Analysis of solid state transformer in microgrid system for power management and power quality impro

International Journal of Research in Advanced Technology - IJORAT Vol. 2, Issue 2, February 2016

All Rights Reserved © 2016 IJORAT 1

ANALYSIS OF SOLID STATE TRANSFORMER IN

MICROGRID SYSTEM FOR POWER MANAGEMENT

AND POWER QUALITY IMPROVEMENT V.Chandrasekaran 1

, Mr.R.Sathishkumar.M.E.2,

PG Scholar, Department of Electrical and Electronics Engineering, Anna University, Regional Office Madurai, Tamilnadu.

Faculty, Department of Electrical and Electronics Engineering, Anna University, Regional Office Madurai,Tamilnadu.

Abstract: In this paper , the reduction of multiple reverse conversions in an individual AC or DC microgrid is

proposed through SST. It also facilitates connections to variable renewable AC, DC sources and loads to power

systems. In the present work power management and power quality measurement of the system is carried out by

enabling islanding mode operation, Solid State Transformer (SST) enabled operation (grid connected), and the

seamless power transfer between two modes. The proposed power management strategy includes three control

levels, primary control for the local controller, secondary control for the DC microgrid bus voltage recovery and

tertiary control to manage the battery state of charge. Here photovoltaic system and battery are used for the

development of microgrid. This brings promising advantages such as power flow control, voltage sag compensation,

fault current limitation, etc., which are not possible with conventional transformers. Therefore, the SST can enhance

stability and controllability of the power distribution grid. The SST and Power converters are properly coordinated

in the AC or DC Microgrid for better Power management and Power quality. The proposed system results are

verified with MATLAB/ SIMULINK environment .

Keywords: - DC microgrid- Islanding mode- Solid state transformer(SST)-enable mode and Battery

I. INTRODUCTION

In recent years, the complexity of the electrical

grid has grown due to the increased use of renewable energy

and other distributed generation sources. Distributed

generation (DG) is getting more and more attention along

with the rapid development for renewable energy technology

in the last decade. Since the output power of distributed

renewable energy resource (DRER) power depends on some

unpredictable conditions of nature, such as solar irradiation

and wind speed, supplying a reliable and qualified power

based on DG is the major challenge

Fig. 1. SST enabled AC/DC microgrid

for engineers, and microgrid provide a promising solution.

Power electronic-based DRERs and distributed energy

storage devices (DESDs) constitute the microgrid, which can

not only deliver flexible and reliable power to the

conventional grid, but can also operate in islanding mode in

rural areas [1]. To adjust with this complexity, new

technologies are required for better control and a more

reliable operation of the grid. One of such technologies is the

solid-state transformer (SST). The SST technology is quite

new and therefore the knowledge on the behaviour of these

systems in the grid is rather limited [2]-[4].

In DC microgrid [5], it is easier to integrate renewable

resources, especially for some dc type sources such as PV,

fuel cell, battery, super capacitor, etc., and they can directly

power future homes, dc loads, such as electric vehicles,

light-emitting diodes, and projectors. However, the existing

dc microgrid can only interface with the distribution system

by using a heavy and bulky line frequency transformer plus

rectifier, which takes too much space. In addition, Passive

transformer interfacing with the distribution system may not

provide grid support functions such as Var compensation,

harmonic filtering, etc. Developing the new microgrid

system for economical way, the conventional 50/60 Hz

power transformer was replaced and SST will be inserted in

the distribution system. The SST is consists of high

frequency transformer and dual active bridge converter[6]-

[10].



To handle a new approach for SST to

implementation of microgrid system integrated with

distributed renewable energy resources such as like

Photovoltaic system and energy storage system. Power

management of the system to enable islanding mode

operation [11], SST enabled operation mode (grid connected

mode), and the seamless power transfer between two modes.

Photovoltaic system with MPPT controller[12] and battery

are used for the development of microgrid, to manage the

battery state of charge, Power quality measurement of such

as power flow control , load control and harmonic

analysis[13]-[14].

II. DESCRIPTION OF AC/ DC MICROGRID

ENABLED BY SST

AC/DC microgrid architecture enabled by SST is

shown in Fig. 1. Only DC microgrid system power

management is considered here. For the AC microgrid

enabled by the SST ac terminal, a typical RL load is used to

represent as the AC microgrid. Since the islanding mode of

system is the same as the traditional DC microgrid, this

paper only focuses on the SST-enabled mode for better

demonstration of the proposal. PV and battery are selected

as typical DRERs and DESD respectively to construct a DC

microgrid, and the DC bus is connected to SST dc output

terminal. SST can be considered an interface between low

voltage AC and DC system to the distribution system. PV

always supply power to the system, while the battery is

considered an energy buffer to balance the system power

supply and demand when battery‘s SOC is within the

operation range SST can operate bi-directionally. When the

microgrid supplies more power than the loads need, the extra

power will feed back to the utility, and vice versa. More

details about the power flow will be discussed in Section III.

A. Solid State Transformer Concept

The Solid State Transformer (SST) provides an

alternative to the LFT. It uses power electronics devices and

a high-frequency transformer to achieve voltage conversion

and isolation. It should be noted that the SST is not a 1:1

replacement of the LFT, but rather a multi-functional device,

where one of its functions is transforming one AC level to

another.

Fig. 2. SST Concept

Other functions and benefits of the SST which are

absent in the LFT[6],[9] are High controllability due to the

use of power electronics, reduced size and weight because of

its high-frequency transformer. The transformer size is

inverse proportional to its frequency; hence a higher

frequency results in a smaller transformer. Unity power

factor because the AC/DC stage acts as a power correction

device. Unity power factor will usually increase the

available active power by 20%. Not being affected by

voltage swell or sag as there is a DC link in the solid state

transformer. Capability to maintain output power for a few

cycles due to the energy stored in the DC link capacitor.

Once the power electronics used in the solid state

transformer are turned off, the flow of electricity will stop

and the circuit is interrupted. Function as circuit breaker, fast

fault detection and protection.

B. Configuration of SST

The selection of the appropriate topology for SST

implementation is a key aspect. The main issue is addressed

by comparing some of the potential topologies that support

bidirectional power flow as a minimum requirement. In

order to select these potential topologies for comparison, a

number of topologies proposed for SST as well as for

general AC-AC power conversion have been studied.

Three SST configurations that cover all the possible

SST topologies are identified as follows:

1. Two-stage with low voltage DC (LVDC) link.

2. Two stage with high voltage DC (HVDC) links.

3. Three-stage with both HVDC and LVDC links.

Fig. 3. Three-stage with both HVDC and LVDC links

Of the three possible classifications, fig. 3. Shows a

three-stage architecture, with two DCs is the most feasible

because of its high flexibility and control performance. The

DC links decouple the HV-from the LV-side allowing for

independent reactive power control and input voltage sag

ride-though. This topology also allows better control of

voltages and currents on both primary and secondary side

[3],[4],[6]. It consists of an AC-DC conversion stage at the

HV-side, a DC-DC conversion stage with high-frequency

transformer for isolation and a DC-AC conversion stage at

the LV-side.

C. DC-DC Converter Topologies

Fig. 4. Shows a Single-phase Dual Active Bridge

(DAB) converter consists of a full bridge circuit on the

primary and the secondary side, with a HF transformer in

between. The DAB utilizes the leakage inductance of the

transformer to provide energy storage and to modify the

shape of the current waveform. The major advantages of the

DAB are the low number of passive components, evenly

shared currents in the switches and soft switching properties.

The drawback is that, depending on the modulation scheme



and operating voltage, large RMS currents can flow through

the DC capacitors, especially on the secondary side.

The Single-phase Dual Active Bridge (DAB)

achieves good efficiency while keeping the number of

passive components low. This allows for a simple and

compact circuit. For this reason the will be used for the

DC-DC conversion stage of the SST [5].

Fig. 4. Single-phase Dual Active Bridge converter

III. SST AND PV INTERFACED WITH DC MICRO

GRID SYSTEM.

A. SYSTEM INTRODUCTION

The Solid state transformer(SST) enables active power

management of the dc microgrid, which consists of DRER,

DESD, and loads, and transmits power between the

distribution system and the low-voltage dc system (230 V)

as shown fig. 5. These devices are connected to the common

230V bus by dc/dc converters. Compared with the

conventional transformer plus rectifier architecture, the SST-

enabled dc microgrid not only behaves as an active grid

interface requiring decreased weight and space but can also

potentially supply reactive power, compensate harmonic

currents, etc. Furthermore, it provides an interface for both

ac and dc residential grids to the distribution system. In such

a system, the islanding mode is defined when the dc

microgrid disconnects from the SST. When the dc microgrid

is connected to the SST, it is defined as the SST-enabled

mode.

Fig. 5. SST and Solar PV interfaced with DC microgrid

Systems

Photovoltaic cell (PV) is selected as the typical

DRER and it is connected to the dc bus, while the battery is

selected as the typical DESD. The battery and the PV

because of its simplicity in structure and control, and it can

obtain zero-voltage switching under a wide operation range.

The microgrid system information is both complicated and

time varying. The output power of a DRER always changes,

and the load condition fluctuates. Therefore, to supply

reliable and high-quality power, the main control objective is

to maintain system power balance, as follows:

(1)

Fig. 6. DC Bus Power flow

Where, PSST is the power supplied by the SST, PDC

microgrid is the power supplied by the sources in the DC

microgrid and PLoad includes the load power in DC

microgrid.

(2)

(3)

Based on the system structure shown in Fig. 5 can be

obtained as follows:

(4)

Here, the battery power is defined as positive when it

outputs power. The power of the battery can be calculated as

follows:

(5)

Where, Vb is the battery module dc terminal output voltage

and Ibis the battery module output current. The SST output

power can be defined as follows:

(6)

Where, Vdc is the SST dc terminal output voltage and Idc is

the SST dc output current.

Fig. 6 depicts the equivalent circuit of DC bus,where the Ceq

is the equivalent capacitor on the dc bus. Therefore, the bus

voltage dynamic can be given as follows

(7)



Thus, the system power unbalance will cause the bus voltage

change. From this perspective, the bus voltage represents the

system power status.

B. Design of High Frequency Transformer

The transformer losses are strongly related to

frequency. These losses contribute to the economics

of the system in which they operate. There are two losses

mainly contributing to the total transformer losses [8] are:

1) The core loss (which represents the no load loss).

2) The winding or copper loss.

High frequency transformers in solid state transformer

point out for the performance and overall efficiency of SST

system, so it is important to select the right materials and

optimize the design to fulfill all requirements in the

operating condition. Depending on the frequency, High

frequency transformer material is categorized in Table I,

[8], [7].

At low frequency, the eddy currents can be reduced by

laminating the core in the direction of the induced voltage.

As frequency rises the required laminations become

impracticable, and research is made to find alternative

material which naturally have low eddy currents by virtue of

the granular structure. The core loss, which is determined by

the core materials and the design, is a function of the

amplitude and frequency of the applied voltage [11]. Core

manufacturers have gradually improved core material

properties, including the Ferrites which are widely used at

present. Also, different types of core material characteristics

specification described in Table II. High frequency

transformer is designed as dry-type for environmental and

safety issues. Typical High frequency transformer 1000VA ,

1000Hz,415V/230V are designed parameters in Table III.

C. Design of Photovoltiac (PV) system

PV modules share a common DC bus through power

electronic interface, in DAB topology. DAB achieves zero

voltage switching (ZVS) in a wide operation range,

guaranteeing the high efficiency. PV panel current and

voltage are sensed for control purpose. Incremental and

Conductance method is implemented in order to find the

optimum operating voltage and achieve MPPT [12]. PV

array delivering a maximum of 1200W at 1000 W/m2 sun

irradiance are designed parameters in Table IV.

D. Islanding Mode Operation

When system operates in islanding mode, the battery has

to regulate the dc bus voltage alone.

(8)

PPV is equal or larger than zero, the power direction

of battery is determined by the difference between the PPV

and PDC load. The power of the battery will be larger than

zero when PDC Load is larger than Ppv , while the power of

the battery will be less than zero when PDC Load is smaller

than Ppv. The dc bus voltage range is defined as from 200 to

230 V in the presented system design. In islanding mode,

only the battery is used to regulate the dc bus voltage.

(9)

Where, Vb is the reference for the DC bus voltage, Vo is

bus voltage value without load and it is set to 230 V, Rb is

the virtual output impedance, and Ib is the battery output

current. For the PV module, it always operates in maximum

power point tracking mode (MPPT) to deliver power to the

system. The load is divided into the critical load and the

noncritical load. When the PV has no output power to the

system, the bus voltage will drop. The battery has to source

more power to the load and the battery state of charge (SOC)

will decrease rapidly. To ensure that the DC microgrid can

operate as long as possible in islanding mode, the battery

SOC has to be considered. Therefore, to avoid battery SOC

dropping fast, only the non-critical load operate in a PV

system. When PV system will be not given for power, the

non critical load will be shedding from the system.

E. SST Enabled Mode Operation.

Solar Power does not supply to load and Battery will

not enough power because of lower state of charge (SOC)

An appropriate SOC value is necessary for the battery to

supply the dc bus voltage while operating in islanding mode.

So, the DC microgrid needs to connect to the SST. When the

system operates in SST-enabled mode, the dc bus voltage

will be regulated by the SST, and therefore SST dc output is

a stiff bus as seen from the dc microgrid. While, PV system

is produce the power supply to the DC microgrid system.

The SST dc terminal voltage is sensed and compared with

the DC microgrid bus voltage the SST will be disconnected

from the microgrid and battery will be in charging mode.

IV. SIMULATION RESULTS

A Single phase,1000W, 415/230V solid State

Transformer and a1000-W,230V PV module, 10AH battery

module are designed to constitute the dc microgrid. The DC

microgrid connected with the critical DC load of 650W,

non-critical DC load of 200W and AC load of 100W. Fig. 7

shows a single-phase SST was designed for Dual active

bridge (DAB) converters are connected with dc link. In the

last stage, single-phase inverter is connected to provide 230-

V AC load. When the PV generation unit is operating with

MPPT control, the maximum power is 1000W and the

corresponding MPPT voltage is about 230V. The nominal

battery voltage is 230Vand the capacity is 10 Ah.

The dc microgrid operates in islanding mode. Initially,

only the battery supplies power to the load. Then PV

connects to the system and supply power to the load. Since

the PV‘s output power is larger than the load, the battery



switches to the charging mode automatically and the bus

voltage is higher than 230V.

When the noncritical load (200W) connects to the

system, the bus voltage drops and the battery switches back

to the discharging mode. When the PV power will not be

available the non-critical load is to load shedding. But

critical load always connected to the system to the bus. After

the PV disconnects from the system, the battery has to

supply the power to the load alone and the bus voltage

decreases. When the bus voltage drops below 230 V, the

noncritical load is shed from the system, and the bus voltage

can recover.

Fig. 7. Simulation Model of SST , Solar system and

Battery with interfaced with DC microgrid system

When the PV is connected back to the system the bus

voltage increases. After PV system produces the power the

noncritical load is reconnected to the system automatically.

The dc microgrid bus voltage is less than 230 V because

the battery and the PV have been supplying power to the

load. SST begins to operate, the microgrid bus voltage

increases with the secondary control time step until it

reaches 230 V. Then the dc microgrid connects to the SST,

and seamless power transfer is achieved. For the PV module,

there is no change in its output voltage and current because it

always operates in MPPT mode.

A. Controller Model

Fig. 8 shows a controller performs to the following

duties, It connects PV system to the DC microgrid if it

generates above 900W. Also the battery will be in charging

mode and SST will be isolated. PV generates below 900W,

the battery will be in discharging mode. Monitoring State of

Charge (SOC) of battery between 99.90% to 99.99%.

Below 99.90% of SOC, SST will be connected with the DC

microgrid.

Fig. 8. Controller Model.

B. PV Subsystem Model

The PV system is modeling based on the equivalent

circuit model which has already stated in theory section.

The photocurrent generated when the sunlight hits the

solar cell can be represented with a current source and the

P-N transition area of the solar cell can be represented

with a diode. The shunt and series resistances represent

the losses due to the body of the semiconductor. PV array

delivering a maximum of 1200W at 1000 W/m2 sun

irradiance is designed parameters in table IV.

C. Results

The Voltage and Current Wave Form of Microgrid

System With Load During Operation (Critical Load, Non-

Critical Load and AC Load) is discussed below with

Fig.9,Fig.10 and Fig.11.

Islanding mode, Solar system operates at 0 to 1sec, 2.3 to

3.5 and 5.5 to 7 sec.1000W and 230V is generated by PV

which is connected to a critical load, non critical load and

battery through microgrid. When the Power and Voltage of

PV is reduced to 900W and 230V, the Battery will supply

voltage to the critical load and AC load through microgrid at

1 to 2.3 sec and 3.5 to 5.0 sec.

SST enabled mode, When Battery state of charge (SOC)

decreases below 99.90 % at 5.0 sec, SST will supply voltage

to critical load and AC load through microgrid. If PV power

increases above 900W and 230V at 5.5 sec, SST tends to

OFF condition and PV becomes ON condition so that the

battery is in charging mode.



0 1 2 3 4 5 6 7 8

0

100

200

300

SOLAR VOLTAGE

0 1 2 3 4 5 6 7 80

100

200

300

SST VOLTAGE

0 1 2 3 4 5 6 7 80

100

200

300

CRITICAL LOAD VOLTAGE

0 1 2 3 4 5 6 7 8

0

200400

NON-CRITICAL LOAD VOLTAGE

0 1 2 3 4 5 6 7 8

211

212

213

BATTERY VOLTGE

TIME

Fig. 9 Voltage wave form of SST, PV, Critical load, Non-

critical Load, Battery during operation

(operating in islanding mode and SST enabled mode)

0 1 2 3 4 5 6 7 8

0

5

10

SST CURRENT

0 1 2 3 4 5 6 7 8

0

5

10

SOLAR OUTPUT CURRENT

0 1 2 3 4 5 6 7 8

0

2

4

CRITICAL LOAD CURRENT

0 1 2 3 4 5 6 7 80

0.5

1

NON-CRITICAL LOAD CURRENT

0 1 2 3 4 5 6 7 8

-2

0

2

4

BATTERY CURRENT

TIME Fig. 10. Current wave form of SST, Solar, Critical load,

Non-critical Load, Battery during operation (operating

in islanding mode and SST enabled mode)

0 0.02 0.04 0.06 0.08 0.1-200

-100

0

100

200

TIME

AC L

OAD

VOL

TAGE

( V

)

0 0.02 0.04 0.06 0.08 0.1-0.4

-0.2

0

0.2

0.4

TIME

AC L

OAD

CURR

ENT(

A)

Fig.11.Output Current of AC Load

(operating in islanding mode and SST enable mode )

0 1 2 3 4 5 6 7 8 90

50

100

Harmonic order

AC Load Voltage

Fundamental (50Hz) = 191.2 , THD= 0.47 %

Mag

(%

of

Fun

dam

enta

l)

0 1 2 3 4 5 6 7 8 90

50

100

Harmonic order

Ac Load Current

Fundamental (50Hz) = 0.3685 , THD= 0.32%

Mag

(%

of

Fun

dam

enta

l)

Fig.12. FFT Analysis of AC Load.

Fig. 12 shows a Total harmonics value of AC load.

Total harmonics disortion(THD) current in 0.32 %

Total harmonics disortion(THD) voltage in 0.47%

The above harmonic distortion value is acceptable IEEE

Standard (below 5%).

V. CONCLUSION

In DC microgrid system, which includes DRER (PV)

and DESD (battery). SST is adopted to interface the DC

microgrid, Critical load, Non-Critical Load and AC load.

The proposed controller for SST, PV and battery are also

presented based on their different characteristics. In this

power management, critical load will not be disturbed at any

time but non critical load will depend upon the PV source. In

this case excess of PV energy, if available it‘s stored in

battery system. If any generating source is not available the



battery source can be utilized. In addition, since SOC of

battery is considered into the power management. The

proposed power management was constructed and the

corresponding model was simulated.These sources often

have a varying voltage or frequency or can even be a DC

voltage. This system concluded that the SST is flexible

enough to allow connection of these sources to the

traditional grid. Due to the use of power electronics devices,

the SST has high controllability and lesser losses because

eddy current loss and iron loss smaller compared with

traditional transformer. Size and weight be reduced, because

of its high-frequency transformer.

VI. ACKNOWLEDGEMENT

The authors thank the management of the Anna University,

Regional Office,Madurai,Tamilnadu.for their continued

support and encouragement throughout the course of the

project.

APPENDIX A

TABLE I

HIGH FREQUENCY TRANSFORMER MATERIAL

Frequency Material

Winding

Type

Core

3 KHz Typical

solenoid

Meglas C-Core made up of

amorphous alloy

20 KHz or

Above 20

KHz

Coaxial

cores

Nano crystalline toroidal

TABLE II

TYPES OF CORE MATERIALS CHARACTERISTICS

Characteristic

/ Material

Nano

crystalline

Fine met

FT-3M

Ferrite

3F3 Super

alloy Amorphous

2605SA

Saturation

flux density

Bsat(T)

1.23 0.45 0.79-

0.87 1.57

Curie temp

Tc(°C) 570

200 430 392

Max

Operation

temp (°C)

150 120 125 150

TABLE III

HIGH FREQUENCY TRANSFORMER PARAMETERS

Input

Power/

Frequency

1000VA

/

1000Hz

Flux

Density(Bm)

1.25

Wb/m2

Primary

volt/

current

415V /

2.4A

Primary

conductor

resistance/

Inductance

0.0371Ω/

5.90µH

Secondary

Volt/

current

230V /

4.34A

Secondary

conductor

resistance/

Inductance

.00987Ω/1.

57µH

Volume of

core

191.77c

m3

Core weight 1.495 kg

Total

copper loss

0.427wat

ts

Total core

loss 2.99 watts

TABLE IV

PHITOVOLTAIC SYSTEM PARAMETERS

Open-circuit voltage(Voc) 256.8 V

Short-circuit current( Isc) 5.96A

Voltage at maximum power(Vmp) 218.80V

current at maximum power(Imp) 5.58 A

Maximum Power(Pmp) 1220.90W

REFERENCES

1. Xunwei Yu, Xu She, ,Xijun Ni, and Alex. Q. Huang. (2014),

‗System Integration and Hierarchical Power Management

Strategy for a Solid-State Transformer Interfaced Microgrid

System‘, IEEE Transaction Power Electronics, Vol. 29, No. 8,

August 2014.

2. W. van der Merwe and T. Mouton, ―Solid-state transformer

topology selection,‖ in 2009 IEEE International Conference

on Industrial Technology, 2009, pp. 1–6.

3. S. Falcones and R. Ayyanar. (2010), ―Topology comparison

for Solid State Transformer implementation,‖ in IEEE PES

General Meeting, pp. 1–8.

4. W.Hui,T.Xing-guo,L.Qing-min,Z.Fei,D.Zhan-feng, L.Zhen-

he,andL.Nan,― Development and applicability analysis of

intelligent solid state transformer,‖ in 2011 4th International

Conference on Electric Utility Deregulation and Restructuring

and Power Technologies (DRPT), 2011, pp. 1150–1154.

5. Tiefu Zhao, JieZeng, Subhashish Bhattacharya, Mesut E.

Baran, Alex Q. Huang. (2009), ‗An Average Model of Solid

State Transformer for Dynamic System Simulation‘ 978-1-

4244-4241-6/09/ IEEE.



6. L. Heinemann and G. Mauthe, ―The universal power

electronics based distribution transformer, an unified

approach,‖ 2001 IEEE 32nd Annu. Power Electron. Spec.

Conf. (IEEE Cat. No.01CH37230), vol. 2, pp. 504–509.

7. G. Chin, ―Review of magnetic properties of Fe-Ni alloys‖,

Magnetics, IEEE Transactions on, Vol. 7, Issue 1, Mar 1971,

pp. 102 – 113.

8. B.L. Theraja ―ELECTRICAL TECHNOLOGY II‖ S chand

publications.

9. S. Bhattacharya, T. Zhao, G. Wang, S. Dutta, S. Baek, Y. Du,

B. Parkhideh, X. Zhou, and A. Q. Huang, ―Design and

development of Generation-I silicon based Solid State

Transformer,‖ in 2010 Twenty-Fifth Annual IEEE Applied

Power Electronics Conference and Exposition (APEC), 2010,

pp. 1666–1673.

10. Haifeng Fan,Hui Li,(2010), ‗A Novel Phase-Shift

Bidirectional DC-DC Converter with an Extended High-

Efficiency Range for 20 kVA Solid State Transformer‘ 978-1-

4244-5287-3/10/ IEEE.

11. D. Chen, L. Xu, and L. Yao. (2013), ‗DC voltage variation

based autonomous control of dc microgrids‘, IEEE

Transaction. Power Del., vol. 28, no. 2, pp. 637–648.

12. Ch.Kalpana, Ch.SaiBabu, J.SuryaKumari. (2013), ‗Design and

Implementation of different MPPT Algorithms for PV

System‘, International Journal of Science, Engineering and

Technology Research, Vol.2, Issue 10.

13. J. M. Guerrero, J. C. Vasquez, J. Matas, L. Vicuna, and M.

Castilla (2011), ‗Hierarchical control of droop-controlled ac

and dc microgrids—A genera lapproach toward

standardization‘, IEEE Transaction. Ind. Electronics, vol.

58,no. 1, pp. 158–172.

14. R. S. Balog,W. W.Weaver, and P. T. Krein.(2012), ‗The load

as an energy asset in a distributed dc smart grid architecture‘,

IEEE Transaction,Smart Grid, vol. 3,no. 1, pp. 253–260.

Chandrasekaran V received his B.E in

electrical and electronics Engineering from

Thiagarajar college of engineering, Madurai, India

in 2012. He is currently pursuing his PG in the

Department of Power systems engineering,

AnnaUniversity, Regional Office, Madurai,

Tamilnadu,India. his area of interest includes Power

system and Microgrid.

R.Sathishkumar, Working as Lecturer in Anna

University, Regional Campus at madurai.

Completed his Post graduate in power system

engineering at Government college of

Technology, Coimbatore, Completed his bachelor

of engineering in Electrical and electronics

engineering at Sethu Institute of Technology,

Kariapatti. His area of interests are power

systems, Smart grid, Renewable Energy sources.

Analysis of solid state transformer in microgrid system for power management and power quality impro

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