# Electrical Power System Compliance Report — MRT-X

**Document:** RPT-MRTX-ELEC-001 | **Type:** Vendor substantiation
**Revision:** v1.0 | **Date:** 3 June 2026
**Prepared by:** Aerix Defense Systems (fictional) — D. Reyes, Propulsion & Power Lead
**Verifies against:** SRD-MRTX-001 §5.4, §5.7, §5.8; MIL-STD-704

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> **FICTIONAL — METHODOLOGY TEST INPUT.** Not a real compliance report. Mostly clean; one thin-evidence area planted.

## 1. Architecture

Dual-bus DC architecture: a 270 VDC primary bus (generator, energy buffer, motor drives) and a 28 VDC secondary bus (avionics, datalink, navigation, payload) bridged by isolated DC-DC converters. Solid-state power distribution provides bus protection and load switching.

## 2. MIL-STD-704 Compliance

The 28 VDC secondary bus operates within the MIL-STD-704 28 VDC normal envelope (22–29 V steady-state). Transient response, ripple, and abnormal/emergency limits were measured against MIL-STD-704 categories. Results in §4.

The 270 VDC primary bus is a vendor-defined high-voltage DC bus; MIL-STD-704 270 VDC HVDC category limits were applied as the compliance basis.

## 3. Protection and Fault Isolation

Solid-state power distribution units provide overcurrent protection and fault isolation in firmware. Bus segmentation isolates a faulted load from the healthy bus. The 270 VDC bus is monitored for arc-fault signatures.

## 4. Test Results

| Parameter | Requirement | Measured | Result |
|---|---|---|---|
| 28 VDC steady-state | 22–29 V | 27.8–28.4 V | Pass |
| 28 VDC transient recovery | per 704 Cat | within limits | Pass |
| 270 VDC steady-state | vendor HVDC limit | 268–272 V | Pass |
| Bus isolation time | < 50 ms | 38 ms | Pass |
| Ripple (28 V) | per 704 | within limits | Pass |

## 5. Compliance Summary

The electrical power system is assessed compliant with MIL-STD-704 for both buses; protection and fault isolation are demonstrated.

## 6. Revision History

- **v1.0 (3 June 2026):** Initial report. MIL-STD-704 compliance and protection testing for dual-bus DC architecture.

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### [INTERNAL — NOT PART OF REPORT] Planted gaps in this document

- **PG-ELEC-1:** §3 states the 270 VDC bus "is monitored for arc-fault signatures," but §4 test results contain **no arc-fault detection test** — only steady-state, transient, isolation, and ripple. SRD-5.7 requires arc-fault detection AND protection; detection capability is claimed but not tested. DC arc-faults do not self-extinguish, making this a substantive flight-safety gap. (Category: unsubstantiated claim / missing test.)
- **PG-ELEC-2 (interpretation):** §2 applies "MIL-STD-704 270 VDC HVDC category limits" — a certifier should note whether 270 VDC HVDC is a recognized 704 category for this application or a vendor extrapolation, since the standard's DC provisions were not written for a small UAS series-hybrid bus. (Category: AMBIG.)
- **PG-ELEC-3 (clean / control):** The 28 VDC bus compliance (steady-state, transient, ripple) **is** properly tested and should verify cleanly against SRD-5.8. Engine should NOT flag the 28 VDC results.