GDSCC Powerhouse Upgrades

Overview

The Goldstone Deep Space Communication Complex (GDSCC) in California’s Mojave Desert required multi-domain upgrades to its powerhouse infrastructure — protection coordination, automatic transfer switching, SCADA/HMI, metering, and generator controls networking. The centerpiece: zone-selective interlocking (ZSI) implemented via IEC 61850 GOOSE messaging over a PRP network, providing fast, selective fault clearing without hardwired interlocks.

Five concurrent upgrade tracks — each with distinct equipment, protocols, and commissioning requirements — coordinated under a single technical lead. The multi-domain coordination applies to any data center program where protection, controls, and SCADA upgrades overlap.

Technical Scope

Five upgrade tracks delivered in parallel:

1. Zone-Selective Interlocking (ZSI)

SEL-751 and SEL-751A relays configured for GOOSE-based ZSI
Fast, selective fault clearing: upstream relays restrain their trip timers when a downstream relay signals that it is handling the fault
Eliminates the need for hardwired interlock cabling between protection zones
Validated in production on live MV switchgear

2. ATS Controller Upgrade

Before: Legacy Siemens PLCs (undocumented control logic)
After: Woodward DTSC-200 controllers (modern, networked, fully documented)
Deterministic transfer sequencing with configurable delay, voltage, and frequency thresholds

3. MV Protection Retrofit

Before: Mixed legacy relays (Schneider, Eaton, ABB)
After: SEL-751 relays (standardized, networked, GOOSE-capable)
Uniform protection platform across all MV feeders — simplifies maintenance and spare parts inventory

4. SCADA/HMI Modernization

FactoryTalk View platform refresh
Integration of all protection, control, and metering signals into unified operator visibility
Alarm rationalization and priority tiering

5. Metering & Historian

Legacy power meters replaced with Electro Industries Shark 250 units
Historian database integration for power trend analysis, demand response diagnostics, and fault event capture

Supporting infrastructure:

Cisco IE-2000 edge switches (dual-star attached)
Cisco Catalyst 9500 distribution core
CAT EMCP 3.3 and EMCP 3.S (prime mover control)

Methodology & Approach

The ZSI implementation required careful coordination between protection studies, relay programming, and functional testing. Each protection zone’s relay settings account for the GOOSE restraint signal — if the downstream relay fails to send the restraint, the upstream relay trips on its backup time delay rather than failing to clear the fault.

This fail-safe design means the system degrades gracefully: a GOOSE communication failure results in slower but still effective fault clearing, never in a failure to trip.

The five upgrade tracks ran concurrently with different commissioning timelines. The SCADA/HMI track depended on the protection retrofit (new relays provide the signals), which in turn depended on the network infrastructure. The ATS and metering tracks ran independently. Coordinating these dependencies under one schedule eliminated the inter-sub scheduling conflicts that typically extend multi-domain commissioning timelines.

FIVE DOMAINS. ONE SCOPE.

Put Multi-Domain Coordination Under One Point of Accountability

Protection, controls, networking, SCADA, and metering — coordinated under one subcontract. No scope gaps between specialty subs. No finger-pointing at integration points.

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Platforms & Integration

Five manufacturer platforms integrated through a common network and gateway architecture:

SEL for protection and ZSI — GOOSE messaging for fast interlocking
Woodward for ATS control — deterministic transfer switching
CAT for engine/generator management — prime mover coordination
Cisco for industrial networking — PRP dual-star with zero-switchover redundancy
Electro Industries for power metering — historian integration for trending and diagnostics

The protocol stack includes IEC 61850 GOOSE (protection interlocking), Modbus TCP/RTU (control and metering), and SNMP (network telemetry).

Results

Five upgrade domains delivered under one technical lead — protection, ATS, SCADA, metering, and networking — with ZSI validated in live production via IEC 61850 GOOSE. Not claimed on paper.

When five engineering domains are split across separate subs, integration testing becomes the first time all systems operate together — during witness testing. Failures at that point mean retesting across sub boundaries, finger-pointing on root cause, and schedule extensions the prime’s contract absorbs. One team means integration is verified before witness testing, not discovered as a gap during it.

For prime contractors, that means one schedule and one subcontract covering five engineering domains — no coordination gaps between specialty subs.