Load Flow (Power Flow) Study
Evaluate voltage profile, thermal loading, and reactive power performance for planning, upgrades, and interconnection readiness.
What This Study Is
A load flow (power flow) study calculates steady-state voltages, real and reactive power flows, and equipment loading across a power system under defined operating conditions. It is the foundation for identifying voltage violations, overloads, reactive limitations, and control behavior issues before construction, energization, or operational changes.
Load flow analysis evaluates how power flows through the network, where voltages sag or rise, which equipment approaches thermal limits, and whether reactive power resources are adequate. Results inform equipment selection, control strategies, and system upgrade decisions.
This study is required by utilities, ISOs/RTOs, and regulatory bodies to ensure proposed changes do not degrade system performance or create reliability risks.
When This Study Is Required
Generator/BESS Interconnection
Screening or full study package requirements
Facility Expansion
Feeder/substation upgrades, transformer changes
Voltage Complaint Troubleshooting
Reactive power planning and voltage regulation
Utility/ISO Requirements
Engineering review and planning case updates
What eGridSync Delivers
Study scope definition and assumptions documentation
Base case development / validation (topology, voltages, ratings)
Voltage profile analysis (min/max buses, weak areas)
Thermal loading checks (lines, transformers, interfaces)
Reactive power / VAR support assessment (limits, Q capability)
Control mode review (PV voltage control, PF targets, Q limits)
Scenario and sensitivity cases (seasonal, topology, dispatch)
Violation identification and root-cause notes
Mitigation options (reactive devices, taps, upgrades, controls)
Final report with summary tables and recommended actions
Inputs Required (Data Request Checklist)
| Item | Examples | Why Needed |
|---|---|---|
| One-line diagram & POI details | POI bus, voltage, breaker config | Define topology and interconnection point |
| Project size & controls | MW/MVA, PF mode, voltage control settings | Accurately model operating behavior |
| Equipment ratings | Lines, transformers, shunts, breakers | Identify overloads/constraints |
| Existing planning case | Utility/RTO case, internal PSSE case | Reduce setup time and match system assumptions |
| Generator/BESS models | Inverter controls, Q limits, P limits | Reactive and voltage behavior |
| Operating scenarios | peak/light load, dispatch assumptions | Validate for required conditions |
Assumptions & Typical Settings
Seasonal Conditions
Per utility study guidelines and ambient temperature assumptions
Topology Assumptions
Normal and contingency configurations as required
Equipment Ratings
Limits per provided data sources and standards
Control Modes
Voltage control and reactive limits clearly defined
Outputs & Reporting
Base Case Summary
Model notes and validation results
Voltage Profile & Loading Tables
Bus voltages, line/transformer loading percentages
Constraint List
Limiting elements with severity and root cause
Mitigation Recommendations
Pros/cons of solutions, utility-ready report package
Common Issues Identified
Undervoltage/Overvoltage
At POI or weak buses requiring reactive support or tap changes
Thermal Overloads
Transformers/lines exceeding ratings under normal or contingency conditions
Reactive Limitations
Control instability in steady state or inadequate VAR reserves
Incomplete Model Data
Causing unrealistic results and requiring data reconciliation
Frequently Asked Questions
What is the difference between load flow and stability?
Load flow is steady-state; stability evaluates time-domain dynamic response after disturbances.
Do you need a PSSE case from the utility?
It helps, but we can build from your data and utility-provided short-circuit/load assumptions if available.
What are typical outputs?
Voltage/thermal constraint lists, summary tables, and mitigation options.
Can you model inverter controls?
Yes, provided control settings and model data are available.
Will you recommend mitigation?
Yes—reactive devices, taps, upgrades, and control changes as appropriate.
How do you handle different operating scenarios?
We run defined seasonal and dispatch cases and document assumptions.
What if my one-line is not finalized?
We can begin with preliminary topology and update as design matures.
Does this support interconnection?
Yes—load flow is a core component of most interconnection study packages.
What if results show violations?
We provide prioritized mitigation options and reruns if required.
What information speeds things up most?
POI details, ratings, and a validated base case.
Ready for Load Flow Analysis?
For detailed engineering analysis and execution, contact eGridSync.