以多相交错型DC-DC变换器为研究对象,首先对变换器主电感进行磁集成研究,通过归一化等效电感分析,给出多相磁耦合电感设计准则。采用小信号对变换器Buck模式进行建模,推演出状态变量到控制变量的传递函数。然后依据三相磁耦合变换器的开环特性,并结合平均电流控制的不足,设计出对应补偿网络,提出补偿电流环的改进平均电流控制策略。最后通过仿真和实验,证明了所提出的新型控制策略,较之传统控制方式,可优化系统稳态及暂态特性。同时,磁耦合电感设计还改善了相电流纹波,提高了变换器暂态电流响应速度。
Taking the heterogeneity interlocking DC-DC converter as the object of study, firstly, this paper conducts the magnetic integration research on the main inductance of the converter, and proposes the design criterion of the heterogeneity magnetic coupling inductance through the analysis of normalized equivalent inductance. The research conducts the model building of the Buck mode of the converter with the small-signal, and deduces the transfer function from the state variables to control variables. Secondly, based on both the open-loop features of three-phase magnetic coupling converter and the deficiency of average current control, the control strategy of the improved average current for the bucking current loop is proposed. Finally, through the simulation and experiment, it proves that the proposed new type control strategy can optimize the stable state and transient behavior of the system compared with the traditional control mode. Meanwhile, the design of the magnetic coupling inductance also improves the phase current ripple, as well as enhances the response speed of the transient current of the converter.