A new adaptive clamp for improving weighted efficiency in grid‐tied photovoltaic interleaved two‐switch flyback micro‐inverter

Abstract

Summary This paper proposes a new adaptive clamp based on the hybrid operation of the interleaved two‐switch flyback micro‐inverter in one‐phase and two‐phase discontinuous conduction modes (DCM) depending on the output power of the PV panel. The proposed adaptive clamp controls the second switch of the two‐switch flyback structure based on the drain‐to‐source voltage spike of the flyback's main switch during the turn‐off process. Thus, in low‐voltage regions, a conventional flyback (single‐switch) operation is achieved with reduced switching, gate driving, and clamp diodes losses. Also, in the low output powers of the micro‐inverter, only one phase of the micro‐inverter operates to decrease the power loss associated with one phase. The theoretical analysis, simulation, and experimental results show the effectiveness of the proposed adaptive clamp and the phase control methods in improving the efficiency in all power ranges.

A simple and highly efficient flyback inverter control strategy for AC module application

“…Between these technologies, the low-power inverter which is called a micro-inverter or ac module is put on every PV panel, enabling the maximum power point (MPP) to be individually tracked. As a consequence, the power losses due to partial shading and PV module mismatch can be reduced [7][8][9][10][11]. Moreover, the specifications like easier maintenance and higher reliability of the ac module systems are other benefits of them [12][13][14][15][16][17].…”

High‐gain dual‐input multiple‐output ( DIMO ) boost converter for low‐power grid‐connected microinverter applications

“…In Reference 15, the interleaved flyback microinverter which consists of an adaptive snubber circuit and operated in boundary and discontinuous conduction mode has been presented. The snubber circuit enables the use of lower power MOSFETs as a switching component.…”

An FPGA‐based switching photovoltaic‐connected inverter topology for leakage current suppression in grid‐connected utilizations

“…The grid-connected PV inverters should be used in accordance with the grid standards and the applicable laws so as to comply with system protection and operation criteria. [10][11][12][13][14][15][16][17] Electrical factors such as leakage current protection, network frequency monitoring, active and reactive power control, and power quality are among these factors. [18][19][20][21] To this end, the most stringent and accurate standards are announced for PV systems to ensure the safety and reliability requirements of the system.…”

“…However, this performance places a heavy burden on system investments. The grid‐connected PV inverters should be used in accordance with the grid standards and the applicable laws so as to comply with system protection and operation criteria 10–17 . Electrical factors such as leakage current protection, network frequency monitoring, active and reactive power control, and power quality are among these factors 18–21 .…”