This document summarizes the design and simulation of a Dynamic Voltage Restorer (DVR) using Sinusoidal Pulse Width Modulation (SPWM). A DVR is a series connected device that compensates for voltage sags and swells in distribution systems. The document describes the components of a DVR including injection transformers, a capacitor bank, voltage source inverter, and passive filters. It also explains how d-q-0 transformation is used to detect voltage sags and calculate the compensating voltage. Simulation results in MATLAB/Simulink show a DVR successfully compensating for a 50% voltage sag over 0.2 seconds using d-q control theory and SPWM pulses to the inverter switches.

1. Journal for Research| Volume 01| Issue 10 | December 2015
ISSN: 2395-7549
All rights reserved by www.journalforresearch.org 1
Design and Simulation of Dynamic Voltage
Restorer (DVR)
Mr. Sushant S. Sananse Ms. Alka Thakur
PG Student Associate Professor
Department of Electrical Engineering Department of Electrical Engineering
SSSIST, Sehore SSSIST, Sehore
Abstract
This paper gives a systematic technique of the design and simulation of Dynamic Voltage Restorer (DVR) the use of Sinusoidal
Pulse Width Modulation (SPWM). though electricity great associated problems like voltage sags/swells arise both at the
transmission aspect as well as the distribution facet, the terminology used for the compensation devices is exclusive. DVR is a
series linked tool used for compensating voltage sags and swells at the distribution side. on this work, a step by step technique is
given to determine out the additives which can be required for the layout and simulation of DVR. The detection of sags/swells is
completed with the assist of d-q-o concept, whereas the manager of the voltage source inverter is achieved with the assist of SPWM.
The VSI has been applied with the assist of both Bipolar SPWM in addition to Unipolar SPWM and the results were compared.
The simulation becomes achieved with the help of SIMULINK & MATLAB and the consequences have been located to be in
accordance with concept.
Keywords: Dynamic Voltage Restorer (DVR), d-q-o theory, Sinusoidal Pulse Width Modulation (SPWM), Voltage sag
_______________________________________________________________________________________________________
I. INTRODUCTION
With the speedy era improvements in industrial manage techniques; electric powered utilities are experiencing extra disturbing
necessities at the energy best from the massive business electricity customers. Such energy best issues were higher preferred whilst
the price paid, because of the economic losses as a result of them, is big. These issues are contemplated inside the newer versions
of power great standards, together with IEEE 1159-1995 (IEEE, 1995) and IEC6100-4-30 (IEC, 2003). among the diverse energy
best troubles, the voltage sag, normally as a consequence of the faults on parallel transmission/distribution feeders, is attracting
quite a large amount of attention from researchers of both enterprise and academia. A definitive solution to this hassle at huge
energy levels has been commonly known as dynamic voltage restorer (DVR), below the rubric of the custom power concept
brought by way of EPRI (Hingorani, 1999). The principle feature of DVR is to mitigate the voltage sag, despite the fact that once
in a while, extra capabilities such as harmonic compensation and reactive energy compensation also are integrated to the tool.
Strength satisfactory standards for connection of an inverter to the grid are nevertheless beneath improvement, because
previously, there have been a few similar high power applications. In (IEEE, 1992) it's far said that the energy great is decided by
means of the voltage quality, whilst the voltage is a controlled o variable. Voltage sags in an electrical grid are famous phenomenon
due to the finite clearing time of the faults and the propagation of sags from the transmission and/or distribution device to the low
voltage hundreds. The principle of voltage sags and interruptions for electric networks is thoroughly described inside the paintings
of Bollen (1999).
Dynamic voltage restorer (DVR) has been diagnosed as a fee powerful solution for the safety of sensitive Hundreds from voltage
sags (Fitzer et al., 2004). DVR is by and large used for the distribution system through injecting compensating voltage in series
with the delivery network when an upstream fault is detected (Zhan et al., 2001; Kara et al., 1998; Nielsen et al., 2004). Hundreds
linked downstream of the DVR are thus included from any voltage sags because of faults elsewhere at the community. With a view
to deliver awesome ac energy, the controlled pulse width modulation (PWM) inverter and L-C output filter ought to convert a dc
voltage source (for instance, batteries) to a sinusoidal ac voltage with low voltage THD and speedy transient response beneath load
disturbances.
Another vital thing of energy nice is harmonic distortion. Widespread requirements for harmonic distortion May be determined
in fashionable as seen inside the paintings of Casadeiet al. (2005) and specifically for connection of dispensed resources to grid in
Iqbal et al. (2006). PWM control is the most effective method that offers a easy technique for manipulate of analogy structures
with the processor’s digital output (Grandi et al., 2006). With the supply of low price, excessive overall performance DSP chips,
characterised by the execution of most instructions in one guidance cycle, complicated manage algorithms may be completed with
rapid speed, making very high sampling fee viable for digitally-managed inverters (Hadiouche et al., 2006).
Lately, strategies to supply an output voltage with low total harmonic distortion (THD) in a 3-section pulse width modulation
(PWM) inverter have been proposed (Maria et al., 2007). in this paper, the implementation of a virtual signal processor (DSP) the
usage of an improved d-q-0 primarily based controller became done for you to manage inverter pulses, and then the output of the
inverter turned into injected thru the injection transformer of the DVR. The improvement of the controller is easy to design and

2. Design and Simulation of Dynamic Voltage Restorer (DVR)
(J4R/ Volume 01 / Issue 10 / 001)
All rights reserved by www.journalforresearch.org 2
does now not rely a good deal on circuit parameters. The dc price of the capacitor and harmonic ripple cutting-edge due to input
energy circuit can be reduced
II. THE CONCEPT OF THE DVR IN THE DISTRIBUTION SYSTEM
DVR Operation and Additives:
A electricity electronic converter based collection compensator that may protect crucial loads from all deliver side disturbances
aside from outages is called a dynamic Omar and Rahim 1097 voltage restorer (Blaabjerg et al., 2004; Ojo et al., 2005).discern 1
suggests the configuration of the DVR such as an inverter, collection or injection transformer, inverter manage gadget and
electricity storage. the principle feature of a DVR is the protection of touchy load from any disturbances coming from community.
Injection Transformers:
In a 3-phase gadget, both three single-segment transformer units and one 3 section transformer unit can be used for voltage injection
cause (Zhan et al., 2000)
Capacitor Bank
DVR has a big DC capacitor to make certain stiff DC voltage input to inverter.
Inverter
An Inverter machine is used to transform dc storage into ac form (Ravi et al., 2007). Voltage supply inverter (VSI) of low voltage
and excessive modern with step up injection transformer is used for this reason in the DVR repayment approach (Perera et al.,
2006)
Passive Filters
To transform the inverted PWM waveform into a sinusoidal waveform Passive filters are used. this is done by means of doing
away with the unwanted harmonic components generated VSI movement. higher orders harmonic additives distort the compensated
output voltage (Zhan et al., 2000).
storage unit
It’s far chargeable for power storage in DC shape. Flywheels, batteries, superconducting magnetic electricity storage (SMES) and
extraordinary capacitors may be used as strength garage devices. It resources the real energy necessities of the gadget whilst DVR
is used for repayment (Banaei et al., 2006). The fundamental concept of a DVR is to inject the missing voltage cycles into the
gadget thru series injection transformer on every occasion voltage sags are gift in the device deliver voltage.
III.DYNAMIC VOLTAGE RESTORERS
A DVR is a tool that injects a dynamically controlled voltage V (t) collection to the bus voltage through a booster transformer as
depicted in parent L There are three single segment booster transformers related to a three section converter with energy storage
device and manipulate circuit [8]. The amplitudes of the 3 injected phase voltages are managed including to put off any destructive
consequences of a bus fault to the weight voltage V1. because of this any differential voltage because of temporary disturbances
in the ac feeder may be compensated with the aid of an equivalent voltage generated by the converter and injected at the medium
voltage level through the booster transformer.
The DVR works independently of the sort of fault or any occasion that occurs within the machine, furnished that the entire
machine remains connected to the deliver grid, i.e. the road breaker does now not trip. For most realistic cases, a greater good
value layout can be carried out through simplest compensating the high quality- and poor collection components of the voltage
disturbance seen on the input of the DVR. this feature is affordable because for a regular distribution bus conjugation, the zero
collection a part of a disturbance will now not bypass through the step down transformers because of countless impedance for this
thing. For maximum of the time the DVR has, truly, "nothing to do," besides tracking the bus voltage. this indicates it does no
longer inject any voltage (V(t)=zero) based of the burden cutting-edge. therefore, it's miles advised to in particular recognition on
the losses of a DVR at some stage in ordinary operation. specific capabilities addressing this loss difficulty were implemented in
its layout, which are a transformer design with low impedance and the semiconductor gadgets used for switching. An equal circuit
diagram of the DVR and the principle of collection injection for sag repayment is depicted in figure 2

3. Design and Simulation of Dynamic Voltage Restorer (DVR)
(J4R/ Volume 01 / Issue 10 / 001)
All rights reserved by www.journalforresearch.org 3
Fig. 1: Schematic diagram of DVR System
Fig. 2 Equivalent circuit of DVR
IV.D-Q-0 TRANSFORMATION
Direct–quadrature–zero (d-q-0) transformation additionally referred to as Park’s transformation is mathematical transformation
used to simplify the evaluation of 3-phase circuits. Within the case of balanced 3-phase circuits, software of the d-q-0
transformation reduces the three AC portions to 2 DC quantities. Simplified calculations can then be performed on those imaginary
DC quantities before acting the inverse rework to get better the real three-section AC outcomes.
The dq0 approach offers the sag depth information with start and end instances. The quantities are expressed as the immediate
area vectors. firstly convert the voltage from a-b-c reference frame to d-q-0 reference with the aid of using following equation
 





















c
b
a
q
d
v
v
v
T
v
v
v
0
….. (3)







































c
b
a
q
d
v
v
v
v
v
v
2
1
2
1
2
1
1)
3
2
sin()sin(
1)
3
2
cos()cos(
0




..… (4)
Where,
T is the transformation metrics Va,Vb Vc, , are instantaneous supply voltage of segment A, B and C respectively and Vd ,Vq ,V0
are d-axis ,q-axis, zero-axis factor of reference body respectively.
The theta (θ) is described by means of the attitude among phase A to the d-axis [17]. Above equation defines the transformation
from three section gadget a, b, c to dq0 desk bound frame. In this modification, segment A is aligned to the d-axis that is in
quadrature with the q-axis.
The manipulate is based totally on the contrast of a voltage reference and the measured terminal voltage (Va ,Vb ,Vc ). The
voltage sags is detected when the deliver drops below 90% of the reference value. both the voltages want to be transformed to dq
body and the difference in voltage in d-q body gives injected voltage in same body of reference. Then the d-q frame signal to be
transformed to abc body of reference the usage of inverse transformation given as follows:
 






















0
1
v
v
v
T
v
v
v
q
d
c
b
a
.… (5)

4. Design and Simulation of Dynamic Voltage Restorer (DVR)
(J4R/ Volume 01 / Issue 10 / 001)
All rights reserved by www.journalforresearch.org 4







































o
q
d
c
b
a
v
v
v
v
v
v
2
1
11
2
1
)
3
2
sin()
3
2
cos(
2
1
)sin()cos(





…. (6)
These injected voltage in abc frame of reference act as the control signal for the voltage source inverter. The pulses to the
switches are generated using sinusoidal PWM technique (SPWM)
V. SIMULATION RESULTS
A MATLAB simulation is carried out to discover the performance of DVR for repayment of voltage sag the usage of d-q principle.
A three-φ energy device with the parameters given in table 2 is simulated using simpered device block set. An RL load is
considered for the observe. A voltage supply inverter is designed the use of MOSFET because the switching devices and DC
voltage for the inverter calculated as 800V
Table - 1 System parameter and constant valve
Parameter Valve
Source voltage per phase 200V
DC Bus Voltage 800V
Filter Inductance 0.17µH
Filter Capacitance 26µF
Load Resistance 40 Ω
Load Inductance 60mH
Fig. 3: shows the d-q transformation in MATLAB/SIMULINK for generation of reference voltage

5. Design and Simulation of Dynamic Voltage Restorer (DVR)
(J4R/ Volume 01 / Issue 10 / 001)
All rights reserved by www.journalforresearch.org 5
Fig. 4: Simulink diagram showing generation of reference voltage using d-q theory
Three phase programmable voltage source has been used for generating 50% voltage sag for the period of 0.2s and twitch time of
sag is 0.15s and finish time is o.35s as shown in Fig.8 (a). Fig.8 (b) shows d constituent which gives the depth of sag.
(a) (b)
Fig. 5: (a) source voltage with sag, (b) shows and component
The recompense voltage is generated by associating the orientation voltage in d-q frame with d-q position frame voltage of the
definite power system voltage. The alteration in these voltages is to be inoculated by the voltage source inverter. This voltage will
act as the reference recompensing voltage for the inverter. This is shown in Fig. 6
Fig. 6: shows Reference voltage Fig. 7: Voltage to be injected
A sine triangular PWM Technique is used to generate pulses to the switches of three phase inverter. The output of the three phase
inverter is connected in series with the transmission line with the help of series transformers as shown in Fig. 10 PLL block is used
to synchronize the supply voltage and the injected voltage
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5
-150
-100
-50
0
50
100
150
time in sec.
Vinject

6. Design and Simulation of Dynamic Voltage Restorer (DVR)
(J4R/ Volume 01 / Issue 10 / 001)
All rights reserved by www.journalforresearch.org 6
Fig. 8: Simulink diagram showing the DVR in the distribution system
Fig. 9: Three phase load voltage Fig. 10: Three phase source voltage
VI.CONCLUSION
This paper has proposed and modeled the Dynamic Voltage Restorer (DVR) based totally on sinusoidal PWM technique the use
of MATLAB/SIMULINK. The reference voltage generated primarily based on d-q reference theory. the principle blessings of this
DVR is low value and it’s control is easy. The DVR can mitigate lengthy period sag also. The validity of proposed method is
permitted by using consequences to the simulated in MATLAB/SIMULINK
REFERENCES
[1] Roger C. Dugan, Mark F. McGranaghan, Surya Santoso, H. Wayne Beaty, “Electrical Power Systems Quality”, Chapter 1 & 2 pp. 1-30, Second
Edition, Tata McGraw-Hill, 2004.
[2] M. H. J Bollen, Understanding Power Quality Problems, Voltage Sags and Interruption, Piscataway, NJ: IEEE Press, 1999
[3] Sincy George and Vivek Agarwal “A DSP Based Control Algorithm for Series Active Filter for Optimized Compensation under Non-Sinusoidal and
Unbalanced Voltage Conditions” IEEE transaction on Power Delivery, vol.22, issue 1, January 2007, pp. 302-310.
[4] Sincy George and Vivek Agarwal “Optimum Control of Selective and Total Harmonic Distortion in Current and Voltage under Non-sinusoidal Conditions”
IEEE transaction on Power Delivery, vol. 23, issue 2, April 2008, pp. 937-944.
[5] Ian K.P. Ross, MIEE, Omniverter Inc. “voltage sags: an explanation - causes, effects and correction -part I” November/ December 2007
[6] IEEE Standards Board (1995), “IEEE Std. 1159-1995”, IEEE Recommended Practice for Monitoring Electric Power Quality”. IEEE Inc. New York.
[7] S.S. Choi, J. D. Li and D.M. Vilathgamuwa, “A generalized voltage compensation strategy for mitigating the impacts of voltage sags/swells,” IEEE Trans.
on Power Delivery, vol. 20, no.3, pp.2289-2297, July 200
[8] Fawzi AL Jowder “Modeling and Simulation of Dynamic Vltage Restorer (DVR) Based on Hysteresis Vltage Control” in The 33rd Annual Conference of
the IEEE Industrial Electronics Society (IECON)
[9] Changjiang Zhan, Vigna Kumaran Ramachadaramurthy, Atputharajah Nicholas Jenkins, "Dynamic Voltage Restorer Based on Voltage-Space Vector PWM
Control," IEEE Trans. Induistrial Applications, vol. 37, No.6 pp. 1855-1863, November/December 2001in Proc.
[10] Saripalli Rajesh, Mahesh K. Mishra, and Sridhar K , “Design and Simulation of Dynamic Voltage Restorer (DVR) Using Sinusoidal Pulse Width Modulation
(SPWM)” 16th NATIONAL POWER SYSTEMS CONFERENCE, 15th-17th DECEMBER, 2010
[11] H.P.Tiwari, “Capacitor Rating Selection for Voltage Sag Compensation in DVR System”International Journal of Innovation, Management and Technology,
Vol. 1, No. 3,August2010 ISSN: 2010-0248