html{display:none} Transmission Planning | Schweitzer Engineering Laboratories

Transmission Planning

Analysis and Design Covering a Wide-Range of Scenarios

Transmission Planning

SEL offers transmission planning analysis and design services over a wide range of study scenarios, from 69 kV to 525 kV. Using the GE PSLF software package and user-written tools, we can perform Western Electricity Coordinating Council (WECC) path-rating studies, FERC generator interconnection studies, wires-to-wires interconnection studies, NERC compliance studies (MOD-026, MOD-027, PRC-006, and PRC-019), import/export studies, load-serving studies, and underfrequency load shedding (UFLS)/undervoltage load shedding (UVLS) studies. We will provide hard and electronic copies of all reports and models for future use. With over 30 years of experience, we can analyze and provide recommendations for a variety of planning and operating power system scenarios. 

Software tools include:

  • GE PSLF and ProvisoHD transient, post-transient, and voltage stability analysis
  • CAPE and ASPEN breaker duty and relay coordination studies
  • EasyPower power flow and short-circuit analysis
  • SKM Power*Tools power flow analysis, short-circuit analysis, and motor starting
  • Simulink/Simscape
  • ASPEN OneLiner

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Key Offerings

  • Black start assessment, motor-starting analysis, and reactor-sizing studies.
  • Analysis of facility equipment/operating practices for reliably meeting existing and future load needs.
  • Identification of facilities necessary for new generators while meeting FERC generator interconnection requirements.
  • Fulfillment of compliance requirements for NERC modeling and planning standards.
  • Transmission regulatory studies to meet state resource planning statutes.
  • Analysis of local- and wide-area power system disturbances, including diagnosis and recommendations.
  • Transformer emergency loading above nameplate rating calculations.
  • Protective scheme coordination studies.

Even if you are not required to perform these specific types of analyses, you can benefit from transmission planning best practices. We provide hard and electronic copies of all reports and models for future use. It is easy to update system models for future planning needs, saving time and money versus creating new models.

Southeast Power Study

SEL provides WECC path-rating (shown below), total transfer capability (TTC), and transfer capability studies as part of our transmission planning services. We can perform studies at voltage levels from 69 kV to 525 kV. In addition to cut-plane studies, we can perform transmission service and export capability studies upon request. Import capability studies, including reliability must-run (RMR) analysis, are available. We can also perform out-of-step studies, breaker duty studies, relay coordination, and remedial action scheme design.

Transmission Planning - Power Study

Example Reports

As part of any analysis or design effort, SEL can provide both transient and post-transient assessments to meet your needs. Transient stability analysis (left) includes but is not limited to model validation and NERC MOD-026 and -027 acceptance studies. We can perform Q-V and P-V post-transient analysis (right) on any size of system. In addition, we can perform reactive margin studies and voltage and thermal overload studies on high-voltage (HV) to extra-high-voltage (EHV) systems.

Transmission Planning Example Reports


To support NERC Standard FAC-008 Compliance requirements, SEL can provide an industry established methodology for calculating transformer emergency ratings for all-oil immersed BES transformers as well as ratings for different overload levels and time frames.

Load Beyond


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