PWAM Controlled Quasi-Z Source Motor Drive

ABSTRACT:

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

CIRCUIT DIAGRAM:

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.

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