Pulse Density Modulation Pattern Pulse Density Modulation Pattern Optimization using Genetic Optimization using Genetic
AlgorithmsAlgorithmsDemian Pimentel, Ahmed Chériti,
Mohamed Ben Slima and Pierre Sicard
Presented at IECON 2006Presented at IECON 2006
By Pierre Sicard, Member, IEEEBy Pierre Sicard, Member, IEEE
November 2006November 2006
Prepared by D. PimentelPrepared by D. Pimentel
22
PresentatiPresentation layouton layout
33
I. Power electronics devicesII. Pulse-density modulation (PDM)III. Genetic algorithms (GA)IV. Application of GA to PDM pattern
generationV. Simulation resultsVI. Conclusions
Presentation layoutPresentation layout
44
I.Power Power electronielectroni
cs cs devicesdevices
55I.Power electronics Power electronics devicesdevices
Undesirable effects of PE devices on power distribution lines
66
Desired characteristics of new PE designs
Few total harmonic distortion (THD)High power factor (PF)High conversion efficiencyEntirely digital controlsCost and size reduction
I.Power electronics Power electronics devicesdevices
77
II.PDMPDM
88
Modulation technique used for resonant converters
Advantages compared to PWM▲ Higher power factor▼ Lower total harmonic distortion
▶Lower electromagnetic noise ◀Ease of implementation
DisadvantagesPF decreases as pulse-density decreasesTHD increases as pulse-density decreasesDiscrete output characteristicNon-linear power vs pulse-density curve
II.PDMPDM
99II.PDMPDM
Experimental Power Factor and THD for a PDM one-phase converter using 16 modulation levels
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
6 13 19 25 31 38 44 50 57 63 69 75 81 88 94 100
Pulse density (%)
Power factor
THD (%)
1010II.PDMPDM
0
10
20
30
40
50
60
70
80
90
100O
utp
ut
Po
we
r (%
)
6 13 19 25 31 38 44 50 57 63 69 75 81 88 94 100
Pulse density (%)
analyticalapproximation
simulation
2max seqoutput NseqPP
Output power vs. pulse density for a PDM one-phase converter using 16 modulation levels
1111II.PDMPDMSwitching modes
1212
Non-regular PDMpattern
generation
II.PDMPDM
Logic Control signals
1313
III.Genetic Genetic algorithmalgorithm
ss
1414
Rarely used for PE applicationsCan be employed for
OptimizationSearch problems
JargonChromosomesPopulationGenerationEnvironmentFitness function
GoalBring individuals within a population to
“evolve” towards desired solutionsStochastic process
III.Genetic algorithmsGenetic algorithms
1515III.Genetic algorithmsGenetic algorithmsAG representation and flow chart
1616III.Genetic algorithmsGenetic algorithmsAG common operators
1717
IV.GA GA applicatiapplicati
onon
1818
PDM optimal pattern generation using GAGA algorithm programmed using Matlab®
Simulink® was used to evaluate fitness▶Simulation of power system (SimPowerSystems)
Research spacePDM sequences are represented by bit stringsSynchronization of PDM sequences with line voltage
▶Length equals 1/120 s▶Resonant frequency = 15.96 kHz▶String length = 133 resonant cycles
Mutation operator was used“1” represents a pulse“0” represents a dead pulse
IV.GA applicationGA application
1919IV.GA applicationGA application
Simulink® block diagram
2020
Relationship betwen PF and THD
Fitness function
Termination conditions
IV.GA applicationGA application
21
cos
THDPF
targetedevaluatedTHD
targetedevaluatedPF
THDTHDfitness
PFPFfitness
stop
0
and
0
THD
PF
fitness
fitness
Pulse Densi
ty
8/ 133
16/ 133
24/ 133
32/ 133
40/ 133
PF 0.60.75
0.80.85
0.9
THD 1.3 0.8 0.7 0.6 0.5
2121
V.SimulatiSimulation on
resultsresults
2222V.Simulation resultsSimulation results
Load voltage produced by several AG-generated patterns with different pulse densities
2323V.Simulation resultsSimulation resultsLine current created by several AG-generated patterns with different pulse
densities
2424V.Simulation resultsSimulation results
Two similar AG-generated patterns
2525V.Simulation resultsSimulation results
Comparison: AG patterns perform significantly better.
2626
VI.ConclusioConclusionsns
2727
Significant improvement of PFSignificant reduction of THDEasy practical implementation of GA
patterns (single microcontroller)GA algorithm could be used to improve PF in
the range of 25-95% pulse-densityAlgorithm could be hardware-implemented
for auto-tuning devicesComponent agingChanging noisy environmentsLoad variationsSwitching frequency change
Additional parameters optimisationDC-link capacitor
VI.ConclusionsConclusions
2828
VII.ReferencReferenceses
2929
K. Bose, “Energy, Environment, and Advances in Power Electronics,” IEEE Transactions on Power Elec-tronics, Vol. 15, No. 4, pp. 688-701, 2000.
M. M. Morcos and J. C. Gómez, “Electric Power Qual-ity, The Strong Connection with Power Electronics,” IEEE power and energy magazine, pp. 18-25, Septem-ber / October 2003.
H. Fujita and H. Akagi, "Control and Performance of a Pulse-Density-Modulated Series-Resonant Inverter for Corona Discharge Process,” IEEE Transactions on Industry Applications, vol. 35, no. 3, pp. 621-627, May / June 1999.
H. Fujita and H. Akagi, "Pulse-Density-Modulated Power Control of a 4 kW, 450 kHz Voltage-Source In-verter for Induction Melting Applications,” IEEE Transactions on Industry Applications, vol. 32, no. 2, pp. 279-286, March / April 1996.
J. Essadaoui, P. Sicard, É. Ngandui and A. Chériti, “Power Inverter Control for Induction Heating by Pulse Density Modulation with Improved Power Factor,” IEEE Canadian Conference on Electrical and Com-puter Engineering – Toward a Caring and Human Technology, Canada, pp. 515-520, May 2003.
A. Sandali, A. Chériti, and P. Sicard, “Comparison of the Various PDM Control Modes,” IEEE International Conference on Industrial Technology, pp. 574-579, 2004.
Fairchild Semiconductor, “Induction Heating System Topology Review,” Discrete Application, Power De-vice Division, Fairchild Semiconductor, AN9012, June 2000.
J. M. Corrêa, E. D. Hutto, F. A. Farrett, and M. G. Simões, “A Fuzzy-Controlled Pulse Density Modula-tion Strategy for a Series Resonant Inverter with Wide Load Range,” Power Electronics Specialists Confer-ence, vol.4, p. 1650-1655, June 2003.
M.P. Kazmierkowski, M Cichowlas, and M. Jasinski, “Artificial Intelligence based controllers for industrial PWM power converters,” IEEE International Confer-ence on Industrial Informatics, p. 187-191, August 2003.
B. Ozpineci, J. O. P. Pinto, and L. M. Tolbert, “Pulse-Width Optimization in a Pulse Density Modulated High Frequency AC-AC Converter Using Genetic Algo-rithms,” IEEE International Conference on Systems, Man, and Cybernetics, vol. 3, p. 1924-1929, 2001.
VII.ReferencesReferences