基于电容电荷平衡的Boost型变换器控制研究

摘要

In view of the limitation on the performance of the Boost converter when the general controller is used, such as low-bandwidth and sluggish dynamic response. This paper proposes a novel nonlinear control scheme which is based on the capacitor charge balance control (CBC). Combined with the linear/nonlinear control method, the traditional voltage mode control is taken during the steady-state of the Boost converter, the scheme switches to the nonlinear control method while the load current has a step change. Using the CBC algorithm during the calculation of the switching time, the optimal dynamic performance of the Boost converter is achieved. Finally, the simulation results and the experimental results of the prototype show that the proposed algorithm, compared with the traditional voltage mode control, can significantly improve the dynamic performance of the Boost converter, such as the overshoot, dynamic setting time.%　　针对Boost型功率变换器的常规控制算法存在系统带宽较窄、动态响应缓慢等问题，基于电容电荷平衡原理提出一种新的非线性控制方案。该控制方案采用线性/非线性相结合的复合控制方法，当Boost变换器工作在稳态时采用传统的电压模式控制算法，而当负载电流发生跃变时，则采用非线性控制算法，通过电容电荷平衡控制计算开关管开通和关断的切换时间，从而保证Boost变换器获得最佳的动态性能。对自制的样机进行仿真验证和实验研究，结果表明，该方案能明显改善Boost型DC/DC变换器的超调量、调节时间等动态性能。