We will strive to develop and maintain consistency in the powerflow models used for planning efforts and in assessing whether and under what conditions transmission service is available. The starting point for ATC powerflow models will be models contained in the NERC and Regional data banks. We will use load forecasts provided by our end-use load-serving customers as input into future model building efforts, both internally and in conjunction with NERC, Regional Entity (RE), and Regional Transmission Operator (RTO) initiatives. These forecasts may be adjusted by ATC if adjustments are needed for transmission planning purposes either with concurrence from our customers or independently of our customers. All ATC powerflow models will be developed using PTI PSS/E software.

(Applicable NERC Standards: MOD-010-0-B, MOD-011-B, MOD-012-0-B)

Voltage Schedule

1. The powerflow models will implement ATC's generator voltage schedule. The generator voltage schedule is defined as a:

• Target voltage of 102% of the nominal transmission voltage as measured at the point of interconnection between the generator and the transmission network unless another voltage schedule has been identified and,

• Normal voltage range of 95% to 105% of nominal transmission voltage.

Due to limitations imposed by the NERC model building process, the generator voltage schedule target modeled in the NERC powerflow models may only approximate ATC's voltage schedule at the point of interconnection.

(NERC VAR-001)

2. Generators that do not have automatic voltage regulation (AVR) or are not controllable (unmanned stations and no remote control) have been considered. When modeling these generators, special attention must be given to the limitations of these units.

Generation Dispatch

1. Generation reported by ATC's members will be dispatched in accordance with contractual and local or regional economic dispatch considerations as applicable.
2. Designated Network Resources will be dispatched out of merit order if they have been identified as must run units.
3. Power-Voltage (P-V) analysis models wind generation at its full output level.
4. Generator Interconnection studies will model wind generation following the guidelines in the MISO Business Practice Manual for Generator Interconnections.
5. Generally, for each system load condition case, wind generation is modeled at 20% of its reported output level for general planning studies, although sensitivity analyses may dispatch wind generators at various output levels.

Net Scheduled Interchange

1. Net scheduled interchange for the ATC system will be coordinated with the necessary regional and interregional parties.
2. Net scheduled interchange for the ATC system may be altered to evaluate realistic system conditions of significance for system planning purposes.