Improved Z-Source Inverter with Reduced Z-Source Capacitor Voltage Stress and Soft-Start Capability

ABSTRACT:

This paper proposes an improved Z-source inverter topology. Compared to the traditional Z source inverter, it can reduce the Z-source capacitor voltage stress significantly to perform the same voltage boost, and has inherent limitation to inrush current at startup. The control strategy of the proposed Z-source inverter is exactly the same as the traditional one, so all the existing control strategy can be used directly. A soft-start strategy is also proposed to suppress the inrush surge and the resonance of Z-source capacitors and inductors. The operation principle of the proposed topology and comparison with the traditional topology are analyzed in detail. Simulation and experimental results are given to demonstrate the new features of the improved topology.

KEYWORDS:

1.      Inrush current

2.      Soft start

3.      Z-source inverter.

SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

 EXPECTED SIMULATION RESULTS:

CONCLUSION:

This paper has presented a new Z-source inverter topology. Compared to the previous Z-source inverter, the improved topology has several merits.

1) The Z-source capacitor voltage stress is reduced greatly to perform the same boost ability; thus, low-voltage capacitors can be utilized to reduce the system cost and volume;

2) The inrush current and resonance of Z-source capacitors and inductors in traditional topology can be suppressed with a proper soft-start strategy. Simulation and experimental results verified the aforesaid merits of the proposed topology.

REFERENCES:

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