National Aeronautics and Space Administration

Intelligent Power Controller

Development for Human Deep Space

Exploration

Anne M. McNelis

NASA Glenn Research Center

Presentation to

Energy Tech 2015

Cleveland, Ohio

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

• Objectives of Autonomous Controller

• Mission Manager and Autonomous Control Interface

• Power System Simulations for Test and Verification

• Summary

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The Capability Driven Framework

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Communication Challenge

5

• Currently EPS systems require

continual support through ground

based mission operations.

• As missions extend beyond LEO,

communication latency time

increases.

Space Power Systems

6

Notional Deep Space Vehicle Power Architecture

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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”

Traditional vs Autonomous Spacecraft Controller

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Autonomous Control Objectives

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Simplified Autonomous Control Architecture

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Autonomous Power Controller

Normal Mode

Fault Mode

EPS Hardware

Vehicle Manager

Mission Oversight

Vehicle Manager • Manages operation of overall spacecraft • Requests power availability from the

Autonomous Power Controller as needed • Generates Load Schedule based on

power availability

Autonomous Power Controller • Provides the Mission Manager with

power availability • Executes Mission Manager load

schedule • Executes Normal Mode Operation • Responds and report faults within the

EPS system EPS Hardware (Reactive Control) • Provides close-loop control of the power

hardware (BCDU’s, solar array regulators, Switchgear etc.)

• Accepts control set points from the Intelligent Controller

Intelligent Power Controller

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National Aeronautics and Space Administration

www.nasa.gov 9

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.

Near Earth SystemsExploration Systems

Intelligent Control Function Architecture

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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

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Power System Fault Management Functions

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National Aeronautics and Space Administration

www.nasa.gov 16

Assess / Manage Power System

State

• Preventative state -- Normal

operation, continue

indefinitely without

interruption

• 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

Restorative

State

Preventative

State

Emergency

State

Controlled State Transition

Uncontrolled State Transition

Fault Mgmt Functions

• Identify Failures

• Contingency Analysis

• Develop corrective actions

• Component Health Monitor

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Mission Manager Intelligent Power Control Interface

EPS Model Library: Units and Assemblies Systems

ISS

Deep Space Habitat

Battery Cells

PV Cells

Isolating Converter

RPC

RBI

Electrical Power System (EPS) Simulation Development

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National Aeronautics and Space Administration

www.nasa.gov

Control / Distributed

Simulation Platform

• Execute a real-time

state average EPS

• Multi-core PC’s with 8

processors each

• PC’s interconnected

through high speed

Ethernet

• Synchronized via read

write data base via

communication bus

• Capability to interface

with real power

hardware both locally

and remotely

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Control T&V Simulation Architecture

Intelligent Control Development at NASA GRC

• NASA’s Advanced Exploration Systems (AES) Modular Power Systems

(AMPS) projects at GRC are developing intelligent control technologies

for space applications.

– Dynamic EPS Simulations (SBIR with PCKrause and Associates)

• Component, system, direct layer control, failure simulation.

– Autonomous Power Controller (APC) Development

• Distributed Controller, Failure detection (ARC), Power distribution

and loads management, nominal and fault operations.

– Hardware and Software in the Loop Demonstrations Utilizing hardware

testbeds at GRC and JSC

• Interface between APC, Simulink and hardware testbed

components.

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Summary

• Intelligent Power Systems are key for long term 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.

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