ABSTRACT:
Single-stage
power conversion with simple circuit arrangement is one of the attractive
features of direct bipolar voltage ac-ac converters. This increases their
potency in various applications that require voltage and frequency regulation.
The grid voltage compensators, direct variable speed ac-ac drives, and induction
heating systems require inverting and non-inverting operation of the input
voltage. Their size, cost, and circuit complexity directly depend on the number
of switching transistors, as the operation of each transistor requires the use
of one gate drive circuit (GDC) and one isolated dc power supply (IDCPS). The
size and cost of GDC and IDCPS are much larger than that of switching
transistors. The use of fewer switching transistors also ensures low conversion
losses and simplifies the switching schemes. Therefore, this research proposes
a new ac-ac converter that is realized as a bipolar boost ac voltage controller
having a low count of switching transistors. The suggested topology also
eliminates the shoot-through of the input source or output filtering capacitor.
The characteristics of the proposed circuit are explored through simulation
results obtained through the Simulink platform. The confirmation of the
simulation results is validated through the laboratory prototype.
KEYWORDS:
1. AC
converter
2. Bipolar
voltage
3. Grid
voltage compensator
4. Induction
heating system
5. Shoot
through
SOFTWARE: MATLAB/SIMULINK
CIRCUIT DIAGRAM:
Figure 1. Existing Power Converting Topologies
Reported In (A) [13] And (B) [20].
EXPECTED SIMULATION RESULTS:
Figure 2. Instantaneous Power Losses Of Low-Frequency
(A) Diodes And (B) Diode-Mosfet Pairs.
Figure 3. Simulated Waveforms: (A) & (B)
Input-Output Voltage; (C) & (D) High-Frequency Switching Voltage; (E) To
(J) Low-Frequency Switching Voltage.
Figure 4. Simulated Waveforms: (A) & (C) Output
And Input Currents With A Resistive Load; (B) & (D) Output And Input
Currents With An Inductive Load.
Figure 5. Practically Recorded Waveforms: (A)
& (B) Input-Output Voltage; (C) & (D) High-Frequency Switching Voltage;
(E) To (J) Low-Frequency Switching Voltage.
CONCLUSION:
This
research is focused on the analysis and development of a new direct ac-ac power
converting topology that may be applied in applications having variable bipolar
voltage boost characteristics. The suggested circuit may be operated to have a
non-inverted and inverted output with voltage boost characteristics. The
regulation in the output bipolar voltage is ensured through the PWM control.
The developed topology has eliminated the use of two switching transistors.
This reduction has eliminated the requirement of two GDC and IDCPS circuits. This
achievement not only simplifies the switching schemes but also reduces the
overall size and cost of the power converting topology. The size, cost, and
losses of the GDS and IDCPS are larger than that of the switching transistor. The
performance evaluation of the developed topology is compared with the existing
circuits. The comparison of the simulated results with the practical results
validates the effectiveness of the developed topology.
REFERENCES:
[1] O. C. D. S. Filho, B. R. D. Almeida, D. D. S. O. Júnior, and T.
R. F. Neto, ``High-frequency isolatedAC_DC_AC interleaved converter for power
quality applications,'' IEEE Trans. Ind. Appl., vol. 54, no. 5, pp.
4594_4602, Sep. 2018.
[2] D.-C. Lee and Y.-S. Kim, ``Control of
single-phase-to-three-phase AC/DC/ACPWMconverters for induction motor drives,''
IEEE Trans. Ind. Electron., vol. 54, no. 2, pp. 797_804, Apr. 2007.
[3] P. Alemi, Y.-C. Jeung, and D.-C. Lee, ``DC-link capacitance minimization
in T-type three-level AC/DC/AC PWM converters,'' IEEE Trans. Ind. Electron.,
vol. 62, no. 3, pp. 1382_1391, Mar. 2015.
[4] N. Ashraf, G. Abbas, R. Abbassi, and H. Jerbi, ``Power quality
analysis of the output voltage of AC voltage and frequency controllers realized
with various voltage control techniques,'' Appl. Sci., vol. 11, no. 2,
p. 538, Jan. 2021.
[5] H. Qin and J. W. Kimball, ``Solid-state transformer
architecture using AC_AC dual-active-bridge converter,'' IEEE Trans. Ind.
Electron., vol. 60, no. 9, pp. 3720_3730, Sep. 2013, doi: 10.1109/TIE.2012.2204710.
