Northern Power Systems, Inc.

Norwich Technologies, Inc.

Northern Power Systems Utility Scale, Inc.

Weg Electric Corp

Jonathan A Lynch

Garrett Lee Bywaters

Troy O McBride

Joel Stettenheim

Leif Johnson

Per Erik Kristoffer Edstrom

Oliver James Brambles

Daniel P Costin

Clint C Coleman

Christopher M Bevington

William L Danforth

Robert H Rolland

Jeffrey K Petter

Peter Mongeau

Mark S Piercey

Trevor H Cole

Thomas D Kohler

Paul A Smith

Peter P Mongeau

A thermal energy storage system comprising a working fluid to store and transfer thermal energy between a heat source and a thermal load and a vessel to store the working fluid. The vessel has an interior region and a floating separator piston in the interior region to separate a hot portion from a cold portion of the working fluid. There is a first manifold thermally coupled to an output of the heat source and to an input of the thermal load and fluidly coupled to the interior region of the vessel and a second manifold thermally coupled to an input of the heat source and an output of the thermal load and fluidly coupled to the interior region of the vessel. There is a controller configured to maintain the working fluid in a liquid state.

Thermal energy storage system including a plurality of vessels each having hot and cold liquid portions separated by a floating piston

Thermal energy storage system including a vessel having hot and cold liquid portions separated by floating piston

A thermal energy storage system for comprising a working fluid to store and transfer thermal energy between a heat source and a thermal load and a plurality of vessels to store the working fluid. Each vessel has an interior region and a floating separator piston in the interior region to separate a hot portion from a cold portion of the working fluid. There is a first manifold thermally coupled to an output of the heat source and to an input of the thermal load and fluidly coupled to the interior region of the vessels and a second manifold thermally coupled to an input of the heat source and an output of the thermal load and fluidly coupled to the interior region of the vessels. The vessels are arranged in parallel.

Thermal energy storage system with parallel connected vessels

A piston ring configured to be disposed in a floating piston for use in a vessel of a thermal energy storage system to separate a hot working fluid from a cold working fluid, wherein the piston ring comprises of a plurality of arc segments, each arc segment interconnected by a joint.

Piston ring for floating piston in a thermal energy storage system

A floating piston configured to be disposed in a vessel of a thermal energy storage system to separate a hot working fluid from a cold working fluid. The floating piston includes a piston body having a first end, a second end, and a central region. There is a compressible member which is disposed in the central region of the piston and which is configured to engage with an inner surface of the vessel when the piston is disposed in the vessel.

Floating separator piston for a thermal energy storage system

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.

Method and apparatus for permanent magnet attachment in an electromechanical machine

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.

Load reduction system and method for a wind power unit

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.

Electromagnetic rotary machines having modular active-coil portions and modules for such machines

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. In this manner, permanent magnets may be installed on the magnet carrying structure by an interference fit, without using bolts or adhesives, to facilitate both assembly and removal for maintenance and repair.

A wind turbine comprising an electrical generator that includes a rotor assembly. A wind rotor that includes a wind rotor hub is directly coupled to the rotor assembly via a simplified connection. The wind rotor and generator rotor assembly are rotatably mounted on a central spindle via a bearing assembly. The wind rotor hub includes an opening having a diameter larger than the outside diameter of the central spindle adjacent the bearing assembly so as to allow access to the bearing assembly from a cavity inside the wind rotor hub. The spindle is attached to a turret supported by a tower. Each of the spindle, turret and tower has an interior cavity that permits personnel to traverse therethrough to the cavity of the wind rotor hub. The wind turbine further includes a frictional braking system for slowing, stopping or keeping stopped the rotation of the wind rotor and rotor assembly.

Wind turbine/generator set and method of making same

Wind turbine/generator set having a stator cooling system located between stator frame and active coils

Wind turbine having a direct-drive drivetrain

A wind turbine () comprising an electrical generator () that includes a rotor assembly (). A wind rotor () that includes a wind rotor hub () is directly coupled to the rotor assembly via a simplified connection. The wind rotor and generator rotor assembly are rotatably mounted on a central spindle () via a bearing assembly (). The wind rotor hub includes an opening () having a diameter larger than the outside diameter of the central spindle adjacent the bearing assembly so as to allow access to the bearing assembly from a cavity () inside the wind rotor hub. The spindle is attached to a turret () supported by a tower (). Each of the spindle, turret and tower has an interior cavity () that permits personnel to traverse therethrough to the cavity of the wind rotor hub. The wind turbine further includes a frictional braking system () for slowing, stopping or keeping stopped the rotation of the wind rotor and rotor assembly.

A control system () for a power converter () designed to convert DC power from a source () such as a battery, flywheel or fuel cell into AC power. The control system includes an impedance current regulator () for providing an impedance current signal to a summing unit () where it may be combined with real and reactive current command signals provided from respective sources (). The resultant current signal provided by the summing unit is provided to a voltage correction unit () that uses the resultant current signal in developing a correction voltage signal provided to the power converter. The correction voltage signal contains information used by the power converter in adjusting the real and reactive currents in its output AC power based on the ability of the AC power network to accept changes in current. Multiple power converters having the control system of the present invention may be connected in parallel to a single AC load or multiple AC loads, without the need for a separate control system interconnecting the power converters. The control system may be advantageously incorporated into a distributed generation network and in uninterruptible power systems, whether or not such systems are included in a distributed generation network.

Parallel-connected inverters with separate controllers having impedance current regulators

A control system ( ) for a power converter ( ) designed to convert DC power from a source ( ) such as a battery, flywheel or fuel cell into AC power. The control system includes an impedance current regulator ( ) for providing an impedance current signal to a summing unit ( ) where it may be combined with real and reactive current command signals provided from respective sources ( ). The resultant current signal provided by the summing unit is provided to a voltage correction unit ( ) that uses the resultant current signal in developing a correction voltage signal provided to the power converter. The correction voltage signal contains information used by the power converter in adjusting the real and reactive currents in its output AC power based on the ability of the AC power network to accept changes in current. Multiple power converters having the control system of the present invention may be connected in parallel to a single AC load or multiple AC loads, without the need for a separate control system interconnecting the power converters. The control system may be advantageously incorporated into a distributed generation network and in uninterruptible power systems, whether or not such systems are included in a distributed generation network.

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St. Johnsbury, VT, United States of America

Jonathan A Lynch