Design and optimization of 99% CEC efficiency soft-switching photovoltaic inverter

Abstract

Driven by worldwide demands for renewable energy source, photovoltaic (PV) inverters, which are the most important part for energy conversion, have seen a considerable amount of innovations in recent years. The trends for PV inverters are toward high efficiency, high reliability, low ground leakage current, low-output ac-current distortion, and reactive power capability. This paper provides an efficiency optimized design of an Auxiliary Resonant Snubber with CoupledMagnetic Reset Zero-voltage switching (ZVS) inverter for PV application. The main device is Power MOSFETs, which have low conduction loss and could achieve ZVS in all load condition. The auxiliary devices are low current, low cost IGBTs and Diodes, which could achieve zero-current switching (ZCS). To achieve high efficiency, resonant circuit is analyzed to optimally design the resonant components, which is based on the guarantee of full range ZVS, gating delay-time design, and lower power loss in auxiliary circuit. The power loss model is also analyzed to select suitable power device and further improve the efficiency. At last, experiment results of a 5kW single phase inverter in PV system was presented, which has more than 99% CEC efficiency and work in full load condition without cooling fan. Besides, reactive power capability is also demonstrated.

Fuel Cells and Their Applications in Energy Systems

“…Filter component size and associated costs can be reduced by increasing the switching frequency. Soft-switching that allows the inverter to switch at a higher frequency while maintaining high efficiency is attractive for stationary fuel cell applications [117][118][119][120][121][122][123][124][125][126][127][128][129][130][131][132][133][134]. High-efficiency design can also reduce the size of the heat sink and associated cost.…”

“…High-efficiency design can also reduce the size of the heat sink and associated cost. Among different soft-switching inverters, the auxiliary resonant snubber approaches, which have been reported to exhibit greater than 99% efficiency using silicon devices [130,131], are quite suitable for medium-power applications.…”

MPPT Híbrido Aplicado à Associação dos Conversores Boost ZVT e Inversor H6 Para Aplicações Fotovoltaicas

“…Esse método assume que o inversor opera com maiores carregamentos (maior irradiação solar). A eficiência europeia e a eficiência CEC são obtidos respectivamente através de [14], [20] Simulando-se os carregamentos exigidos, obteve-se a eficiência europeia de 95,8% e a eficiência CEC de 96,01% para o conversor fotovoltaico em estudo.…”

Sensorless adaptive control of resonant snubber inverter for photovoltaic applications

“…While able to achieve high efficiency, the additional components and additional losses traditionally associated with the soft switching action increase size and cost, especially at lower power levels [5][6][7][8].…”