Interconnection studies

The following analyses and procedures should be performed for all new or modified interconnection facilities (generation, transmission, and end-user) to the ATC system to properly assess their reliability impact on the interconnected systems. For some analyses, a formal study report may be appropriate. For other analyses, a simple statement of assumptions and rationale may be sufficient.

Types of Analysis

The analyses are to include steady state, short-circuit, and dynamic assessments that include the requirements in TPL-001-4.

Compliance with Applicable Planning Criteria

The analyses and procedures are to comply with all applicable NERC, Regional Entity, and individual system planning criteria of the affected parties.

Coordination with Affected Entities

The results of the analyses will be jointly evaluated and coordinated by the affected entities.

Essential Documentation

All analyses should include the evaluation assumptions, system performance, alternatives considered, and any jointly coordinated recommendations.

Specific Study Methodologies

Generator Interconnection Studies

1. Shall utilize AC solution methods in PSS/E or MUST to screen for overloaded elements. Linear DC analysis may only be used to determine Distribution Factors (PTDF and LODF) for MISO generator interconnection studies and the impact of multiple Generator Interconnection Requests on a transmission facility for cost allocation purposes.
2. Steady-state analysis shall utilize the following generation dispatch:
   • Shoulder Load Levels: Studied generation, local competing requests, and existing local generation dispatched at their expected output level. This corresponds to base load generating facilities being dispatched at their P_max, combined cycle generating facilities dispatched at 50 percent of their P_max, peaking units offline, and all wind generation at 100 percent of their P_max.
   • Summer Peak Load Levels: Studied generation, local competing requests, and existing local generation dispatched at their expected output level. This corresponds to base load and combined cycle generating facilities being dispatched at their P_max, peaking units at their P_max, and all wind generation at 20 of their P_max.
   • Additional/Alternative Seasonal Load Levels: If deemed necessary to adequately assess system reliability in the study area, other seasonal models may be required. Generating facilities should be dispatched at expected output levels, regardless of fuel type, in accordance with historical data and ATC Control Area merit order or ATC-wide merit order, depending upon what type of case is selected. In general, lighter load conditions should dispatch wind generation at 100 percent of their P_max and winter peaking load conditions should dispatch wind generation at 20 percent of their P_max.
3. Dynamic stability studies shall dispatch generation in the study area to ensure expected more severe operating scenarios are assessed. Generally, this will involve dispatching all generation local to the study area regardless of fuel type, load level, or merit order. Engineering judgment and potentially sensitivity analysis should be utilized to determine a severe, yet credible dispatch.
4. Existing generators in the study area with Interconnection Agreements allowing for higher seasonal output (e.g., combustion turbines with increased output capability at colder ambient temperatures) shall be modeled at that output level during dynamic stability studies. New Interconnection Requests with higher seasonal output levels will be analyzed at the higher output if the Interconnection Customer elects the additional capacity in the MISO Generator Interconnection Process.

 

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