Bidirectional marx DC–DC converter for offshore wind farm application

Abstract

The bidirectional DC–DC converter explained here is based on the Marx principle and is capable of achieving step-up and step-down voltage transformations at kV level and is able to handle MW-level power transfers in both directions. The main features of this topology are the absence of a high-frequency transformer, reduced weight, volume, and soft switching to reduce the switching losses. In the boost mode, five capacitors are charged in parallel and discharged in series to achieve the step-up action, and in the buck mode, the converse action takes place. The operating principle is explained, and the steady-state analysis of the converter is given. Matlab/Simulink simulation of a 50 MW converter, interfacing 6 kV, and 30 kV systems supports and validates the theoretical analysis, enables positive supporting the conclusions to be made.

Keywords

• wind power plants
• DC-DC power convertors
• offshore installations
• power capacitors
• offshore wind farm application
• voltage transformations
• MW-level power transfers
• switching losses reduction
• bidirectional Marx DC–DC converter
• boost mode
• Matlab-Simulink simulation
• steady-state analysis
• voltage 30.0 kV
• power 50.0 MW
• voltage 6.0 kV