Michael E. Ropp
Engineers at 32 Ave, Brookings, SD

6429546, Aug 6, 2002

Nov 19, 1999

09/443619

Michael Eugene Ropp - Brookings SD
Ajeet Rohatgi - Marietta GA
Miroslav M. Begovic - Atlanta GA

Georgia Tech Research Corporation - Atlanta GA

H02J 300

307 31, 307 43, 307 38, 307 51, 307 87

A preferred embodiment of the electrical power system of the present invention includes a power conditioning unit which is configured to receive the DC electrical output signal to deliver an AC output signal to a grid-connected load. Preferably, the power conditioning unit includes a controller which is configured to monitor the AC output signal so that the power conditioning unit may cease delivering the AC output signal when a characteristic of the AC output signal satisfies an established criterion.

2011027, Nov 10, 2011

May 9, 2011

13/103721

Michael Ropp - Brookings SD, US

G06F 1/30, H02J 3/38

700293, 307 86, 700286, 700297

A solar power inverter that detects islanding conditions includes a power generation component that generates alternating current (AC) from direct current produced by photovoltaic cells. The inverter generates AC for a load or an electrical power grid. The inverter also includes a component that generates synchrophasors from characteristics of electrically proximate AC. The inverter further includes a component that receives grid synchrophasors transmitted from a location on the electrical power grid (e.g., a transmission substation). The inverter further includes a controller that uses the inverter synchrophasors and the grid synchrophasors to calculate a degree of correlation between the electrical power grid AC frequency and the frequency of the electrically proximate AC. If the degree of correlation dips below a predefined value or exhibits certain patterns or behaviors that are indicative of a loss of mains (e.g., a loss of main power along the electrical power grid), the controller can cause the power generation component to stop generating AC or cause the inverter to intentionally island by electrically disconnecting from the electrical power grid.

2011028, Nov 17, 2011

May 9, 2011

13/103629

Michael Ropp - Brookings SD, US
Steven G. Hummel - Bend OR, US

G06F 1/28, G06F 19/00, G01W 1/00

700297, 702 3

A solar power forecasting system can provide forecasts of solar power output by photovoltaic plants over multiple time frames. A first time frame may be several hours from the time of the forecast, which can allow utility personnel sufficient time to make decisions to counteract a forecasted shortfall in solar power output. For example, the utility personnel can decide to increase power production and/or to purchase additional power to make up for any forecasted shortfall in solar power output. A second time frame can be several minutes from the time of the forecast, which can allow for operations to mitigate effects of a forecasted shortfall in solar power output. Such mitigation operations can include directing an energy management system to shed noncritical loads and/or ramping down the power produced by the photovoltaic plants at a rate that is acceptable to the utility to which the photovoltaic plants provide power.

2011031, Dec 29, 2011

Jun 15, 2011

13/160970

Michael A. Mills-Price - Bend OR, US
Michael Ropp - Brookings SD, US

H02J 7/00, G05F 1/70, G06F 1/26, H02M 7/44

320109, 363 95, 323205, 700297

An electrical power generation system, such as a solar power inverter, can provide dynamic real-time power compensation, so as to mitigate the effects of voltage sags and swells (e.g., on a utility grid) and thereby provide voltage support functionality to a local grid. The electrical power generation system can do so by receiving first synchrophasor measurements that are taken at a point on the utility grid and transmitted to the electrical power generation system and by taking second synchrophasor measurements. The first and second synchrophasors indicate voltage magnitude and frequency of the alternating current (AC) at their respective measurement points. The electrical power generation system can compare the first synchrophasors with the second synchrophasors and based upon the comparison, vary the power factor of the power the electrical power generation system generates (e.g., by either supplying or absorbing reactive power).

2013026, Oct 10, 2013

Nov 29, 2012

13/689153

Michael Ropp - Brookings SD, US

H02J 4/00

307 51

An effective, yet relatively simple and inexpensive, method for detection of islanding in distributed power generation systems. Statistical analysis of the local line frequency, as measured at the distributed generator, is performed to detect when an island has been formed. The statistical characteristics of the local frequency are controlled by the grid when the distributed generator is not islanding. When an island is formed, however, frequency control switches to circuitry associated with the distributed generator. Because the statistical characteristics of the frequency control performed by the distributed generator are markedly different from those of the grid, the islanding condition can be detected and corrected.