About this previous year paper
SMART ENERGY & DELIVERY SYSTEMS (NEE024)
Section-wise Solved Answers & Notes
SECTION – A (10 × 2 = 20 Marks)
Very short & direct answers
(a) Applications of Intelligent Electronic Devices (IED)
IEDs are used in protection, control, monitoring, and automation of power systems.
Applications include: Protection relays
Fault detection Substation automation
Power quality monitoring
(b) Barriers of Smart Grid
Barriers include: High initial investment
Cyber-security risks Lack of standards
Consumer awareness issues Integration of legacy systems
(c) Real-time pricing of sale and purchase of power
Real-time pricing means electricity prices vary with demand and supply in real time, encouraging consumers to shift load during off-peak hours.
(d) Captive power plants
Captive power plants are power generation units owned by industries to meet their own electricity demand and reduce dependency on utilities.
(e) Role of storage (battery) in Smart Grid
Energy storage: Stores excess renewable energy
Improves reliability Supports peak load
Enhances grid stability
(f) Applications of smart sensors
Smart sensors are used for: Voltage and current measurement
Fault detection Condition monitoring
Energy management
(g) Geographic Information System (GIS)
GIS is a computer-based system used to capture, store, analyze, and display geographically referenced data for power system planning and management.
(h) Outage Management System (OMS)
OMS is a system used to detect, analyze, and restore power outages quickly, improving reliability and customer satisfaction.
(i) Phase Shifting Transformers
Phase shifting transformers control power flow in transmission lines by changing the phase angle of voltage.
(j) Smart Grid vs Conventional Distribution Grid
| Smart Grid | Conventional Grid |
|---|---|
| Two-way power flow | One-way power flow |
| Automated & intelligent | Manual operation |
| Real-time monitoring | Limited monitoring |
| Supports renewables | Limited integration |
SECTION – B (Attempt Any Five)
(10 marks each – write in detail in exam)
(a) Wireless Mesh Network in Smart Grid
Wireless mesh networks consist of multiple interconnected nodes that communicate wirelessly.
Advantages: Self-healing communication
Reliable data transfer Scalable architecture
Used in smart metering and distribution automation
(b) Resilient and Self-Healing Grid A self-healing grid can:
Detect faults automatically Isolate faulty sections
Restore supply without human intervention
Benefits: Reduced outage time
Improved reliability Enhanced grid resilience
(c) Role and Functions of GIS in Smart Grid
Role: Asset management
Network planning Fault location
Functions: Mapping of feeders and substations
Load analysis Maintenance planning
(d) Thin Film Solar Cells
Thin film solar cells are made by depositing thin layers of photovoltaic material on substrates.
Advantages: Lightweight
Low material usage Flexible applications
Disadvantages: Lower efficiency than crystalline cells
(e) Feeder Automation
Feeder automation uses sensors, controllers, and communication systems to automatically monitor and control distribution feeders.
Benefits: Faster fault isolation
Reduced power interruption Improved service reliability
(f) Role of Power Quality Audit in Smart Grid Power quality audit identifies:
Voltage sag/swells Harmonics
Power factor issues
It helps in improving efficiency, reducing losses, and ensuring reliable supply.
(g) Plug-in Hybrid Electric Vehicles (PHEV)
PHEVs use both internal combustion engine and electric motor.
Features: Can be charged from grid
Reduce fuel consumption Support vehicle-to-grid (V2G) concept
(h) Present Development & International Policies in Smart Grid
Adoption of smart meters Renewable energy integration
Demand response programs International policies promoting low-carbon and efficient grids
SECTION – C (Attempt Any Two)
(15 marks each)
Q3. Present Development in Smart Grid (Case Study – Outline)
Example case study: Smart metering implementation
Automated substations Integration of solar and wind energy
Demand response programs
Outcomes: Reduced losses
Improved reliability Better consumer participation
Q4. Protection & Control Issues in Micro-Grid
Major issues: Bidirectional power flow
Islanding detection Protection coordination
Voltage and frequency control
Solutions include adaptive protection schemes and intelligent relays.
Q5. Phase Measurement Unit (PMU)
PMU is a device that measures voltage, current, frequency, and phase angle in real time using GPS synchronization.
Applications: Wide Area Monitoring System (WAMS)
State estimation Stability analysis
Blackout prevention