Power Systems Studies – De-Risking Renewable Projects from Feasibility to Energisation
As the use of renewable energy generation becomes more widespread, networks grow more complex and interdependent. With inverter-connected resources rising on the GB network, many systems are operating with lower inertia, reduced system strength and tighter stability margins. Here at Blake Clough, we provide structured power systems analysis to establish technical and commercial viability early on in project development, support engagement with Transmission Operators (TOs) and Distribution Network Operators (DNOs) and ensure that the project achieves grid code compliance and ultimately connects to the network.
Robust and efficient power systems studies minimise clarifications, speed connection decisions and protect programme and cost from feasibility through energisation. Blake Clough has significant experience in understanding issues with compliance and providing solutions and mitigations.
Why Do We Need Power Systems Consultants For Modern Grids?
Traditional synchronous machines supply inertia and high fault current, strengthening the grid. Inverter-based sources such as solar, wind, and batteries contribute far less, which weakens short circuit levels and complicates fault detection, protection selectivity, and equipment rating. The increase of converter-connected sources is also elevating harmonic distortion. As inverter-based generation and storage grow alongside residual synchronous plant, new stability risks emerge from machine–converter interactions, spanning small-signal and large-signal modes, including sub-synchronous oscillations and voltage control problems.
A Power System study is a structured set of analyses that tests how a network and connected plant will perform under normal operation and credible disturbances. The goal is to quantify operating limits, confirm compliance with the codes and standards , and identify practical mitigations before design and procurement are finalised. Ultimately, power systems studies should help to ensure that projects are connected compliantly, safely and in accordance with development timescales.
A power system study can inform the preparation and validation of single line diagrams, and assist in making well-informed design decisions. Clear assumptions, version control, and traceability ensure that results can be reproduced and reviewed by operators. Well-scoped power systems analysis reduces clarifications, supports efficient engagement with TOs and DNOs, and forms the basis for decisions from feasibility through to energisation.
Load Flow (Power Flow) Studies
Load flow studies form the base of power systems analysis for developers and network owners. A robust load flow study provides early assurance that the voltage at the point of connection stays within the allowable limits, transformers and cables operate within their thermal ratings, any losses are quantified, and that the aggregated inverter capability complies with the GB Grid Code and EREC G99 at the point of connection. The load flow study is also a critical step in designing an efficient electrical system, assisting in making design choices such as number of cables, voltage levels, number of transformers etc.
Fault Level/Short Circuit Studies
Short circuit studies calculate the maximum fault currents that could occur within an electrical network, for both three phase faults and single phase to earth faults. The results of the studies are then used to check that all equipment, such as switchgear, transformers and cables, can safely withstand the expected fault level. This includes verifying thermal and mechanical withstand ratings and, where applicable, making and breaking capabilities. In Great Britain, these assessments are undertaken in accordance with IEC 60909 and EREC G74.
Protection Coordination and Arc Flash Studies
A protection coordination study provides grading of protection functions to ensure faults are cleared selectively and within the required times, covering relay settings, fuse characteristics and breaker timing across feeders, transformers and generators. Grading and coordination are developed with reference to the ENA TS 48 series. The confirmed fault levels and protection settings also provide input to arc flash assessments.
An arc flash study assesses potential arc flash hazards in an electrical system by reviewing its design, construction and operating conditions, then identifying where risks may occur and calculating the incident energy and arc flash boundary. This is then used to establish the energy that could be released and the distance at which a person may be exposed. Based on these results, it recommends risk-reduction measures such as installing protective devices, adjusting protection settings or modifying the system design. In Great Britain, protection coordination and arc flash assessments are undertaken in accordance with IEEE 1584
Harmonic Studies
Harmonic studies quantify the total harmonic distortion a plant can expect to experience and assess resonance risk from converters and other non-linear loads. The EREC G5/5 standard sets out a rigorous process for assessing harmonic emissions from new generation and storage connections to UK networks. Compliance must be demonstrated for both incremental and total harmonic voltage distortion at the point of common coupling, with assessment up to the 100th harmonic order and explicit consideration of background levels, coincident connections, resonance risk, and impacts beyond the immediate point of connection.
Stability Studies
Stability analysis aims to quantify and mitigate instability issues caused by inverter and grid interaction using complementary techniques. Small-signal studies identify system modes and potential instabilities in the frequency domain, while electromagnetic transient (EMT) simulations capture time-domain dynamics and confirm theoretical findings. When instabilities are identified, mitigation measures such as damping control optimisation, reduced series compensation, synchronous condensers, or static series compensators can be applied to improve network resilience. Together, these approaches provide a robust framework for maintaining stable operation in modern, converter-dominated power systems.
In addition to the studies described above, power system studies in Great Britain commonly include following:
- Voltage fluctuation and flicker assessment in accordance with EREC P28
- Voltage unbalance assessment in accordance with EREC P29
- Insulation coordination in accordance with IEC 60071 Parts 1 and 2
- Earthing and grounding studies in accordance with ENA TS 41 24, BS EN 50522, IEEE 80 and BS 7430
Different regulations apply in different regions. Across the European Union, Regulation 2016/631 (known as “Requirements for Generators” or RfG) sets minimum capability and testing requirements for Plant from 1 MW to more than 100 MW (Type A, B, C, D ), with operational parameters set nationally by each TSO or regulator. In North America, IEEE 1547-2018 governs distribution-level interconnection of distributed energy resources, IEEE 2800-2022 defines interconnection capability and performance for transmission-connected inverter-based resources, and NERC PRC-024-3 specifies frequency and voltage protection settings to avoid unnecessary tripping during defined excursions. In Canada, many jurisdictions reference CSA C22.3 No. 9:20 for Distributed Energy Resource (DER ) interconnection at distribution. In Australia, generator performance is assessed against the National Electricity Rules Schedule 5.2.5 and associated AEMO guidance, forming the negotiated Generator Performance Standards.
How Do We Complete Power Systems Studies?
Power systems studies at Blake Clough are built in power systems software such as DIgSILENT PowerFactory or PSSe. The network model is assembled and tested in PowerFactory to run load flow studies, short circuit calculations, harmonic studies, stability studies and dynamic studies. This provides a consistent environment for voltage, thermal and fault duty checks, and frequency and voltage performance across credible events.
Power Systems Computer Aided Design (PSCAD) is introduced when electromagnetic transient details are required. Converter dominated schemes and fast control interactions benefit from PSCAD’s time domain simulations, complementing the PowerFactory model with higher resolution where needed. Using both tools allows our studies to cover a wide breadth of scenarios with the depth required for critical behaviours such as ride through and control dynamics.
As a specialist power systems consultancy, Blake Clough delivers reliable power systems studies and analyses that de-risk decisions and move projects towards energisation. We build models in DIgSILENT PowerFactory for onshore and offshore wind, solar, battery storage, and hybrid projects. These models are used for network modelling, load flow, short circuit, harmonics, stability and dynamic studies. PSCAD is used where electromagnetic transient detail is required. The outcome of our studies is clear, traceable evidence that designs comply with regulations, alongside actionable recommendations which can be undertaken if projects do not meet the requirements. Blake Clough helps projects secure credible and compliant connection strategies in the UK and internationally.
Our typical Power System analysis study packages include:
- Load flow study
- Reactive power capability & compensation equipment sizing & specification
- Short-circuit / fault level study and equipment rating
- Voltage Control and Reactive Power Stability
- Frequency Response (LFSM-O, LFSM-U, FSM)
- Fault Ride Through (FRT)
- Fast Fault Current Injection (FFCI)
- G5/4 or G5/5 harmonics, including filter design
- Electromagnetic transients, transformer energisation,
- voltage fluctuations and flicker
- AC System voltage variations
- Insulation Coordination
- Protection coordination
- Arc flash
- Earthing Study
Our Track Record
Blake Clough Consulting has extensive experience delivering complex power system studies across onshore and offshore networks worldwide. Our work spans from grid code compliance and dynamic stability analysis to innovative hybrid renewable system design and HVDC integration. Further information can be found without our capability statements.