中频圆导线变压器漏感的精确解析计算

Accurate Analytical Calculation of Leakage Inductance of Round Conductor Transformer under the Medium Frequency

中频变压器作为反激直流变换器的核心部件,变压器漏感过大时产生的尖峰电压对开关器件的影响是不可忽视的。另外在谐振直流变换器中,变压器漏感需要与谐振电容、频率匹配才能使电路达到理想工作状态。因此,在设计直流变换器时,对变压器漏感进行精确的计算变得尤为重要。现有计算漏感的数值法无法灵活地运用于变压器设计中,解析法得到广泛的推广。目前中频圆导线变压器漏感的解析计算法大多基于面积等效法,但是等效后会使变压器窗口处绝缘区域面积偏大,漏感计算结果不够准确。另外也有对中频圆导线的频率效应进行直接分析,但忽略了匝间的不规则空隙,导致漏感计算结果偏小。为此,该文提出一种更加精确的漏感解析计算方法,不仅对圆导线的频率效应进行分析,而且考虑了匝间不规则空隙,以提高漏感的解析计算精度。最后基于搭建的变压器样机进行实验,验证了所提方法的正确性和有效性。

As the critical power component of fly-back DC/DC converter,excessive leakage inductance of the medium-frequency transformer causes the peak voltage on the switching device which can not be ignored.In addition,in resonant DC/DC converter,the leakage inductance needs to be matched with resonant capacitance and frequency,so that the circuit can reach the ideal working state.So it is very important to calculate the leakage inductance of transformer accurately when designing DC/DC converter.The existing numerical methods for calculating leakage inductance cannot be flexibly applied in transformer design,so analytical methods are widely used.At present,most analytical methods for leakage inductance of round conductor transformer under medium frequency are based on the equivalent method.However,after equivalence,the insulation area of transformer window is larger,and the calculation result of leakage inductance is not accurate enough.In addition,there is an analytical method proposed to directly analyze the frequency effect of round conductor under medium frequency,but the irregular gap between turns is ignored,resulting in inaccurate leakage inductance calculation result.Therefore,a more accurate analytical calculation method of leakage inductance is proposed in this paper,which not only analyzes the frequency effect of the round conductor,but also takes the irregular gap between turns into account,so as to improve the analytical calculation accuracy of leakage inductance.Finally,based on the transformer prototypes,the experiment verified the correctness and effectiveness of the proposed method.