# Project Specification **Status:** Draft **Project:** Residential Energy Router Hub **Scope:** Concept-level system design only; not construction-ready, certification-approved, or suitable for installation. ## Project Overview Outdoor US residential energy router integrating a **200 A continuous 120/240 V split-phase service pass-through**, **20-30 kW continuous bidirectional conversion**, **15-20 kW solar MPPT**, **15-20 kW 600-800 V battery interface**, and **10-15 kW bidirectional miscellaneous DC port**. The grid converter target is a **50 kHz SiC three-level T-type NPC stage** with reinforced capacitive-isolated gate drivers, direct cold-plate cooling, a default **160 A PCS limit**, and design toward a **UL 1741 SB target**. ## Intended Use - Outdoor wall-mounted residential energy management equipment in a NEMA 3R concept enclosure. - Parallel energy exchange at an internal split-phase bus while a service-rated bypass carries normal 200 A premises load. - Concept basis for architecture studies, simulation, supplier engagement, PE review, utility coordination, and NRTL planning. - Not a meter-main, service entrance, transfer switch, inverter, or ESS product certification claim. ## What the Device Should Do - Maintain passive grid pass-through when controls or auxiliary power fail. - Exchange 20-30 kW bidirectionally with the 240 V line-to-line bus; target 40-50 kVA short-duration surge. - Track 15-20 kW PV maximum power, control a 15-20 kW HV battery port, and operate a 10-15 kW bidirectional DC port. - Keep measured panel current at or below a configurable limit, default 160 A, by curtailing battery first, then solar, then miscellaneous DC. - Detect abnormal current, voltage, insulation, ground-fault, arc-fault, thermal, islanding, sensor, and logic conditions and place controllable sources in a fail-safe state. ## Main Features - Normally closed mechanically latched/service-rated 200 A bypass independent of semiconductor conversion. - 240 V line-to-line SiC three-level T-type NPC converter; neutral sensing and split-phase imbalance limits. - Common 600-800 V HV DC link with independent PV, battery, and miscellaneous DC converters. - Reinforced capacitive-isolated gate drivers only; CMTI greater than 100 kV/us, target 150-200 kV/us class. - TI C2000 Delfino-class real-time controller or equivalent, plus separate safety logic and analog clamp chain. - Closed liquid loop with direct power-module cold plates and internal liquid-to-air exchanger with forced air. ## System Architecture ```mermaid flowchart TD GRID[Utility 120 240 V split phase] --> BYPASS[200 A service rated normally closed bypass] BYPASS --> BUS[Internal split phase bus and panel output] BUS <--> INV[20 to 30 kW SiC T type NPC grid converter] INV <--> DCLINK[600 to 800 V common HV DC link] PV[15 to 20 kW PV array] --> MPPT[Independent PV MPPT DC DC] MPPT --> DCLINK BAT[15 to 20 kW battery port] <--> BATDC[Bidirectional battery DC DC precharge contactors IMD GFD] BATDC <--> DCLINK AUXDC[10 to 15 kW miscellaneous DC port] <--> AUXCONV[Bidirectional miscellaneous DC DC] AUXCONV <--> DCLINK CT[Service CTs and redundant sensing] --> PCS[PCS supervisor and 160 A limiter] PCS --> INV PCS --> MPPT PCS --> BATDC PCS --> AUXCONV SAFE[Safety logic analog clamp watchdog trip matrix] --> INV SAFE --> MPPT SAFE --> BATDC SAFE --> AUXCONV COOL[Closed liquid loop cold plates radiator fans] --> INV COOL --> MPPT COOL --> BATDC COOL --> AUXCONV ``` ## Hardware Subsystems 1. Certified/service-rated switchgear and busbar bay. 2. Grid inverter power stage and LCL or equivalent grid interface. 3. Common HV DC link with discharge, sensing, OVP, and segmentation. 4. Independent PV MPPT DC/DC. 5. Battery bidirectional DC/DC with precharge, contactors, IMD, and DC ground-fault detection. 6. Miscellaneous bidirectional DC/DC. 7. Safety/control compartment with real-time MCU, safety supervisor, isolated I/O, watchdogs, and communications. 8. Sealed cooling loop and rain-shedding forced-air heat exchanger path. ## Interfaces and Connections - Utility and panel: 120/240 V split-phase, L1, L2, neutral sense, equipment ground, 200 A pass-through. - PV: HV DC conductors, equipment ground, rapid-shutdown/arc-fault interfaces as applicable. - Battery: 600-800 V DC, contactor command/feedback, precharge, IMD, GFD, BMS communications, emergency inhibit. - Miscellaneous DC: bidirectional 600-800 V class interface with contactors and protection. - Service CTs: redundant or plausibility-checked current channels. - Communications: isolated Ethernet/CAN/RS-485 or equivalent, service/debug isolated from HV domains. ## Power and Runtime Expectations Grid-connected stationary equipment; no stand-alone runtime requirement is assumed. Control power should be ride-through capable long enough to open source contactors and log faults. Loss of logic power or sensing isolates battery and controllable sources while the mechanically latched bypass remains closed. ## Power Tree and Power Budget | Path | Preliminary continuous target | Notes | |---|---:|---| | Grid pass-through | 200 A at 120/240 V | Independent service-rated path; not through inverter | | Grid converter | 20-30 kW | 240 V L-L; 40-50 kVA short surge target | | PV MPPT | 15-20 kW | Independent input operating envelope TBD | | Battery port | 15-20 kW | 600-800 V; about 19-33 A before margin | | Misc DC port | 10-15 kW | 600-800 V; about 13-25 A before margin | | Auxiliary controls | Concept 300-800 W peak | Pumps, fans, contactors, controls; detailed budget TBD | ## Manufacturing and Assembly Expectations - Segregated sheet-metal cabinet zones, finger-safe barriers, busbar supports, service clearances, and field-wiring space. - Power modules mounted directly to cold plates; laminated bus structures preferred. - Final conductor, busbar, lug, breaker, fuse, contactor, insulation, creepage, clearance, SCCR, and torque selections require detailed engineering and NRTL review. ## Firmware-Relevant Hardware Requirements - Deterministic fast current/voltage loops and PWM timing. - Independent safety state machine outside the application control loop. - Dual CT plausibility, sensor range diagnostics, watchdogs, trip-zone inputs, event capture, secure update, and calibration records. - PCS limiter must remain bounded under stale, failed, or contradictory sensor data. ## Physical Design Expectations - Concept envelope about 1100 mm H x 750 mm W x 350 mm D. - Wall-mounted NEMA 3R rain hood, gasketed front door, lower cable entry, service labels, lifting and mounting provisions. - Closed coolant loop; external air contacts only heat-exchanger airflow surfaces, not HV electronics. ## Important Design Decisions - The 200 A path is normally closed, mechanically latched, and independent of semiconductors. - Conversion is parallel to the internal bus; the inverter is not sized to carry the full service current. - Final neutral topology, isolation method, service-entrance rating, fault-current withstand/SCCR, meter-main compatibility, and utility interconnection remain study items. ## Assumptions - Nominal HV bus 700 V within a 600-800 V operating range. - Concept converter efficiency 96.5-98.0 percent depending on path and load. - Outdoor ambient and solar loading basis remain to be defined; thermal concept uses conservative preliminary ranges. - A certified upstream/downstream service arrangement will be required. ## Success Criteria - All concept files consistently preserve the specified architecture and fail-safe behavior. - PCS strategy demonstrates a credible 160 A calculation and independent analog clamp. - Enclosure assets compile, have durable links, and are explicitly unplaced because no PCB/layout parent exists. - NRTL, utility, AHJ, and licensed PE review are identified as mandatory next phases. ## Change Notes - Initial Draft concept package created from the user requirements. - No schematic components or detailed circuits added.