Performance analysis of active clamped interleaved
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The document presents a performance analysis of an active-clamped interleaved fly-back inverter designed for photovoltaic applications, proposing a new control strategy that combines active clamp and phase control. The study demonstrates that the interleaving technique reduces ripple, lowers component costs, and enhances efficiency, especially under varying power conditions from solar energy. Simulations conducted using MATLAB indicate significant improvements in switching loss and performance metrics when integrated with photovoltaic systems.
![IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
__________________________________________________________________________________________
Volume: 02 Issue: 11 | Nov-2013, Available @ http://www.ijret.org 722
MPPT control. the 120 HZ harmonic frequency which distorts
the PV voltage and PV current are removed by the decoupling
capacitor. there are main switches, diodes, transformers, in each
phase. The voltage spikes across the main switch is reduced by
the clamp circuit. the isolation between the PV module and the
grid line is produced by the transformer .it also boosts the
voltage. the connection between the AC power produced by the
transformer and grid line is employed by the unfolding bridge.
The steady state operating stages are given below.
Fig. 2 Equivalent circuits in steady-state operation
(a) Mode 1 [t0 –t1 ]. (b) Mode 2 [t1 –t2 ]. (c) Mode 3 [t2 –t3 ].
(d) Mode 4 [t3 –t4 ]. (e) Mode 5 [t4 –t5 ].
(f) Mode 6 [t5 –t6 ]. (g) Mode 7 [t6 –t7 ]. (h) Mode 8 [t7 –t8 ].
(i) Mode 9 [t8 –t9 ]. (j) Mode 10 [t9 –t10 ].
Due to the simplicity of control the discontinuous mode is
considered.the main switches are provided with two gate
signals of 180degree phase shift.sp1 and sp2 are the main
switches.sa1 sa2 are the active clamp switches.the gate signals
of the clamp switches are applied for short time to reduce the
conduction loss of the switches. The ILFI activates a single-
phase converter without the active clamp circuit using the phase
control method and the active clamp control method because
the output power of the PV module is higher than half of the PV
module maximum power and the voltage spike across main
switch Sp1 is smaller than the Sp1 voltage rating. Therefore,
the second-phase converter loss and clamp circuit loss can be
removed. In Fig. 3(b), the ILFI activates a single-phase
converter with the active clamp circuit using the phase control
method because the output power of the PV module is smaller
than half of the PV module maximum power and the voltage
spike across the Sp1 is larger than the Sp1 voltage rating.
Therefore, the second-phase converter loss can be eliminated.
When the output power of the PV module is larger than half of
PV module maximum power and the voltage spikes across main
switch Sp1 , and Sp2 is larger than the Sp1 ,and Sp2 voltage
rating, the ILFI is fully activated as represented.
3. ACTIVE CLAMP CONTROL METHOD
Solar irradiance and atmospheric temperature influence the
output power of the PV module. based on the irradiance values
of the weather conditions the efficiency of the ILFI has to be
improved. the active clamp circuit reduces the voltage spikes
across the main switch. ILFI is made of two phases. The losses
are reduced by controlling each phase of the ILFI the sp1
voltage without the clamp circuit. the sum of input voltage vin
through the PV module ,the feedback voltage, spike
voltagevsp1 forms the voltage across sp1 when sp1 is turned
off.sp1 is failed when the vsp1 is above the switch rating
voltage VRT .thus active clamp circuits have been used in
flyback inverter for reducing voltage across main switch. the
waveform of the main switch when the clamp circuit is
used.clamp capacitor Cc1 absorbs the energy in the Llk1 of the
transformer.this reduces the voltage spike across the main
switch.thus a new active clamp control has been used to reduce
the conduction loss ,switching loss of the clamp circuit.
4. MODELLING OF PV ARRAY
The only way to generate power from sun is done by usage of
photovoltaic cells. besides being efficient they are convenient to
use. silicon is the material used for manufacturing of PV cells.
solar cell preparation should be in a very clean environment. In
this technology the energy from sun is transformed into direct
current electricity.maximum power point is a unique operating
point supplying maximum power to the load which is present in
a PV array. tracking the maximum power point of the PV array
is done to improve the efficiency of the photovoltaic energy
system MPPT is an electronic system that operates the
Photovoltaic (PV) modules in a manner that allows the modules
to produce all the power capable of PV module MPPT is not a
mechanical tracking system that “physically moves” the
modules to make them point more directly at the sun. MPPT is
a fully electronic system that varies the electrical operating
point of the modules, so that the modules are able to deliver
maximum available power. Additional power harvested from
the modules is then made available as increased battery charge
current.
Fig 4 equilant circuit](https://image.slidesharecdn.com/performanceanalysisofactive-clampedinterleaved-140807010647-phpapp01/85/Performance-analysis-of-active-clamped-interleaved-2-320.jpg)
![IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
__________________________________________________________________________________________
Volume: 02 Issue: 11 | Nov-2013, Available @ http://www.ijret.org 725
Table 1
Calculation:
Switching loss: Coss*Vds*Fsw
= 400*10^-12*70000
= 0.00154
Motor load: without PV
Input voltage-100V
Output current-2A
Output voltage-300V
Motor speed-1300rpm
Motor torque-0.5
With PV for R load
PV input voltage- 32.4V
Output voltage- 49V
Output current -0.3A
With PV for motor load(single phase induction motor)
PV input voltage-32.4V
Output voltage-80V
Output current -1A
Motor speed- 112rpm
CONCLUSIONS
Thus the interleaved flyback inverter has been simulated using
MATLAB. Active clamp control method has been proposed to
reduce the switching loss of the interleaved flyback inverter.the
proposed inverter is simulated using PV . this paper can be
further improved by using other forms of renewable energy
sources.
REFERENCES:
[1] C. T. Choi, C. K. Li, and S. K. Kok(1999), “Control of
an active clamp discontinuousconduction mode flyback
converter,” in Proc. IEEE Power Electron.Drive Syst.
Conf., vol. 2, pp. 1120–1123.
[2] R. Watson, F. C. Lee, and G. Hua (1996), “Utilization
of an active-clamp circuitto achieve soft switching in
flyback converters,” IEEE Trans. PowerElectron., vol.
11, no. 1, pp. 162–169.
[3] Y.-K. Lo and J.-Y. Lin (2007), “Active-clamping ZVS
flyback converter employingtwo transformers,” IEEE
Trans. Power Electron., vol. 22, no. 6,pp. 2416–2423.
[4] G.-B. Koo and M.-J. Youn (2004), “A new zero voltage
switching active clampflyback converter,” in Proc. IEEE
Power Electron. Spec. Conf., Pp. 508–510.
[5] F. Max Savio, R. Hemantha Kumar and M. Sasikumar
(2013), “Power Optimisation and Performance
Evolution of High Step-Up Solar PV System For Dc
Drives”, International Journal of Advanced Research in
Electrical, Electronics and Instrumentation Engineering
(IJAREEIE),Vol. 2, Issue 10, Pp. 4620-4627.
[6] A.Amalin Rishma and, P.Rajarajeswari (2012), ‘High
Efficiency Modified Pulse-Width Modulation
Bidirectional Converter for Medium Power Drives”
International Journal of Application or Innovation in
Engineering & Management (IJAIEM),Vol.1, Issue 2,
Pp. 94-100.
[7] T. M. Chen and C.-T. M. Chen and C.-L. Chen (2002),
“Analysis and design of asymmetrical halfbridge
Flyback converter,” IEE Proc.-Electr. Power Appl., vol.
149, no. 6,pp. 433–440.
[8] M.Ragavendran and Dr. M. Sasikumar (2013), “Three-
Port Full-Bridge Converters With Wide Voltage Range
Input For Solar Power Systems’ International Journal Of
Engineering And Computer Science, Volume 2 Issue
6,Pp. 1777-1683.
[9] N. Kasa, T. Iida, and L. Chen(2005), “Flyback inverter
controlled by sensorless current MPPT for photovoltaic
power system,” IEEE Trans. Ind. Electron., vol. 52, no.
4, pp. 1145–1152.
[10] D. Fu, Y. Liu, F. C. Lee, and M. Xu (2009), “A novel
driving scheme for synchronous rectifiers for LLC
resonant converters,” IEEE Trans. PowerElectron., vol.
24, no. 9, pp. 1321–1329.
[11] D. Fu, Y. Liu, F. C Lee, andM. Xu(2008), “An improved
novel driving scheme ofsynchronous rectifiers for LLC
resonant converters,” in Proc. IEEE Appl.Power
Electron. Conf., pp. 510–516.
[12] A. C. Kyritsis, E. C. Tatakis, and N. P. Papanikolaou
(2008), “Optimum design of the current-source flyback
inverter for decentralized grid-connected Photovoltaic
systems,” IEEE Trans. Energy Convers., vol. 23, no. 1,
pp. 281–293.
[13] J. Zhang, X. Huang, X. Wu (2010), “A high efficiency
Flyback converter with newactive clamp technique,”
IEEE Trans. Power Electron.,vol. 25, no. 7, p. 1775–
1785.
[14] Sasikumar M. and Chenthur Pandian S. (2012),
‘Modified Bi-Directional AC/DC Power Converter with
Power Factor Correction’, International Journal of
Engineering-Transactions B: Applications, Vol. 25,
Issue 3, Pp. 175-180.
Input voltage Output voltage Output current
30v 140v 1.4A
50v 200v 2A
75v 290v 3A
100v 400v 3.9A](https://image.slidesharecdn.com/performanceanalysisofactive-clampedinterleaved-140807010647-phpapp01/85/Performance-analysis-of-active-clamped-interleaved-5-320.jpg)
Performance analysis of active clamped interleaved
- 1. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308 __________________________________________________________________________________________ Volume: 02 Issue: 11 | Nov-2013, Available @ http://www.ijret.org 721 PERFORMANCE ANALYSIS OF ACTIVE-CLAMPED INTERLEAVED FLY-BACK INVERTER FOR PHOTOVOLTAIC APPLICATIONS C.Kirthana1 , R.Deepa2 , M.SasiKumar3 1,2 PG Scholar, Department of Power Electronics & Drives, Jeppiaar Engineering College, Chennai 3 Professor and Head, Department of Electrical and Electronics &Drives, Jeppiaar Engineering College, Chennai kirthi46@gmail.com, deepa.red7@gmail.com, pmsasi77@gmail.com Abstract A new control strategy has been proposed for the interleaved flyback inverter. the proposed method consists of two control strategies, they are active clamp control and phase control. Based on the output power of the PV module each converter phase of an ILFI is controlled. due to the active clamp control method the energy in the leakage inductance can be fully recycled. the concept of interleaving reduces the ripple and reduces the usage of capacitors. The induction motor drive has been used the speed performance of the drive has been analyzed .simulations are done using MATLAB. The parameters are analyzed without PV and with PV. The explanations, theories and results are discussed further. Keywords- interleaved flyback inverter, active clamp, photovoltaic, induction motor drive --------------------------------------------------------------------***-------------------------------------------------------------------- 1. INTRODUCTION Nowadays the standby power loss and efficiency of the power supply are of major concern .the average efficiency instead of full load efficiency is important for external power supplies such as adaptors. the challenge for the power supply design is created by the light load and full load efficiency. for offline applications flyback converters are used generally due to its simplicity and low cost.to dissipate the leakage energy when the switch is off an RCD clamp circuit is used. To minimize the voltage spikes across the switch becomes difficult with the presence of well coupled transformer with minimized leakage inductance.this results in usage of a labor intensive manufacturing process. by reducing the leakage inductance energy loss the efficiency can be improved. The concept of interleaving enables these converter topologies to operate at increased power levels. The benefits of interleaving include Reduced RMS current in the input capacitors enabling the use of less expensive and fewer input capacitors Ripple current cancellation in the output capacitor, enabling the use of less expensive and fewer output capacitors Reduction of peak currents in primary and secondary transformer windings. Improved transient response as a result of reducing output filter inductance and higher output ripple frequency Separation of heat generating components allowing for reduced heat sink requirements . Improved form factor for low profile solutions Reduced EMI as a result of reduced peak currents (2L interleaved forward converter. 2. ILFI STRUCTURE & MODES OF OPERATION Fig. 1 ILFI structure The ILFI is designed for a PV AC module system. A decoupling capacitor, first phase converter, second phase converter, unfolding bridge, and C-L filter are present in the proposed inverter. The maximum power point tracking is essential for the generation of peak power in the PV AC module system. constant PV voltage and PV current are required for
- 2. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308 __________________________________________________________________________________________ Volume: 02 Issue: 11 | Nov-2013, Available @ http://www.ijret.org 722 MPPT control. the 120 HZ harmonic frequency which distorts the PV voltage and PV current are removed by the decoupling capacitor. there are main switches, diodes, transformers, in each phase. The voltage spikes across the main switch is reduced by the clamp circuit. the isolation between the PV module and the grid line is produced by the transformer .it also boosts the voltage. the connection between the AC power produced by the transformer and grid line is employed by the unfolding bridge. The steady state operating stages are given below. Fig. 2 Equivalent circuits in steady-state operation (a) Mode 1 [t0 –t1 ]. (b) Mode 2 [t1 –t2 ]. (c) Mode 3 [t2 –t3 ]. (d) Mode 4 [t3 –t4 ]. (e) Mode 5 [t4 –t5 ]. (f) Mode 6 [t5 –t6 ]. (g) Mode 7 [t6 –t7 ]. (h) Mode 8 [t7 –t8 ]. (i) Mode 9 [t8 –t9 ]. (j) Mode 10 [t9 –t10 ]. Due to the simplicity of control the discontinuous mode is considered.the main switches are provided with two gate signals of 180degree phase shift.sp1 and sp2 are the main switches.sa1 sa2 are the active clamp switches.the gate signals of the clamp switches are applied for short time to reduce the conduction loss of the switches. The ILFI activates a single- phase converter without the active clamp circuit using the phase control method and the active clamp control method because the output power of the PV module is higher than half of the PV module maximum power and the voltage spike across main switch Sp1 is smaller than the Sp1 voltage rating. Therefore, the second-phase converter loss and clamp circuit loss can be removed. In Fig. 3(b), the ILFI activates a single-phase converter with the active clamp circuit using the phase control method because the output power of the PV module is smaller than half of the PV module maximum power and the voltage spike across the Sp1 is larger than the Sp1 voltage rating. Therefore, the second-phase converter loss can be eliminated. When the output power of the PV module is larger than half of PV module maximum power and the voltage spikes across main switch Sp1 , and Sp2 is larger than the Sp1 ,and Sp2 voltage rating, the ILFI is fully activated as represented. 3. ACTIVE CLAMP CONTROL METHOD Solar irradiance and atmospheric temperature influence the output power of the PV module. based on the irradiance values of the weather conditions the efficiency of the ILFI has to be improved. the active clamp circuit reduces the voltage spikes across the main switch. ILFI is made of two phases. The losses are reduced by controlling each phase of the ILFI the sp1 voltage without the clamp circuit. the sum of input voltage vin through the PV module ,the feedback voltage, spike voltagevsp1 forms the voltage across sp1 when sp1 is turned off.sp1 is failed when the vsp1 is above the switch rating voltage VRT .thus active clamp circuits have been used in flyback inverter for reducing voltage across main switch. the waveform of the main switch when the clamp circuit is used.clamp capacitor Cc1 absorbs the energy in the Llk1 of the transformer.this reduces the voltage spike across the main switch.thus a new active clamp control has been used to reduce the conduction loss ,switching loss of the clamp circuit. 4. MODELLING OF PV ARRAY The only way to generate power from sun is done by usage of photovoltaic cells. besides being efficient they are convenient to use. silicon is the material used for manufacturing of PV cells. solar cell preparation should be in a very clean environment. In this technology the energy from sun is transformed into direct current electricity.maximum power point is a unique operating point supplying maximum power to the load which is present in a PV array. tracking the maximum power point of the PV array is done to improve the efficiency of the photovoltaic energy system MPPT is an electronic system that operates the Photovoltaic (PV) modules in a manner that allows the modules to produce all the power capable of PV module MPPT is not a mechanical tracking system that “physically moves” the modules to make them point more directly at the sun. MPPT is a fully electronic system that varies the electrical operating point of the modules, so that the modules are able to deliver maximum available power. Additional power harvested from the modules is then made available as increased battery charge current. Fig 4 equilant circuit
- 3. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308 __________________________________________________________________________________________ Volume: 02 Issue: 11 | Nov-2013, Available @ http://www.ijret.org 723 5. CURRENT CONDUCTION IN SOLAR CELL An ultra thin layer of phosphorus-doped (N type) silicon on top of (P type ) silicon form a PV cell. when these two materials are in contact an electrical field is created called P-N junction .a momentum and direction is provided by this electrical field when sun light strikes the surface of a pv cell. thus when the solar cell is connected to the electrical field current flow takes place. area of the cell,atmospheric conditions determine the current from a PV cell. When the individual cells are connected in series, the voltage produced by the combination is the algebraic sum of the individual cell voltages. Whereas when the cells are connected in parallel, the resultant current is the algebraic sum of the individual cell currents. So depending upon our power requirement we connect the PV cells in series and parallel combinations to form a Photovoltaic array. 6. SIMULATION AND RESULTS Fig. 5 simulink model of a PV array Fig. 6 subsystem From the Fig it can be observed that, the equations for the photovoltaic current Ipv and diode saturation current Io are modeled individually and then put together to obtain the equation for the PV panel. The series resistance Rs and parallel resistance Rp for the configuration of our panel is estimated taking into account the number of series and parallel cells (Ns and Np) Fig. 7 ILFI simulink model Fig. 8 pulse generation
- 4. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308 __________________________________________________________________________________________ Volume: 02 Issue: 11 | Nov-2013, Available @ http://www.ijret.org 724 Fig 9 output current and voltage waveform Fig. 10 ILFI fed induction motor model Fig.11 motor speed and torque waveform without PV Fig. 12 simulink model with PV Fig. 13 output current and voltage waveform Fig.14 motor speed and torque waveform with PV
- 5. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308 __________________________________________________________________________________________ Volume: 02 Issue: 11 | Nov-2013, Available @ http://www.ijret.org 725 Table 1 Calculation: Switching loss: Coss*Vds*Fsw = 400*10^-12*70000 = 0.00154 Motor load: without PV Input voltage-100V Output current-2A Output voltage-300V Motor speed-1300rpm Motor torque-0.5 With PV for R load PV input voltage- 32.4V Output voltage- 49V Output current -0.3A With PV for motor load(single phase induction motor) PV input voltage-32.4V Output voltage-80V Output current -1A Motor speed- 112rpm CONCLUSIONS Thus the interleaved flyback inverter has been simulated using MATLAB. Active clamp control method has been proposed to reduce the switching loss of the interleaved flyback inverter.the proposed inverter is simulated using PV . this paper can be further improved by using other forms of renewable energy sources. REFERENCES: [1] C. T. Choi, C. K. Li, and S. K. Kok(1999), “Control of an active clamp discontinuousconduction mode flyback converter,” in Proc. IEEE Power Electron.Drive Syst. Conf., vol. 2, pp. 1120–1123. [2] R. Watson, F. C. Lee, and G. Hua (1996), “Utilization of an active-clamp circuitto achieve soft switching in flyback converters,” IEEE Trans. PowerElectron., vol. 11, no. 1, pp. 162–169. [3] Y.-K. Lo and J.-Y. Lin (2007), “Active-clamping ZVS flyback converter employingtwo transformers,” IEEE Trans. Power Electron., vol. 22, no. 6,pp. 2416–2423. [4] G.-B. Koo and M.-J. Youn (2004), “A new zero voltage switching active clampflyback converter,” in Proc. IEEE Power Electron. Spec. Conf., Pp. 508–510. [5] F. Max Savio, R. Hemantha Kumar and M. Sasikumar (2013), “Power Optimisation and Performance Evolution of High Step-Up Solar PV System For Dc Drives”, International Journal of Advanced Research in Electrical, Electronics and Instrumentation Engineering (IJAREEIE),Vol. 2, Issue 10, Pp. 4620-4627. [6] A.Amalin Rishma and, P.Rajarajeswari (2012), ‘High Efficiency Modified Pulse-Width Modulation Bidirectional Converter for Medium Power Drives” International Journal of Application or Innovation in Engineering & Management (IJAIEM),Vol.1, Issue 2, Pp. 94-100. [7] T. M. Chen and C.-T. M. Chen and C.-L. Chen (2002), “Analysis and design of asymmetrical halfbridge Flyback converter,” IEE Proc.-Electr. Power Appl., vol. 149, no. 6,pp. 433–440. [8] M.Ragavendran and Dr. M. Sasikumar (2013), “Three- Port Full-Bridge Converters With Wide Voltage Range Input For Solar Power Systems’ International Journal Of Engineering And Computer Science, Volume 2 Issue 6,Pp. 1777-1683. [9] N. Kasa, T. Iida, and L. Chen(2005), “Flyback inverter controlled by sensorless current MPPT for photovoltaic power system,” IEEE Trans. Ind. Electron., vol. 52, no. 4, pp. 1145–1152. [10] D. Fu, Y. Liu, F. C. Lee, and M. Xu (2009), “A novel driving scheme for synchronous rectifiers for LLC resonant converters,” IEEE Trans. PowerElectron., vol. 24, no. 9, pp. 1321–1329. [11] D. Fu, Y. Liu, F. C Lee, andM. Xu(2008), “An improved novel driving scheme ofsynchronous rectifiers for LLC resonant converters,” in Proc. IEEE Appl.Power Electron. Conf., pp. 510–516. [12] A. C. Kyritsis, E. C. Tatakis, and N. P. Papanikolaou (2008), “Optimum design of the current-source flyback inverter for decentralized grid-connected Photovoltaic systems,” IEEE Trans. Energy Convers., vol. 23, no. 1, pp. 281–293. [13] J. Zhang, X. Huang, X. Wu (2010), “A high efficiency Flyback converter with newactive clamp technique,” IEEE Trans. Power Electron.,vol. 25, no. 7, p. 1775– 1785. [14] Sasikumar M. and Chenthur Pandian S. (2012), ‘Modified Bi-Directional AC/DC Power Converter with Power Factor Correction’, International Journal of Engineering-Transactions B: Applications, Vol. 25, Issue 3, Pp. 175-180. Input voltage Output voltage Output current 30v 140v 1.4A 50v 200v 2A 75v 290v 3A 100v 400v 3.9A
- 6. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308 __________________________________________________________________________________________ Volume: 02 Issue: 11 | Nov-2013, Available @ http://www.ijret.org 726 REFERENCES C. Kirthana is currently pursuing the M.E Degree from Jeppiaar Engineering College, Anna University, Chennai, India. He received his B.E degree in Electrical and Electronics Engineering in 2012 from Jeppiaar Engineering College, Anna University, India. His current research interests include Induction Motor Drives and Power Electronics. R. Deepa is currently pursuing the M.E Degree from Jeppiaar Engineering College, Anna University, Chennai, India. He received his B.E degree in Electrical and Electronics Engineering in 2012 from Jeppiaar Engineering College, Anna University, India. His current research interests include Induction Motor Drives and Power Electronics. Dr. M. Sasikumar was born in Tamilnadu, India on June 17, 1977. He received the B.E degree in electrical and electronics engineering from K.S.Rangasamy College of Technology, Madras University, India in 1999, and the M.Tech degree in power electronics from VIT University, Vellore in 2006. He has obtained his Ph.d. degree from Sathyabama university, Chennai, tamilnadu, India in 2011. Currently, he is working as a Professor in Jeppiaar Engineering College, Anna University, Chennai. He has 12 years of teaching experience. He has published over 30 technical papers in National and International Conferences /proceedings / journals.