M.A. Thesis:

design and simulation of high efficiency quasi resonant dc/dc converter to connect an offshore wind farm to hvdc lines

Nowdays, the use of clean energies has become very important, and more energy can be extracted by contracting a large number of wind turbines alongside each other and offshore because of the proper environment (offshore wind turbines). The energy transfer from these wind farms is HVDC, HVAC, where DC lines are better than AC lines because of the amount of reactive power used by the zero line. Considering that the wind turbine output voltage was considered to be 4 KV, which is not suitable for energy transfer, a converter should be designed to increase the voltage level up to 40KV. The proposed converter is made up of an incremental quasi-resonant converter method, which selects its switching frequency near the resonant frequency along with the rectifier rectifier section, which consists of two semiconductor semiconductor transducers that can be switched at zero voltage (zvs ) At the moment the switches are switched on and the switching current is set to zero at the moment of shutdown for the output diode. Due to the fact that the circuit in this case is sensitive to the switching frequency, the switching frequency in the algorithm is fixed and the voltage change is used to change the duty cycle. The values ??of the elements are then simulated by the Simulink MATLAB software and calculated by the software. Low-voltage zero voltage, high-frequency operation, low voltage stresses and reduces the losses of the transducer

Keywords: Wind turbine farms, quasi-resonant converters, zero-voltage switching (zvs