The Ybus matrix of a 100 bus interconnected system is 80% sparse. Then, the number of transmission lines in the system must be
- A. 950
- B. 3000
- C. 1900
- D. 1500
Answer: A. 950
Explanation: For 100 buses, total Ybus entries = 10,000. 80% sparsity gives 20% non-zero entries = 2000. Off-diagonal non-zero entries = 2000 − 100 = 1900. By symmetry, number of lines = 1900 / 2 = 950.