Islanding
Study (PSCAD)
Overview
Islanding occurs when a portion of the distribution or transmission network, along with its connected generation, continues to operate independently after becoming electrically isolated from the main grid. Undetected islanding poses serious safety risks to utility workers and can cause equipment damage from out-of-phase reclosing. The Islanding Study assesses both the risk of unintentional islanding and the performance of anti-islanding protection schemes.
What the Study Covers
Anti-islanding Protection Scheme Performance
Using PSCAD transient simulations, the study models the dynamics of the islanded network across a range of generation and load imbalance conditions:
Scenario Modelling
Island formation scenario modelling: identification of credible islanding conditions based on network topology and switching events
Drift Analysis
Voltage and frequency drift analysis within the island after grid disconnection
Protection Assessment
Anti-islanding protection assessment: evaluation of passive methods (ROCOF, vector shift) and active methods (frequency injection, impedance measurement)
NDZ Mapping
Non-detection zone (NDZ) mapping: identifying generation-load balance conditions where passive protection may fail
Intentional Islanding
Intentional islanding performance: voltage and frequency control capability during planned island operation
Reclosing Coordination
Reclosing coordination: ensuring out-of-phase reclosing does not occur before island detection and trip confirmation
Applicable Standards
-
01
IEEE 1547
Standard for Interconnection and Interoperability of Distributed Energy Resources — anti-islanding requirements
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02
IEC 62116
Test procedure for islanding prevention measures for utility-interconnected inverters
Typical Applications
Islanding studies are required for all grid-connected distributed energy resources including solar PV, wind, BESS, combined heat and power (CHP) plants, and microgrids — especially where the utility imposes mandatory anti-islanding protection as a condition of the interconnection agreement.
Benefits
Ensures compliance with utility interconnection requirements for distributed generation
Eliminates risk of harm to utility field crews from energised isolated network sections
Prevents out-of-phase reclosing damage to generators and transformers
Supports intentional islanding design for microgrids and resilient energy systems
Why We Are the Best for Islanding
Studies in India
India's distributed generation landscape is transforming at pace, with rooftop solar, captive wind, and industrial BESS deployments growing across every state. Simultaneously, DISCOMs are tightening their interconnection requirements, and the consequences of islanding-related incidents — whether a field crew safety event or a generator tripped by out-of-phase reclosing — are receiving increasing regulatory attention.
Islanding analysis in the Indian context is complicated by network characteristics that differ from the markets where most protection standards were originally developed: high feeder impedance, frequent voltage fluctuations, variable power quality, and protection schemes not originally designed with significant embedded generation in mind. Our islanding studies are calibrated to these realities, not imported from standardised templates.
- → Non-detection zone (NDZ) mapping using PSCAD — a level of rigour rarely offered by consultants relying solely on simplified tools
- → Indian DISCOM protection practice review: assessment of whether existing ROCOF and vector shift relay settings are fit for purpose with growing DG penetration
- → Microgrid islanding design support: governor and voltage regulator tuning for stable intentional island operation
- → IEC 62116 and IEEE 1547 compliance guidance: study findings translated into inverter and relay configuration requirements
- → Cross-disciplinary integration: islanding protection design coordinated with grid compliance, transformer loading, and black start studies for a conflict-free overall protection strategy
