AC Rectifier Module
Stirling Alternator AC-to-DC Rectifier
The AC rectifier module is a full-bridge power converter that transforms variable-frequency alternating current from Stirling engine alternators into a stable direct-current bus voltage. Utilizing silicon carbide Schottky diodes or radiation-hardened MOSFETs with LC filters, the circuit smooths pulsating current and prevents electromagnetic interference from feeding back into the alternator. On the lunar surface, the rectifier must tolerate elevated operating temperatures near power reactors, adapt to alternator frequency shifts driven by load and temperature fluctuations, and execute seamless transitions when backup Stirling units engage, all while withstanding radiation exposure across a 100-year operational life.
Full-bridge rectifier converting Stirling alternator AC output to DC for the power bus
Purpose
Convert variable-frequency AC from Stirling engines to stable DC bus voltage
Context
Child of L2-PWR-CONV within the Lunar Ark power generation system
Principles
- ▸Full-bridge diode or synchronous rectifier converts AC to pulsating DC
- ▸LC output filter smooths rectified waveform to acceptable ripple levels
- ▸Synchronous rectification using MOSFETs improves efficiency over diode rectifiers
- ▸Input filter prevents EMI from switching transients feeding back to alternator
Typical implementations
- ▸Sunpower Stirling alternator and rectifier systems (Kilopower heritage)
- ▸SiC Schottky diode rectifiers for high-efficiency high-temperature operation
- ▸Rad-hard MOSFET synchronous rectifiers (Microchip, ST Microelectronics)
Lunar considerations
- ▸Stirling frequency varies with load and temperature requiring robust rectifier design
- ▸Radiation-hardened switching components required for 100-year lunar operation
- ▸High operating temperature near reactor requires wide-temperature components
- ▸Must handle seamless transition when backup Stirling units switch in
Specifications
Functional
| primary function | Full-bridge rectifier converting Stirling alternator AC output to DC for the power bus |
Physical
| materials | SiC Schottky diodes, Ferrite core inductors, Ceramic capacitors, Rad-hard gate drivers |
Interfaces
Provides
- Rectified DC power for voltage regulation
Requires
- AC electrical output from Stirling alternators
Cite this entry
Lunar Ark Codex. "AC Rectifier Module" (L3-PWR-CONV-ACRECT). Retrieved 10 September 2026, from https://lunarark.com/entry/L3-PWR-CONV-ACRECT
Licensed CC-BY-SA 4.0. You may reuse and adapt this entry with attribution, under the same licence.