The document discusses various types of energy storage systems and their uses and characteristics. It describes several types of energy storage including compressed air, pumped hydro, batteries, flywheels, and supercapacitors. It provides details on superconducting magnetic energy storage, battery energy storage systems such as lithium-ion and lead-acid, and operational challenges with batteries. The document also discusses compressed air energy storage, pumped hydro storage, and flywheel energy storage. It covers the use of geographical information systems and intelligent electronic devices in power distribution systems.

1. Energy Storage System

2. Storage systems: ITS Importance
 Previously energy storage systems were only used to provide power to switchgear
during cold start-up of the generating units.
 Now-a-days they are used to store energy available from renewable sources in
which there is no control on generation.
 By storing the energy from variable sources (PV and wind) the energy could be
used more efficiently whenever required.
 Storage applications can be used to mitigate the congestion pattern during peak
demand time.

3. Types of Energy storage
1. compressed air energy storage
2. pumped storage
3. super conducting magnetic energy storage
4. super capacitor
5. hydrogen
6. Flywheel
7. Battery

5. Super Conducting Magnetic Energy
Storage
 SMES is basically a type of magnetic energy storage by flowing of direct current in
a coil of superconducting material.
 The superconducting material is immersed in a liquid helium at a temperature as
low as 4.2 kelvin within a vacuum insulated cryostat chamber.
 SMES can be used as controllable current source whose magnitude and phase can
be changed within a cycle.
 SMES needs to be connected with some power electronic converter inverter
systems so that we can use this controllable current for a specific purpose

6. Battery Energy Storage System
 batteries are some of the special types of energy storage system with efficiencies almost very high
and it can respond to this load changes almost instantaneously. E.g. lead acid battery in the
advanced form can be used as a storage to provide power in a range of 10 megawatt for a duration
of 4 hours
 Batteries are quiet and nonpolluting.
 They can be installed near load centres.
 Their efficiencies are in the range of 85% and can respond to load changes within 20 ms.
 battery can be charged with electricity and it is discharged also in the form of electrical power, but
its storage is in chemical form.
 there are two types of battery; one is non rechargeable, another is rechargeable.

7. Secondary/Rechargeable Battery
 They are divided into two categories based on the operating temperature of the
electrolyte.
 Rechargeable lead-acid and nickel-cadmium batteries have been used widely by
utilities for small scale backup and load levelling, etc.

8. Improvement in Battery performance

9. Lithium-ion battery & Lead–Acid
Batteries
 lithium-ion battery has the greatest applications like a cell phone or a laptop
computer.
 They have the highest power density (110–140 Wh/kg) of all batteries on the
commercial market on a per-unit-of volume basis.
 lead–acid batteries have the lowest cost of all battery technologies.
 Even though the lead–acid battery is relatively inexpensive, it is very heavy, with a
limited usable energy by weight.

10. Operational problems with battery usage
 The storage battery must be at discharge state in the morning to prepare for charging around
noon.
 If the lead-acid battery is left in a discharge state, it may deteriorate and shorten the life time.
 The frequency of use of the storage batteries may be varied by the impedance of the distribution
line and by a power flow condition.
 There are round-trip energy losses of the storage battery and power conditioning system increases
when charging and discharging larger amounts of energy.

11. Compressed Air Energy Storage
 It involves the storage of compressed air in disused underground cavities.
 An underground storage complex can be created using a network of large diameter pipes. Later,
the compressed air can be released as part of the generation cycle, providing a cycle efficiency of
approximately 75%.
 A modern CAES is a peaking gas turbine power plant that consumes less than 40% of the gas used
in a combined-cycle gas turbine (and less than 60% gas is used by a single-cycle gas turbine) to
produce the same amount of electric output power.

12. Super Capacitor/Ultra Capacitor
 Ultra capacitors can be used wherever a large amount of power is required for a short period of
time.
 These are double layer capacitors that offer significantly high energy density, meaning they are
able to hold hundreds of times more electrical charge compared to standard capacitors.
 SC/UC consist of a pair of metal foil electrodes, each of which has an activated carbon material
deposed on one side. These sides are separated by a proper membrane and then rolled into a
package.
 Compared to similar size batteries, ultra capacitors have higher power density, quick
charge/discharge rate and a longer lifecycle.
 Unlike standard capacitors, ultra capacitors have an electrolyte between the plates rather than a
dielectric, meaning they store energy in an electric field rather than in a chemical reaction. Unlike
batteries, they are resilient to high temperatures and charge much faster than batteries.

13. Pumped Storage Hydro plant
• The basic structure of a conventional PHS system
consists of two water reservoirs which are built at
different elevations.
• During off peak time,the water is pumped from the
lower to the upper reservoir, a process described as
‘‘charging.’’
• The process is reversed, when it is required, by
allowing the water to flow back from the upper to the
lower reservoir.
• The flow of water is used to power a turbine with a
generator to produce electricity, which is described as
‘‘discharging.’’
• PHS power plants represent approximately 99% of
world wide installed electrical storage capacity, which
is almost 3% of global generation capacity.

14. Flywheel energy storage
 Flywheel energy storage systems (FESS) use electric energy input which is stored in the form
of kinetic energy. Kinetic energy can be described as “energy of motion,” in this case the motion of
a spinning mass, called a rotor.
 When short-term backup power is required because utility power fluctuates or is lost, the inertia
allows the rotor to continue spinning and the resulting kinetic energy is converted to electricity.

15. Geographical Information System
 Towards the improvement of the Power Distribution System, distribution companies had faced lots
of problems with inadequate data of asset facilities and customer information. This is one area
where GIS (Geographical Information System) come into play with Smart Grid.
 GIS is a framework for gathering, managing and analyzing data to make smarter decisions. GIS
provides a link between utility assets and customers information.
 GIS (Geographic Information Systems), an enterprise system to convert data into digital information
for better decision making with the help of maps. This involves creation of spatial data, building
networks and sharing them with the public as this will give people to directly access the current
situations and the progress being made by the companies.
 The invention and adoptability of Smart Grid in larger cities ensures that customers and the utility
company have transparency in the information being shared. This demanded better decision-
making system and GIS was able to fit to the role to perfection.
 All assets in the utility network has spatial component attached to it, be it, power generation plants,
transmission units, customer locations etc. and GIS can help us in displaying this spatial information
and performing various spatial analysis to better understand the problem at hand.

16. GIS consists of several layers of information (fig.1)
and overlaying them on top of each other based
on its spatial entity makes it more powerful in
decision making systems. There are 2 types of
information layers –Raster and Vector. Raster
data is generally represented in the form of
imagery and can be used to show land use
patterns or elevation data. There are 3 types of
vector data – Points, Lines and Polygons. They are
classified based on the geometry
information they can hold and all features in the
real world would fall into one of these categories.

17.  GIS adds spatial dimension to decision-making, so utilities know where customers are
adding solar panels, what areas of network are at high risk and how to prioritize
replacement of assets. GIS doesn’t provide additional power that a region demands, but
rather it would help us answer questions like which county in the state provides largest
amount of solar power and we could better solve power transmission problems based on
answers we have obtained.

18. Intelligent Electronic Devices (IED)
 The name Intelligent Electronic Device (IED) describes a range of devices that perform one or
more of functions of protection, measurement, fault recording and control. An IED consists of
a signal processing unit, a microprocessor with input and output devices, and a
communication interface. An intelligent electronic device (IED) is a device that is added to
industrial control systems (ICS) to enable advanced power automation.
 IED configuration consist of
 ➢ Analog/Digital Input from Power Equipment and Sensors
 ➢ Analog to Digital Convertor (ADC)/Digital to Analog Converter (DAC)
 ➢ Digital Signal Processing Unit (DSP)
 ➢ Flex-logic unit
 ➢ Virtual Input/ Output
 ➢ Internal RAM/ROM
 ➢ Display

19.  In the electric power industry, an intelligent electronic device (IED) is an integrated
microprocessor-based controller of power system equipment, such as circuit breakers,
transformers and capacitor banks.
 IEDs receive data from sensors and power equipment and can issue control commands, such
as tripping circuit breakers if they sense voltage, current, or frequency anomalies, or
raise/lower tap positions in order to maintain the desired voltage level.
 IEDs are used as a more modern alternative to, or a complement of, setup with traditional
remote terminal units (RTUs). Unlike the RTUs, IEDs are integrated with the devices they
control and offer a standardized set of measuring and control points that is easier to
configure and require less wiring.
 Most IEDs have a communication port and built-in support for standard communication
protocols (DNP3, IEC104 or IEC61850), so they can communicate directly with the SCADA
system or a substation programmable logic controller. Alternatively, they can be connected to
a substation RTU that acts as a gateway towards the SCADA server.
 Intelligent electronic devices (IEDs) are Microprocessor-Based devices with the capability to
exchange data and control signals with another device (IED, Electronic Meter, Controller,
SCADA, etc.) over a communications link. IEDs perform Protection, Monitoring, Control, and
Data Acquisition functions in Generating Stations, Substations, and Along Feeders and are
critical to the operations of the electric network.

20.  IEDs are widely used in substations for different purposes. In some cases, they are
separately used to achieve individual functions, such as Differential Protection, Distance
Protection, Over- current Protection, Metering, and Monitoring. There are also
Multifunctional IEDs that can perform several Protection, Monitoring, Control, and User
Interfacing functions on one hardware platform.
 IEDs receive measurements and status information from substation equipment and pass it
into the Process Bus of the Local SCADA. The substation systems are connected to the
Control Centre where the SCADA master is located and the information is passed to the
EMS Applications.
 IEDs are a key component of substation integration and automation technology. Substation
integration involves integrating protection, control, and data acquisition functions into a
minimal number of platforms to reduce capital and operating costs, reduce panel and
control room space, and eliminate redundant equipment and databases.
 IED technology can help utilities improve reliability, gain operational efficiencies, and
enable asset management programs including predictive maintenance, life extensions, and
improved planning.

21. Protection, Monitoring, and Control Devices (IED)
 Intelligent electronic devices (IEDs) are microprocessor-based devices with the capability to
exchange data and control signals with another device (IED, electronic meter, controller,
SCADA, etc.) over a communications link. IEDs perform protection, monitoring, control, and
data acquisition functions in generating stations, substations, and along feeders and are critical to
the operations of the electric network.
 IEDs are widely used in substations for different purposes. In some cases, they are separately
used to achieve individual functions, such as differential protection, distance protection, over
current protection, metering, and monitoring. There are also multifunctional IEDs that can
perform several protection, monitoring, control, and user interfacing functions on one hardware
platform.
 The main advantages of multifunctional IEDs are that they are fully IEC 61850 compatible and
compact in size and that they combine various functions in one design, allowing for a reduction
in size of the overall systems and an increase in efficiency and improvement in robustness and
providing extensible solutions based on mainstream communications technology.
 IED technology can help utilities improve reliability, gain operational efficiencies, and enable
asset management programs including predictive maintenance, life extensions, and improved
planning.