The invention discloses a high-
gain active lossless clamping converter including a built-in
transformer and a
voltage-multiplying structure. The high-
gain active lossless clamping converter comprises one input
inductor, one power switch tube, one clamping switch tube, two
voltage-multiplying diodes, two output diodes, one clamping
capacitor, one DC (
Direct Current) blocking
capacitor, two
voltage-multiplying capacitors, two output capacitors and the built-in
transformer, wherein the built-in
transformer is provided with two windings. According to the high-
gain active lossless clamping converter disclosed by the invention, the built-in transformer is utilized for expanding the voltage gain of the high-gain active lossless clamping converter and reducing the voltage stress of the power switch tube, the
leakage inductance of the built-in transformer is utilized for realizing zero-voltage switching of the switch tubes and restraining inverse restoring current of the diodes, a clamping circuit formed by the clamping switch tube and the clamping
capacitor is capable of effectively absorbing the
voltage spike when the power switch tube is switched off and realizing the lossless transfer of energy, a voltage-multiplying circuit structure is utilized for further increasing the gain of the high-gain active lossless clamping converter and further reducing the voltage stress of the power switch tube and the diodes, the circuit structure is simple, the control is convenient, and the high-gain active lossless clamping converter is suitable for a photovoltaic grid-connected power generation conversion occasion in small power, high gain and high efficiency.