Background
An independent water plant (IWP) in the Gulf region planned to expand its desalination capacity as part of broader infrastructure development. Located adjacent to a power generation facility, the plant included seawater intake and outfall systems, electrical infrastructure, and potable water storage.
As capacity increased, the electrical demand profile became more complex. This required validation that new facility loads, particularly large motor-driven processes, could be successfully interconnected and operate reliably within the utility provider’s transmission network.
Challenge
The integration of large industrial loads, motor starts, and switching events introduced multiple risks at the point of common coupling (PCC), including:
- Voltage dips and slow voltage recovery
- Fault current exceedances
- Harmonic distortion and phase imbalance
Without validated modeling and demonstrated grid code compliance, the project faced:
- Potential delays in interconnection approval
- Uncertainty in equipment sizing and protection coordination
- Increased risk of adverse impact on the transmission network
The core challenge was ensuring that the plant could meet grid code requirements while maintaining stable operation under worst-case and contingency conditions, particularly during high-impact events such as motor starting.
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Solution
EPE developed detailed PSCAD-based system models and executed a structured program of steady-state, dynamic, and electromagnetic transient (EMT) studies to evaluate system performance under normal, contingency, and worst-case operating scenarios.
The objective was to evaluate system behavior under worst-case and contingency scenarios, benchmark results against the utility's grid code limits, and provide technical reports with clear compliance verification.
The scope included:
- Load flow and contingency analysis (steady-state)
- Short circuit and equipment rating verification
- Motor starting simulations
- Voltage recovery assessment
- Electromagnetic transient (EMT) studies
- Harmonic and phase unbalance analysis
All studies were benchmarked against utility grid code limits to support compliance verification and interconnection approval.
Targeted mitigation measures were identified where required, including equipment adjustments and voltage support measures to ensure stable system response.
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Key Insight
Although sufficient grid capacity was available, the limiting factor was system performance at the PCC under transient conditions.
Motor starting events and disturbance scenarios drove voltage behaviour and recovery characteristics, demonstrating that compliance depended not only on capacity, but on how the system responded dynamically during critical operating conditions.
Result
The client obtained validated, utility-ready study reports and system models that:
- Demonstrated grid code compliance
- Supported efficient utility review and interconnection approval
- Reduced uncertainty in equipment sizing and protection settings
- Confirmed the plant could interconnect and operate reliably without adverse impact on the transmission network
This established a clear pathway to reliable interconnection and stable operation of the expanded desalination facility.