混合导通模式Boost PFC的控制策略研究

Research on digital control technology of MCM Boost PFC

工作在宽负载输出应用场合的Boost PFC变换器(如不间断电源)单独采用连续导通模式算法和断续导通模式算法时存在电流畸变问题,本文针对此问题提出了混合导通模式控制策略。详细分析了混合导通模式控制策略的工作原理及其控制优势,基于DSP设计了相对应的数字控制解决方案,仿真和实验结果验证了该控制策略的有效性、可靠性。

In order to overcome the problems when the Boost PFC converter has to be operated with a wide range of output power, as in uninterruptible power supplies （UPS）, a novel mixed conduction mode （MCM） digital control strategy with fixed switching frequency is proposed in this paper. This control strategy is composed of a current con- trol loop and a voltage control loop. The voltage control loop guarantees the steady of the output voltage, while the current control loop comprises two control laws （one for the continuous conduction mode （CCM） and another for the discontinuous conduction mode （DCM）） and operation mode selection algorithm, which is responsible for de- tecting the operation mode and selecting the appropriate control law. The operating principle and the advantages of this control strategy are analyzed, and the corresponding digital control solution is designed based on DSP. Simula- tion and experimental results confirm the effective and reliability of the proposed control strategy.