scholarly journals Hybrid Current-Mode Control of PSFB Converter to Compensate Slew Interval and Prevent Magnetic Saturation of Transformers

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1395 ◽  
Author(s):  
Jae-Hak Ko ◽  
Seung-Woo Baek ◽  
Kang-Mun Lee ◽  
Hag-Wone Kim ◽  
Kwan-Yul Cho ◽  
...  
Keyword(s):  
Current Mode ◽  
Current Mode Control ◽  
Mode Control ◽  
Switching Losses ◽  
Dc Power ◽  
Compensation Methods ◽  
Slope Compensation ◽  
Power Stage ◽  
Control Response ◽  
In Series

This paper proposes a newly developed hybrid current-mode control (HCMC) method for phase-shifted full-bridge (PSFB) converters. Generally, PSFB converters have been widely used in various DC-DC power applications owing to their ease of control and low switching losses. However, the transformer can be saturated by volt-second imbalance of the magnetizing inductance. Therefore, a blocking capacitor can be used in series with the transformer, or peak current-mode control methods with slope compensation can be applied, to prevent transformer saturation. However, blocking capacitors increase the material cost and make the power stage bulky. Moreover, the overcompensation by slope compensation methods delays the control response. This paper proposes a hybrid current-mode control (HCMC) for PSFB converters to solve these problems. A blocking capacitor and slope compensation are not required in the proposed HCMC method for PSFB converters. The proposed HCMC method has no transformer saturation and output response delay, and the efficacy of this method has been verified through simulations and experiments.

scholarly journals Small-signal modeling of current-mode controlled modular DC-DC converters using the state-space algebraic approach

2020 ◽  
Vol 10 (1) ◽  
pp. 139
Author(s):  
Nuha M. Radaydeh ◽  
M. R. D. Al-Mothafar
Keyword(s):  
State Space ◽  
Algebraic Approach ◽  
Current Mode ◽  
The State ◽  
Switching Frequency ◽  
Small Signal ◽  
Symbolic Form ◽  
Current Mode Control ◽  
Mode Control ◽  
Power Stage

<p>Small-signal models are useful tools to preliminary understand the dynamics of interconnected systems like modular dc-dc converters which find a wide range of industrial applications. This work proposes a state-space-based averaged small-signal model in symbolic form for a peak current-mode controlled parallel-input/parallel-output buck converter operating in the continuous-conduction mode. In modeling the converter power-stage each module is independently represented. For modeling the current-mode control the state-space algebraic approach is used to incorporate the current-mode control-law into the power-stage equations. For each module two parasitic elements in addition to the current-loop sampling action are included in the derivation. Furthermore, the control-to-output voltage transfer functions are presented in symbolic form for two cases of interest: the first when the converter has two non-identical modules to study the effect of inductor mismatch, and the second when the converter is composed of <em>n</em>-connected identical modules to assess the effect of varying the number of modules. All responses from PSIM cycle-by-cycle simulations are in good agreement with the mathematical model predictions up to half the switching frequency.</p>

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