Large-Scale Grid Compliance Assessment for a Renewable Energy Development

Power Projects has been awarded the Grid Connectivity and Grid Compliance Study for a 1564 MWac solar power project connected at a 400 kV Point of Interconnection (POI). The study involves detailed RMS and EMT validation to ensure full compliance with applicable grid code requirements.

The project comprises multi-developer integration within a shared transmission infrastructure, requiring coordinated modelling, system-level validation, and consistent representation of all generating assets.

With increasing renewable penetration at transmission level, such studies are critical to ensure secure, stable, and compliant operation of large-scale inverter-based resources under both steady-state and dynamic conditions.

The assessment is being carried out using industry-standard simulation platforms including PSS®E and PSCAD.

System Overview

The project consists of a large-scale solar PV generation facility integrated into a 400 kV transmission network.

The system includes:

  • Utility-scale solar PV generation capacity of 1564 MW ac
  • 400 kV Point of Interconnection (POI)
  • Multiple developer contributions within a shared grid interface
  • Step-up transformer and collector network infrastructure
  • Reactive power and voltage control capability through inverter-based resources

This configuration introduces a complex transmission-level interface, where system performance is strongly influenced by inverter behaviour, network strength, and coordinated control interaction.

Scope and Approach

The study involves detailed system modelling, simulation, and grid compliance assessment using PSS®E and PSCAD.

The assessment covers steady-state, power quality, and dynamic performance verification at the 400 kV POI under a range of operating conditions.

Key aspects of the study include:

  • Load flow analysis under varying generation and demand conditions
  • Reactive power capability and voltage regulation assessment
  • Power quality evaluation including harmonics, flicker, and DC injection
  • Dynamic and transient performance validation under grid disturbances
  • Coordination and integration of multiple developer models

These studies ensure that the plant meets relevant grid code requirements and performs reliably under both normal and disturbed system conditions.

Key Engineering Challenges

Multi-Developer System Integration

The project requires integration of multiple generating units developed by different stakeholders within a shared transmission network. This necessitates consistent modelling assumptions and careful system alignment to ensure accurate representation of overall plant behaviour.

High Renewable Penetration at Transmission Level

Large-scale solar PV injection significantly influences voltage profiles, reactive power flow, and system strength at the POI, requiring detailed validation of inverter-based response characteristics.

Dynamic Grid Performance Requirements

The system must maintain stable operation during faults, voltage excursions, and frequency variations while ensuring compliance with grid code ride-through requirements.

Performance Assessment

Steady-State and Reactive Power Evaluation

Load flow studies were conducted at the 400 kV POI to assess voltage profiles and reactive power capability under lagging, unity, and leading power factor conditions. The analysis ensures adequate voltage control and compliance across operating scenarios.

Power Quality Assessment

Power quality studies were performed to evaluate harmonic performance, flicker levels, and DC injection at the POI under varying operating conditions. These assessments ensure compliance with applicable transmission network standards.

Dynamic and Transient Performance

The dynamic assessment includes validation of plant behaviour under grid disturbances, including:

  • Low Voltage Ride Through (LVRT)
  • High Voltage Ride Through (HVRT)
  • Frequency ride-through capability (47.5–52 Hz)
  • Frequency response with droop control (3% and 6%)
  • Active power ramp rate performance (+10% per minute)
  • Reactive power response under voltage and power factor control modes

Time-domain simulation results are used to confirm stable and compliant system behaviour under disturbance conditions.

Project Delivery

The study is being delivered through a structured engineering workflow comprising system data validation, detailed modelling, scenario-based simulation, and compliance assessment.

Deliverables include:

  • Load flow and system performance results
  • Power quality and harmonic analysis reports
  • Dynamic simulation outputs (RMS and EMT)
  • Grid compliance documentation and technical reporting

The project is scheduled for completion within a 10-week timeframe, subject to receipt of complete project data from all stakeholders.

Conclusion

Large-scale renewable energy integration at transmission level introduces increasing complexity in system planning, control interaction, and grid stability management.

This study demonstrates that:

  • Multi-developer integration requires consistent and validated system modelling
  • High levels of solar PV penetration significantly influence system voltage and reactive power behaviour
  • Combined RMS and EMT analysis is essential for accurate grid compliance assessment

About Power Projects

Established in 2006, Power Projects is a specialist engineering consultancy providing services in:

  • Power system studies
  • Grid compliance
  • PSCAD modelling
  • Protection engineering
  • Renewable integration

The company supports utilities, developers, and OEMs using tools such as PSS®E, PSCAD, DIgSILENT PowerFactory, and ETAP.