模块化隔离型直流变换器的同轴变压器设计

针对直流变换器（DC/DC）中变压器绕组之间的高压绝缘问题，提出采用高压电缆作为同轴变压器绕组的绝缘方法和该种同轴变压器的优化设计方法.考虑直流风电场的实际情况，对应用于模块化隔离型DC/DC变换器的中频同轴变压器进行设计，对变压器的结构和参数优化进行研究，得出变压器优化设计的最优解.在仿真实验中，利用Ansys软件进行变压器的温度场仿真.以额定容量250 kV·A的中频同轴变压器为例，进行优化设计.结果表明：变压器体积为0.022 3 m3，重量为47.11 kg，变压器满载时的最高温度为98.5℃，励磁电感和泄漏电感值均满足设计要求，验证了同轴变压器设计方法的有效性和可行性.
Abstract: An insulation method using high voltage insulated cable as the coaxial transformer winding was proposed aiming at the problem of high voltage insulation between transformer windings in DC/DC converters. The design and optimization method of the transformer was propased. A medium frequency coaxial transformer was designed in modular isolated DC/DC converter (MIDC) considering the actual pure DC wind farm. Transformer structure and parameter optimization was analyzed, and the optimization results were obtained. Ansys temperature field simulation of the transformer was conducted. A rated 250 kV·A medium frequency coaxial transformer was designed. Results showed that the optimal volume and weight were 0.022 3 m3 and 47.11 kg, the highest temperature of the transformer was 98.5℃ under full-load working condition, and the magnetic inductance and leakage inductance value both met the design requirements. Simulations verified the validity and feasibility of the proposed coaxial transformer design method.