Optimization Design of 90-kW High-Power <i>LLC</i> Converter for Wind Power Applications

Wind power dc step-up collection technology is a relatively new technical route that is currently gaining attention and being researched. Within this field, the dc boost converter is considered to be the most crucial conversion device. The LLC converter is seen as a suitable option due to its low switching loss. However, the design method of the LLC converter with a wide input voltage range has some drawbacks, such as large voltage stress on the resonant capacitor, high current stress on the switching device, and significant magnetic component loss. To address these issues, this article proposes a high-power and high-efficiency LLC converter design method specifically for wind power dc collection scenarios. The design takes into account various factors, including switching devices, magnetic component losses, voltage/current stress of devices, and actual operating conditions of the circuit. A prototype of 5 kV–90 kW was created, and corresponding experimental results were obtained to validate the effectiveness of the design method.