. The internal components include an EMI filter, a ripple filter, a power converter, and a control interface that communicates with a control system of a power conversion system. The control interface includes a memory that stores information related to the power converter modules so as to improve interchangability of similar power modules with the multiphase power converter.
    Type: Grant
    Filed: October 14, 2013
    Date of Patent: October 11, 2016
    Assignee: Northern Power Systems, Inc.
    Inventors: Kiran Kumar Kulihithalu Channakeshava, Jeffrey K. Petter
  • Patent number: 9359994
    Abstract: A module-handling tool for facilitating installation, servicing, and/or dismantling of a electromagnetic rotary machine, such as an electrical power generator or electric motor, having a modularized active portion. In one embodiment, module-handling tool is configured for a machine having a modularized stator having a number of removable modules. In one example of such stator-module-handling tool, the tool is designed and configured to hold a stator module and be temporarily secured to the rotor of the machine during the process of installing the stator module into the machine or removing the module from the machine. In this example, the module-handling tool also acts as a module carrier for transporting a module to or from the machine.
    Type: Grant
    Filed: September 22, 2011
    Date of Patent: June 7, 2016
    Assignee: Northern Power Systems, Inc.
    Inventors: Garrett L. Bywaters, Trevor H. Cole, Etienne Hancock
  • Patent number: 9077212
    Abstract: An apparatus and method for cooling the rotor in an electromechanical machine such as a wind turbine generator is disclosed. Fluid cooling passages may be formed in the rotor, defined at least in part by a support member for magnets mounted on the rotor. Cooling fluid intake may be through the stator surrounding the rotor.
    Type: Grant
    Filed: September 22, 2011
    Date of Patent: July 7, 2015
    Assignee: Northern Power Systems, Inc.
    Inventors: Trevor H. Cole, Etienne Hancock, Adam R. Olsen
  • Patent number: 8922038
    Abstract: A wind power unit that includes a tower and a support structure that cantilevers from the upper end of the tower. The wind power unit includes an electrical transformer that is suspended from the support structure. In one embodiment, the transformer extends through an opening in the bottom portion of a nacelle that encloses the support structure and includes electrical connections on its upper end that are accessible from inside the nacelle via a service opening in a floor located above the transformer.
    Type: Grant
    Filed: October 19, 2011
    Date of Patent: December 30, 2014
    Assignee: Northern Power Systems, Inc.
    Inventors: Garrett L. Bywaters, Trevor H. Cole
  • Patent number: 8912704
    Abstract: A method and apparatus for reducing or eliminating the effects of torque ripple and cogging torque and otherwise improving performance in an electromechanical machine such as a motor or generator. The rotor and/or stator is conceptually sectionalized and the sections spaced apart by amount sufficient to alleviate deleterious aspects of cogging torque and torque ripple. Positioning of the stator teeth or rotor magnets is determined based on the calculated spacing. Conceptual sections may be formed as physically individual segments. Unwound teeth may be disposed in end spaces between sections occupying less than the entire area of the end space.
    Type: Grant
    Filed: September 22, 2011
    Date of Patent: December 16, 2014
    Assignee: Northern Power Systems, Inc.
    Inventors: Jeffrey K. Petter, Hector Hurtado
  • Patent number: 8890349
    Abstract: A wind power unit control system that dynamically corrects for yaw angle error based on sensed conditions and switches operation of the wind power unit to a correct operating mode based on its current operational state and the sensed conditions.
    Type: Grant
    Filed: January 21, 2013
    Date of Patent: November 18, 2014
    Assignee: Northern Power Systems, Inc.
    Inventors: Jonathan A. Lynch, Garrett L. Bywaters
  • Patent number: 8816546
    Abstract: Electromagnetic rotary machines, such as electrical power generators and electric motors, that have one or more active portions modularized into a set of modules. Each of the modules is secured to a support frame via a sliding-interlock system that allows that module to be slidingly engaged with the support frame. In some embodiments, each module can include an integrated coolant conduit that carries a coolant to cool the active portion during operation. The modules can each be self-contained in the respect that essentially all that needs to be done to form the active portion and corresponding portion of the cooling system is to install the modules and make any remaining electrical and coolant conduit connections.
    Type: Grant
    Filed: September 22, 2011
    Date of Patent: August 26, 2014
    Assignee: Northern Power Systems, Inc.
    Inventors: Garrett L. Bywaters, Trevor H. Cole, Jonathan A. Lynch, Jeffrey K. Petter
  • Patent number: 8816520
    Abstract: Systems and methods for reducing dynamic loading in an idled wind power unit include sensing at least one parameter indicative of dynamic loading and executing a reduced torque brake mode, which may comprise a controlled brake and brake-release sequence, with the turbine braking system when the sensed parameter exceeds a selected value. The reduced torque brake mode absorbs energy and reduces dynamic loading thereby.
    Type: Grant
    Filed: December 9, 2011
    Date of Patent: August 26, 2014
    Assignee: Northern Power Systems, Inc.
    Inventors: Garrett L. Bywaters, Austin Cate, Jeffrey K. Petter
  • Patent number: 8792259
    Abstract: Software embodied in a machine-readable storage medium and useful for controlling alternating-current (AC) output of a power converter connected to an AC power network. The software is designed and configured to estimate the phase of the voltage on the AC power network that will be on the network when the network recovers from a fault. Such software allows a power-network-connected power source to ride-through a fault event and continue supplying power thereto at the designed phase and frequency. In one embodiment, the software provides this estimate by tracking the phase with a response time changed in inverse proportion to the voltage on the power network.
    Type: Grant
    Filed: May 29, 2013
    Date of Patent: July 29, 2014
    Assignee: Northern Power Systems, Inc.
    Inventor: Jeffrey K. Petter
  • Patent number: 8789274
    Abstract: A method and system for attaching a service device to a wind turbine of a wind power unit, using the wind turbine to rotate the service device into one or more service positions, and using the service device to perform servicing on the wind power unit. In some embodiments, a blade of the wind turbine is removed and the service device is mounted in its place. In other embodiments, the service device is mounted to a device mount approximately in a saddle region between adjacent blades. In one example, the service device is a crane. In another example, the service device is a stator module installation/removal tool.
    Type: Grant
    Filed: September 22, 2011
    Date of Patent: July 29, 2014
    Assignee: Northern Power Systems, Inc.
    Inventors: Garrett L. Bywaters, Trevor H. Cole, Adam R. Olsen
  • Patent number: 8786151
    Abstract: A rotor-stator structure including plural bumper elements that may employ synthetic sliding bearing surfaces, mounted to the stator, and designed to contact a machined surface on the rotor if generator structural deflection occurs during operation. During normal operation, the bearing surface is not in contact with the machine rotor. If extreme loads are imposed on the rotor or stator structures, or other issue like bearing failure, causes the air gap to close, the bumper elements will “touch down” on a machined surface on the rotor to maintain a minimum air gap.
    Type: Grant
    Filed: December 13, 2011
    Date of Patent: July 22, 2014
    Assignee: Northern Power Systems, Inc.
    Inventors: Trevor H. Cole, Garrett L. Bywaters, Adam R. Olsen, Daniel Costin
  • Patent number: 8664787
    Abstract: A speed setting system that generates a speed control command for controlling the rotational speed of a stall-controlled wind turbine of a wind-powered machine. The speed setting system generates the speed command as a function of performance variation of the wind turbine due to environmental and/or other factors. The speed setting system utilizes a performance-compensation term that is slowly adjusted to compensate for relatively long-term performance variation. In one example, the performance-compensation term is adjusted only when the current power output of the wind turbine is at least 80% of the rated output power to ensure the wind speed is sufficiently high.
    Type: Grant
    Filed: April 5, 2010
    Date of Patent: March 4, 2014
    Assignee: Northern Power Systems, Inc.
    Inventor: Jeffrey K. Petter
  • Publication number: 20120147637
    Abstract: A power converter control system having a phase tracker that is designed and configured to estimate the phase of the voltage on the power network that will be on the network when network recovers from a fault on the network. Such a power converter control system allows a power-network-connected power source to ride-through a fault event and continue supplying power thereto at the designed phase and frequency. In one embodiment, the phase tracker provides this estimate by having a response time slow enough that the voltage drop or sag caused by the fault substantially does not affect the control system. In another embodiment, the phase detector is designed and configured to freeze the frequency of its output upon detection of a fault event on the power network.
    Type: Application
    Filed: October 18, 2011
    Publication date: June 14, 2012
    Applicant: NORTHERN POWER SYSTEMS, INC.
    Inventor: Jeffrey K. Petter
  • Publication number: 20120146333
    Abstract: Systems and methods for reducing dynamic loading in an idled wind power unit include sensing at least one parameter indicative of dynamic loading and executing a reduced torque brake mode, which may comprise a controlled brake and brake-release sequence, with the turbine braking system when the sensed parameter exceeds a selected value. The reduced torque brake mode absorbs energy and reduces dynamic loading thereby.
    Type: Application
    Filed: December 9, 2011
    Publication date: June 14, 2012
    Applicant: NORTHERN POWER SYSTEMS, INC.
    Inventors: Garrett L. Bywaters, Austin Cate, Jeffrey K. Petter
  • Publication number: 20120146335
    Abstract: A wind power unit that includes a tower and a support structure that cantilevers from the upper end of the tower. The wind power unit includes an electrical transformer that is suspended from the support structure. In one embodiment, the transformer extends through an opening in the bottom portion of a nacelle that encloses the support structure and includes electrical connections on its upper end that are accessible from inside the nacelle via a service opening in a floor located above the transformer.
    Type: Application
    Filed: October 19, 2011
    Publication date: June 14, 2012
    Applicant: NORTHERN POWER SYSTEMS, INC.
    Inventors: Garrett L. Bywaters, Trevor H. Cole
  • Publication number: 20120073134
    Abstract: A method and system for attaching a service device to a wind turbine of a wind power unit, using the wind turbine to rotate the service device into one or more service positions, and using the service device to perform servicing on the wind power unit. In some embodiments, a blade of the wind turbine is removed and the service device is mounted in its place. In other embodiments, the service device is mounted to a device mount approximately in a saddle region between adjacent blades. In one example, the service device is a crane. In another example, the service device is a stator module installation/removal tool.
    Type: Application
    Filed: September 22, 2011
    Publication date: March 29, 2012
    Applicant: NORTHERN POWER SYSTEMS, INC.
    Inventors: Garrett L. Bywaters, Trevor H. Cole, Adam R. Olsen
  • Publication number: 20120075051
    Abstract: A magnetic device producing a small amount of leakage flux and capable of substantially eliminating the amount of leakage flux that escapes the magnetic core of the device. The device includes at least a portion of an electronic circuit that includes an interphase transformer arranged on a magnetic core. The reactor windings on each leg of the magnetic core are disposed in close proximity to each other and can be wound concentrically or in a bifilar fashion. The resulting combination of the magnetic core and windings provides a high degree of magnetic coupling between reactor windings disposed on the same leg and between reactor windings disposed on differing legs. The high degree of magnetic coupling substantially reduces the amount of leakage flux that can affect other metal objects proximate the magnetic device.
    Type: Application
    Filed: June 7, 2011
    Publication date: March 29, 2012
    Applicant: NORTHERN POWER SYSTEMS, INC.
    Inventors: Jeffrey K. Petter, Magdalena E. Dale
  • Publication number: 20120073117
    Abstract: Methods of precisely positioning a rotor of a machine into one or more service positions for the purpose of servicing the machine. In some embodiments, the machine includes A rotor and a stator segmented into multiple removable stator modules. During servicing, a stator-module replacement tool is precisely located in any one or more of multiple service positions corresponding to the multiple stator modules by selectively energizing the machine. In other embodiments, the machine includes a stator and a rotor having multiple removable permanent magnets corresponding respectively to multiple service positions. During servicing, the rotor is precisely located in any one or more of multiple service positions corresponding to the permanent magnets by selectively energizing the machine. A servicing control system is disclosed for controlling the excitation of a machine stator in a manner that effects precise positioning of the rotor into a selected service position.
    Type: Application
    Filed: September 22, 2011
    Publication date: March 29, 2012
    Applicant: NORTHERN POWER SYSTEMS, INC.
    Inventor: Eric L. Benedict