Final talk trident-05-10-2021- dr p k rout-converted
1. Challenges in Smart Grid
Prof. (Dr.) Pravat Kumar Rout
EEE Department, SOA (Deemed to be) University
1
2. China power cuts: What is causing the country's blackouts?
The country has in the past struggled to balance electricity
supplies with demand, which has often left many of China's
provinces at risk of power outages.
During times of peak power consumption in the summer
and winter the problem becomes particularly acute.
As the world starts to reopen after the pandemic, demand
for Chinese goods is surging and the factories making them
need a lot more power.
Rules imposed by Beijing as it attempts to make the country
carbon neutral by 2060 have seen coal production slow,
even as the country still relies on coal for more than half of
its power.
And as electricity demand has risen, the price of coal has
been pushed up.
But with the government strictly controlling electricity prices,
coal-fired power plants are unwilling to operate at a loss,
with many drastically reducing their output instead.
2
China still relies on coal for
more than half of its power
3. 2012 Indian Blackouts
Two severe power blackouts affected most of
northern and eastern India on 30 and 31 July
2012.
It affected a total of 700 million people across
20 Indian states. Overdrawing of electricity by
certain states and weak inter-regional power
transmission corridors were cited as the
reasons behind the blackout.
3
4. Maharashtra cyber cell submits report on
Mumbai power outage, confirms
malware attack hit power grid in October
12 2020
Ukraine power 'hack attacks' explained: US
investigators have accused Russia-based hackers
of being behind an attack that caused blackouts
across Ukraine in December 2020.
Cyber attack on Critical Infrastructure: Russia and
the Ukrainian Power Grid Attacks
4
Blackout in
Mumbai by cyber
attach
Cyber Attach to Power Grids
5. Electric/ Power Grid
A network of electrical transmission lines
connecting a multiplicity of generating
stations to loads over a wide area. In other
words electrical grid or power grid is defined
as the network which interconnects the
generation, transmission and distribution unit.
Type:
✓ Regional Grid – The Regional grid is
formed by interconnecting the different
transmission system of a particular area
through the transmission line.
✓ National Grid – It is formed by
interconnecting the different regional
grid.
5
7. Indian Power Scenario
India is the world's third largest producer and third largest consumer of electricity.
The national electric grid in India has an installed capacity of 388.134 GW as of 31
August 2021.
Renewable power plants, which also include large hydroelectric plants, constitute
37% of India's total installed capacity.
Share of renewable energy: 21.26%
The break up of renewable energy sources is: Solar power (36,910.53 MW), Wind
power (38,433.55 MW), Biomass (10,145.92 MW), Small hydro (4,740.47 MW), and
Waste-to-energy (168.64 MW)
Share of fossil energy: 75.38%
7
8. Renewable Energy Production in India and
Future Challenges
Renewable energy sources have a
combined installed capacity of 96+ GW.
As of 31 June 2021, the total installed
capacity for Renewable is 96.95 GW
The following is the break up of total
installed capacity for Renewable, as of 31
May 2021:
Wind power: 39.44 GW
Solar Power: 41.09 GW
Bio-Power: 10.34 GW
Small Hydro Power: 4.79 GW
8
9. Factors need to focus for improvement to
Traditional Grid System
Generation
Transmission
Distribution
Load/Consumer
9
Pollution
Dependency on conventional energy sources
Enhancing the controllability
Enhancing protection
Enhancing energy management and utilization
Quality power
Enhancing reliability and secure
Cost-effectiveness
Overall efficiency
12. What is Smart grid?
Smarter
Generation
Transmission
Distribution
Customer participation
Operations
Markets
Service Providers
Overall Objective
Smart/best/optimal utilization of all
the available resources
12
13. Major Factors for the Transition to Smart Grid?
Advanced power
electronics and sensor
devices
Computation
and
Information
Technology
Communication
Technology
13 IEEE:
✓ Smart grid is a large ‘System of Systems’, where
each functional domain consists of three layers: (i)
the power and energy layer, (ii) the communication
layer, and (iii) the IT/computer layer.
✓ Layers (ii) and (iii) above are the enabling
infrastructure that makes the existing power and
energy infrastructure ‘smarter’.
17. Major changes for the transition to micro-grid
17
✓Distribution Generation
✓Energy Storage Devices
✓Load
✓Electric Vehicle Charging Stations
IEEE
✓A micro-grid is a group of interconnected loads
and distributed energy resources within clearly
defined electrical boundaries that acts as a single
controllable entity with respect to the grid
✓A micro-grid can connect and disconnect from
the grid to enable it to operate in both grid-
connected or island mode.
22. 22
AC Micro-grid Configuration
✓AC to DC converter, or 'rectifier'
✓DC to AC converter, or 'inverter'
✓AC to AC frequency converter,
or 'transformer'
✓DC to DC voltage, or 'current
converter'
23. ➢ Short-circuit current (SCC) level
➢ False tripping
➢ Blindness of protection
➢ Prohibition of automatic reclosing
➢ Unsynchronized reclosing
➢ Reach of an impedance relay
➢ Bi-directional power flow
➢ Sympathetic Tripping
➢ Single phase power insertion
➢ Power variation and equipment rating
➢ Standardization
Protectional Challenges in AC Microgrid
23
24. 1: Short-circuit current Level
24
Fault current in an integrated mode of
operation
✓There is a sustainable difference in the SCC
level in both grid-connected and islanded
modes of operation.
✓This is because in the grid-connected mode of
operation, the fault current is contributed by
both utility grid as well as DGs that is shown in
figure.
✓However, in the islanded mode of operation,
the fault current is contributed by DGs only.
25. 2: False Tripping of Feeder
25
Direction of current in an false tripping
scenario
✓It generally occurs within the substation, if the
fault current of a feeder is assisted by the fault
current generated from a DG of a neighboring
feeder as depicted in figure.
✓Here, the protection scheme of the neighboring
feeder might work to isolate the circuit.
✓This is called false tripping or spurious
separation or unnecessary outage of feeder.
26. 3: Blindness of protection
26
✓ Feeder impedance increases with DG connection to
the network and thus the fault current limit is reduced as the
current level regulates by the impedance of the circuit.
✓ This further adversely affects the relay performance as
it decreases the operational zone of operation.
✓ These issues with the presence of DGs in a microgrid to
the variation of OCR (overcurrent relay) operating zone
with respect to feeder impedance change is known as the
blindness of protection.
Blindness of Protection
27. 4: Prohibition of automatic reclosing
27
Micro-grid system with automatic
recloser configuration
✓For the recloser operation, particularly in a radial distribution
system to clear the transient fault, the downstream part of the
recloser is disconnected.
✓In a DG integrated system, both DG and network supply
towards fault current.
✓ The network must be disconnected by the recloser as per
figure shown under fault conditions. However, the DG is still
there to provide the fault current.
✓ This leads to a recloser defect and it may convert transient
fault into a permanent fault. This is known as the prohibition of
automatic reclosing.
***Perhaps the most significant difference between a recloser and a breaker is that the recloser was
designed as a selfcontrolled device. Standards have been established and capabilities determined
within the characteristics of the integral control scheme of the recloser.
Affects to the operation of
✓Relay
✓ Circuit breakers
✓ Re-closer
✓ Isolators
✓Sectionalizes
28. 5: Unsynchronized reclosing
28
Closer arrangement to avoid
unsynchronized reclosing
✓A closer is inserted between the two energized
systems during DG connection to a network as
depicted in figure.
✓The serious damage may occur to the DGs as
well as accompanied sensitive equipment due to
the connection without considering
synchronism e.g. unsynchronized reclosing.
29. 6: Reach of an impedance relay
29
✓The distance measured between the fault point and
the location of the relay is the major factor upon which
the reach of impedance relay depends.
✓The maximum distance means the range in which
minimum fault current is detected when the DG is
according to the define zone settings.
***The distance relay is also referred to as the impedance relay or distance protection element or voltage-
controlled device. It's working mainly depends on the distance between the impedances of the points where
the fault occurs and where the relay is installed (feeding point).
30. 7: Bi-directional Power Flow
30
✓The bi-directional power flow in feeders of a
micro-grid is one of the major challenges in case
of DGs integrated micro-grid.
✓ There is a possibility of power flows in the
reverse direction as power flows from both the
sources towards the load.
✓In a distribution system with a fixed generation
limit, when local generation level surpasses local
consumption level, there is a change in the
direction of power flow.
***Transformers are bidirectional devices, transformers don't know nor care which way power flows
through them. Transformer can pass real power from primary to secondary while simultaneously
passing reactive power from secondary to primary. Transformers are bidirectional.
31. 8: Sympathetic Tripping
31
✓ Sympathetic tripping occurs when the protective
device activates in the external protective zone during
the occurrence of faults assisted by the DGs.
✓ Two relays are operating in the system one after
another as illustrated in Figure.
32. 9: Other Challenges
Single phase power insertion
Power variation and equipment rating
Standardization
32
Major Microgrid technical areas for standardization
34. 34 Microgrid Protection Scheme
Conventional Scheme
Signal and Mathematical based
Scheme
Data based and Intelligent
Scheme
Adaptive
protection
Distance
protection
Differential
protection
Voltage
based
protection
Overcurrent
based
protection
Symmetrical or
sequential based
protection
Communication
based protection
Pattern
recognition
based
protection
S-
transform
HHT
FFT
Mathematical
morphology
based
protection
Multi-agent
based
protection
Storage
devices
and
breakers
Artificial
intelligence
based
protection
· Efficiency in grid-connected and islanded mode
· Adaptability to change of rating
· Inter-operability
· Handling balanced and unbalanced condition
· Reaction to fault current level
· Effectiveness in primary and backup protection
· Power flow and communication system
· Signal property retrieval methodology
· Complexity in component wise analysis
· Suitability of method as per non-linearity
· Harmonics and filter properties for problem
formulation
· Detection speed and accuracy considering all
fault types
· Accumulation and normalization of
data
· No. of random variables and agents
· Optimization of parameters and
accuracy
· Case of integration with other
methods
· Better synchronization with grid
condition and parameters
Features
Features
Features
AC micro-grid protection schemes
36. ➢ Fault current nature and direction
➢ Difficult to co-ordinate between over-current relays
➢ Non-Suitability of AC circuit breaker
➢ Change in short circuit level
➢ Grounding
➢ Non Zero Crossing
➢ High Sensitivity of inverters to fault currents
➢ Connection and configuration between standalone and integrated
micro-grid
Challenges in DC Micro-grid protection
36
37. 37
1: Fault current nature and direction
The nature of the fault current analysis is crucial
to design a protective scheme. There are two
types of faults associated with the DC micro-grid
system as:
• Pole to Pole (PP) fault, which is in the low
impedance category.
• Pole to Ground (PG) fault, which is in the high
impedance category.
38. 2: Difficult to co-ordinate between over-current relays
relays
38
✓Coordination of current-based relays in the DC
microgrid is a challenge to achieve and plays a
vital role in designing a reliable and safety
protection scheme.
✓This issue primarily arises due to the reduced
value of line resistance and a faster rate of
rising of the fault currents to its peak value
39. 3: Non-suitability of AC CBs
✓In distribution systems, ACCBs are used as a fault current interrupter
based on cross zero-point concepts in every half cycle and it has the
capability of clearing the fault in less than 10 milliseconds.
✓However, it fails to implement in DC microgrid due to the lack of a
zero-crossing point in DC fault currents.
✓Secondly, the DC microgrid needs a faster fault current interrupter
than the AC microgrid for the safety of voltage source converters
(VSCs)
39
40. 4: Change in short circuit level
40
✓In DC microgrid systems, the fault currents are restricted by the
converters and are normally lesser than the threshold value.
✓On the contrary, the short-circuit level and direction are also
affected by the different operational modes of DC micro-grids.
✓In the islanded mode of operation, the fault current is 5 times
greater than the threshold value, as DERs only contribute to it.
✓Whereas in the grid-connected mode of operation, both grid and
DERs contribute towards the fault current and so that it rises to 20-50
times more than the threshold value.
41. 5: Grounding
41
✓Grounding plays a very crucial role in DC microgrid to facilitate fault detection, to minimize leakage
currents, and to reduce common-mode voltage for personal safety.
✓Different types of fault characteristics give rise to different types of grounding and that affects the
relay setting and protection configuration.
✓At present TN, TT, and IT are the three types of grounding systems that are extensively used in the DC
microgrid system as depicted in figure.
43. 6: High sensitivity of the Inverter to fault current
43
✓The inverters within the microgrid have low current
capacity in comparison to the system fault current.
✓This issue is at an alarming condition under the grid-
connected mode of operation than in the islanded mode of
operation as the fault current level is low in this case.
✓This affects the sensitivity and coordination of current-
based relays which in turn may cause delays in the relay
operations.
44. 7: Non-zero crossing point
44
✓The CBs designed for the AC microgrid system
fail to implement in DC microgrid due to the
absence of a zero-crossing point at every half-
period.
✓The absence of the natural technique of
extinguishing an arc put forth this as a
challenging issue and need any additional
method to make the DC be zero.
45. 8: Connection and configuration between standalone
and integrated micro-grid
45
✓DC micro-grid provides a good energy option
for unreachable areas in standalone mode. The
converter calibration and controlling low
voltage ratings for the devices are the main
area of concern.
✓The uninterrupted supply in an integrated grid
can be achieved by altering different topologies.
✓The different topologies need more careful
consideration to protect the DC microgrid. In the
absence of other sources, power optimization
and utilization are another concern in the case
of standalone DC micro-grid.
48. 48 The existing protection schemes of the micro-grid should be designed and planned with
new approaches to get the new features like high reliability and security
The integration of DGs, ESS changes the characteristics of the overall system like
bidirectional power flow, low inertia system, and variable impedance, etc.
The short circuit current level changes drastically with a wide range from the grid-connected
to the islanded mode of operation.
The communication infrastructure are based upon two factors such as local information
without the communication and wide-area measurement with communication. However,
the combination of these two things affects micro-grid protection.
The time delay related to communication links plays a vital role in micro-grid digital
protection design.
The method of analyzing the distorted signal data and detect the fault on-time are another
major key factors in micro-grid protection.
Relay type and coordination of relays affect the complete planning of the protection
scheme in a micro-grid.
Challenges
towards the
protection of
Hybrid micro-grid
49. 49
HYBRID
MICROGRID
INTEGRATION
WITH AC
SUBGRID
INTEGRATION
WITH DC
SUBGRID
1. Short-circuit level
2.False tripping of feeder
3.Blindness of protection
4.Prohibition of automatic
reclosing
5.Unsynchronized reclosing
6.Reach of an impedance relay
7.Bi-directional power flow
8.Sympathetic tripping
9. Single phase power insertion
Challenges
Challenges
1.Fault current direction
2.Difficulties in the coordination
of current-based relay
3.Non-suitability of AC circuit
breakers
4.Change in short-circuit level
5.Grounding
6.The high sensitivity of
inverters to fault current
7.Non-zero crossing point
Protection strategies
Adaptive protection strategy
Distance protection strategy
Pattern Recognition based protection strategy
Harmonic-content based protection strategy
Wavelet Transform based protection strategy
Travelling wave-based protection strategy
Multiagent based protection strategy
Protection strategies
ANN-based protection strategy
Reconfigurable grounding systems
DC current interruption approaches
50. 50
Protection challenges in smart transmission system
Technology Development Quality Power to All
Households
Reduction of Transmission
and Distribution Loss
Interoperability and Cyber
Security
Consumer Support
It is necessary to create a
new communication
infrastructure which is
resilient from attack and
highly reliable. Advanced
components like smart
appliances, smart
meters, efficient energy
storage devices, high
voltage DC transmission
devices, flexible AC
transmission system
(FACTS) devices etc. are
to be developed and
implemented.
A vast growth of power
system network is needed
for the next several years
for supply energy to all
households in a reliable
manner. The quality of
supply is also to be
ensured to fulfil smart grid
vision. The existing grid is
to be renovated and
expanded to ensure
quality supply to all
households.
The T&D loss are to be
reduced to world
standards. The main
factors which affect the
T&D loss are technical
losses due to weak grid
and financial losses like
theft and collection
efficiency reduction. The
utilities should have to
address these issues
seriously.
The interoperability and
cyber security can be
achieved only through
rigorous implementation
of various standards. The
interoperability standards
includes advanced
metering infrastructure
(AMI),, phasor
measurement unit
(PMU) communications,
physical and electrical
interconnections between
utility and distributed
generation (DG), security
for intelligent electronic
devices (IEDs),
One of the main
challenges in the smart
grid implementation is
lack of consumer
awareness about the issues
in the power sector.
Consumer support is a
must for implementation
of smart grid to reduce
peak load consumption
and promote distributed
renewable energy
generation. The smart
grid implementation will
improve quality and
reliability of power
supply.
India's T&D losses have been over 20 per cent of generation,
which is more than twice the world average.
51. 51
Protection challenges in smart generation system
➢ The fluctuating and unpredictable nature of renewable energy sources like solar
photovoltaic and wind mill require complex technologies to integrate with
existing smart grid.
➢ The harmonics developed from the complex power electronics circuits used for
integration also make many troubles in the power system.
➢ Other draw-back of renewable energy generation is requirement of large land
area.
➢ The reliability of protection circuits to isolate it from the existing grid whenever
required is a great challenge in the integration of renewable energy sources.
➢ Lack of technically skilled man power and wrong selection of optimal place for
implementation will also affect the renewable energy integration
53. Microgrid Control
Integrated control strategies refer to hierarchical
structures which usually consist of primary, secondary,
and tertiary control .
The primary control stabilizes the voltage and frequency
and offers plug-and-play capability for DGs.
The secondary control, as a centralized controller,
compensates for the voltage and frequency deviations
to enhance the power quality.
Tertiary control considers the optimal power flowing of
the whole micro-grids or interaction with main grid . In
addition, hierarchical control has other special functions:
1) distributed intelligent management system ; 2)
voltage unbalance compensation for optimal power
quality ; 3) self-healing networks ; 4) smart home with a
cost-effective energy ecosystem; and 5) generation
scheduling.
So, the hierarchical structure of micro-grids can be
regarded as an intelligent, integrated, and multi-agent
system. Power sharing comes under primary control.
53
54. Challenges from control prospective
Two operating mode of operation: Grid connected and Islanding
Topological changes in network
Execution of microgrid control hierarchy in both the modes of operation
Intermittence in the generation of several micro-sources
Generation system undergoing a power flow bidirectional
Balanced generation and loading in a microgrid
Low Inertia system
Non-linear and complex dynamics
Frequency and voltage control , Reactive power management
Communication , Wide area control challenges
Sub-synchronous resonance
Control issues specific to various DGs
54
55. Two operating mode of operation: Grid connected and Islanding
55
ISLANDED MICROGRID GRID-CONNECTED MICROGRID
Microgrid’s Central Controller (MGCC)
✓Power deficit
✓Frequency deviation
✓Voltage deviation
✓ Load shedding
✓ Instability issues
✓Grid Synchronization
56. Topological changes in network
56
1.Physical – The physical network topology refers to
the actual connections (wires, cables, etc.) of how the
network is arranged. Setup, maintenance, and
provisioning tasks require insight into the physical
network.
2.Logical – The logical network topology is a higher-
level idea of how the network is set up, including which
nodes connect to each other and in which ways, as well
as how data is transmitted through the network. Logical
network topology includes any virtual and cloud
resources.
What is a network?
✓ Reconfiguration
✓ Placement of switches and isolators
✓ Protection issues
✓ Load balancing
57. Execution of microgrid control hierarchy in both the modes of operation
57
Example:
✓All DGs operate on P/Q control
mode of operation during Grid
connected mode.
✓ Under islanded mode of operation
the master DG switched to U/f control
mode of operation.
✓ The slave DGs are under same P/Q
mode of operation.
Master Slave Control
58. 58
Peer to peer control
Example:
✓All DGs are same and nobody is
the master or slave
✓ Works under drop control mode
of operation
✓ Droop characteristics of all the
DGs are different
✓ Droop control allows to work
independently for all the DGs
✓Control characteristics are greatly
differ for all the types of DGs
Droop control characteristics
59. Intermittence in the generation of several micro-sources
59
✓Difficult to bring demand supply balance considering all uncertainties
✓Coordination control referring to distribution of DGs
✓Stability issues
60. Generation system undergoing a power flow bidirectional
60
✓ Bidirectional converter control (switching frequency regulation )
✓ Power balance control between the micro-grids (energy management)
✓ Distortion grid problem (harmonics, unbalanced load, switching transient of inverter, reactive power
compensation, voltage stability )
61. Balanced generation and loading in a microgrid
61
✓ Load shedding challenges
✓Load insertion challenges
✓ Resynchronization issues
✓ Balance power supply to
load
62. Low Inertia system
In a traditional power system, most of the power
generates from sources like coal, nuclear, hydroelectric
power. The common element utilized in those power
plants is the synchronous generator (SG), shown in Fig.
(a). The kinetic energy stored in the rotating parts of the
SG is a vital property for frequency dynamics and
stability.
A traditional power system can contribute inertia to the
power system. Inertia helps to limit the ROCOF
following a contingency event.
In a future power system, both RES and loads are
integrated into the grid through power electronic
converters, as shown in Fig. 3(b). Hence, the inertia of
the future power system is reduced as compared with
the traditional system.
62
ROCOF: Rate of change of Frequency
✓ frequency variation
✓ losses
✓ low damping capacity to oscillation
63. Non-linear and complex dynamics
63
✓ Control is difficult
✓ Traditional PI
controller cannot
provide robust control
✓ Nonlinear and robust
control techniques can
enhance the
performance
✓ Coordinated and
communication based
control strategy may be
more fruitful
64. Frequency and voltage control, Reactive power management
64
✓ Many of the RES are not
generating reactive power
✓ In autonomous mode of
operation it is difficult to maintain
power balance that leads to
frequency and voltage control
✓ Deal with intermittent
generation is difficult
65. Communication , Wide area control challenges
65
• Central approach: In this strategy, a central controller is used
to regulate all the DG units. The controller computes the actual
load current demand and transfers this to the DG units and
also transfers the error voltages to all the involved units.
• Master/slave approach: In this strategy, the master module is
used to regulate the voltage control and transfer the reference
current to the slave module.
• Instantaneous current transfer approach: In this strategy, the
reference voltage and current signals are transmitted between
the DG modules.
✓ Security
✓ Reliability
✓ Energy management
✓Load management
66. Sub-synchronous resonance
66
✓System Modeling for Analyzing Sub-synchronous
Resonance (SSR) ... SSR is a state in which the power
system exchanges the energy with the generator
turbine at one or more frequencies below the
synchronous one where the synchronous frequency is
defined as the one corresponding to the rotor average
speed.
✓ During SSR, electrical energy is exchanged between
generators and transmission systems below power
frequency. It happens due to interaction of a series
compensated transmission line with a generator.
✓It results in oscillation in the shaft and power
oscillation.
Sub-synchronous resonance in Wind Farms
67. Control issues related to wind
Wind generation is less predictable as compared
to the solar system . The wind turbine is placed in
an isolated and remote area from the main grid.
This increases the economic cost and transmission
losses.
If the voltage loss is not calculated properly, the
load voltage would be low.
The motion of the wind is not constant over the
day or season. The wind blows strongly at night
and in the winter. When the production is excess
than the demand, the current flow in the opposite
direction which reduces the protection of the
loads. (MPPT control, pitch control, stall control)
To solve these problems, an extra
control is required to step down the
voltage.
Capacitor banks are used which store
the electric power and inject the
reactive power into the main grid.
The load current is decreased which
increases the load voltage.
Any variation of the wind produces
fluctuation of the voltage. This
fluctuation can not be solved by the
capacitor bank alone. It is replaced by
a static var compensator (SVR)
67
68. Control issues related to Solar
The production of electricity from the
solar becomes un-predictable with
the presence of the cloud on the
solar panel.
Due to the cloud, enough light can
not fall on the solar panel, which
reduces the production of the
electricity.
Rain is the other drawback for the
production of the electricity from the
solar system.
Again the generation of electricity is
correlated with the daily condition,
seasonal condition and the
characteristics of the area.
These uncertainties and variability of the
solar system produce a challenge to control
the main grid and requires an additional
technique to control the system. (MPPT
control, ESS coordination)
Again little adaptation is required for
installing a small solar PV. But with the
increasing of solar panel, the adaptation
increases and thus, increases the cost and
complexity.
Distributed solar plants do not provide real-
time generation data which make the
operation complex.
Voltage oscillation has an impact on the
solar generation due to lack of reactive
power generation.
68
69. Control issues in renewable energy resources
integration: In general
The microgrid generally very nonlinear in
nature due to the nonlinear dynamics of the
various distributed generations (DGs) and
unknown behavior of loads.
As many DGs are integrated with the micro-
grid having different characteristics, the
coordination control with mutual influence
is difficult.
To improve the fault ride through condition,
the energy storage devices have to be
controlled along with DGs. This leads to
develop a complex control strategy.
The reactive power support regulation
is another factor in micro-grid with DGs
not producing the reactive power.
Power quality issues are to be
emphasized more, as the harmonic
injection level is high due to many
reasons form power electronics
devices and nonlinear loads
particularly.
Topological changes makes difficult to
formulate a control strategy to cope
with the system changes.
69
71. Challenges from Demand Side Management
71
DSM is rightly defined as the planning,
implementation, and monitoring of utility
activities that are planned to
consumer/customer use of electricity in a
way that will produce desired changes in
the time pattern and magnitude of load
shape.
72. History of DSM and its evolution
72
After 2020: DSM developing further through IoT, Big data, Game theory, hybrid optimization techniques, etc.
2010-2020: DSM developed through various optimization techniques, machine learning, etc.
2000-2010: Developed market driven DSM or Demand Response schemes
1990-2000: Network based DSM starts progressing using concepts of BEMS, HEMS
1985-1990: Environment driven DSM developed
1984: Clark Gellings introduces the DSM technique
1970: Initiation of Load Management at Distribution levels and Consumer end
73. 73 DSM in a smart grid ecosystem
Major component of DSM
74. Strategies used in DSM
74
DSM strategies that can be employed are generally categorized into:
Energy efficiency: Focused on the permanent improvement of load
consumption by reduction of the load profile at the device level
through energy efficiency enhancement measures.
Time of use: Division of fixed pricing from the utility, into a 24 hourly
time-period basis of several time intervals and allocation of dynamic
pricing at each time period.
Spinning reserve: The backup power available to the electric grid
system that can be put into effect for balancing discrepancy or
shortfalls between consumption and generation.
Demand response: Deviations in load consumption by end-user side
consumers from their standard usage patterns in response to the
change in unit tariffs, or on the basis of incentivized programs.
75. Residential Demand Side Management (RDSM)
DSM can be implemented at residential as well as commercial establishments in a
manner very similar to each other. Since residential loads are much more flexible
than commercial loads, they can implement DSM techniques in a much more
flexible way.
The DSM activity can be classified into a two-level process:
Level I:– Load shape modification
Level II:– End-user side modifications, alternative technological implementation,
and market implementation techniques
75
76. Load curve modification
The process of load shape modification can be implemented in several ways, where
the prime objectives are the minimization of peak curves and electricity unit tariffs:
76
78. RDSM implementation challenges
Renewable energy integration
Energy consumption profile of
the smart devices
Operation and parametric
constraints
Central and distributed
management of RDMS
EV Integration
Load categorization
78
79. Energy consumption of household appliances
79 Household Appliances Type of load Energy (in KWh)
(Power*Total running time in
hours)
Power (in KW)
Air Conditioner Regulatable 8 2
Air Purifier
Shiftable,
Reschedulable
0.6 0.1
Computer (Monitor
& Printer)
Fixed 1 0.25
Dishwasher Schedulable 3 1.33
Electric Hairdryer Fixed 1 2
Electric iron Fixed 1 2
EV Charger Reschedulable 32 4
Exhaust Fan
Shiftable,
Controllable
0.2 0.1
Fan Fixed 0.8 0.1
Food Blender Fixed 0.2 0.4
Induction Cooker Fixed 2 2
LED Lights Fixed 0.4 0.08
Microwave Fixed 0.75 1.5
Refrigerator Fixed 1.8 0.3
Room heater Regulatable 6 2
Television Fixed 0.6 0.2
Washing Machine Shiftable 1.2 0.6
Water Heater Curtailable 2.5 2.5
Water Pump Reschedulable 1.5 1.5
80. EV integration challenges
EV battery degradation due to energy throughput,
depth of discharge(DoD), and overheating
Uncoordinated EV charging among clusters of
consumers.
Higher cost of ownership as compared to ICE
vehicles
Transformer overloading and thermal overloading of
grid conductors
Higher penetration of current harmonics
Energy conversion losses due to charge/discharge at
high rates
No implementation of dynamic pricing available to
reduce peak load curves
80
81. Control challenges for DSM Implementation
Implementation of centralized controllers for both
the control decision and control activities to
achieve Direct Load Controls (DLCs), interruptible
tariffs, demand-bidding programs
Provision of a generalized DSM method to the
customers with greater control over their energy
consumption needs to be implemented.
The lack of enabling technologies, unavailability
of smart meters capable of two-way
communication, diversified consumer behaviour,
and the monopolism by the investor-owned
utility(IOU) holds back the DR implementation in a
widespread manner.
81
82. Renewable energy integration challenges
Lack of system scalability to overcome the multi-vendor problem, system
upgrade, and system expansion.
Integration of volatile power sources like wind and solar influence present
challenges to stable grid operation.
Proper billing tariffs according to the periods of peak usage need to be
implemented to reduce overdependence on primary grid power and shift to
renewable energy sources.
Large scale implementation of PV and wind installations are still not the norm and
hesitation of consumers to become prosumers greatly limits the power injection
capability.
Islanding/Frequency matching
82
83. Operation and parametric constraints
Electrical demand/supply balance
Temperature constraints
Battery energy storage SoC and depth of discharge(DoD) constraints
Grid operation power limits
User comfort restrictions
Appliance prioritization
Appliance operating time/period
Energy consumption of individual appliance
83
84. Other challenges in DSM integration
Lack of a coordinated and efficient Information and communication technology (ICT)
architecture.
Competitiveness of robust traditional approaches as compared to DSM based
solutions.
Inappropriate market structure
lack of proper incentive programs.
84
85. DSM optimization Challenges
In DSM implementation, the focus is :
▪ To optimize the DSM architecture and workflow to ensure maximum efficiency in
utilization of energy consumption at residential premises
▪ To ensure maximum benefits to the consumer and utility operators at the minimum cost
of the process of energy supply and demand.
DSM optimization puts focus on :
▪ Reduction of PAR in energy consumption.
▪ Reduction of electricity tariff for the customer without compromising much on the user
comfort.
▪ Management and maintenance of privacy, security, and reliability.
85
86. How to bring about a more efficient DSM implementation
By usage of more robust or proven optimization techniques to complement standard
DSM applications.
By integration of more renewable energy sources and energy sources into the smart
grid ecosystem.
By architectural setup using more efficient and reliable communication protocols and
standards.
By introduction of a more market driven and market oriented approach to both
prosumers as well as consumers.
All of the above can be encapsulated in the form of a Virtual Power Plant
86
87. What is a VIRTUAL POWER PLANT?
A VPP is a conceptualised power plant made up of small DERs, controllable loads,
and Energy Storage Systems(ESSs) which operates on the principles of Information
and Communication Technology(ICT) to manage the dispatch and scheduling of
power and loads using a centrally managed cloud based software setup.
87
88. Why to consider VPPs?
The VPP is complementary to the traditional
power generation by formation of virtual
pools of sources of generation.
The VPPs have great flexibility in terms of fuel
selection (solar, wind, hydro).
The uncertainties of power demand can be
optimized by integration of local generation.
Improved and lower power generation costs
Reduction in emission of greenhouse gases.
Maximizing profits and sustainability.
88
Legend
Power flow
Data Flow
89. Challenges to the implementation of VPP
89
Technical
challenges
Regulatory
challenges
Environmental
challenges
Commercial
challenges
91. Market driven approach of DSM and VPP
The flexibility in the operation of VPP is mainly achieved using its market
participation principles.
To ensure maximum cost effectiveness and reduction in overall energy
consumption, the participation of VPP entities in market is crucial.
91
92. Issues in market oriented approach in a smart grid system
Power generation in most of the DGs involves uncertainties related to the operation,
characteristics, system flexibility to operate with synchronism, and adequate stability.
Standardization of protocols and rules in market environment for entities is a necessity
for ideal operation.
Complex market mechanisms can lead to inefficient coordination in participating
units.
Interconnection of multiple DGs and its coordination from an economic point of view
is a difficult task.
Varying tariff of electricity in deregulated markets can lead to confusion and
complexity.
Shortfalls/excess of generation of energy can lead to an unbalanced market.
92
93. Issues in market oriented approach in a smart grid
system... continue
Most DGs are placed in the distribution system. However, the wholesale markets
operate at the transmission level.
Market concepts require transmission sector development, corridor allocation, and
system operating principles, and standards. All these factors are either at the
developing stage or not conducive.
The security of supply, environmental protection, and social goals to provide along
with economic efficiency and energy policy in market design.
Accountability of independent regulatory authorities need to be emphasized for
better services.
Non-discriminatory Third Party regulatory entities need to be participate in the market
to form idealistic trading and prevent monopoly.
93
95. Major challenges at planning and design stage
Placement of distribution generation for enhancing power loss and voltage stability.
DG with Energy storage system for enhancing energy management efficiently.
Placement of PMU for enhancing observation and data retrieving.
Placement of electric vehicle charging system for enhancing reliability, flexibility, and efficiency.
Switching placement for reconfiguration to meet the load under feeder disconnection and fault.
Substation placement for better operational efficiency.
Transformer placement for better power management.
Sensor placement for correct monitoring and information gathering
Placement of FACTS for better power control, power quality, enhancing the power transform
capability
95
96. Issues and challenges related to DGs integration
96
1: Integration of DGs
into distribution sector
results many problems
related to control,
protection, and energy
management
2: DG characteristics
are highly nonlinear
and having complex
dynamics. It affects to
the system
performance
3: Placement and size
of all the essential
components during the
design and planning
stage affects critically
to overall system
performance
4: Renewable based
power generation
mostly dependent on
the environment.
5: Energy storage
systems are very
essential for energy
management.
However, its
integration with the
DGs and operation in
a coordinated way is
complex.
6: Design and
planning need
optimization
techniques not only for
the present topology
but also incorporating
the fast changing
conditions.
97. 97
Type-1
DGs that can deliver only
active power, Examples:
photovoltaic, micro-
turbines, and
fuel cells
Type-2
DGs that can deliver only
reactive power, Examples:
synchronous condenser.
Type-4
DGs that can deliver
active power but consume
reactive. Examples: wind
farm.
Types of DG that can be connected in distribution system.
Type-3
DGs that can deliver both
active and reactive power,
Examples: synchronous
generators
99. Smart Grid Challenges in India
High rate of growth in power sector is needed to support economic growth and
employment generation
Estimated demand by 2032 is 900 GW – almost quadrupling the existing capacity
Present the per capita consumption is one-fourth of the world average!
79 Million households yet to be electrified (2011 census)
To address the above challenges, the Indian power system is expected to grow 8-10% per
annum for next several decades - managing a rapidly growing power system of this size
requires smarter systems
India is pursuing one of world’s largest grid connected renewable energy programs
Integration of such renewable resources require smarter systems
India launched the National Electric Mobility Mission with a target of 6 million EVs by 2020
Successful rollout of EVs with required smarter systems
Reduction of T&D losses continues to be top priority of both Government and utilities
Smart grid technologies will increase visibility and control of power flows in in real time
Developed nations with reliable electric grids are investing in smart metering, data
communications and advanced IT systems and analytics, tools for forecasting, scheduling
and dispatching to further their smart grid journey…developing countries like India need to
invest in both strengthening the electrical network as well as adding communications, IT and
automation systems to build a strong and smart grid.
99
102. Evolutionary Optimization
Higher probability to fall on Global
Optimization (Not trapped at local minima in
case of classical technique)
Less Computational Complexity
Derivative Free
Exact Mathematical Expression (Not being
applicable to certain class of objective
functions in case of classical techniques)
102
103. ?
Black-Box Optimization
Optimization Algorithm:
only allowed to evaluate f (direct search)
decision vector x objective
vector f(x)
objective function
(e.g. simulation model)
Problem Definition: optimization of continuous nonlinear functions
finding the best solution in problem space
104. Components of the evolutionary optimization
Objective Function: An objective function
which we want to minimize or maximize.
Design Variables: A set of unknowns or
variables which affect the value of the
objective function.
Constraints: A set of constraints that allow
the unknowns to take on certain values
but exclude others.
104
106. 106
Type-1
DGs that can deliver only
active power, Examples:
photovoltaic, micro-
turbines, and
fuel cells
Type-2
DGs that can deliver only
reactive power, Examples:
synchronous condenser.
Type-4
DGs that can deliver
active power but consume
reactive. Examples: wind
farm.
Types of DG that can be connected in distribution system.
Type-3
DGs that can deliver both
active and reactive power,
Examples: synchronous
generators
107. 107
Read the Line, Bus
and Load data Initialize the DG rating, Power
Factor and Location
Perform Load Flow on the Radial
Distribution System and Evaluate
the fitness function
Update the DG rating, Power
Factor, and Location using any
Suitable Optimization Technique
Perform Load Flow on the Radial
Distribution System and Evaluate
the fitness function
Store the Optimal DG
Rating, Power Factor
and Location
Steps involved in Optimal design and placement of DGs
108. 108 Optimal design and placement of DGs
Various steps involved are:
➢ Step 1: Reading the Line, Bus and Load data.
➢ Step 2: Random initialization of DG size, power factor and DG location.
➢ Step 3: Performing Load Flow in the Radial Distribution System.
➢ Step 4: Evaluation of fitness function.
➢ Step 5: Up-dation of DG size, power factor and DG location using
Optimization Techniques.
➢ Step 6: Repetition of steps 3-4 until stopping criterion are met.
➢ Step 7: Selection of optimal DG size, power factor and DG location.
110. 110
Signal processing applications to power system protection
Wavelet
Transform
•A wavelet is a mathematical function used to divide a given function or continuous-time signal
into different scale components.
Fourier
Transform
•A Fourier transform is a mathematical transform that decomposes functions depending on
space or time into functions depending on spatial or temporal frequency
Hilbert
Huang
Transform
•The Hilbert–Huang transform is a way to decompose a signal into so-called intrinsic mode
functions along with a trend, and obtain instantaneous frequency data. It is designed to work
well for data that is nonstationary and nonlinear.
S-transform
•The advantages of S-Transform are that it can observe how the frequency of the signal changes
with time and has a straightforward interpretability of the results. Furthermore, it provides multi-
resolution analysis while retaining the absolute phase of each frequency.
Mathematical
morphology
•Mathematical morphology is a theory and technique for the analysis and processing of
geometrical structures, based on set theory, lattice theory, topology, and random functions.
111. 111
Signal processing and artificial intelligence techniques
applications in classification of power quality
disturbances
Step-1: Data Extraction
Step-2: Feature Extraction
Step-3: Feature Selection
Step-4 : Classification
112. 112
Application of signal processing
Safety and
security
Fault
detection
Vehicular
Technology
Instrumentation
Smart
meters
PLC
Power
quality
Islanding
Detection
Applications
114. References
Sarangi, Swetalina, Binod Kumar Sahu, and Pravat Kumar Rout. "Distributed generation hybrid AC/DC
microgrid protection: A critical review on issues, strategies, and future directions." International Journal of
Energy Research 44.5 (2020): 3347-3364.
Sarangi, Swetalina, Binod Kumar Sahu, and Pravat Kumar Rout. "A comprehensive review of distribution
generation integrated DC microgrid protection: issues, strategies, and future direction." International Journal
of Energy Research 45.4 (2021): 5006-5031.
Sarangi, Swetalina, Binod Kumar Sahu, and Pravat Kumar Rout. "Review of distributed generator integrated
AC microgrid protection: issues, strategies, and future trends." International Journal of Energy
Research (2021).
Chandak, Sheetal, and Pravat K. Rout. "The implementation framework of a microgrid: A
review." International Journal of Energy Research 45.3 (2021): 3523-3547.
Sahoo, Buddhadeva, Sangram Keshari Routray, and Pravat Kumar Rout. "AC, DC, and hybrid control
strategies for smart microgrid application: A review." International Transactions on Electrical Energy
Systems 31.1 (2021): e12683.
Mishra, Manohar, Sheetal Chandak, and Pravat Kumar Rout. "Taxonomy of islanding detection techniques for
distributed generation in microgrid." Renewable Energy Focus 31 (2019): 9-30.
114