Its about Low voltage direct current networks new technology being used in world wide for distribution system

2. Low Voltage Direct
Current Networks
Muhammad Rizwan khan- MEE181011

3. Smart Grid
 Electricity networks that can intelligently integrate the behavior
and actions of all users connected to it - generators, consumers
and those that do both – in order to efficiently deliver
sustainable, economic and secure electricity supplies.
 A smart grid employs innovative products and services together
with intelligent monitoring, control, communication, and self-
healing technologies

4. Background
Thomas Edison Inventor of DC
1879
Nikola Tesla Inventor of AC
The first distribution power
system to supply electricity to
customers in a district area
(Edison’s Pearl Street Station)
was introduced in 1882 as low
voltage direct current (LVDC)

5. High Voltage AC in Transmission and
Distribution
AC is Manageable economically for long
distances (transmission)
High Power Loses
5-20% of energy is lost as heat in
conversion
Additional cost of cooling systems
for the heat generated

6. Low Voltage Direct Current
Networks
LVDC Distribution System/Network
LVDC system consists of
• low-voltage DC at distribution side
• power electronic devices applied in the electricity distribution

7. IEC International Standards have defined two voltage
standards:
• Low voltage: 0 to 1500 V
• Extra low voltage: 0 to 120 V
Commonly used DC voltage for distribution is 750V
In d.c the voltage have constant polarity and in a.c. the voltage
changes in a sinusoidal shape

8. Fundamentals of technology
LVDC distribution is future smart distribution system due to its
high efficiency and reliability
Part of Smart grid
 Renewable energy in DC
 Power electronics convertors, Rectifiers
Inverter to convert DC to AC
boost converter
Buck converter

9. Advancement of electronics
devices in last decades
Mobile equipment, LED lighting,
IT equipment, data servers,
electric vehicles
semiconductor device
Evolution of DC motors
Aerospace industry’s

10. Advantages of LVDC
• Safe and reliable electric energy
• Constantly good-quality voltage supply for customers
• Easy-to-control connection point for small-scale generation units
and storages
• Ready-to-use platform for smart metering, demand management
and network control
• Low costs of constructing and operating the distribution network
• Effects of short-time faults in the MV grid are not experienced by
the customers

11. • Negligible interference with other
electronic devices
• Distributed generation and storage units
such as solar panels etc. can easily be
connected to DC grid with
synchronization
• Four times more power can be
distributed
• compatibility with environmentally
friendly electronic devices

12. Latest Developments
DC micro grids system
Decentralize the energy network
Integration of renewable energy sources
DC grid can sustain itself as an island grid

13.  The online grid monitoring can easily be perform by using ICT
system which consists of
• Networking devices
• Embedded PCs
• Communication interfaces
• Internet protocols

14. Protection
LVDC is more complex compared to the traditional
Against short circuit faults molded case circuit breakers can be
used over current relay protection and fuses
• short circuit in a positive pole and negative pole
• short circuit between positive and negative pole with and without
neutral connection
• earth fault in positive, neutral and negative conductor
current limiter
Negative voltages after fault situations can be protected with
reverse connected diode in front of customer-end inverter

15. In customer DC network short circuit,
circuit breakers and fuses are used
when inverter short circuit capability is
high
For ground fault protection Insulation
monitors are used

16. Applications over world wide
solar photovoltaic energy locally produced
LVDC distribution system is planned to be constructed in an
island of South Korea
PV in Cruise ships

17. Aerospace & Electronics, laboratories
• Flight Management Computers
• Radar Warning Systems
• Fuel Quantity Measurement System
• Weapon Interface Units
• Military Vehicle Display Systems
• Naval Vessel Command & Utility Systems
• High Power DC Regulated Aircraft Bus
• Pulsed Laser Systems

18. How to Implement this in
Pakistan
 we have to improve the infrastructure in order to implement
LVDC
DC smart grids for Rural Electrification is planed in Pakistan
Quaid-e-Azam Solar Park