This paper
proposes a novel pulse-width-amplitude modulation (PWAM) method for three-phase
quasi-Z source inverter system in motor drive application. It is demonstrated that
it operates at only 1/3 switching frequency of traditional PWM methods, with
less harmonic distortion. As a result, switching actions and losses are also
reduced significantly. With the proposed modulation, the required capacitance
is reduced greatly, which makes a system of smaller volume and lighter weight.
Compared to traditional PWM methods, the higher efficiency and better reliability
are confirmed in PWAM controlled motor drive system. The motor drive with the proposed
hybrid PWAM modulation method presents good performance in simulation. Theoretical
analysis is provided to verify the inverter efficiency and design improvements.
KEYWORDS:
1.
Quasi-Z-source
inverter
2.
Pulse-width-amplitude
modulation
3. Motor drive
SOFTWARE:
MATLAB/SIMULINK
Fig.
1. Quasi-Z source inverter based motor drive [8].
Fig.
2. Topology in the second sector.
EXPECTED SIMULATION RESULTS:
Fig.
3. Outcomes of rotation speed r, current ia and torque Tm
of motor (f=30 Hz).
Fig.
4. Simulation results of three-phase qZSI when using PWAM method. (a) qZS
capacitor voltages vc1and vc2; (b) qZS inductor currents iL1
and iL2; (c) qZSI’s dc-link voltage vpn; (d) qZSI’s
output line to line voltage vab(f=30 Hz).
Fig.
5. Simulation results of three-phase qZSI when using PWAM method. (a) qZS
capacitor voltages vc1and vc2 ; (b) qZS inductor currents
iL1 and iL2; (c) qZSI’s dc-link voltage vpn;
(d) qZSI’s output line to line voltage vab(f=50 Hz).
Fig.
6. Outcomes of rotation speed r, current ia and torque Tm
of motor (f=50 Hz).
CONCLUSION:
In this paper, a novel modulation method
for three-phase qZSI motor drive was introduced. The qZSI allows dc-link 6ɷ voltage
ripples, as a result that the required qZS inductance and capacitance are
reduced significantly. Besides, compared to traditional SPWM, only one third of
the switches are doing switching actions, which reduced the number of switching
time and loss significantly. By using the proposed PWAM modulation method, the
motor drive operates well and efficiently.
REFERENCES:
[1] H. W. van der Broeck, H. C.
Skudelny, G. V. Stanke, “Analysis and Realization of a Pulsewidth Modulator
Based on Voltage Space Vectors,” IEEE Transactions on Industry Applications,
1988, pp. 142- 150.
[2] H. Abu-Rub, M. Malinowski, K.
Al-Haddad: Power Electronics for Renewable Energy Systems, Transportation
and Industrial Applications, Hoboken, NJ: John Wiley & Sons Ltd., 2014.
[3] C. Y. Leong, N. P. van der Duijn Schouten,
P. D. Malliband, R. A. McMahon, “A Comparison of Power Losses for Small
Induction Motor Drives Adopting Squarewave and Sinusoidal PWM Excitation,” Second
International Conference on Power Electronics, Machines and Drives (PEDG),
2004, pp. 286-290.
[4] H. Zhang, B. Ge, Y. Liu, D. Sun, “A
Hybrid Modulation Method for Single-Phase Quasi-Z Source Inverter,” in 2014
IEEE Energy Conversion Congress and Exposition (ECCE), pp.4444-4449, 2014.
[5] D. Sun, B. Ge, X. Yan, D. Bi, H.
Zhang, Y. Liu, H. Abu-Rub, L. BenBrahim, F.Z. Peng, "Modeling, impedance design,
and efficiency analysis of quasi-Z source module in cascaded multilevel
photovoltaic power system," IEEE Transactions on Industrial Electronics,
vol.61, no.11, pp.6108-6117, Nov. 2014.
