Hybrid cascaded inverter for photovoltaic generation systems

作者：Lu Xiaonan^*; Sun Kai; Ma Yiwei; Huang Lipei

来源：Journal of Tsinghua University(Science and Technology), 2011, 51(3): 351-355.

• AC-side
• Carrier Method
• Cascaded inverters
• DC side
• DC voltage
• Flexible operation
• H-bridges
• High voltage
• Hybrid cascaded inverter
• Hybrid power
• Inverter system
• Low switching frequency
• Low voltages
• Modulation method
• Modulation methods
• MOS-FET
• Output voltages
• Output waveform
• Photovoltaic generation
• Photovoltaic generation system
• Power circuit

An improved single-phase hybrid cascaded inverter was developed using MOSFET/IGBT to give a high converting efficiency for photovoltaic (PV) generation systems. The inverter has three H-bridges, with series-connected AC sides and isolated DC sides. The DC voltages are in the ratio of 1:2:4. The high voltage and middle voltage H-bridges are based on an IGBT, while the low voltage H-bridge is based on a MOSFET. The low switching frequency provides more output voltage levels at the AC side in the hybrid cascaded inverter, which improves the efficiency. The hybrid power switches effectively utilized the advantages of each kind of device to enable a flexible operation of the inverter system. The voltage graduational method and the pulse width modulation (PWM) carrier method are used in the implemented prototype. The results are evaluated based on the AC output waveforms and the main power circuit efficiency. The effectivenesses of the inverter system and the two modulation methods are validated by simulations and tests.

• 出版日期2011
• 单位清华大学