Steven J Fredette

US Patent:

7038329, May 2, 2006

Filed:

Nov 4, 2004

Appl. No.:

10/982628

Inventors:

Steven J. Fredette - South Windsor CT, US
Rishi Grover - Vernon CT, US

Assignee:

UTC Power, LLC - South Windsor CT

International Classification:

F02D 29/06

US Classification:

290 40C, 318438, 307127

Abstract:

A prime mover () in a heat recovery system drives an induction generator () which feeds power to a utility grid () through a breaker () but also powers a load including auxiliary induction motors (). To provide acceptable waveform and power factor, the auxiliary equipment is driven through IGBT switched bridge converters () by DC voltage () generated by an IGBT switched bridge converter (), instead of three-phase diode rectifiers (). The switched bridge converter controller () is responsive to a system process controller () which causes the switched bridge controller () to be driven in response to the voltage () and current () on the generator bus (). This eliminates the need for harmonic filters () and power factor capacitors () while improving the quality of the power generated. The controller () trips the breaker if the voltage, frequency or power factor is out of limits.

US Patent:

7087329, Aug 8, 2006

Filed:

Nov 19, 2003

Appl. No.:

10/717089

Inventors:

David G. Converse - Hampden MA, US
Steven J. Fredette - South Windsor CT, US

Assignee:

UTC Fuel Cells, LLC - South Windsor CT

International Classification:

H01M 8/04
H01M 10/44
H02J 7/02

US Classification:

429 13, 320101, 307 46

Abstract:

A fuel cell stack () with output lines () has a bank of supercapacitors () or batteries () connected across the output lines, either directly or through a DC/DC converter (). The fuel cell stack receives fuel either from a reformer () or a source () of hydrogen. Power is supplied through a power conditioning system () to a load (), all under the control of a controller (). The supercapacitors or batteries receive additional charge from excess power when there is a sudden decrease in the load, and provide charge to the output power lines () when there is a sudden increase in load demand. In one embodiment, the voltage of the supercapacitors or batteries always follow the voltage of the fuel cell stack, thereby providing or receiving commensurate charge. With the DC/DC converter, the supercapacitors or batteries may be operated at voltages which are a multiple or a fraction of fuel cell stack voltage, and may have voltages boosted or bucked to aid in response to transients.

US Patent:

7617062, Nov 10, 2009

Filed:

Oct 29, 2004

Appl. No.:

10/976486

Inventors:

Steven Fredette - South Windsor CT, US

Assignee:

UTC Power Corporation - South Windsor CT

International Classification:

G06F 19/00

US Classification:

702106

Abstract:

A process for determining the DC current in a fuel cell power plant includes the steps of determining current value from a power electronics converter of a power conditioning system of the power plant; determining a correction factor based upon losses within the converter; and correcting the current value from the converter with the correction factor to determine DC current in the fuel cell. This process also includes determining voltage within the converter and use of the voltage along with the corrected current to determine the desired DC current value.

US Patent:

7790303, Sep 7, 2010

Filed:

Nov 14, 2005

Appl. No.:

11/274240

Inventors:

Steven J. Fredette - South Windsor CT, US

Assignee:

UTC Power Corporation - South Windsor CT

International Classification:

H01M 8/00

US Classification:

429 13, 429 22

Abstract:

During fuel cell startup and shutdown or other power reduction transitions of a fuel cell power plant, the excess electric energy generated by consumption of reactants is extracted by a storage control () in response to a controller () as current applied to an energy storage system (a battery). In a boost embodiment, an inductor () and a diode () connect one terminal () of the stack () of the battery. An electronic switch connects the juncture of the inductor and the diode to both the other terminal () of the stack and the battery. The switch is alternately gated on and off by a signal () from a controller () until sufficient energy is transferred from the stack to the battery. In a buck environment, the switch and the inductor () connect one terminal () of the stack to the battery. A diode connects the juncture of the switch with the inductor to the other terminal () of the fuel cell stack and the battery.

US Patent:

7955746, Jun 7, 2011

Filed:

Jul 16, 2010

Appl. No.:

12/804220

Inventors:

Steven J. Fredette - South Windsor CT, US

Assignee:

UTC Power Corporation - South Windsor CT

International Classification:

H01M 8/04

US Classification:

429429, 429430, 429431, 429432

Abstract:

During fuel cell startup and shutdown or other power reduction transitions of a fuel cell power plant, the excess electric energy generated by consumption of reactants is extracted by a storage control () in response to a controller () as current applied to an energy storage system (a battery). In a boost embodiment, an inductor () and a diode () connect one terminal () of the stack () of the battery. An electronic switch connects the juncture of the inductor and the diode to both the other terminal () of the stack and the battery. The switch is alternately gated on and off by a signal () from a controller () until sufficient energy is transferred from the stack to the battery. In a buck environment, the switch and the inductor () connect one terminal () of the stack to the battery. A diode connects the juncture of the switch with the inductor to the other terminal () of the fuel cell stack and the battery.

US Patent:

8232760, Jul 31, 2012

Filed:

Aug 14, 2009

Appl. No.:

12/541320

Inventors:

Bin Lu - Kenosha WI, US
Ting Yan - Brookfield WI, US
Steven John Fredette - Waukesha WI, US
Charles John Luebke - Sussex WI, US

Assignee:

Easton Corporation - Cleveland OH

International Classification:

H02P 27/00
H02P 27/04

US Classification:

318807, 318798, 318806

Abstract:

A system and method for controlling an AC motor drive includes a control system programmed with an energy algorithm configured to optimize operation of the motor drive. Specifically, the control system input an initial voltage-frequency command to the AC motor drive based on an initial voltage/frequency (V/Hz) curve, receives a real-time output of the AC motor drive generated according to the initial voltage-frequency command, and feedback a plurality of modified voltage-frequency commands to the AC motor drive, each of the plurality of modified voltage-frequency commands comprising a deviation from the initial V/Hz curve. The control system also determines a real-time value of the motor parameter corresponding to each of the plurality of modified voltage-frequency commands, and feeds back a modified voltage-frequency command to the AC motor drive so that the real-time value of the motor parameter is within a motor parameter tolerance range.

US Patent:

8253273, Aug 28, 2012

Filed:

Jul 26, 2007

Appl. No.:

12/452658

Inventors:

Steven J. Fredette - South Windsor CT, US

Assignee:

UTC Power Corporation - South Windsor CT

International Classification:

H02J 9/00
H02J 3/38

US Classification:

307 64, 307 51

Abstract:

A power system () combines a power source () having a DC output (A, B) with an AC supply from the AC grid () to provide AC to customer's loads () and DC to various DC auxiliary loads (A). The DC output of the DC power source () is connected in steady-state to the DC input (A, B, ) of a converter/bi-directional inverter () for conversion therein to AC for connection (A, ) to the customer's loads () and (B) to any AC auxiliary loads (). During start-up of the DC power source (), an open isolation switch () disconnects that DC power source () from the bi-directional inverter (). A start-up power supply () selectively connects () between the AC power grid () and the bi-directional inverter () and/or DC controllers (A) to provide a supply of rectified DC power at the inverter DC input and to certain DC auxiliary loads (). DC power is supplied to the auxiliary loads () from the inverter DC input substantially continuously during start-up and steady state.

US Patent:

8358136, Jan 22, 2013

Filed:

Sep 20, 2007

Appl. No.:

12/733435

Inventors:

Steven J. Fredette - South Windsor CT, US

Assignee:

UTC Power Corporation - South Windsor CT

International Classification:

G01N 27/416

US Classification:

324434, 320118, 320132

Abstract:

An arrangement for monitoring the current or state of charge (SOC) of an energy system () having one or more series-connected strings (S, S,. . . S) of battery cells (C, C,. . . C). The battery cells each have respective dissipative devices (D, D,. . . D) selectively connectable in parallel therewith for balancing cell voltages in the string. The dissipative devices are of predetermined, typically equal, impedance value. The voltage across each cell (V, V,. . . V) may be separately monitored, such that by dividing the monitored voltage across a cell by the impedance value of a dissipative device connected in parallel therewith, the dissipative current is determined. A summation of all of the dissipative currents yields an error value, which error value is then removed from the measured gross current (I) flowing through the combined battery cells and dissipative devices to yield a corrected value of current (I). A corrected SOC value (Q) is obtainable in a similar manner.