NASA Glenn Research Center Intelligent Power System Control Development for Deep Space Exploration

Transcription

1 National Aeronautics and Space Administration NASA Glenn Research Center Intelligent Power System Control Development for Deep Space Exploration Anne M. McNelis NASA Glenn Research Center Presentation to Energy Tech 2016 Cleveland, Ohio 1

2 Agenda Overview of NASA s Deep Space Exploration Vision Communication Challenge for Deep Space Vehicle (EPS) Notional Deep Space Vehicle Power Architecture Traditional Space Vehicle Control Architecture Autonomous Control Architecture Control Function Objectives of Autonomous Controller Power System Simulations for Test and Verification GRC Testbed for Hardware in the Loop Verification Status and Future Plans Summary 2

3 The Future of Human Space Exploration NASA s Building Blocks to Mars U.S. companies provide affordable access to low Earth orbit Pushing the boundaries in cis-lunar space Developing planetary independence by exploring Mars, its moons, and other deep space destinations Mastering the fundamentals aboard the International Space Station The next step: traveling beyond low-earth orbit with the Space Launch System rocket and Orion crew capsule 3 Missions: 6 to 12 months Return: hours Missions: 1 month up to 12 months Return: days Missions: 2 to 3 years Return: months Earth Reliant Proving Ground Earth Independent

4 Communication Challenge Currently Electrical Power Systems (EPS) require continual support through ground based mission operations. As missions extend beyond Low Earth Orbit (LEO), communication latency time increases. Communications bandwidth is a factor of 100 less than ISS Power is the Most Critical System-- every system onboard needs power Mission Communications bandwidth Communications latency time Deep Space Vehicle < 2 Mbps (DSN) 15 to 45 minutes Apollo / Orion < 2 Mbps (DSN) 1-2 seconds ISS Mbps (TDRS) Real-time 4

5 Space Power Systems 5

6 Notional Deep Space Vehicle Crew of 4 to 6 Provide living space for long duration missions Solar Array / Battery System 24+ KW Potential to be operated in Low Lunar Orbit, Near Rectilinear Orbit or Deep Space Provides docking accommodation for multiple vehicles resupply as well as landers Platform for the checkout and validation of advanced technologies Closed loop life support systems Advanced automation systems Etc. Deep space vehicle concepts 6

7 Notional Deep Space Vehicle Electrical Power System Characteristics Multi-junction solar array power 24 kw for user loads kw for electric propulsion Two independent power channels with multi-level cross-strapping Lithium Ion battery storage 300+ amp*hrs Sized for 1.5 hr eclipses Distribution 120 V secondary (SAE AS 5698 power quality Spec) 2 kw power transfer between visiting vehicles Notional Deep space vehicle concept 7

8 Notional Deep Space Vehicle Power Architecture 8

9 Typical Spacecraft Control Architecture Mission Operations (Planning and Execution) Power Thermal.. ELCSS Spacecraft Control Reactive Control Reactive Control Reactive Control Reactive Control Power Thermal.. ECLSS 9 9

10 Power System Reactive Layer Controller S/A Voltage Control Switchgear Trip Control Secondary Voltage Control DDCU RPC MBSU DCSU SSU RBI RBI DDCU RPC RBI RBI RBI 1 of 8 power channels B C D U B C D U B C D U B C D U Battery Charge Control DDCU RPC 10 10

11 Traditional vs Autonomous Spacecraft Controller Traditional Spacecraft Controller Architecture Autonomous Spacecraft Controller Architecture Transitioning some traditional ground based control functions to the vehicle Development of an Autonomously Controlled Spacecraft is consistent with the Future of Human Space Exploration roadmap and enables the transition from Earth Reliant systems to Earth Independent Systems 11

12 Intelligent Power Controller National Aeronautics and Space Administration Exploration Systems Near Earth Systems An Intelligent Power Controller utilizes advanced hardware and control technology and works in conjunction with the spacecraft mission manager to autonomously manage and control distributed power generation and storage assets, power distribution networks, and loads for both near earth and space exploration systems

13 Autonomous Control Objectives 13

14 Intelligent Control Functions Energy Management Power availability timeline Set points for array regulation, battery charging / discharging, Detect generation and storage failures Power System Model Generation model using orbital parameters Energy storage model Power load flow State Estimator Power System Network management Power network security Power quality Detect soft faults Report hard faults Configure switchgear Power System Coordination Communicate with Manager Coordinate with identical power channel entities and/or vehicles 14

15 Simplified Autonomous Control Architecture Mission Operations Monitors vehicle operations Adjusts long term mission objectives Mission Operations Vehicle Manager Plan vehicle operation to achieve mission objectives Coordinate vehicle subsystems Autonomous Power Controller Monitor / control normal mode of operation Respond and report faults of the EPS system EPS Hardware (Reactive Control) Provides close-loop control of the EPS hardware Vehicle Manager Autonomous Power Controller Reactive Layer EPS Hardware 15

16 Autonomous Control State Diagram Assess / Manage Power System State Normal State -- Normal operation, system operating on plan, continue indefinitely without interruption Abnormal State No faults in hardware but system is not performing as planned Emergency State Fault occurs relieve system stress and prevent further deterioration Restorative State System is degraded but safe restore power flow to all loads in a safe manner in minimum time 16

17 Intelligent Controller Data Flow Mission Operations Navigation Vectors Traffic / Array Pointing Constraints Spacecraft (other subsystems) State Proposed load profile Vehicle Manager Autonomous Power Controller Energy Availability Load Profile Evaluation EPS Operating State ORU State of Health Caution/Warning Proposed Corrective Action(s) Array Pointing Vectors Array Voltage S.P. Battery Charge/Discharge SP. Switchgear Positions Reactive Layer EPS Hardware Array Voltage Battery Current Voltage Main Bus Current / Voltage Secondary Bus Voltage / Current Switch States 17

18 Autonomous Controller Structure State Estimation Load Flow Failure Detector Contingency Planner Fault Identifier (Constraint Suspension Test) PVGC Generation Capacity Optimizer and Configuration Manager MYSQL Database Failure Identifier (Table Look-up) Network Configuration Manager Graphical User Interface Internal Controller Functions SIMULINK Real-time Simulation Model Hardware Test Bed Interface Vehicle Manager External Interface Functions 18

19 Test and Evaluation Approach Deep Space Vehicle Power System Test Bed Autonomous Controller Real Time Simulation 19

20 Dynamic Electric Power System Modeling NASA s Advanced Exploration Systems (AES) Modular Power Systems (AMPS) projects at GRC are developing intelligent control technologies for space applications. Common Electrical Power System (EPS) elements have been developed to be used within space electrical power system simulations. Library of elements can be used on any number of configurations and used to simulate various power system Simulink applications Simulation characteristics include the following: Provides real time, dynamic simulation of multiple connected power systems such as multiple channels of ISS or Deep Space architectures Average value modeling of power electronics Faster, accurate circuit simulation for switching elements based on state equation approach Features a communication infrastructure to synchronize simulations running on multiple processors. Validation of the EPS elements was achieved by simulation of interconnecting channels of ISS and comparison to available ISS power system Saber hardware model data. 20

21 Electrical Power System (EPS) Simulation Development EPS Model Library: Units and Assemblies Systems PV Cells Isolating Converter Deep Space Habitat Battery Cells RPC RBI ISS 21

22 Autonomous Power System Test Bed (GRC) GRC s Power System Testbed is evolving into a platform to evaluate the performance of the autonomous control with real hardware Contains Solar simulators / regulators Batteries / simulators Power Distribution Equipment MBSU s PDU s Multiple Load Types 22

23 Status and Future Plans Accomplishments: Defined and implemented an autonomous vehicle control architecture Implemented a distributed facility to develop and test the Autonomous Power Controller (APC), Vehicle Manager, and test bed hardware Developed a real-time simulation of a notional Deep Space Vehicle power system Developed a prototype of an Autonomous Power Controller (APC) for Normal and Failure Modes capable of long-term energy management Demonstrated an APC controller with remote hardware at NASA JSC Future Plans Improve the development of APC algorithms for long term energy management of the electrical power system (EPS) of deep space vehicle architectures. Improved capability to identify and diagnose power system faults Develop contingency capabilities to optimally manage resource allocation and load scheduling. Develop and integrate APC with NASA GRC s power system test bed for hardware in the loop evaluation 23

24 Summary Intelligent Power Systems are key for long duration missions and operations far from earth. Development of an Autonomously Controlled Spacecraft is consistent with the Future of Human Space Exploration roadmap and enables the transition from Earth Reliant systems to Earth Independent Systems. Verification of developmental space EPS autonomous power controllers will be achieved through real-time EPS simulations, hardware in the loop and power system test bed validation efforts. 24

25 Questions??? 25