A startup scheme for zero-voltage-switching PV inverter

In order to guarantee all the switching devices of the inverter working in the safe operation area, zero voltage switching (ZVS) operation is needed even at the startup stage. To help the ZVS inverter achieving completely soft switching at the startup stage, a startup scheme is proposed. The startup scheme adds a pre-charge stage before the general startup stage. The pre-charge stage is realized by a simple pre-charge circuit and a ZVS pre-charge pulse sequence. The pre-charge circuit works before the general startup stage only and is guaranteed by principle to be deactivated during the normal operation stage. The pre-charge pulse sequence is designed to achieve ZVS operation in the pre-charge stage. The experiment on a 3kW prototype shows the startup scheme realizes ZVS operation at the startup stage and the voltage stress on the power devices is minimized.

[1]  Deepak Divan,et al.  The Resonant DC Link Converter--A New Concept in Static Power Conversion , 1986, 1986 Annual Meeting Industry Applications Society.

[2]  Deepak Divan,et al.  Zero-switching-loss inverters for high-power applications , 1989 .

[3]  John Shen,et al.  A comparison of soft and hard-switching losses in three phase micro-inverters , 2011, 2011 IEEE Energy Conversion Congress and Exposition.

[4]  Dehong Xu,et al.  A family of novel zero-voltage switching three-phase PWM converters topology for distributed generation , 2011, 8th International Conference on Power Electronics - ECCE Asia.

[5]  Denizar Cruz Martins,et al.  A ZVS PWM full-bridge inverter with active clamping technique using the reverse recovery energy of the diodes , 2002, IEEE 2002 28th Annual Conference of the Industrial Electronics Society. IECON 02.

[6]  Ashoka K. S. Bhat,et al.  Zero voltage switching DC link single-phase pulse width modulated voltage source inverter , 2002, APEC. Seventeenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.02CH37335).

[7]  Dehong Xu,et al.  A soft-switching full-bridge inverter with high efficiency , 2013, 2013 IEEE Energy Conversion Congress and Exposition.

[8]  A.K.S. Bhat,et al.  Zero-Voltage Switching DC Link Single-Phase Pulsewidth-Modulated Voltage Source Inverter , 2007, IEEE Transactions on Power Electronics.