Interconnection Engineering & Smart Inverter Codes
Utility Grid Codes & Interconnection Standards
Technical rules for distributed energy resources: Low-Voltage Ride-Through (LVRT), autonomous frequency-watt droop, Volt-VAR feeder stabilization, anti-islanding, and utility communications.
Low Voltage (LV < 1kV)IEEE 1547-2018 & UL 1741-SB
North American Interconnection (IEEE 1547-2018 / CA Rule 21)
Territory: United States (CAISO, ERCOT, PJM, NYISO)
Fault Ride-Through (LVRT / HVRT)
Remain connected down to 0.50 p.u. voltage for up to 10.0 seconds (Mandatory Trip at < 0.45 p.u. within 0.16s)
Frequency Operating Window & Droop
Continuous operation between 58.8 Hz and 61.2 Hz; Mandatory trip at < 56.5 Hz or > 62.0 Hz
Anti-Islanding Disconnection Time
Must disconnect within 2.0 seconds upon loss of grid reference
Autonomous Reactive Power (VAR) Modes
- Volt-VAR (autonomous curve)
- Constant Power Factor (0.90 leading/lagging)
- Volt-Watt curtailment
Mandatory Features & Telemetry
- Autonomous Voltage Support during distribution voltage sag
- Dynamic reactive current injection during balanced and unbalanced faults
- Remote curtailment and telemetry capability for utility dispatch
Protocol: IEEE 2030.5 (SEP 2.0) via SunSpec CSIP or DNP3