Discrete-Time Modeling and Stability Analysis of Peak-Current-Mode Controlled Buck Converter with Constant Current Load

The high-power Asymmetric half-bridge Converter (AHBC) LED constant current driver controlled by digital current mode is a fourth-order system. Static operating point, parasitic resistance, load characteristics, sampling effect, modulation mode and loop delay will have great influence on its dynamic performance. In this paper, the small-signal pulse transfer function of the driver is established by the discrete-time modeling method for the two operating points corresponding to the three modulation modes of the trailing edge, leading edge and double edge. And, the effects of parasitic parameters, delay effect, sampling effect and load effect are fully considered in modeling. For a large number of complex exponential matrix operations, the first order Taylor formula is used for approximate calculation after the coefficient matrix is obtained by substituting the data. Then, Matlab software is used to compare and analyze the discrete-time model and the discrete-average model. The results show that the proposed discrete-time model can more accurately characterize the resonant peak and high-frequency dynamic characteristics, and is very suitable for the design of high frequency digital controller.

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Dynamics and stabilization of peak current-mode controlled buck converter with constant current load

Chinese Physics B ◽

10.1088/1674-1056/24/10/100504 ◽

2015 ◽

Vol 24 (10) ◽

pp. 100504 ◽

Cited By ~ 2

Author(s):

Min-Rui Leng ◽

Guo-Hua Zhou ◽

Kai-Tun Zhang ◽

Zhen-Hua Li

Keyword(s):

Current Mode ◽

Buck Converter ◽

Constant Current ◽

Current Load ◽

Peak Current

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Discrete-Time Modeling of High Power Asymmetric Half-Bridge LED Constant-Current Driver Controlled by Digital Current Mode

IEEE Access ◽

10.1109/access.2021.3059961 ◽

2021 ◽

Vol 9 ◽

pp. 30456-30468

Author(s):

Zhiyong Qiao ◽

Shunli Wang ◽

Ronghai Wang ◽

Yile Shi ◽

Xin Xiong ◽

...

Keyword(s):

Discrete Time ◽

High Power ◽

Current Mode ◽

Constant Current ◽

Time Modeling ◽

Discrete Time Modeling

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COMPLEX DYNAMICS AND FAST-SLOW SCALE INSTABILITY IN CURRENT-MODE CONTROLLED BUCK CONVERTER WITH CONSTANT CURRENT LOAD

International Journal of Bifurcation and Chaos ◽

10.1142/s0218127413500624 ◽

2013 ◽

Vol 23 (04) ◽

pp. 1350062 ◽

Cited By ~ 10

Author(s):

GUOHUA ZHOU ◽

BOCHENG BAO ◽

JIANPING XU

Keyword(s):

Complex Dynamics ◽

Period Doubling ◽

Current Mode ◽

Input Voltage ◽

Second Order ◽

Buck Converter ◽

Constant Current ◽

Current Load ◽

Time Model ◽

Conduction Mode

The complex dynamics and coexisting fast-slow scale instability in current-mode controlled buck converter with constant current load (CCL), operating in both continuous conduction mode (CCM) and discontinuous conduction mode (DCM), are investigated in this paper. Via cycle-by-cycle computer simulation and experimental measurement of current-mode controlled buck converter with CCL, it is found that a unique fast-slow scale instability exists in the second-order switching converter. It is also found that a unique period-doubling accompanied by Neimark–Sacker bifurcation exists in this simple second-order converter, which is different from period-doubling or Neimark–Sacker bifurcations reported previously. Based on a nonlinear discrete-time model and the corresponding Jacobian, the effects of CCL and input voltage on the dynamics of current-mode controlled buck converter are investigated and verified theoretically. Fixed point analysis for slow-scale low-frequency oscillation is also given to verify the dynamics and the coexisting fast-slow scale instability.

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