 Open Access
 Total Downloads : 16
 Authors : K.Manokar, R.Sankarnarayanan, P.Kathiravan, T.Suresh
 Paper ID : IJERTCONV2IS05060
 Volume & Issue : NCICCT – 2014 (Volume 2 – Issue 05)
 Published (First Online): 30072018
 ISSN (Online) : 22780181
 Publisher Name : IJERT
 License: This work is licensed under a Creative Commons Attribution 4.0 International License
Hybrid Technology With Battery Balancing
Department of Electrical and Electronics Engineering
K.Manokar1 
R.Sankarnarayanan 2 
P.Kathiravan3 
T.Suresh4 

Roever Engineering College 
Roever Engineering College 
Roever Engineering College 
Roever Engineering College 

Perambalur,Tamilnadu. 
Perambalur,Tamilnadu. 
Perambalur,Tamilnadu. 
Perambalur,Tamilnadu. 

manokark1991@gmail.com 
sankarkrishsankar@gmail.com 
kathir2351@gmail.com 
tsuresp993@gmail.com 
Abstract In this paper, hybrid (solar and wind power) technology with battery balancing function is proposed. All the inverters are connected to the battery bank individually. Number of batteries are connected to make the battery bank and it can be controlled according to battery voltages to implement the battery balancing function, the design equation is derived. Experimental set of the batterybalancing discharge function is achieved practically. Finally, a prototype is designed and implemented to verify the feasibility and excellent performance.
Index Terms
A multilevel inverter, batterybalancing. MPPT, HarmonicReduction.

INTRODUCTION
IN RECENT years, environmental concerns and the continuous depletion of fossil fuel reserves have spurred significant interest in renewable energy sources. However, renewable energy sources such as wind turbines and photovoltaics are intermittent in nature and produce fluctuating active power. The multi level inverter was first introduced in 1975. The three level converters was the first multi level inverter introduced. A multilevel converter is a power electronic system that synthesizes a desired output voltage from several levels of dc voltages as inputs. With an increasing number of dc voltage sources, the converter output voltage waveform approaches a nearly sinusoidal waveform while using a fundamental frequencyswitching scheme. The primary advantage of multi level inverter is their small output voltage, results in higher output quality, lower harmonic component, better electro magnetic computability, and lower switching losses.
Fig. 1.Renewable Energy System
Interconnecting these intermittent sources to the utility grid on a large scale could affect the voltage/frequency control of the grid An energy storage system which contains a large capacity of the battery bank is indispensable for countering uneven compensation In order to reduce energy loss in transmission lines and increase the overall battery
capacity, the battery bank is series connected for a highvoltage dc power supply Because of the manufacturing capacity, The internal impedance and the selfdischarge rate are different in each battery Therefore, the power conversion system requires a batterybalancing circuit.
To adjust each battery voltage to be equal. There have been some batterybalancing circuits made to control the battery capacity, and these can be classified as dissipative batterybalancing circuits non dissipative batterybalancing circuits.
The simplest dissipative batterybalancing circuit is made by shunting a resistor across each cell in the string to make the cell maximum voltage equal to prevent voltage unbalance. This dissipative circuit is not good for energy preservation. The nondissipative battery balancing circuits approach is based on dc/dc converters, such as the flyback converter [3],[5],[7] the buckboost converter .the switch capacitor converter , etc The principle is to transfer energy from the higher voltage cell to the lower voltage cell less power loss; it is more energy efficient. However, an additional batterybalancing circuit not only increases circuits complexity and cost but also reduces efficiency hybrid technology with battery balancing is proposed. Additionally, the switch angle is controlled to contain the ac output voltage with minimal total harmonic distortion (THD).
Power Point Tracking (MPPT) techniques are needed to maintain the PV arrays operating point at its MPP. The P&O, incremental conductance (INC) method are the most known methods to track the MPP by updating repeatedly the operating voltage of the PV array varying the duty cycle of the power converter with a fixed step size. However, by incorporating maximum power point tracking (MPPT) algorithms, the photovoltaic systems power transfer efficiency can be improved significantly as it can continuously maintain the operating point of the solar panel at the MPP pertaining to that irradiation and temperature.
This paper presents a PV system array connected to Cascaded HBridge type multilevel inverter to achieve sinusoidal voltage
waveform and output sinusoidal current to the load with a simple power electronic solution. The topologies of multilevel inverters are classified in to three types the Flying capacitor inverter, the Diode clamped inverter and the Cascaded bridge inverter. The cascaded multicarrier multilevel inverter strategy reduced total harmonic. Now requirement of filter size also becomes less. Voltage and harmonics are plotted and compared with normal PWM inverter to capitalise the required result.
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SYSTEM DESCRIPTIONS
Among topologies of multilevel inverters, the cascaded multilevel inverter with separate dc sources is superior to the other multilevel structures in terms of its structure which is simple and modular. the conventional 2N + 1level multilevel inverter composed of N individual fullbridge inverters and N batterie
Fig.3. 2N + 1level inverter with battery balancing.
B = {B1, B2, . . . , Bn, . . . , BN }. (1)
TABLE 1
Relationships Of The Output Voltages Of Individual FullBridge Inverters And Their Switch States.
Each individual fullbridge inverter has a separate battery source Bn.
Thus, the individual fullbridge inverter can provide three different voltage outputs +VBn , 0, and VBn by different combinations of the
four switches Sn,A+, Sn,A, Sn,B+, and Sn,B as shown in Table I.
The output voltage vo of the multilevel inverter is equal to the sum of the voltages of the individual fullbridge inverters, shown as
N
vo =VBn (2)
n=1
where Vbn is the voltage of battery Bn. The set of the batteries providing the output voltage in the multilevel inverter can be defined as
Bsel = {B1, B2, . . . , Bn, . . . , BM }, M N. (3)
= { }
*
Bsort B1 , B , . . . , Bn , . . . , BN
EXISTING SYSTEM
Renewable energy sources such as wind turbines and photovoltaics are intermittent in nature and produce fluctuating active power. Interconnecting these intermittent sources to the utility grid on a large scale could affect the voltage/frequency control of the grid and lead to severe power quality issues. An energy storage system which contains a
large capacity of the battery bank is indispensable for countering uneven
2
in which the relation of battery voltages is V
Bn
VBn 1
(4)
compensation.
PROPOSED SYSTEM
1
n =1,n=2N . This means that the battery with the highest voltage is denoted as B , the battery with the second highest voltage is denoted as
*
Better battery storage performances, many battery charging strategies have been presented.
In order to reduce energy loss in transmission lines and increase the
B2 , and the battery with the lowest voltage is denoted as BN . Using
the Fourier series analysis, the rootmeansquare (rms) voltage and the hth harmonic H(h) of the quasisinusoidal wave can be expressed as [34][36]
,
v
B2
1
h,rms B , . . . , BN
overall battery capacity, the battery bank is series connected for a high voltage dc power supply.

DESIGN EXAMPLE
In order to verify the performance of the proposed singlephase
= 4 VB1 cosh 1 +VB1 cosh 2 +
2h
h = 1, 3, 5, 7.
+V cosh ,
B1 N
Â· Â·
(5)
multilevel inverter with battery balancing, a sevenlevel inverter for providing a 110V ac source is designed and implemented. The circuit specifications are listed in Table II. Fig shows the block diagram of the realized sevenlevel inverter that comprises three individual fullbridge
According to (5), the switching angles 1, 2, . . . , N can be found such that the THD is minimized and the rms of the fundamental frequency is
close to the reference voltage v1,rms_ref . After that, M batteries for output voltage are decided according to the switching angles 1, 2, . . . , N . Finally, these M batteries with higher voltage are chosen and shown as
,
B = B , B . . . , B . (6)
}
inverters and a controller. By using the NewtonRaphson method, we can find a set of switching angles 1, 2, and 3 to meet (9)(11). If the switching angles 1, 2, and 3 cannot meet all of (9)(11), then (9) will be the priority. Since finding a set of switching angles 1, 2, and 3 by using the NewtonRaphson method requires complex computing, the realtime decision and control are difficult to be realized. In this paper, a lookup table is built for the controller to solve this problem.
M { 1 2 M
The output voltage of the multilevel inverter can be expressed as
M
vo =VB = VB + VB +
+ V . (7)
i=1
i 1 2

Â· Â· B M
As shown in Fig. 3, a quasisinusoidal wave can be generated. Assume that the load current IL is constant during a halfcycle of a sinusoidal wave;
the discharge capacities QBn of battery Bn can be expressed as

( 2n) (8)

where n is the nth switch angle and n n+1. Clearly, the discharging capacity of a battery with higher voltage is greater
than that of a battery with lower voltage. Thus, the battery balancing function is achieved.
The output voltage vo of the multilevel inverter is equal to the sum of the voltages of the individual fullbridge inverters.
Each individual fullbridge inverter has a separate battery source Bn. Thus, the individual fullbridge inverter can provide three different voltage outputs +VBn , 0, and VBn by different combinations of the four switches Sn,A+, Sn,A, Sn,B+, and Sn,B as shown in Table I.
The output voltage vo of the multilevel inverter is equal to the sum of the voltages of the individual fullbridge inverters.
Fig.4.System block diagram of the realized prototype
Fig.5.Output voltage waveform of the proposed sevenlevel inverter.
The controller is mean t to achieve battery balancing and selective harmonic elimination the suitable switching angles 1, 2, and 3.


THE CONTROLLER INCLUDES AS

Batterybalancing algorithm

Harmonicreducing algorithm

MOSFET state control algorithm.
In this prototype, a microprocessor HT46R24 is adopted as the controller.
Batterybalancing algorithm
Different algorithms of cell balancing are often discussed when multiple serial cells are used in a battery pack for particular device. The means used to perform cell balancing typically include bypassing some of the cells during charge (and sometimes during discharge) by connecting external loads parallel to the cells through controlling corresponding FETs. The typical bypass current ranges from a few milliamps to amperes.

Normal status
In the S8209B Series, both of CO and DO pin get the VDD level; the voltage between VDD and VSS (VDS) is morethan the overdischarge detection voltage (VDL), and is less than the overcharge detection voltage (VCU) andrespectively, the CTLC pin input voltage (VCTLC) > the CTLC pin voltage "L" (VCTLCL), the CTLD pin input voltage(VCTLD) > the CTLD pin voltage "L" (VCTLDL). This is the normal status.

Overcharge status
In the S8209B Series, the CO pin is in high impedance; when VDS gets VCU or more, or VCTLC gets VCTLCL or less.This is the overcharge status.If VDS gets the overcharge release voltage (VCL) or less, and VCTLC gets the CTLC pin voltage "H" (VCTLCH) or more,the S8209B Series releases the overcharge status to return to the normal status.

Overdischarge status
In the S8209B Series, the DO pin is in high impedance; when VDS gets VDL or less, or VCTLD gets VCTLDL or less. This is the overdischarge status. If VDS gets the overdischarge release voltage (VDU) or more, and VCTLD gets the CTLD pin voltage "H" (VCTLDH) or more, the S8209B Series releases the overdischarge status to return to the normal status.

Cellbalance function
In the S8209B Series, the CB pin gets the level of VDD pin; when VDS gets the cellbalance detection voltage (VBU) or moe. This is the charge cellbalance function. If VDS gets the cellbalance release voltage (VBL) or less again, the S8209B Series sets the CB pin the level of VSS pin. In addition, the CB pin gets the level of VDD pin; when VDS is more than VDL, and VCTLD is VCTLDL or less. This is the discharge cellbalance function. If VCTLD gets VCTLDH or more, or VDS is VDL or less again, the S8209B Series sets the CB pin the level of VSS pin.
Harmonic Reduction:
To eliminate 5th, 7th, and 9th order harmonics, the firing angles for each level is found by solving the following equations.
Cos 5a1 + Cos 5a2 + Cos 5a3 + Cos 5a4 = 0 Cos 7a1 + Cos 7a2 + Cos 7a3 + Cos 7a4 = 0 Cos 9a1 + Cos 9a2 + Cos 9a3 + Cos 9a4=0
The Battery Energy Storage System
An energy storage system is indispensable for compensation of the activepower fluctuations, which is often referred to as power leveling. For example, if a wind turbine generator produces a larger power than an average power over a period of time, say several seconds to 30 min, the energy storage system stores the excess power from the grid. On the other hand, if the generator produces a smaller power, it releases the shortage of power back to the grid. The energy storage system brings a significant enhancement in power quality, stability, and reliability to the grid. Batteries are dc sources, power conversion is required to interface these batteries to the ac system. The most convenient way of conversion is to have a fourquadrant converter so that a bidirectional energy flow can be achieved. Voltage Source Inverters (VSI) have been traditionally used to modulate the energy flow. The voltage source inverter can be controlled to deliver real power or reactive power simultaneously and independently. Hysteresis current control with its simple design can also be used with its inherent advantages. The frontend converter regulates the real and reactive power demand of the power system under linear and nonlinear loads. The proposed scheme has the following features,

Has an integrated battery charging system in the main control function.

Provides load leveling feature.

Provides active filtering to eliminate the harmonics

Ensures unity power factor although the load is inductive

Has simple modular control scheme.

Considerations on the battery energy storage system based on a multilevel cascade PWM converter can be categorized as Follows:

Activepower control of individual converter cells: Production tolerances, uneven temperature conditions, and differences in ageing characteristics may eventually bring one or more battery units to reduced powerhandling capacities. Therefore, an activepower control of individual converter cells is indispensable to enable the multiple battery units operate at different power levels. It is also advantageous when one or more of the battery units are replaced by new ones. This paper discusses the issue in detail.

Optimization between the cascade number and the dc voltage: The ncascade number2 affects communication and reliability issues while the dc voltage affects cost and life issues of battery units. Therefore, optimization between them is an important design consideration.

Battery cost and life: The cost and life of battery units are the major hurdles in putting largescale battery energy storage systems into practical use. Comprehensive research and development have to be achieved on cost reduction and life expansion.

SOCbalancing of battery units: The SOC of a battery is its available capacity expressed as Percentage of its maximum available capacity. Due to batteryunit tolerances, unequal convertercell losses, and so on, SOC imbalance may occur among multiple battery units. This may result in reducing the total availability of the battery units and may also cause over charge/over discharge of a particular battery unit


INVERTER [MOSFET] (DCAC)
Advanced operations.
Theres a lot more that you can do with MATLAB than is listed in this handout. Check
out the MATLAB help or one of the Other Resources if you want to learn more about
the following more advanced tools:

Numerical integration (quad)

Discrete Fourier transform (fft, ifft)

Statistics (mean, median, std, var)

Curve fitting (cftool)

Signal processing (sptool)

Numerical integration of systems of ODEs (ode45)

Mfiles and functions
This circuit is simulated in MATLAB and the harmonics are obtained using FFT analysis. The output waveform is shown in the Fig.
Inverter:
Converts DC to AC power by switching the DC input voltage (or current)in a predetermined sequence so as to generate AC voltage (or current) output.
Filtering:
Output of the inverter is chopped AC voltage with zero DC component.In some applications such as UPS, high purity sine wave output is required.An LC section lowpass filter is normally fitted at the inverter output to reduce the high frequency harmonics. In some applications such as AC motor drive, filtering is not required.
A power inverter, or inverter, is an electrical power converter that changes direct current (DC) to alternating current (AC); the converted AC can be at any required voltage and frequency with the use of appropriate transformers, switching, and control circuits.


SIMULATION OF HYBRID TECHNOLOGYUSING 7 LEVEL INVERTER
MATLAB, which stands for MATrix LABoratory, is a software package developed by MathWorks, Inc. to facilitate numerical computations as well as some symbolic manipulation. The collection of programs (primarily in FORTRAN) that eventually became MATLAB were Developed in the late 1970s by Cleve Moler, who used them in a numerical analysis course he was teaching at the University of New Mexico. Jack Little and Steve Bangert later reprogrammed these routines in C, and added Mfiles, toolboxes, and more powerful graphics(original versions created plots by printing asterisks on the screen). Moler, Little, and Bangert founded MathWorks in California in 1984
MATLAB
MATLAB (MATrix LABoratory) is a tool for numerical computation and visualization The basic data element is a matrix, so if you need a program that manipulates arraybased data it is generally fast to write and run in MATLAB (unless you have very large arrays or lots of computations, in which case youre better off using C or Fortran).
Fig.6.7Level Inverter Simulink diagram.
Fig.7.7 Level Inverter Simulink Output

EXPERIMENT RESULTS
The hardware is fabricated and tested in the laboratory. Top view of the proposed 7level inverter hardware is shown in Fig The control circuit and power circuit of proposed 7level inverter is shown in Fig and c, respectively. The hardware implement tation and hardware output voltage of proposed 7level inverter shown in Fig. the battery discharging voltage and current curves in a fully discharging period. The discharging voltage of the battery pack begins at 52 V and stops at 44 V. The total discharging time is 13 690 s.
Fig.8.Picture of the 1kW prototype
Fig.9.Hardware output of proposed 7level inverter
Fig.10.Battery discharging voltages and currents of the realized prototype.
Fig.11.Battery discharging voltages and currents during 9911000 s.
.
Fig.12.Battery discharging voltage curves of a conventional inverter without battery balancing.
Fig.13. Battery discharging voltage and current curves of the realized prototype.
TABLE 2
Discharging capacities of batteries with and without the batterybalancing function
B2, and B3 discharging with batterybalancing function can obtain a greater discharging capacity to proving to load
Precautions

The application conditions for theinput voltage, output voltage, and load current should not exceed the package power dissipation.

Do not apply an electrostatic discharge to this IC that exceeds the performance ratings of the builtin electrostatic protection circuit.

SII claims no responsibility for any and all disputes arising out of or in connection with any infringement by products including this IC of patents owned by a third party.


CONCLUSION
In this paper, hybrid technology with battery balancing has been proposed and proved successful. The input of each individual inverter is directly connected to a battery. The combination of batteries can be controlled according to the batteries voltages to implement the battery balancing function. A prototype was designed and implemented to verify the feasibility and excellent performance. Experiments show that the batterybalancing discharge function was achieved as we wanted. Additionally, the switch angle is controlled to contain the ac output voltage with minimal THD.
REFERENCES

T. Hirose and H. Matsuo, Standalone hybrid windsolar power generation system applying dump power control without dump load, IEEE Trans. Ind. Electron., vol. 59, no. 2, pp. 988997, Feb. 2012.

H. Kanchev, D. Lu, F. Colas, V. Lazarov, and B. Francois, Energy management and operational planning of a microgrid with a PVbased active generator for smart grid applications, IEEE Trans. Ind. Electron., vol. 58, no. 10, pp. 45834592, Oct. 2012.

Z. Haihua, T. Bhattacharya, T. Duong, T. S. T. Siew, and
M. Khambadkone, Composite energy storage system involving battery and ultracapacitor with dynamic energy management in microgrid applications, IEEE Trans. Power Electron., vol. 26, no. 3, pp. 923 930, Mar. 2011.

H. Qian, J. Zhang, J. S. Lai, and W. Yu, A highefficiency grid tie battery energy storage system, IEEE Trans. Power Electron., vol. 26, no. 3, pp. 886896, Mar. 2011.

Chen Qi and Zhu Ming,"Photovoltaic Module for a standalone PV system,"International Conference on applied physics and Industrial Engineering,pp.94100, ,2012. ESRSA Publication

Z. Haihua, T. Bhattacharya, T. Duong, T. S. T. Siew, and A.
M. Khambadkone, Composite energy storage system involving battery and ultracapacitor with dynamic energy management in microgrid applications, IEEE Trans. Power Electron., vol. 26, no. 3, pp. 923 930, Mar. 2011.

N.Pandiarajan and Ranganath Muthu,"Mathematical Modeling of Photovoltaic module with simulink",International Conference on Electrical Energy systems(ICEES 2011), January 35, 314319, 2011.

H. Taghizadeh and M. T. Hagh, Harmonic elimination of cascade multilevel inverters with nonequal DC sources using particle swarm optimization, IEEE Trans. Ind. Electron., vol. 57, no. 11, pp. 36783684, Nov. 2010.

S. Mekhilef and M. N. A. Kadir, Novel vector control method for threestage hybrid cascaded multilevel inverter, IEEE Trans. Ind. Electron., vol. 58, no. 4, pp. 13391349, Apr. 2011.

A. Shukla, A. Ghosh, and A. Joshi, Flyingcapacitorbased chopper circuit for DC capacitor voltage balancing in diodeclamped multilevel inverter, IEEE Trans. Ind. Electron., vol. 57, no. 7, pp. 22492261, Jul. 2010.

Hassanzadeh, T. Meybodi,M,R.MahmoudiThe.F ,(2011):An improved Firefly Algorithm for optimization in static environment Fifth Iran Data Mining Conference / IDMC 2011.

P. Lezana, J. Pou, T. A. Meynard, J. Rodriguez, S. Ceballos, and F. Richardeau, Survey on fault operation on multilevel inverters, IEEE Trans. Ind. Electron, vol. 57, no. 7, pp. 22072218, Jul. 2010

A. K. Sadigh, S. H. Hosseini, M. Sabahi, and G. B. Gharehpetian, Double flying capacitor multicell converter based on modified phaseshifted pulse width modulation, IEEE Trans. Power Electron., vol. 25, no. 6 pp. 15171526, Jun. 2010.

M. Malinowski, K. Gopakumar, J. Rodriguez, and M. Perez,
A survey on cascaded multilevel inverters, IEEE Trans. Ind. Electron., vol. 57, no. 7, pp. 21972206, Jul. 2010.

P. Lezana, J. Pou, T. A. Meynard, J. Rodriguez, S. Ceballos, and F. Richardeau, Survey on fault operation on multilevel inverters, IEEE Trans. Ind. Electron, vol. 57, no. 7, pp. 22072218, Jul. 2010.

D. Andrea, ''Battery Management Systems for Large Lithium Ion Battery Packs", ISBN 1608071049, Sep 30, 2010.

M. Daowd1, N.Omar1,2, P.Bossche2, J.Mierlo1, "Passive and Active Battery Balancing comparison based on MATLAB Simulation", 2011 IEEE.

D. V. Cadar, D. M. Petreus and T. M. Patarau, An Energy Converter Method for Battery Cell Balancing, IEEE 33rd International Spring Seminar on Electronics Technology (ISSE), pp. 290293, 2010.