|
|
Analysis of Non-Minimum Phase Characteristics and Control Strategies for Single-Inductor Dual-Output Buck-Boost Converters |
Li Huihui, Huang Jinfeng |
School of Electrical Engineering Shanxi University of Technology Xi'an 723001 China |
|
|
Abstract The rapid development of portable electronic devices increases design complexity: more unit modules inside the machine and the power supply voltage levels of different modules are usually different. The single-inductor dual-output (SIDO) Buck-Boost switching converter realizes dual output with one inductor, which has the characteristics of no electromagnetic interference and a simple structure. In addition, the converter has a buck-boost feature, realizing multi-grade voltage output (relative to the input supply voltage). It provides a new solution to the problem of power supply for electronic products that require multiple voltage levels, and has received much attention from scholars at home and abroad. However, this converter is a non-minimum phase system because the voltage of one of the output branches will be negatively regulated when the duty cycle is suddenly changed. The negative regulation phenomenon will lead to a longer transition time, and the converter will form positive feedback and become unstable during the negative regulation time. In addition, the non-minimum phase system cannot use the traditional frequency domain method for controller design, which makes the controller design more complicated. Therefore, it is important to study the non-minimum phase characteristics and control strategy of the SIDO Buck-Boost converter. Firstly, this paper analyzes the working principle of the SIDO Buck-Boost converter and establishes the transient mathematical model of control-output of inductor current continuous conduction mode using the state space averaging method. The analysis of the mathematical model shows that the model of the first conduction branch of the converter contains the right half-plane zero point. In contrast, the model of the back conduction branch does not contain it. By analyzing the negative regulation voltage generation mechanism of the converter, it is found that the negative regulation phenomenon exists in the output voltage of the pilot branch when the sudden change of duty cycle occurs, and does not exist in the output voltage of the back-lead branch. The analysis of the negative regulation voltage mechanism verifies the correctness of the mathematical modeling results. Then, the mathematical model of the internal dynamics of the branch containing the right half-plane zero is established. It is found that when the output voltage of the branch containing the right half-plane zero is selected as the output variable, the system has unstable zero dynamics. When the inductor current is selected as the output variable, the system does not have unstable zero dynamics. Therefore, this paper transforms the control of output voltage into the control of inductor current by introducing inductor current feedback to the branch containing the right half-plane zero, using a two-loop structure, with the inductor current as the controlled quantity in the inner loop and the capacitor voltage as the controlled quantity in the outer loop. As a result, the system is transformed into a minimum-phase system, and the transient response speed of the system is improved. The other branch uses voltage control, simplifying the control structure of the system. Then, the SIDO Buck-Boost converter operating mode and the output ripple voltage are used as constraints to obtain the inductor and capacitor parameters design method. Based on the obtained inductor and capacitor parameters combined with the Routh-Hurwitz stability criterion, the range of control parameters is obtained, and the control parameters are optimized by applying the characteristic root sensitivity theory. Finally, the simulation and experimental platforms are built to test the transient performance of the load and input supply voltage mutations, respectively. The results show that the method of using current control for the branch containing the right half-plane zero point and voltage control for the other branch improves the transient performance of the system compared with the voltage control for both branches, and effectively suppresses the cross-regulation between the output branches, which is of practical engineering application.
|
Received: 01 July 2022
|
|
|
|
|
[1] 郭强, 李山, 谢诗云, 等. 多相交错并联DC-DC变换器单电流传感器控制策略[J]. 电工技术学报, 2022, 37(4): 964-975. Guo Qiang, Li Shan, Xie Shiyun, et al.Single-sensor sampling current control strategy of multiphase interleaved DC-DC converters[J]. Transactions of China Electrotechnical Society, 2022, 37(4): 964-975. [2] 卿晓东, 苏玉刚. 电场耦合无线电能传输技术综述[J]. 电工技术学报, 2021, 36(17): 3649-3663. Qing Xiaodong, Su Yugang.An overview of electric- filed coupling wireless power transfer technology[J]. Transactions of China Electrotechnical Society, 2021, 36(17): 3649-3663. [3] 何杰, 刘钰山, 毕大强, 等. 开关变换器传导干扰抑制策略综述[J]. 电工技术学报, 2022, 37(6): 1455-1472. He Jie, Liu Yushan, Bi Daqiang, et al.Review of conducted electromagnetic interference suppression strategies for switching converters[J]. Transactions of China Electrotechnical Society, 2022, 37(6): 1455-1472. [4] Goh T Y, Ng T W.Single discharge control for single-inductor multiple-output DC-DC Buck con- verters[J]. IEEE Transactions on Power Electronics, 2018, 33(3): 2307-2316. [5] Nayak G, Nuth S.Decoupled voltage-mode control of coupled inductor single-input dual-output Buck converter[J]. IEEE Transactions on Industry Appli- cations, 2020, 56(4): 4040-4050. [6] 王忠杰, 王议锋, 陈庆, 等. 基于GaN的高频Boost变换器优化设计[J]. 电工技术学报, 2021, 36(12): 2495-2504. Wang Zhongjie, Wang Yifeng, Chen Qing, et al.Optimal design of high frequency Boost converter based on GaN[J]. Transactions of China Electro- technical Society, 2021, 36(12): 2495-2504. [7] Zhang Hao, Jing Min, Liu Wei, et al.Multiple- harmonic modeling and analysis of single-inductor dual-output Buck DC-DC converters[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2020, 8(4): 3260-3271. [8] Wang Benfei, Zhang Xinan, Ye Jian, et al.Deadbeat control for a single-inductor multiple-input multiple- output DC-DC converter[J]. IEEE Transactions on Power Electronics, 2019, 34(2): 1914-1924. [9] Nayak G, Nuth S.Decoupled average current control of coupled inductor single-input dual-output Buck converter[J]. IEEE Journal of Emerging and Selected Topics in Industrial Electronics, 2020, 1(2): 152-161. [10] Chen H, Huang C J, Kuo C C, et al.A single-inductor dual-output converter with the stacked mosfet driving technique for low quiescent current and cross regulation[J]. IEEE Transactions on Power Elec- tronics, 2019, 34(3): 2758-2770. [11] Wang Yao, Xu Jianping, Yin Gang.Cross-regulation suppression and stability analysis of capacitor current ripple controlled SIDO CCM Buck converter[J]. IEEE Transactions on Industrial Electronics, 2019, 66(3): 1770-1780. [12] Dong Zheng, Tse C K, Ron Hui S Y. Current source- mode single-inductor multiple-output LED driver with single closed-loop control achieving independent dimming function[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2018, 6(3): 1198-1209. [13] Anitha T, Arulselvi S.Design of linear and nonlinear controller for DC-DC Boost converter with right-half plane zero[J]. International Journal of Power Elec- tronics, 2022, 15(1): 116-130. [14] 祁静静, 吴学智, 王久和, 等. 采用开关电感的Buck变换器CCM和DCM特性分析[J]. 电工技术学报, 2022, 37(16): 4155-4168. Qi Jingjing, Wu Xuezhi, Wang Jiuhe, et al.Chara- cteristics analysis of Buck converter with switched inductor in CCM and DCM[J]. Transactions of China Electrotechnical Society, 2022, 37(16): 4155-4168. [15] 皇金锋, 任舒欣. 含有右半平面零点的宽负载范围DC-DC开关变换器参数设计[J]. 西安交通大学学报, 2021, 55(6): 166-175. Huang Jinfeng, Ren Shuxin.Parameter design of wide load range switched DC-DC converter with RHP zero[J]. Journal of Xi'an Jiaotong University, 2021, 55(6): 166-175. [16] 吴岩, 王玮, 曾国宏, 等. 四开关Buck-Boost变换器的多模式模型预测控制策略[J]. 电工技术学报, 2022, 37(10): 2572-2583. Wu Yan, Wang Wei, Zeng Guohong, et al.Multi-mode model predictive control strategy for the four-switch Buck-Boost converter[J]. Transactions of China Electrotechnical Society, 2022, 37(10): 2572-2583. [17] 周述晗, 周国华, 毛桂华, 等. 电流型控制单电感双输出开关变换器稳定性与瞬态特性分析[J]. 电工技术学报, 2018, 33(6): 1374-1381. Zhou Shuhan, Zhou Guohua, Mao Guihua, et al.Stability and transient response analysis of current- mode controlled single-inductor dual- output con- verter[J]. Transactions of China Electrotechnical Society, 2018, 33(6): 1374-1381. [18] Zhang Hao, Jing Min, Liu Wei, et al.Design-oriented analysis of cross-regulation in single-inductor dual- output Buck-Boost DC-DC converters[J]. Inter- national Journal of Circuit Theory & Applications, 2021, 49(12): 3966-3993. [19] 周国华, 冉祥, 周述晗, 等. 恒定谷值电流型变频控制CCM单电感双输出Boost变换器建模与分析[J].中国电机工程学报, 2018, 38(23): 7015-7025, 7135. Zhou Guohua, Ran Xiang, Zhou Shuhan, et al.Modeling and analysis of CCM single-inductor dual-output Boost converter with fixed valley current mode variable frequency control[J]. Proceedings of the CSEE, 2018, 38(23): 7015-7025, 7135. [20] Wu Jiarong, Lu Yiming.Exact feedback linearisation optimal control for single-inductor dual-output boost converter[J]. IET Power Electronics, 2020, 13(11): 2293-2301. [21] 皇金锋, 刘树林, 董锋斌. DC-DC变换器负调电压产生机理分析与抑制[J]. 电工技术学报, 2016, 31(21): 168-175. Huang Jinfeng, Liu Shulin, Dong Fengbin.Negative voltage mechanism analysis and suppression for DC-DC converter[J]. Transactions of China Electro- technical Society, 2016, 31(21): 168-175. [22] 皇金锋, 李林鸿, 谢锋, 等. 含有右半平面零点的开关DC-DC变换器暂态性能分析及频域法设计[J]. 电工技术学报, 2020, 35(10): 2170-2180. Huang Jinfeng, Li Linhong, Xie Feng, et al.Transient performance analysis and frequency domain design of switched DC-DC converters with right half plane zero[J]. Transactions of China Electrotechnical Society, 2020, 35(10): 2170-2180. [23] 刘树林, 刘健. 开关变换器分析与设计[M]. 北京: 机械工业出版社, 2011. [24] 皇金锋, 谢锋, 李慧慧. 基于特征值灵敏度的共模-差模电压控制SIDO Buck变换器稳定性分析[J]. 电机与控制学报, 2021, 25(11): 114-121. Huang Jinfeng, Xie Feng, Li Huihui.Stability analysis of common-mode voltage and differential- mode voltage controlled SIDO Buck converter based on eigenvalue sensitivity[J]. Electric Machines and Control, 2021, 25(11): 114-121. [25] 皇金锋, 李慧慧, 谢锋. 基于状态反馈精确线性化Buck变换器的微分平坦控制[J]. 工程科学与技术, 2022, 54(6): 248-257. Huang Jinfeng, Li Huihui, Xie Feng.Differential flattening control of Buck converter based on state feedback exact linearization[J]. Advanced Engineering Sciences, 2022, 54(6): 248-257. |
|
|
|