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.
- AC converter
- Bipolar voltage
- Grid voltage compensator
- Induction heating system
- Shoot through
Figure 1. Existing Power Converting Topologies Reported In (A)  And (B) .
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.
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.
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