公开(公告)号：US20190386571A1

公开(公告)日：2019-12-19

申请号：US16478916

申请日：2018-01-29

Applicant: VESTAS WIND SYSTEMS A/S

Inventor： Catalin Gabriel DINCAN ,  Phillip Came KJÆR

IPC: H02M3/335 ,  H02M1/08

Abstract: A DC to DC power converter is described which comprises a transformer, a primary side connected to a primary winding of the transformer, a secondary side connected to a secondary winding of the transformer, and a controller. An input of the secondary side comprises inductor-capacitor (LC) circuitry, and the primary side comprises switching circuitry. The controller is arranged to control switching of the switching circuitry to apply voltage pulses to the primary winding of the transformer, the voltage pulses being separated by zero voltage periods during which a zero or near zero voltage is applied to the transformer, and a frequency of the switching of the switching circuitry is lower than the resonant frequency of the LC circuitry. With this arrangement, operating a sub-resonant mode permits a full resonant cycle of the LC circuitry to pass within a single switching cycle of the first and second switching circuitry, allowing zero current switching, while the output power effectively becomes a function of switching frequency (which varies the number of resonant pulses at the LC circuitry, each pulse transferring a predetermined amount of power). The removal of the voltage pulse, which would be otherwise generated by the switching circuitry, when it is not required, thereby avoids or at least reduces a flux build up at the transformer (to which the voltage pulse is applied). The result can be a highly efficient and controllable series resonant converter.