| 摘要: |
| 针对并联DC-DC开关电源主从模块电流分配精度不均以及面对负载扰动下动态性能、稳定较差等问题，提出一种基于主从均流的并联方法和将分数阶PID与预测函数（PFC）相结合的控制策略。对预测函数算法进行改进：首先，利用v步离散方法对BUCK变换器进行分段仿射建模（PWA）；其次，在保留预测函数控制基础上，引入分数阶PID思想，得到一个新的二次型指标函数；最后，将其与传统PI控制输出效果作对比，利用MATLAB仿真去检验分数阶预测函数（FOPID-PFC）控制策略的可行性和可靠性。仿真结果表明：提出的分数阶PID预测函数，在均流精度上比传统PI高，在面对负载加、减的情况下，超调量和调节时间分别降低了234mv、170 μs和221 mv、210μs，由此验证了BUCK变换器并联系统中，基于主从均流的分数阶预测函数控制策略总体性能优于传统PI控制，且主从模块的电流分配精度也满足预期设想。 |
| 关键词: 并联控制 主从均流 BUCK变换器 分数阶预测函数 均流精度 动态响应 |
| DOI： |
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| Application of Improved Predictive Function in Parallel DC-DC |
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WU Mengtao, WANG Haisheng, YAN Xiaoyu, LIU Bin, GE Lusheng
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School of Electrical and Information Engineering, Anhui University of Technology,Anhui Ma' anshan 243000,China
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| Abstract: |
| For the problems of uneven accuracy of current distribution between master and slave modules in parallel DC-DC switching power supplies and poor dynamic performance and stability in the face of load disturbances, a control strategy based onthe parallel connection of master-slave current sharing was proposed, combining fractional-order PID with predictive function control (PFC). The prediction function algorithm was improved from the following aspects. Firstly, a piece-wise affine modeling (PWA) of BUCK converter was carried out by using v-step discrete method. Secondly,a new quadratic indicator function was obtained by introducing the idea of fractional-order PID based on the retained predictive function control. Finally, the output effect was compared with that of the conventional PI control. MATLAB simulation was used to test the feasibility and reliability of the fractional order prediction function(FOPID-PFC) control strategy. The simulation results showed that the proposed fractional-order PID prediction function is better than the traditional PI in the accuracy of current sharing, and the overshoot and regulation time were reduced by 234mv, 170μs and 221mv, 210μs, respectively, in the case of load addition and load reduction. Therefore, it is verified that the overall performance of the fractional-order prediction function control strategy based on master-slave current sharing is superior to the traditional PI control in BUCK converter parallel system, and the current allocation accuracy of master-slave module also meets the expected assumption. |
| Key words: parallel control master-slave current sharing BUCK converter fractional-order prediction function current sharing accuracy dynamic response |
