The invention discloses a high step-up-ratio converter in bidirectional
voltage outputting for a photovoltaic module. The high step-up-ratio converter comprises two switch tubes, two clamping diodes, two fly-wheel diodes, two output diodes, two clamping capacitors, one
voltage-multiplying
capacitor, two output capacitors and two
coupling inductors, wherein the two
coupling inductors are provided with two windings. According to the high step-up ratio converter disclosed by the invention, the
coupling inductors are utilized for expanding the
voltage gain of the high step-up-ratio converter and reducing the voltage stress of power switch tubes and the diodes, the
leakage inductance of the coupling inductors is utilized for realizing zero-current switching of the switch tubes and restraining inverse restoring current of the diodes, a clamping circuit formed by the clamping diodes and the clamping capacitors is capable of effectively absorbing the
voltage spike when a main switch tube is switched off and realizing the lossless transfer of energy, a voltage-multiply circuit is utilized for further increasing the
gain of the high step-up-ratio converter and further reducing the voltage stress of the power switch tubes and the output diodes, the circuit control is convenient, the
ripple of the input current is small, and the high step-up ratio converter is suitable for a photovoltaic grid-connected power generation conversion occasion in larger power, high
gain and high efficiency.