ABSTRACT:
In this paper, a new PWM scheme and commutation method
is presented for one phase loss operation of three-phase isolated buck
matrix-type rectifier. With the proposed PWM scheme, the maximum allowable
voltage gain for one phase loss operation can be achieved, which permits the
continuous operation of the converter to deliver 2/3 of rated power and regulate
the output voltage with maximum output voltage drop less than 5% of nominal
output voltage. In addition, with the proposed commutation method, a safe
transition from one phase loss operation to normal operation and vice versa can
occur with minimum commutation steps (two-step) under zero voltage switching
(ZVS) condition. The performance of the proposed PWM scheme and commutation
schemes with one phase loss operation is evaluated and verified by simulations
and experiments on a 5kW prototype.
KEYWORDS:
1.
PWM
2.
Commutation
3.
Matrix
converter
4.
Three phase
5.
One phase loss
6.
Isolated
7.
Buck rectifier
8.
ZVS
9.
MOSFET
10. High frequency
SOFTWARE: MATLAB/SIMULINK
CIRCUIT DIAGRAM:
Fig. 1. ZVS three-phase PWM rectifier.
EXPECTED SIMULATION RESULTS:
Fig.
2. Simulated waveforms for 2/3PO_max, vLL = 480V and ma =
0.75 when “phase C” is shorted at t1 and recovered at t2:
(a) input phase voltages, (b) input phase currents, (c) transformer secondary
voltage, (d) output of bridge rectifier, (e) output voltage and battery set
point, (f) output inductor current.
CONCLUSION:
In
this paper, operation of the three-phase isolated Buck matrix-type rectifier
under one phase loss condition is described and a new PWM scheme and commutation
method for the one phase loss operation is proposed. With the proposed
switching scheme and commutation method, two step commutation with ZVS (here
either using ZVS or zero voltage turn-ON) can be realized for one phase loss
operation and also for the transition from normal operation to one phase loss
operation and from one phase loss operation to normal operation. Operation and
performance of the converter with the proposed PWM and commutation method are
verified with simulation and experimental results. Based on the experimental
results obtained from a 5 Kw prototype, it is shown that the converter is able
to deliver 2/3 of maximum output power to the load and regulate the output
voltage with maximum voltage drop less than 5% of nominal output voltage.
Current stress of the converter and input current THD and spectrum analysis are
also provided in the experimental results with one phase loss operation. The
relatively large THD (around 40%) is one of the drawbacks for this converter
when operating under one phase loss condition.
REFERENCES:
[1]
S. Manias and P. D. Ziogas, “A Novel Sinewave in AC to DC Converter with
High-Frequency Transformer Isolation”, IEEE Trans. Industrial Electronics, vol.
IE-32, no. 4, pp. 430-438, Nov., 1985.
[2]
K. Inagaki, T. Furuhashi, A. Ishiguro, M. Ishida, and S. Okuma, “A New PWM
Control Method for ac to dc Converters with High- Frequency Transformer
Isolation”, IEEE Trans. Industry Applications, Vol. 29, No. 3, pp. 486-492,
May/Jun., 1993.
[3]
V. Vlatković and D. Borojević “Digital-Signal-Processor-Based Control of Three-
Phase Space Vector Modulated Converters”, IEEE Trans. Industrial Electronics,
vol. 41, no. 3, pp. 326-336, Jun., 1994.
[4]
V. Vlatković and D. Borojević, and F. C. Lee, “A Zero-Voltage Switched, Three-phase
Isolated PWM Buck Rectifier”, IEEE Trans. Power Electronics, vol. 10, No. 2,
pp. 148-157, Mar., 1995.
[5]
R. García-Gil, J. M. Espí, E. J. Dede, and E. Sanchis-Kilders, “A Bidirectional
and Isolated Three-Phase Rectifier With Soft-Switching Operation,” IEEE Trans.
Industrial Electronics, vol. 52, no. 3, pp. 765-773, Jun, 2005.
