Small Business Innovation Research/Small Business Tech Transfer
Holomorphic Embedded Load Flow for Autonomous Spacecraft Power Systems
Project Description
The proposed innovation advances the ability to apply the Holomorphic Embedding Load Flow Technology (HELM™) method to provide deterministic load flow modeling for spacecraft power systems. Future deep-space vehicles need intelligent, fault-tolerant and autonomous control of power management and distribution. Due to communications latency, control algorithms for future autonomous space power systems need to be very robust, highly reliable and fault tolerant. Modeling of load flows is vital both to design spacecraft power systems and to operate them autonomously. A key element is state estimation—given the available sensors and their readings, what is the real state of the system? What action is required to maintain operation? State estimation is especially important when the system is in an off-nominal condition. Human operators draw upon experience to integrate off-nominal sensor readings and develop a gestalt of system state, but autonomous operation requires computation. Current modeling techniques (i.e., Newton-Raphson (NR) optimization) are not equal to this task due to their iterative nature and initial point dependency. Many off-nominal cases cannot be solved at all using NR. Worse, even more off-nominal cases appear to be solvable using NR, but the solutions are actually invalid. An NR-based autonomous control system faced with off-nominal conditions will reach an incorrect conclusion more often than not, with potentially catastrophic consequences for the spacecraft. By contrast, HELM™ provides deterministic solutions for off-nominal states, without dependence on initial solution seeds, thereby providing the level of fidelity and surety needed to develop an autonomous system. In Phase I, Gridquant Technologies LLC successfully adapted HELM™ to solve the non-linearity problems of a small DC micro-grid, which will enable NASA to develop and implement the advanced architectures needed for future long-term deep-space exploration.
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Anticipated Benefits
The project, when completed (all phases) will provide NASA with a reliable and fast State Estimator that will improve grid observability; optimization algorithms for load management under variable load demand and constrained capacity, yielding reliable results that have been power-flow checked; control-based applications; and auto-healing modules providing optimal (power-flow checked) action sequences for reconfiguration, in order to minimize brownouts and blackouts. These software applications provide the building blocks from which a truly autonomous power system can be built. Such a system is a pre-requisite for successful deep space missions requiring long-term operation with minimal human intervention. We envision that the first NASA system to receive the benefits of this effort will be Solar Electric Propulsion (SEP).
For non NASA opportunities, besides the existing AC grid applications, terrestrial opportunities are evident in AC, DC or AC-DC micro-grids. Terrestrial micro-grids pose unique scenarios for autonomous control because conditions differ substantially when the micro-grid is connected in parallel with the main grid instead of being islanded. Depending on the load/resource balance before islanding, quick actions will be required to ensure frequency and voltage stability. Renewable energy, particularly solar projects, will continue to play a larger role in the energy mix of micro-grids. Roof-top solar photo-voltaics on large commercial buildings coupled with battery storage and micro-turbines would be a good combination for energy efficiency and reliability. Military bases are excellent candidates for larger micro-grids, as they generally have enough land for larger scale solar projects, diesel generators for critical facilities and a significant transmission and distribution grid. The ability to manage electric power systems with minimal human intervention, with the implied cost reduction, will place these products as an appealing technological option to grid operators whether large or small. More »
For non NASA opportunities, besides the existing AC grid applications, terrestrial opportunities are evident in AC, DC or AC-DC micro-grids. Terrestrial micro-grids pose unique scenarios for autonomous control because conditions differ substantially when the micro-grid is connected in parallel with the main grid instead of being islanded. Depending on the load/resource balance before islanding, quick actions will be required to ensure frequency and voltage stability. Renewable energy, particularly solar projects, will continue to play a larger role in the energy mix of micro-grids. Roof-top solar photo-voltaics on large commercial buildings coupled with battery storage and micro-turbines would be a good combination for energy efficiency and reliability. Military bases are excellent candidates for larger micro-grids, as they generally have enough land for larger scale solar projects, diesel generators for critical facilities and a significant transmission and distribution grid. The ability to manage electric power systems with minimal human intervention, with the implied cost reduction, will place these products as an appealing technological option to grid operators whether large or small. More »
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Primary U.S. Work Locations and Key Partners
| Organizations Performing Work | Role | Type | Location |
|---|---|---|---|
| Gridquant Technologies, LCC | Lead Organization | Industry | Duluth, Georgia |
Glenn Research Center
(GRC)
|
Supporting Organization | NASA Center | Cleveland, Ohio |
Primary U.S. Work Locations
-
Georgia
-
Ohio
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