Dynamic Power Allocation for Standalone PV -micro grid ... · MATLAB SIMULINK model is utilized to...

Dynamic Power Allocation fConnected Super capacitor

1M.Tech student, 2Assistant Professor,

Abstract

In some areas where electricity is not available

Standalone microgrid with renewable energy

source is a better solution to overcome

discontinuous electricity problems

popular inexhaustible energy sources are

Hydrogen cells, PV, wind and Geothermal energy.

Amidall the available inexhaustible

PV-microgrid is the one of the popular

available toelectricity need rural areas

Batteries are electrochemical cell

can be charged electrically to deliver

discharged electrical charge when needed. By

doing these charging and discharging

battery may subjected to stresses.To mitigate these

stresses the existing methods consist of Energy

storage system(ESS) technology.

Energy storage system devices,

batteries are popularly used. But due to high

charging rate and discharging rate

LA batteries are decreased.

The proposing method describes a novel multi

supercapacitor-battery HESS with fuzzy logic

controller and its analogousenergy

system.This was progressed by

supercapacitorHybridization and double battery

mode that includes super capacitor and two

batteries of dissimilarcharacteristics

economy LA battery was primary ESS

absorbs low frequency fluctuations and

battery is the secondary ESS which

medium frequency fluctuations. The power division

between the two is control by a scaling factor

willvary in different ways. MATLAB SIMULINK

model is utilized to analyze the working

proposing multilevel Supercapacitor

HESS.Simulation outputs conveyed

proposingmulti-level Supercapacitor

with fuzzy controller can reduce the battery

stresses very effectively and thereby enhances

allocation of power in the system.

Dynamic Power Allocation for Standalone PVnnected Super capacitor-Battery by Using Hybrid Energy

Storage System

1Pendela Madhava,2Sri.S.Sridharrofessor, 3Lecturer (ABIT): Department of Electrical and Electronics Engineering

JNTUA College of Engineering, Ananthapuramu, A.P, India

re electricity is not available,a

id with renewable energy

solution to overcome the

problems.Currently the

sources are Tidal,

eothermal energy.

inexhaustible energy models

popular options

areas.

electrochemical cells and these

charged electrically to deliver power or

discharged electrical charge when needed. By

charging and discharging processes,

battery may subjected to stresses.To mitigate these

consist of Energy

technology.Amid multiple

,lead acid(LA)

. But due to high

charging rate and discharging rate the lifecycle of

The proposing method describes a novel multi-level

with fuzzy logic

energy managing

bythe battery-

and double battery

super capacitor and two

cteristics.The low

primary ESS device that

low frequency fluctuations and Li-ion

the secondary ESS which absorbs the

tuations. The power division

by a scaling factor, it

MATLAB SIMULINK

the working of the

proposing multilevel Supercapacitor-battery

conveyed that the

level Supercapacitor-battery HESS

can reduce the battery

hereby enhancesthe

I. INTRODUCTION

Generally till now many areas

electrical supply.So aStandalone microgrid

provided by inexhaustible energ

a better solution to give reliable electrical supply

Currently, the popular

energysources includeTidal, hydrogen cells,

energy, geothermal and photovoltaic (PV)

Amid allthe available inexhaustible

solar basedPV micro-grid was

for electricity need areas. For

the rural houses located in outer

Fig1.illustrate solar energy power profile

an estimating energy usage structure in

In village areas PV energy is sometimes increasing

and sometimes decreasing. Due to this intermittent

nature the fluctuations will occurred

These fluctuations will cause imbalance

load and generation. So

system(ESS) was needed to decrease

difference between load and generation

ESSenhances the energy usage by diminishing the

power difference between load and generation by

storing extra power in the course of peak power

generation and delivers the reserve

peak time to load. ESSplays paramount

remunerating the reactive power,

voltage fluctuations and flicker

Fig.1.load contour and PV power

inAnantapur.

or Standalone PV-micro grid y Using Hybrid Energy

Storage System

Sri.S.Sridhar,3S.Sunil Naik and Electronics Engineering,

Ananthapuramu, A.P, India.

INTRODUCTION

areas are lacking from

Standalone microgrid

energy sources might be

ion to give reliable electrical supply.

renewable electrical

Tidal, hydrogen cells, wind

photovoltaic (PV) source.

inexhaustibleenergy models

was most popular option

. For example, let us take

outer partof Anantapur. energy power profile and

structure in rural areas.

is sometimes increasing

decreasing. Due to this intermittent

occurred in the system.

ause imbalance between

So, anenergy storage

needed to decrease the power

load and generation.

ESSenhances the energy usage by diminishing the

power difference between load and generation by

storing extra power in the course of peak power

the reserve powerduring off

plays paramount role in

ng the reactive power, extinguish the

and flickering.

and PV power variations

JASC: Journal of Applied Science and Computations

Volume 5, Issue 10, October/2018

ISSN NO: 1076-5131

Page No:538

Among ESS devices, lead acid (LA) batte

popularly using. LAbattery wasa economy less and

robust device. But the snag of LA battery is

smalllifetime predominantlywhile

in cycling applications. The major

factors of LA batteries are

charging/discharging rates, more

LAbattery would work only

charging/discharging cycles which makes

uneconomical as the ESS was major cost device

PV-microgrid.

To control above problems, Hybrid energy storage

systems (HESS) were proposed. HESS

working of numerous ESS devices to neutralize

weakness of storage elements. Most of the

works make clear that HESS has a capacity of

expanding thebattery life.

The major focus of HESS was

damaged load conditions such as

charging/discharging electrical current t

device. Ideally LA battery must

exchange of energy, as a consequence

mismatch betweengeneration and

acquiring the efficient power allotment

ESS elements, bidirectional DC to

are using along with power manag

(PMS). The premier focus of the

Increase the efficiency of energy and power quality

(2) To increase the ESS device lifetime

Among HESS modelsSupercapacitor

is efficiently used in microgrid applications.

Bidirectional DC/DC converters are

allocating the power to the SCand battery

respectively. However, this technique requires

moreDC/DC converters, so it drastically

the complexity of system and total

of the system. Kollimallaetal presented a

actively controlled battery-supercapacitor

with Energy management system, which

controlspower generation-load demand

then utilized the battery current error to monitor

power flow in the SC. But the control technique

was application basedand which won’t suitable

other available systems. A battery

HESS with moreSupercapacitor modules

caneffectively reduce battery stress

controlledSupercapacitor module allowed the more

range of power requirements, which increase

overall efficiencyand ductility of system

multiple number of Supercapacitor

increase total cost and complexity of the system

lead acid (LA) battery is

a economy less and

of LA battery is

it wasoperating

. The major lifeshortening

factors of LA batteries are over

, more DOD. A

only for less

cycles which makes

ESS was major cost device in

ybrid energy storage

. HESSexploitsthe

devices to neutralizethe

. Most of the research

HESS has a capacity of

was to direct the

conditions such as fluctuations in

current to ESS

battery must respond to

, as a consequence of the

generation and load. For

ment to multiple

bidirectional DC to DC converters

management system

the PMS is (1)

and power quality

lifetime.

apacitor-battery HESS

in microgrid applications.

DC/DC converters are using to

to the SCand battery

his technique requires

drastically increases

tal economic value

presented aparallel

supercapacitor HESS

management system, which

load demand difference

error to monitorthe

the control technique

which won’t suitable to

battery-Supercapacitor

apacitor modules

stresses. The self-

apacitor module allowed the more

which increased the

system. But the

apacitormodules

of the system.

This paper presenting a new

technique and its PMS which was evolv

battery-SC hybridization.It involves in

model that includesSupercapacitor

of dissimilarcharacteristics

low cost primary battery is LA battery

absorb low frequency fluctuations, whereas

secondary batteryis Li-ion battery

medium to high frequency fluctuation

allocation of power between them is fixed through

a scaling factor. While high frequency power

absorbed by SC. The error in the LA

battery and supercapacitor is reduced by using the

PI controllers connected to each batteries and SC.

In this paper for decreasing the

PI controller was replaced by using the FUZZY

logic controller.

II. SUPERCAPACITOR

HESS MODELS

In Supercapacitor-Battery HESS

devices are connected to either a common AC or

DC bus. But for a standalone PV micro

bus wasfavored because synchronization is

needed so it reduces the complexity

The following types are using

different Supercapacitor-battery HESS models

connected to common DC bus

A. Battery-only HESS

A conventional battery connected solar

microgrid is presented in fig.

power differences between load and generation

battery bank is connected through DC bus.

This battery regulates the imbalances

charging and discharging processes.

Fig.2. PV microgrid with Battery only ESS

This will perform very effectively during stable

operation. But whenever the fluctuations occurred

a new multilevel HESS

which was evolved by the

hybridization.It involves in two battery

apacitor and 2 batteries

and chemistries. The

is LA battery which will

equency fluctuations, whereas

ion battery that absorbs

frequency fluctuations. The

between them is fixed through

high frequency power is

error in the LA battery,Li-ion

ry and supercapacitor is reduced by using the

PI controllers connected to each batteries and SC.

In this paper for decreasing the error in the system,

replaced by using the FUZZY

SUPERCAPACITOR-BATTERY

Battery HESS, the two ESS

connected to either a common AC or

one PV micro-grid DC

synchronization is not

complexity in the system.

The following types are using toanalyzethe

battery HESS models

connected to common DC bus.

A conventional battery connected solar based

in fig.2. To diminishing the

between load and generation,a

through DC bus.

tery regulates the imbalances through

charging and discharging processes.

with Battery only ESS

This will perform very effectively during stable

operation. But whenever the fluctuations occurred



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the battery needs to performat all times. Due to th

the stresses will develop in battery thereby the life

of battery will reduce.

B. Passive SC-Battery HESS

In present years the Supercapacitor

hybridization for a solar based

becoming more popular. It is found that by

hybridization of SC and battery,the

will decreased by allocating the high frequency

power to Supercapacitor.

Supercapacitor-Battery HESS consist of a

supercapacitor and battery shuntly connected is

presented in fig.3. This topology

any active control mechanism. So it decreases the

complexity and total cost of system.

thebattery and SC were linked with

bus,there will be a chance of terminal voltage

mismatch. So to avoid this HESS must be designed

very carefully. The distribution of load currents is

determined by interior capacitance and resistances

of the both ESS

Fig.4.(a) Equivalent circuit model of passive SC

Where Vco is the initial voltage ofSupercapacitor

is the peak load current, T is time period

ratio and i0(t) is output current. From the above

(1), the allocation of power between battery and

supercapacitor was found by interior

Rb, Rc andsupercapacitor capacity C. In passive

connected HESS the power sharing is

throughout the operation. From fig.4 (

terminal voltage sharing of SC was similar to

at all times. Due to this

in battery thereby the life

Supercapacitor-Battery

ybridization for a solar basedmicrogrid is

becoming more popular. It is found that by

hybridization of SC and battery,the battery stresses

the high frequency

The passive

Battery HESS consist of a

nd battery shuntly connected is

This topology doesn’t require

hanism. So it decreases the

system. But as

with same DC

,there will be a chance of terminal voltage

HESS must be designed

very carefully. The distribution of load currents is

capacitance and resistances

f the both ESS devices.

Fig.3. PV microgrid with passive SC

The equivalent circuit of passively linked SC and

battery was presented in fig.4 (

Supercapacitor is processed

C and series resistance Rc and

was done by ideal voltage source Vb having

resistance ofRb. The battery

Supercapacitor branch current i

circuit model of passive SC-battery HESS (b)Power sharing of passive HESS with

itial voltage ofSupercapacitor, Io

is time period, D is duty

From the above eq

between battery and

interior resistances

supercapacitor capacity C. In passively

connected HESS the power sharing is constant

fig.4 (b) as the

terminal voltage sharing of SC was similar to

battery,the SC in the passive

topology is underutilized.

C. Parallel active SC-Battery HESS

The minimum controllable nature of passive

connected Supercapacitor-

addressed by interconnecting

employing bidirectional DC to DC

passive SC-Battery HESS

t circuit of passively linked SC and

fig.4 (a). The modeling of

by a high capacitance

series resistance Rc and modeling of battery

oltage source Vb having series

The battery current ib(t) and

Supercapacitor branch current ic(t) is derived as

HESS with periodical load

,the SC in the passively constructed HESS

Battery HESS

controllable nature of passive

-battery HESS was

rconnecting the ESS devices

bidirectional DC to DC converters. Due



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to this exchange of power will be done with full

control between energy storage devices.

separation of ESS with DC bus cause

life, good efficiency and flexibility among HESS

devices. The operation of active controlled HES

depends on power management and

control strategy.

A active HESS was presented in fig.5

and batterywere shuntly connected to

through DC to DC converters. T

employed to absorb the low frequency power

fluctuations, whereas supercapacitor was employed

to absorb the high frequency fluctuations

Fig.5.PV microgrid with parallel active SC

HESS

will be done with full

control between energy storage devices. The

with DC bus cause better cycle

flexibility among HESS

of active controlled HESS is

and corresponding

in fig.5, where SC

were shuntly connected to DC bus

DC to DC converters. The battery was

low frequency power

percapacitor was employed

fluctuations.

active SC-battery

Fig.6. power sharing technique

HESS.

Control scheme of active

corresponding PMS strategy was presented

In this PMS strategy a Low pass

employed to reduce the battery stresses by

decomposing the low frequency component of

power demand PHESS. The battery and SC

power signals (PBATT, PSC) were

their control loops and through PI controller

alterbattery current IBATT

current ISC valuesby controlling the duty ratio(D) of

pulse width modulation(PWM) signals.

D. Multi-level HESS with PI controller

Even though SC-battery HESS

battery stresses, but due to fina

problemssuch as converters power rating and

supercapacitor size, the HESS will perform less

to overcome the above problems a multi

supercapacitor-battery HESS model

corresponding PMS strategy

used. The multi-level Supercapac

model by using PI controller is presented

Unlike the above control strategies

mechanism used the two batteries named primary

battery and secondary battery

hybridization, the allocation of power

devices will be improved. Here the primary

battery will hold the more capacity of total

and secondary battery will hold the less capacity

battery capacity. LA battery was operating

asprimary battery and Li-ion battery was

as secondary battery.By using this topology it is

viable to yield smoother battery current I

same capacity of SC. In rainy seasons PV

generation will be decreased. So in these

a diesel generator was a backup

connects to the HESS. The co

generator was done by the PMS

battery SOC is below 40 percent

will charge the primary battery

discharge. The analysis in paper was

considering that electrical

generation is continuous.

Power management of multi-

presented in fig.8. The overall power in

(PHESS) was categorized into three frequency range

powers by using two low pass

power sharing technique of active SC-battery

actively HESS and

corresponding PMS strategy was presented in fig.6.

strategy a Low pass filter(LPF) was

the battery stresses by

decomposing the low frequency component of

The battery and SC reference

) were passed through

control loops and through PI controller for

and supercapacitor

y controlling the duty ratio(D) of

pulse width modulation(PWM) signals.

level HESS with PI controller

battery HESS was diminishedthe

, but due to financial and technical

such as converters power rating and

, the HESS will perform less. So

e problems a multilevel

battery HESS model and the

strategy with PI controller was

level Supercapacitor-battery HESS

PI controller is presented in fig.7.

ke the above control strategies,this control

mechanism used the two batteries named primary

tery. Due to this higher

allocation of power between ESS

devices will be improved. Here the primary LA

capacity of total capacity

dary battery will hold the less capacity of

battery was operating

on battery was operating

By using this topology it is

smoother battery current IBATTwith

same capacity of SC. In rainy seasons PV

generation will be decreased. So in these conditions

a backup source which

to the HESS. The controlling of diesel

generator was done by the PMS. Whenever the LA

is below 40 percent, diesel generator

will charge the primary battery to avoid deep

The analysis in paper was done by

considering that electrical supply through PV

-level HESS is

e overall power in HESS

into three frequency range

by using two low pass filters (LPF).



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Fig.7. multi-level SC-battery HESS with PI controller

in standalone PV microgrid

The low frequency power is the reference to

primary battery, while the medium frequency

power of the PHESS is the referenceto

battery and high frequency power of

used as the reference to the Supercapacitor.

using scaling factor W1 low frequency power also

allocated to secondary battery.

Fig.8.power sharing techniquefor the multi

battery HESS with PI controller

E. Proposed multi-level HESS with Fuzzy logic

controller

A Fuzzy controller is proposed in place of PI

controller in the multilevel HESS model

battery HESS with PI controller

the reference to

primary battery, while the medium frequency

the referenceto the secondary

battery and high frequency power of the PHESS is

the Supercapacitor. By

using scaling factor W1 low frequency power also

for the multi-level SC-

HESS with Fuzzy logic

controller is proposed in place of PI

HESS model.

Fig.9.power allocation strategy for the proposed multi

level HESS with Fuzzy logic controller

Eventhough PMS strategy of

using PI controller reduces the

and thereby reduces the battery stresses

Fuzzy controller will decrease

and thereby mitigate the battery stresses very

efficiently. So the power utilization

will improve.

III. NUMERICAL ANALYSIS

The Matlab Simulink diagram of

HESS with fuzzy logic controller is presented

fig.10. The simulation conditions

used in the model are tabled in Table

controlling of the currents from/to LA battery, Li

ion battery and SC to/from DC bus three

bidirectional DC/DC buck-

used. The total power PHESS is classified as

3types i.e. low power frequency

frequency and high frequency power. Low power

frequency is given to primary

frequency power is given to secondary battery and

high frequency power is given

LA battery is operating as primary batt

Li-ion battery is operating

because of its higher rating

SOC range is more compared to

The scaling factor W1 is set at

SC and batteries were assumed

perfect mode.

power allocation strategy for the proposed multi-

HESS with Fuzzy logic controller

PMS strategy of multi-level HESS by

controller reduces the error in the PHESS

by reduces the battery stresses,but the

roller will decrease the error effectively

and thereby mitigate the battery stresses very

utilization in the system

NUMERICAL ANALYSIS

ulink diagram of proposing

fuzzy logic controller is presented in

fig.10. The simulation conditions and elements

are tabled in Table1. For

the currents from/to LA battery, Li-

to/from DC bus three

-boost converters are

power PHESS is classified as

types i.e. low power frequency, medium power

uency power. Low power

is given to primary LA battery,medium

frequency power is given to secondary battery and

high frequency power is given to Supercapacitor.

as primary battery while

as secondary battery

rating; longer lifetime and

range is more compared to lead acid battery.

The scaling factor W1 is set at0.95. The SOCs of

assumedto be operating in



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Fig.10.Matlab Simulink model of the proposing

Fig.11. 5kw PV generation power profile of

The Simulated power of 5kw Photovoltaic

a sunny day of different loads and cloudy day

normal load recorded in Malaysia is presented

fig.11. The load variations used in the analysis

were collected from survey data. To

working of the multilevel HESS with fuzzy

proposingHESS with Fuzzy controller

eration power profile of different climate conditions in anantapur.

The Simulated power of 5kw Photovoltaic array of

and cloudy day with

recorded in Malaysia is presented in

fig.11. The load variations used in the analysis

data. To analyze the

SS with fuzzy

controller and already existed

models, three different condi

considered and these are presented

are (a) sunny day with normal load (b) sunny day

with heavy load (c) cloudy day with normal load.

ready existed different HESS

three different conditions of loads are

presented in fig.13. These

are (a) sunny day with normal load (b) sunny day

(c) cloudy day with normal load.



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Fig.12. Estimated load power variations

Fig.13. Simulink conditions employed for assess the operation

TABLE 1

PARAMETERS AND CORRESPONDING VALUES OF MATLAB SIMULINK MODEL

ParameterBattery-only ESS Passive-HESS

PV module max power (kw) energy consumption in day(kwh) Battery voltage(v) Primary Battery capacity(Ah) Secondary battery capacity(Ah) Battery internal resistance(Ohm) Supercapacitor capacitance(f) SC series resistance(Ohm) Scaling factor W1 Time-constant(primary LPF)(Sec) Time-constant (secondary LPF)(Sec)

To analyze the comparison between the

HESS modeland remaining HESS models

Simulink models of a standalone solar micro

with battery connected ESS, passive

battery-SC HESS, actively connectedHESS and

load power variations of the rural site.

for assess the operation of different HESS models.

PARAMETERS AND CORRESPONDING VALUES OF MATLAB SIMULINK MODEL

HESS Actively-HESS Proposing-HESS

5- - 27.4 --

48 -- 10001000 1000 950

- - - 0.005 0.005 0.005

- 10001000 - 0.001 0.001 0.001

- -- - --

- --

comparison between the proposing

HESS models,the

Simulink models of a standalone solar micro-grid

ESS, passively connected

connectedHESS and

multilevel HESS using PI controller are designed

with same Supercapacitor and battery parameters.

The primary battery current variations of

multi-level HESS with fuzzy

remaining existing topologies

fig.14. As the SC time constant

- - -

50 0.005

1000 0.001

0.95 600 300

PI controller are designed

with same Supercapacitor and battery parameters.

The primary battery current variations of the

level HESS with fuzzy controller and

remaining existing topologies are presented in

ime constant is within the



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seconds, the smoothness of the passive

HESS is almost constant. And also the peak value

ofbattery current is smallest in proposing HESS

among the five topologies (see table 2).

From fig.15.Thechanges in the SOC of battery

didn’t show any majorvariations amongall

topologies. This is because of the constant

frequency average power component.

current in the whole day for different HESS models

were presented in fig.14.

To find out the efficiency of SC utilization in

multiple HESS models,the variations in SOC

supercapacitor [(max SC SOC)-(min SC SOC)]

analyzed shown in fig.16. and Table

IV. SIMULATION RESULTS

Fig.14 (a) Primary battery currents of Battery

Fig.14 (

Fig.14(c) Primary battery currents of active

assively connected

. And also the peak value

in proposing HESS

the five topologies (see table 2).

changes in the SOC of battery

variations amongall HESS

of the constant low

power component. Battery

ay for different HESS models

y of SC utilization in

,the variations in SOC of

(min SC SOC)] are

. and Table2. In passively

connectedSC-battery HESS, as the terminal v

sharing of SC is same as

Supercapacitor utilization is lowest among all

topologies i.e.less than 10 percent.

multilevel HESS with fuzzy controller

connected SC-battery

havingapproximately equal Supercapacitor usage

of nearly 60 percent. As a result of high SC

utilization in the proposing

controller,the Supercapacitor

sustaining moreamount of

fluctuations in trading of power

devices and hence highly dynamic

stresses are mitigated with less economic value

SIMULATION RESULTS

Primary battery currents of Battery –only ESS topology

Fig.14 (b) Primary battery currents of Passive HESS model

nts of active-HESS model

, as the terminal voltage

sharing of SC is same as the battery, the

Supercapacitor utilization is lowest among all

10 percent. While the

with fuzzy controller and actively

batteryHESS are

equal Supercapacitor usage

of nearly 60 percent. As a result of high SC

utilization in the proposingHESS with fuzzy

the Supercapacitorhas the tendency of

amount of high frequency

fluctuations in trading of power between ESS

and hence highly dynamic battery current

ated with less economic value.



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Fig.14(d) Primary battery currents of multi

Fig.14 (e) primary battery currents of proposing multilevel

Fig.15 (a) Primary battery SOC

Fig.15 (b) Primary battery SOC variation in passive

Fig.15(c) Primary battery SOC variation in Active

nts of multi-level HESS with PI-controller

proposing multilevel HESS with Fuzzy controller

Primary battery SOC variation in Battery-only ESS model

Primary battery SOC variation in passive-HESS model

Primary battery SOC variation in Active-HESS model



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Fig.15 (d) Primary battery state of charge variation in mul

Fig.15 (e) Primary battery SOC variation in proposing multi

Fig.16 (a)Supercapacitor SOC variation

Fig16 (b) SupercapacitorSOC variation

Primary battery state of charge variation in multi-level HESS with PI controller

battery SOC variation in proposing multilevel HESS with Fuzzy controller

Supercapacitor SOC variation in Passive-HESS model

variation in Active-HESS model



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Fig.16(c) Supercapacitor SOC variation

Fig.16 (d) Supercapacitor SOC variation

TABLE2

NUMERICAL VALUES OF SIMULATION RESULTS

HESS topologyWeather/Load conditionMax battery current

Battery only ESS Sunny normal

Sunny heavy

Cloudy normal

Passive-HESS Sunny normal

Sunny heavy

Cloudy normal

Active-HESS Sunny normal

Sunny heavy

Cloudy normal

Multi-level HESS Sunny normal

Sunny heavy

Cloudy normal

Proposed HESS Sunny normal

Sunny heavy

Cloudy normal

V. CONCLUSION

As the reliable continuous electrical supply is

major problem in off-grid rural communities, a

Supercapacitor SOC variation in multilevel HESS with PI controller

Supercapacitor SOC variation in proposing multilevel HESS with Fuzzy controller

NUMERICAL VALUES OF SIMULATION RESULTS

HESS topologyWeather/Load conditionMax battery current(A)SC Utilization(%)

80 -

57

72

78

54

69

75

50

67

67

48

68

60

40

62

continuous electrical supply is a

ral communities, a

standalone solar powered

deviceswill be a option to

electrical supply in these areas. Among the ESS

devices, LA batteries are very popularly used. But

-

-

9.9

9.5

9.7

63.9

63.6

62

60.8

63.4

56.9

30

25

28

standalone solar poweredmicrogrid with ESS

to provide continuous

areas. Among the ESS

batteries are very popularly used. But



ISSN NO: 1076-5131

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due to low lifetime and high cost of LA batteries,

Hybridization of ESS devices with different

characteristicswill give better results. So this paper

proposed a multi-level SC-battery HESS by using

Fuzzy controller for decreasing the battery stresses

in power exchange conditions and thereby enhance

the power efficiency in the system. In this topology

a control strategy named as Power management

system (PMS) is employed by Fuzzy controller and

Low pass filters. To overview the working of this

HESS topology, a Matlab Simulink diagram of

standalone PV microgrid was developed which

gives the good response in mitigating battery

stresses and lifetime also increased by comparing

with other existing models of HESS. The numerical

results showing that the proposing HESS with

fuzzy controller would efficiently decrease the

battery stresses. This suggested that the battery life

can largelyimproved by using the proposed SC-

battery HESS model.

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