--- title: "Advantages of interconnected power system" subject: "Power System Analysis II" chapter: 1 key: "semester_5/power_system_analysis_ii:interconnection-advantages" source: https://www.bctengineer.com/q/semester_5/power_system_analysis_ii/interconnection-advantages site: BCT Engineering --- # Advantages of interconnected power system Power System Analysis II · Chapter 1: Interconnected Power System - Asked in: 2080 Bhadra, 4 marks; 2075 Asoj, 4 marks; 2074 Chaitra, 4 marks (asked 3 times) - Video: [interconnected grid system and its advantages and disadvantages | jitendra sah](https://www.youtube.com/watch?v=kMWhCeUgYz0) — jitendra sah - Answer checked by Claude Sonnet 5.5 on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_5/power_system_analysis_ii/interconnection-advantages - Whole chapter: https://www.bctengineer.com/md/semester_5/power_system_analysis_ii/chapter-1 ## Question What is interconnected power system? List out the advantages of interconnected power system over isolated power system. ## Short answer An interconnected power system links multiple generating stations via tie-lines, operating synchronously. Advantages: higher reliability, shared reserve, load diversity, economic dispatch, use of larger efficient units, power exchange, better frequency regulation, and easier maintenance scheduling. ## Answer An **interconnected power system** is a network in which two or more generating stations or control areas are connected by transmission lines (tie-lines) and operate in parallel at the same frequency, sharing generation and load. A national grid such as Nepal's INPS, which is also tied to India, is an example. #### Advantages over an isolated power system 1. **Higher reliability:** when a generator or plant fails, other plants supply the load through tie-lines. 2. **Reduced reserve capacity:** spinning reserve is shared, so each station needs less standby capacity. 3. **Diversity of loads:** peaks of different areas occur at different times, so total installed capacity is lower and load factor is better. 4. **Economic operation:** cheaper sources (hydro, base-load plants) are used fully and costly units only at peak; economic load dispatch across the whole system. 5. **Larger, efficient units:** bigger machines with lower cost per kW can be installed. 6. **Exchange of surplus power:** extra energy (e.g. wet-season hydro) can be exported and deficit imported. 7. **Better frequency regulation:** large combined inertia keeps frequency more stable for a given load change. 8. **Easier maintenance:** units can be shut down for overhaul without load shedding. A short drawback note: fault levels rise and faults can spread, so better protection and coordination are needed. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. An interconnected power system is one in which: A. several stations or areas are linked by tie-lines and run in parallel at the same frequency B. each station feeds only its own load C. stations run at different frequencies D. only one generator is in service Answer: A. Interconnection means parallel operation, sharing generation and load. (Key point: Definition) 2. How does interconnection improve reliability? A. Faults can never occur B. If a unit fails, other plants supply the load through tie-lines C. Fault levels fall D. Each area needs more reserve Answer: B. Other plants pick up the lost load via tie-lines. (Key point: Reliability) 3. Why is frequency regulation better in an interconnected system? A. Load never changes B. Governors are not needed C. The combined inertia is large, so a load change gives a small frequency change D. Inertia is smaller Answer: C. Large inertia limits frequency deviation. (Key point: Frequency regulation) ## Related in Power System Analysis II - [Real power/frequency control in interconnected system](https://www.bctengineer.com/question.md?key=semester_5%2Fpower_system_analysis_ii%3Areal-power-frequency-control) — Power System Analysis II, chapter 1 - [Merits and demerits of interconnected system](https://www.bctengineer.com/question.md?key=semester_5%2Fpower_system_analysis_ii%3Ainterconnection-merits-demerits) — Power System Analysis II, chapter 1, asked 3× - [Interconnected system load-frequency and Q-V control](https://www.bctengineer.com/question.md?key=semester_5%2Fpower_system_analysis_ii%3Ainterconnection-control-schematic) — Power System Analysis II, chapter 1 - [Interconnection advantages and real power-frequency balance](https://www.bctengineer.com/question.md?key=semester_5%2Fpower_system_analysis_ii%3Ainterconnection-advantages-frequency) — Power System Analysis II, chapter 1, asked 3× - [Line currents with isolated and grounded neutral](https://www.bctengineer.com/question.md?key=semester_5%2Fpower_system_analysis_ii%3Astar-impedance-unbalanced-voltages-neutral) — Power System Analysis II, chapter 4 - [Fault currents of isolated-neutral 380 V generator](https://www.bctengineer.com/question.md?key=semester_5%2Fpower_system_analysis_ii%3Agenerator-faults-380v-isolated-neutral) — Power System Analysis II, chapter 5 ## Related in other subjects - [Interconnected system SLD, isolated vs interconnected, advantages](https://www.bctengineer.com/question.md?key=semester_4%2Fpower_system_analysis_i%3Ainterconnected-sld-isolated-advantages) — Power System Analysis I, chapter 1 - [SLD of interconnected system vs isolated system](https://www.bctengineer.com/question.md?key=semester_4%2Fpower_system_analysis_i%3Ainterconnected-sld-vs-isolated) — Power System Analysis I, chapter 1 - [Interconnected power system and advantages](https://www.bctengineer.com/question.md?key=semester_4%2Fpower_system_analysis_i%3Ainterconnected-system-advantages) — Power System Analysis I, chapter 1 - [Interconnected system SLD and functions of each part](https://www.bctengineer.com/question.md?key=semester_4%2Fpower_system_analysis_i%3Ainterconnected-sld-functions) — Power System Analysis I, chapter 1