脉冲序列控制BIFRED变换器的脉冲组合和电压纹波

Pulse Combination and Voltage Ripple in Pulse Train Controlled BIFRED Converter

升压式-反激式集成的整流/储能直流-直流(BIFRED)变换器是由Boost电路与反激式电路集成实现的,具有电路简单、成本低、负载范围宽等优点,工程应用价值较高。脉冲序列(PT)控制技术是一种新的离散控制技术,比较适用于BIFRED变换器的输出电压调节控制,但PT控制存在着输出电压纹波较大的缺点,因此研究PT控制BIFRED变换器的输出电压纹波具有重要的物理意义。为了更好地表征工作在双断续导电模式(DCM-DCM)下的PT控制BIFRED变换器的电压调节控制性能,通过求解在1个开关周期内流过副边二极管的平均电流,得到了在1个开关周期内高、低功率脉冲作用下的输出电压变化量,由此获得了不同负载时PT控制DCM-DCM BIFRED变换器的控制脉冲组合,并进一步确定了相应的输出电压纹波。通过PSIM仿真软件和硬件试验,得到了不同负载下的时域波形,验证了控制脉冲组合、输出电压纹波理论分析的正确性及控制方案的可行性。

The boost integrated flyback rectifier/energy storage DC-DC （ BIFRED） converter is integrated by a boost circuit and a flyback circuit;its advantages are simple circuitry,low cost,wide load range,and higher engineering applicable value. Pulse train （ PT） control technology is a new type of discrete control technology,which is more suitable for output voltage regulation control of BIFRED converter. However, there is disadvantage of larger output voltage ripple in PT control;therefore, the investigation of output voltage ripple in PT controlled BIFRED converter has important physical significance. To better characterize voltage regulation control performance of PT controlled BIFRED converter operating in dual discontinuous conduction mode （ DCM -DCM） ,the output voltage variations respectively driven by high and low power pulses in a switching cycle are derived by solving the average current flowing through the secondary diode in a switching cycle,from which the control pulse combinations of PT controlled DCM-DCM BIFRED converter under different loads are obtained and the corresponding output voltage ripples are further determined. Based on PSIM circuit simulations and hardware experiments,the time domain waveforms under different load resistances are obtained. The correctness of the theoretical analysis of control pulse combinations and output voltage ripples and the feasibility of control scheme are verified.