单级反激式PFC连续模式下电流有效值计算

单级反激式连续工作模式下功率因数校正电路的输入电压在半个工频周期内呈正弦变化。变压器绕组中的电流是一系列梯形脉冲,并且脉冲宽度以及电流的变化率都随着输入电压的瞬时值变化。依据有效值定义推导出了变压器原副边电流有效值的解析解;在相同的假设条件下,利用积分得出了电流有效值数值计算公式。解析解和数值解分析对比结果表明,两种计算结果具有很好的一致性。通过实验验证,用这种方法设计的变压器在同样温升的前提下,变压器体积大大减小。

Calculation of current RMS in CCM single stage flyback PFC

The input voltage of single stage flyback CCM mode PFC changes with sinusoidal in half cycle.The current flowing through the transformer is series of trapezoidal pulses,the pulse width and the rate of current varies with the instantaneous value of input voltage.Analytical solutions of current RMS in the transformer primary and secondly windings are derived based on the definition of RMS.In the same assumptions,numerical calculations of the current are carried out by using integral.Analytical solution and the numerical calculation results of the current are quite consistent.Experiments show that the design of the transformer by this method,under the premise of the same temperature,the transformer size is greatly reduced.