Finding
The microgrid controller is the one component that must not depend on the network: it islands, balances and black-starts the site on local logic
IEEE 2030.7 defines a microgrid controller by two core functions: dispatch, which balances sources and loads, and transition, which handles planned and unplanned islanding and reconnection. EMS optimization, SCADA screens and cloud forecasting add value, but during an outage the controller, wired directly to inverters, relays and meters, has to run alone.
Controllers run on embedded devices, PLCs or industrial PCs. Leading suppliers: Schneider Electric (EcoStruxure Microgrid), Siemens (SICAM and Spectrum Power microgrid management), Hitachi Energy (e-mesh), ABB, SEL (POWERMAX), GE Vernova, Eaton, PowerSecure and Tesla (site controller with Opticaster and Autobidder). In China, NARI, NR Electric, XJ Electric and Sifang supply controllers and protection, and Huawei and Sungrow ship their own plant controllers with storage.
AI enters at the tertiary and market layers: machine-learning solar and load forecasts, battery cycling optimized for price and degradation, predictive maintenance and digital twins that model the microgrid as part of the facility. The primary and secondary layers stay deterministic. Inverter firmware is now a security issue: in 2025 US officials investigated undocumented communication devices reported in some Chinese-made inverters and batteries, which pushed utilities toward stricter device vetting.
Components
Control components
| Component | Role | Runs |
|---|---|---|
| Microgrid controller | Real-time dispatch, switching, islanding and black start | On site; must survive loss of upper layers |
| Energy management system (EMS) | Optimizes energy flows and costs; may embed the controller | On site or cloud |
| DERMS | Coordinates many DERs across sites; mostly utility-run | Utility control center |
| SCADA | Monitoring, alarms, history | On site, often redundant |
| Protection relays and interlocks | Isolate faults; enable safe islanding | Hard-wired |
| Communications gateway | Translates IEC 61850, DNP3, Modbus, SunSpec | On site |
| Cybersecurity layer | Firewalls, segmentation, authentication, logging | Every layer |
| HMI | Operator screens and controls | On site and remote |
Architectures
Control architectures
| Architecture | How it works | Fits | Weakness |
|---|---|---|---|
| Centralized | One master controller governs all assets | Small commercial sites | Single point of failure |
| Hierarchical | Master controller with sub-controllers by zone or asset type | Campuses, factories, utility-integrated sites | More integration work |
| Distributed / agent-based | Assets coordinate peer to peer | Large, growing or military sites | Harder to verify and certify |
| Cloud-hybrid | Local fail-safe control plus cloud forecasting and optimization | Grid-interactive sites in markets | Depends on secure connectivity for value |
Standards
Standards and commissioning
Before go-live: every source visible to the EMS, islanding and reconnection tested with the utility, operators trained on the HMI, redundant secure communications, and black start rehearsed.
| Standard | Covers |
|---|---|
| IEEE 1547-2018 / UL 1741 SB | Interconnection and inverter grid-support functions |
| IEEE 2030.7 / 2030.8 | Microgrid controller functions and testing |
| IEC 61850 | Substation and DER communication |
| DNP3 (IEEE 1815), Modbus, SunSpec | SCADA and device protocols |
| IEC 62443 | Industrial control system cybersecurity |
| NERC CIP | Cybersecurity for bulk electric system assets |
| NFPA 70B | Maintenance of electrical equipment |
Sources
Sources and scope
- Scope
- Microgrid Controllers
- Sources
- IEEE 2030.7 and 2030.8; IEC 61850 and 62443; vendor documentation
- Updated
- October 2026