Advanced Grid Dynamics Studies

Overview

APS provides advanced RMS and EMT-based studies for complex, evolving power systems, with particular focus on dynamic stability, weak-grid behaviour, harmonic and control interactions, subsynchronous phenomena and converter-dominated network performance. These studies support developers, asset owners, OEMs, consultants, TSOs, DSOs and DNOs during grid connection, design verification, technical due diligence and operational planning.

Modern power systems are increasingly influenced by inverter-based resources (IBRs), long cable networks, power electronic converters, FACTS devices, HVDC links, battery energy storage systems (BESS) and complex protection and control schemes. These technologies can introduce dynamic and control interactions that are not always visible through conventional load-flow or short-circuit studies.

APS applies simulation-based engineering assessment using RMS, EMT, frequency-domain and control-system analysis methods to identify risks, verify performance and support practical mitigation. The work is carried out in line with recognised international frameworks, including IEEE 2800 and IEEE 2800.2, IEEE Std 1110 and IEEE Std 1204, IEC 61400-21-1 and IEC 61400-27, IEC 62747 and the IEC 61000 series, together with relevant CIGRE Technical Brochures covering system strength, converter interaction, impedance-based stability and grid-forming performance.

Studies can be performed using DIgSILENT PowerFactory, PSCAD™/EMTDC™, EMTP®, PSS®E and RSCAD/RTDS. APS can assess normal operating conditions, fault and switching events, weak-grid and low-SCR scenarios, control interactions, resonance conditions and recovery behaviour. Where required, mitigation options including control parameter tuning, grid-forming functionality, filtering, damping schemes, system-strength remediation and protection coordination can be evaluated.

Key Services

APS provides study-led grid dynamics services for projects where converter-based generation, HVDC, FACTS or weak-grid conditions may introduce stability, resonance or control-interaction risks. The service combines detailed dynamic modelling, model validation, frequency-domain screening, time-domain simulation and mitigation design.

• Dynamic and transient stability studies for generation, transmission and distribution-connected projects More info
• Weak-grid assessment and converter-grid interaction studies, including SCR and system-strength evaluation More info
• Inverter-Based Resource (IBR) performance assessment, model validation and control review More info
• Subsynchronous Control Interaction (SSCI), Torsional Interaction (SSTI) and Resonance (SSR) screening More info
• Harmonic resonance, temporary overvoltage (TOV) and control interaction studies More info
• Grid-forming (GFM) and grid-following (GFL) converter performance assessment More info
• Battery energy storage system (BESS) dynamic performance studies More info
• Renewable generation plant modelling, validation and performance assessment More info
• Distributed Energy Resource (DER) integration studies using RMS and EMT simulation More info
• Microgrid modelling, control strategy review and operational optimisation More info
• Protection and control interaction assessment in converter-dominated networks More info
• Transformer energisation, inrush, sympathetic interaction and dynamic overvoltage assessment More info
• FACTS, STATCOM, SVC and HVDC interaction studies More info
• Frequency-domain impedance scanning and resonance risk assessment More info
• Time-domain simulation of faults, switching events, disturbances and recovery behaviour More info

Typical Applications

These studies are suitable for projects where inverter-based resources, HVDC links, long cable networks or weak-grid conditions may introduce dynamic stability, resonance or control-interaction risks, particularly where low short-circuit ratio, high converter penetration or sensitive control systems increase the likelihood of adverse interaction.

• Offshore and onshore wind farms
• Solar PV farms
• Battery energy storage systems
• Hybrid renewable and co-located generation projects
• Grid-connected generation requiring connection compliance
• HVDC and MTDC interconnectors
• FACTS, STATCOM and SVC installations
• Data centres and mission-critical facilities
• EV charging infrastructure
• Industrial plants with large power electronic loads
• MV substations and private networks
• Weak-grid and remote-end connection points

Technical Value

The objective of the study is to provide a technically justified assessment of dynamic stability, weak-grid behaviour, resonance and control-interaction risks before they become connection, compliance, design or operational issues.

APS combines detailed RMS and EMT modelling with frequency-domain and control-system analysis to help clients understand how inverter-based resources, HVDC, FACTS and complex control schemes interact with the wider network. The study can identify whether stability margins, damping performance, harmonic and resonance behaviour, and converter response under weak-grid conditions are within acceptable limits, and whether mitigation is required.

The assessment supports early design decisions, grid connection compliance, control parameter selection, equipment specification, system-strength evaluation and mitigation system optimisation, in line with applicable IEEE, IEC, CIGRE and connection-code requirements. This allows project teams to move from uncertainty to a clear engineering position supported by modelling evidence, validated models and technically robust recommendations.

By combining RMS, EMT and frequency-domain simulation with validated equipment models, network data, fault-level information and control representations, APS helps clients reduce stability and resonance risks, demonstrate connection compliance, optimise control and mitigation strategies, and ensure that dynamic performance requirements have been properly considered.