THEORY EXAMINATION (SEM–VI) 2016-17 SMART ENERGY & DELIVERY SYSTEMS

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

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