The MATLAB Simulink software is used for modelling and controlling rooftop solar panels to act like Virtual Power Plant. It required the knowledge of DER integration with the grid, and the use of power electronics controllers to maintain the uniform voltage profile at the point of injection. This also helps in reducing the burden on the transmission lines since power is generated and supplied locally. This helps in maintaining the voltage profile to 1 per unit.

1. Modelling, Simulation and Control
of Virtual Power Plant
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Presented By:
Bhashmang Adhvaryu 160110109002
Chintan Bhalodiya 160110109004
Naitik Gandhi 160110109014
Guided By:
Prof. Chintan R Patel
G H PATEL COLLEGE OF ENGINEERING & TECHNOLOGY

2. Project Outline
 Introduction
 Objectives
 Modelling & Simulation
 Result Analysis
 Conclusions
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3. Introduction
 In the present scenario, the number of distributed energy
resources(DERs) like rooftop solar panels is increasing drastically.
 The roof-mounted solar PV systems are current-controlled and
inject power on the basis of the MPPT algorithm which injects peak
power available at a given time, providing the maximum utilization
of PV system.
 This injection is only of active power*, which varies with the solar
irradiance. As a result, there can be voltage rise at the point of
injection and the grid stability may be compromised if the amount
of such injection is increased.
 As load increases, more current is drawn, so voltage dip is
observed especially in the radial distribution system. As a result
feeder voltage is not constant at 1 pu, which may drive the power
system towards instability.
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Current scenario:

4. Virtual Power Plant
 A virtual power plant is a system that integrates
several types of power sources to give reliable overall
power supply.
 The aforementioned problem can be solved by
employing control action as in the thermal, nuclear &
hydropower plants.
 To achieve this, DERs should be considered as
concentrated energy sources, and power plant like
control is employed.
 This converts the DERs into a Virtual Power Plant.
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5. Need of VPP:
 Improving the voltage profile of the feeder.
 Relieving grid during peak hours.
 Improving system stability.
 Desired active power(W) and reactive
power(VAR) injection.
 Maximum utilization of energy resources.
 Actual power plant like control.
 Increased efficiency.
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6. Distributed Energy Resources:
 Distributed energy resources (DERs) are electricity
generation units (typically in the range of 3 kW to
50 MW) located within the electric distribution
system near the end-user.
 They are parallel to the electric utility or stand-
alone units. DERs have been available for many
years, and are known by different names such as
generators, back-up generators, or on-site power
systems.
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Basics

7. Solar PV:
 Solar Photovoltaic (PV) is a technology that converts sunlight
(solar radiation) into direct current electricity by using
semiconductors.
 When the sun hits the semiconductor within the PV cell, electrons
are freed and form an electric current.
Inverter:
 A solar inverter or PV inverter is a type of
electrical converter which converts the variable direct
current (DC) output of a photovoltaic (PV) solar panel into
a utility frequency alternating current (AC) that can be fed into a
commercial electrical grid or used by a local, off-grid electrical
network.
 It is a critical balance of system (BOS)–component in
a photovoltaic system, allowing the use of ordinary AC-powered
equipment.
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8. Harmonic filters:
 The output of the PWM inverter is distorted
and contains harmonics.
 Harmonic filters reduce distortion by
diverting harmonic currents in low
impedance paths.
PID controller:
 A PID controller continuously calculates error
by comparing process value(PV) with set
value(SV).
 To provide a close-loop control a PID
controller is required.
 It maintains the constant output voltage
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9. Problem Definition
 During peak demand, the power system is under stress. Peak
load power stations can be employed but its reaction to
load fluctuations is slow.
 Due to concentrated generation in conventional plants and
large inertia, flexibility is reduced and the efficiency is less.
 The use of peak load plants to react to small load
fluctuations is not economical, but if these fluctuations are
not met then they may reduce the system stability limit which
is not desired.
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10. Objectives
 To create and simulate the Virtual Power Plant model using MATLAB
Simulink toolbox.
 To observe the improvement done by using a coordinated injection
of various DERs into the distribution system.
 To improve the voltage profile of the radial feeder using the VPP
concept.
 To simulate various cases and maintain the voltage at 1 PU with the
help of VPP.
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11. Modelling
MATLAB (matrix laboratory) is a numerical computing environment
and proprietary programming language developed by MathWorks, which
allows matrix manipulations, plotting of functions and data,
implementation of algorithms, creation of user interfaces, and interfacing
with programs written in other languages,
including C, C++, C#, Java, Fortran and Python.
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MATLAB:
Simulink:
Simulink is a MATLAB-based graphical programming environment for
modelling, simulating and analyzing multidomain dynamical systems. Its
primary interface is a graphical block diagramming tool and a
customizable set of block libraries. Simulink is widely used in automatic
control and digital signal processing for multidomain simulation
and model-based design.
We have used this Simulink Toolbox of MATLAB Software for simulation of
various scenarios of our project

12. Single Line Diagram
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13. Simulations
 We have simulated 5 cases which show the effect caused by load fluctuations on
feeder voltage.
 Feeder voltage should remain constant (i.e. 1 PU) when it is loaded for the system to
operate stably under given load conditions.
 The cases used here are:
1) A sudden increase in load.
2) A sudden decrease in load.
3) The increase followed by a decrease in load.
4) The increase followed by a decrease in load in the selected area.
5) Combined simulation of all cases.
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14. Simulink Model 14

15. PV System Model 15

16. Case-1: Sudden Increase in Load
Uncontrolled injection (Combined) 16
 The load is increased at t=0.5s.

17. 17
Case-1: Sudden Increase in Load
Uncontrolled injection (Feeder Voltages)
 The load is increased at t=0.5s.

18. Case-1: Sudden Increase in Load
Controlled injection (Combined) 18
 The load is increased at t=0.5s.

19. Case-1: Sudden Increase in Load
Controlled injection (Feeder Voltages) 19
 The load is increased at t=0.5s.

20. 20
Case-2: Sudden Decrease in Load
Uncontrolled injection (Combined)
 The load is decreased at t=0.5s.

21. 21
Case-2: Sudden Decrease in Load
Uncontrolled injection (Feeder Voltages)
 The load is decreased at t=0.5s.

22. 22
Case-2: Sudden Decrease in Load
Controlled injection (Combined)
 The load is decreased at t=0.5s.

23. 23
Case-2: Sudden Decrease in Load
Controlled injection (Feeder Voltages)
 The load is decreased at t=0.5s.

24. 24
Case-3: Increment followed by Decrement
Uncontrolled injection (Combined)
 The load is increased at t=0.25s and then decreased at t=0.55s.

25. 25
Case-3: Increment followed by Decrement
Uncontrolled injection (Feeder Voltages)
 The load is increased at t=0.25s and then decreased at t=0.55s.

26. 26
Case-3: Increment followed by Decrement
Controlled injection (Combined)
 The load is increased at t=0.25s and then decreased at t=0.55s.

27. 27
Case-3: Increment followed by Decrement
Controlled injection (Feeder Voltages)
 The load is increased at t=0.25s and then decreased at t=0.55s.

28. 28
Case-4: Inc. followed by Dec. on selected Buses
Uncontrolled injection (Combined)
 The load is increased at t=0.25s and then decreased at t=0.55s on branches 1 & 3 whereas the
load on branches 2 & 4 is kept constant.

29. 29
Case-4: Inc. followed by Dec. on selected Buses
Controlled injection (Combined)
 The load is increased at t=0.25s and then decreased at t=0.55s on branches 1 & 3 whereas the
load on branches 2 & 4 is kept constant.

30. 30
Case-5: Combined Simulation (Voltage Profile)
Branch-1: Fully Controlled, Branch-2: Uncontrolled
 The load is increased at t=0.25s and then decreased at t=0.55s on branches 1 & 2, where branch
1 is fully controlled whereas branch 2 is uncontrolled keeping the load on branches 3 & 4
constant.

31. 31
Case-5: Combined Simulation (Current Profile)
Branch-1: Fully Controlled, Branch-2: Uncontrolled
 The load is increased at t=0.25s and then decreased at t=0.55s on branches 1 & 2, where branch
1 is fully controlled whereas branch 2 is uncontrolled keeping the load on branches 3 & 4
constant.

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Case-5: Combined Simulation (Power)
Branch-1: Fully Controlled, Branch-2: Uncontrolled
 The load is increased at t=0.25s and then decreased at t=0.55s on branches 1 & 2, where branch
1 is fully controlled whereas branch 2 is uncontrolled keeping the load on branches 3 & 4
constant.

33. Result Analysis
 When there is an increase in the load, the current drawn is increased, so to provide the
same power voltage is reduced.
 By providing a close loop control of DERs, their power output can be increased without
causing a dip in voltage.
 This is evident from Case 1 and Case 3 that without employing injection control, the feeder
voltage fluctuates with load fluctuations.
 From Cases- 2, 4 & 5, it is evident that by employing injection control, the feeder voltage
remains constant nearly at 1 PU.
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34. Summary
 In the present scenario the number of distributed energy resources(DER’s) like
rooftop solar panels, scattered wind turbines have increased drastically. This
calls for better coordination such that these DERs can be used so that they are
able to achieve their full potential and can help in maintaining grid stability.
 Currently, these DERs operate uncontrollably i.e. their output is constant
irrespective of demand. The above-mentioned goal can be achieved by
obtaining a controlled injection.
 In controlled injection, the active(W) and reactive power(VAR) supplied by the
DER is fully controlled. By doing this, problems like voltage dip on feeder can be
solved. This helps in improving the voltage profile of the power system by
relieving some load from it.
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35. References
 A book on “ELECTRICAL POWER SYSTEM” by C.L. Wadhwa.
 A book on “MODERN POWER SYSTEM ANALYSIS” by D.P Kothari and I. J. Nagrath.
 M. Bazilian; I. Onyeji; M. Liebreich; et al. (2013). "Re-considering the economics of photovoltaic
power" (PDF). Renewable energy. Archived (PDF) from the original on 31 August 2014. Retrieved 31
August 2014.
 Fraunhofer ISE Levelized Cost of Electricity Study, November 2013, p. 19.
 "Technology Roadmap: Solar Photovoltaic Energy" (PDF). IEA. Archived (PDF) from the original on 7
October 2014.
 “Modelling and simulation of virtual power plant in energy management system applications” by
Naina P M, Haile-Selassie Rajamani and K. S. Swarup, IEEE Xplore Digital Library.

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