L2-PWR-MGMT CRITICAL POWER ENERGY Level 2 · hardware

Power Management & Control

Power Management and Distribution Controller (PMDC)

The Power Management and Distribution Controller is a redundant 25-kilogram processing unit that autonomously manages settlement power generation, coordinating primary nuclear reactors, supplemental solar arrays, and emergency radioisotope thermoelectric generators. Because communication delays with Earth make ground-in-the-loop control impractical, the system must operate autonomously for 100 years, managing load-following adjustments and adapting to unanticipated hardware degradation modes. Operating on radiation-hardened processors consuming 50 watts, the controller executes a 10 Hz control loop capable of detecting electrical faults within 100 milliseconds and isolating them within 500 milliseconds, utilizing five progressive graceful degradation levels to stabilize power distribution.

Autonomous control, monitoring, and decision-making system for all power generation sources and conversion equipment

Purpose

Provide fully autonomous management of the Ark's power generation: source selection and switching, load-following for the reactor, solar MPPT oversight, RTG health tracking, predictive failure management, and graceful degradation strategies. This is the 'brain' of L1-PWR.

Context

Centralized intelligence for power generation that coordinates L2-PWR-NUC, L2-PWR-SOL, L2-PWR-RTG, and L2-PWR-CONV. Interfaces heavily with L1-CDH for high-level directives and with L1-MNT for maintenance scheduling. Must operate autonomously for 100 years including handling novel failure scenarios not pre-programmed.

Principles

▸Power system autonomy requires real-time monitoring, decision-making, and actuation
▸Source prioritization: nuclear (primary) → solar (supplement) → RTG (emergency)
▸Load-following: reactor power adjusts to match demand, reducing thermal cycling
▸Predictive maintenance uses trend analysis to anticipate failures before they occur
▸Graceful degradation: systematically shed non-critical loads as power budget decreases
▸Fault isolation: detect and isolate failed sources/converters without losing healthy ones
▸State estimation: infer system health from sensor data using models

Typical implementations

▸ISS Power Resource Officer (PRO) functions automated
▸Spacecraft power management units (PMU) with embedded processors
▸Industrial SCADA-like monitoring with space-qualified hardware
▸Rule-based + model-based autonomy (hybrid approach)
▸Triple-modular redundancy (TMR) for control computers

Lunar considerations

▸100-year autonomous operation requires adaptive/learning algorithms, not just fixed rules
▸Must handle degradation modes not anticipated at design time
▸Communication delays with Earth make ground-in-the-loop control impractical
▸Must coordinate with L1-CDH for system-wide power priority decisions
▸Sensor degradation over time requires self-calibration capability
▸Software updates via L1-COM when Earth link available

Specifications

Functional

primary function	Autonomous monitoring, control, and optimization of all power generation assets
inputs	Telemetry from L2-PWR-NUC (reactor status, temperatures, power output), Telemetry from L2-PWR-SOL (array performance, illumination, dust status), Telemetry from L2-PWR-RTG (power output, temperatures, degradation rate), Telemetry from L2-PWR-CONV (converter efficiency, fault status), System-level directives from L1-CDH (power priorities, load schedules)
outputs	Control commands to reactor (power level, scram), Control commands to solar (tracking, MPPT setpoints), Control commands to converters (enable/disable, setpoints), Health reports to L1-CDH, Maintenance requests to L1-MNT, Load shedding directives to L1-PDM
control loop rate hz	10
fault detection time ms	100
fault isolation time ms	500
autonomous decision capability	True
predictive maintenance	True
graceful degradation levels	5

Physical

mass kg	25
dimensions	Redundant processor boxes, each ~30x20x15 cm
materials	Rad-hard processors (e.g., LEON4, RAD750 class), ECC radiation-tolerant memory, MIL-STD-1553 or SpaceWire bus interfaces, Aluminum chassis with thermal interface
operating temp c	-40 to +70 (inside shielded enclosure)
radiation	Must tolerate >300 krad(Si) with spot shielding
power	Internally redundant power supply

Operational

power consumption w	50
thermal range c	-40, 70
lifetime years	30
mtbf hours	500000

Interfaces

Provides

→Nuclear Power Subsystemdatacritical
Reactor control commands: power level setpoints, startup/shutdown, scram
→Solar Power Subsystemdataessential
Solar array commands: tracking setpoints, MPPT modes
→Power Conversion & Conditioningdatacritical
Converter commands: source priority, enable/disable, voltage setpoints
→Command & Data Handlingdatacritical
Power system health summary, generation status, available power budget
→Power Distribution & Managementdatacritical
Load shedding directives, available power budget for distribution planning
→Preventive Maintenance Systemdataessential
Predictive maintenance alerts, component health trends, replacement scheduling

Requires

←Nuclear Power Subsystemdatacritical
Reactor telemetry: temperatures, power, control rod position, fuel burnup
←Solar Power Subsystemdataessential
Array telemetry: current, voltage, temperature, pointing, dust level
←Radioisotope Thermoelectric Generatorsdataessential
RTG telemetry: temperatures, power output, degradation metrics
←Power Conversion & Conditioningdatacritical
Converter telemetry: efficiency, fault status, thermal readings per channel
←Command & Data Handlingdatacritical
System-level directives: power priority tables, operating mode commands
←Power Distribution & Managementpowercritical
Regulated power for MGMT electronics (~50W, from critical bus)
←Radiation Shieldingenvironmentalessential
Radiation shielding for control electronics (>300 krad lifetime dose)