Energy transmission system of wind turbine generator system

The invention discloses an energy transmission system of a wind turbine generator system. The energy transmission system comprises a generator, a converter and a grid-side transformer, which are connected in sequence; the converter comprises a three-phase rectifying module, a first sub-converter and a second sub-converter, wherein a tandem type cascade connection is formed between the first sub-converter and the second sub-converter through common ground connection, the voltage loaded by each sub-converter is reduced to half of the output voltage of an original three-phase rectifying module so as to lower the voltage level and to conveniently select an existing full control type power electronic device; and each sub-converter consists of a plurality of pressure-boosting inverse modules which are connected in parallel and play the function of parallel shunt. According to the invention, the current rating of the required full power electronic device is reduced, an existing full control type power electronic dev