Richard E Griessel

US Patent:

6879053, Apr 12, 2005

Filed:

Oct 22, 2003

Appl. No.:

10/691030

Inventors:

Richard Shaun Welches - Amherst NH, US
Daniel P. Hohm - Nashua NH, US
Jian Wen - North Andover MA, US
Kevin E LeRow - Lowell MA, US
Richard Griessel - Derry NH, US
Thomas O'Reilly - Hollis NH, US

Assignee:

Youtility, Inc. - Hudson NH

International Classification:

H02P009/00

US Classification:

290 6, 290 1 A, 290 4 R, 290 31, 290 32, 290 36, 290 38 R, 322 24, 322 10, 322 12, 322 13, 322 20

Abstract:

The invention in the simplest form is an improved variable speed engine/generator set with an integrated power conditioning system and control method, used to generate high quality AC power with optimum fuel efficiency and reduced emissions. The variable speed generator control scheme allows for load adaptive speed control of engine and generator field. The transformerless power inverter topology and control method provides the necessary output frequency, voltage and/or current waveform regulation, harmonic distortion rejection, and provides for single phase, or unbalanced loading.

US Patent:

20020036430, Mar 28, 2002

Filed:

Sep 28, 2001

Appl. No.:

09/966241

Inventors:

Richard Welches - Amherst NH, US
Richard Griessel - Derry NH, US
Jian Wen - North Andover MA, US

International Classification:

H02J003/00

US Classification:

307/018000

Abstract:

The invention in the simplest form is a system for managing distributed power sources connected to a power grid. The present invention manages power flow to/from the power grid whether for a stand-alone power sourece or for local area utility grid or microgrid. When two or more power sources are interconnected by the local grid, each source has a power conditioning unit and a circuit breaker manager for controlling and regulating the electric flow to/from the grid. The individual power sources are able to independently draw power from the grid when required without extensive master control schemes. In a preferred embodiment the power sources are reformer equipped fuel cells and the heat from the fuel cell is used as a heat source for efficiency.

US Patent:

20030012038, Jan 16, 2003

Filed:

Oct 29, 2001

Appl. No.:

10/052802

Inventors:

Richard Welches - Amherst NH, US
Richard Griessel - Derry NH, US
Peter Beckedahl - Nashua NH, US
Karl Bond - Hudson NH, US

International Classification:

H02J003/00

US Classification:

363/034000

Abstract:

The invention in the simplest form is a power conditioning and inverting system for improved and efficient power generation. In particular, the present invention is a modulated dc link scheme that dramatically reduces the switching frequency ripple across the PWM output filter inductor and provides cost, size, and weight reductions, as well as efficiency enhancements. In a preferred embodiment of the present invention, the DC-DC converter control takes a feedback signal proportional to the inverter output voltage. This feedback is “summed” into the primary DC-DC volts command thereby causing the dc bus/link voltage to vary at a multiple of the output fundamental frequency causing the DC link to become a signal at a fundamental frequency voltage with a dc offset. The tooth modulator DC supply tracks the AC output voltage, reducing the difference between the applied DC volts and the AC output volts, thereby reducing inductor core losses.

US Patent:

20040084965, May 6, 2004

Filed:

Oct 22, 2003

Appl. No.:

10/691357

Inventors:

Richard Welches - Amherst NH, US
Daniel Hohm - Nashua NH, US
Jian Wen - North Andover MA, US
Kevin LeRow - Lowell MA, US
Richard Griessel - Derry NH, US

International Classification:

H02J007/00

US Classification:

307/064000

Abstract:

The invention in the simplest form is an improved hybrid power converter with uninterruptible power supply (UPS) and power quality capabilities as well as an integrated variable speed power source and control method that is used to generate high quality, uninterruptible AC power utilizing fewer batteries and operating at optimum fuel efficiency and with reduced emissions. The variable speed generator control scheme allows for load adaptive speed control of a power source such as an engine and generator. The transformerless hybrid power converter topology and control method provides the necessary output frequency, voltage and/or current waveform regulation, harmonic distortion rejection, and provides for single-phase or unbalanced loading. The transformerless hybrid power converter also provides inline or offline UPS capability, line voltage and/or frequency sag and surge compensation, peak shaving capability, VAR compensation and active harmonic filtering.