Project Overview

1. Project Overview With de-regulation of the electric power industry immanent, the transmission system has to be highly reliable and cost effective. • Review current and future problems • Develop Solutions that will provide the customer with high quality reliable power • Test the solution against a 2004 base case using PTI’s PSS/E (Power Simulation Software). • Choose the best solution that will provide the customer with high quality reliable power, yet at a low cost.

2. Problem Definition • Low voltage problems in the Mecosta area during heavy load conditions. • Capacitor bank installed at the Mecosta 138kV substation to temporarily fix the problem. • During a single contingency (single problem) on the grid, the current design will not support the system. • The increasing load is leading to overloading problems that the system will not be able to tolerate much longer.

3. Problem Area The Problem Area is centered around Mecosta, Michigan, near Cadillac. The two primary customers in this part of the service territory are Acuglas and Evart Products.

4. Design Approach • Add New Lines • Reconductor Lines • Add Capacitor Banks • Tie Into 345kV System Isolated System Low Voltage Problems Simulation/Testing Evaluate Solutions & Submit

5. Design Specifications • Equipment loading should not exceed 100% of its normal loading (line loading, transformer loading, etc). • Voltages on the EHV network should be between 0.97 & 1.05 p.u., during normal conditions (FERC Form 715). • Develop all solutions and contingencies under a 2004 base case. • Consider customer concerns and “right of way” when considering pole/tower designs. • Tweak solutions for economic and system stability reasons.

6. Tools and Standards Used • PTI’s PSS/E (Power System Simulator for Engineering). • Aspen Powerflow to Calculate impedance of lines • Federal Energy Regulatory Commission Standards (FERC form 715) • Consumers Energy Co. Standards and Specifications

7. Impedance Calculations • Used Aspen Line Constants Software to calculate impedance's to be entered into PSS/E

8. Possible Solutions Lake Co. Chase Ohman Rd. Jct. $8.1 Million 1. Add New Conductor 138 kV 138 kV 19 miles 18 miles 2. Add New Conductor Clare Ohman Rd. Jct. $5.6 Million 138 kV 27 miles Ohman Rd. Jct. Wexford $5.5 Million 3. Add New Conductor 138 kV 26 miles

9. Possible Solutions -continued $5.5 Million New Sub (345kV) Stronach (138 kV) 4. Tie into 345kV grid (still in progress) 138 kV < 1 mile 5. Add New Conductor Chase Ohman Rd. Jct. $4.1 Million 138 kV 18 miles 6. Add New Conductor Chase Ohman Rd. Jct. Clare 138 kV 138 kV $10 Million 18 miles 27 miles

10. Contingencies Tippy Generator Out x x x All other x’s indicate line taken out x x x x Croton Generator Out Cobb Generator Out x x

11. Comparison of Base Case and Possible Solutions Without Any Contingencies

12. Comparison of Base Case and Possible Solutions With Contingency One

13. Comparison of Base Case and Possible Solutions With Contingency Three

14. Work In Progress • Look at each solution on a basis of: • engineering standards and specifications • cost of implementation • environmental factors • Using the information above, determine which solution will be of best interest to Consumers Energy and turn in the Concept Approval. • Design required additions to substations and transmission system. Create CAD drawings of these solutions. • Develop and present our final recommendations to Consumers Energy.

15. Conclusions • These solutions will support the current grid with a single contingency. • Each solution was developed with an estimated 2004 base case, ensuring reliability through the year 2004. • Simulation showed line reconductoring was not a very useful solution. Adding addition lines, capacitor banks, and tying into the 345kV system gave the best results.