# Fast Unloading Transient Recovery of Buck Converters Using Series-Inductor Auxiliary Circuit Based Sequence Switching Control

Title | Fast Unloading Transient Recovery of Buck Converters Using Series-Inductor Auxiliary Circuit Based Sequence Switching Control |

Publication Type | Conference Paper |

Year of Publication | 2018 |

Authors | Zhao, Z., Lu, W., Ma, J., Li, S., Zhou, L. |

Conference Name | 2018 IEEE International Power Electronics and Application Conference and Exposition (PEAC) |

Publisher | IEEE |

ISBN Number | 978-1-5386-6054-6 |

Keywords | buck converter, Buck converters, capacitor-charge balance principle, control systems, equivalent inductance, fast transient regulation, fast unloading transient event, fast unloading transient recovery, Inductance, Inductors, load transient response, low-voltage high-current synchronous buck converter, output current ripple reduction, power convertors, pubcrawl, resilience, Resiliency, sequence switching control (SSC), sequence switching control scheme, series inductor auxiliary circuit based sequence switching control, series-inductor auxiliary circuit, SSC control scheme, Steady-state, Switching circuits, switching systems (control), switching time sequence, System recovery, time-optimal control scheme, Transient analysis, transient response, unloading transient response, variable inductance circuit, voltage 12 V to 3.3 V, voltage overshoot |

Abstract | This paper presents a sequence switching control (SSC) scheme for buck converters with a series-inductor auxiliary circuit, aiming at improving the load transient response. During an unloading transient, the series inductor is controlled as a small equivalent inductance so as to achieve a fast transient regulation. While in the steady state, the series inductor behaves as a large inductance to reduce the output current ripple. Furthermore, on the basis of the proposed variable inductance circuit, a SSC control scheme is proposed and implemented in a digital form. With the proposed control scheme the unloading transient event is divided into n+1 sub-periods, and in each sub-period, the capacitor-charge balance principle is used to determine the switching time sequence. Furthermore, its feasibility is validated in experiment with a 12V-3.3V low-voltage high-current synchronous buck converter. Experimental results demonstrate that the voltage overshoot of the proposed SSC scheme has improved more than 74% compared to that of the time-optimal control (TOC) scheme. |

URL | https://ieeexplore.ieee.org/document/8590384 |

DOI | 10.1109/PEAC.2018.8590384 |

Citation Key | zhao_fast_2018 |

- System recovery
- sequence switching control scheme
- series inductor auxiliary circuit based sequence switching control
- series-inductor auxiliary circuit
- SSC control scheme
- Steady-state
- Switching circuits
- switching systems (control)
- switching time sequence
- sequence switching control (SSC)
- time-optimal control scheme
- Transient analysis
- transient response
- unloading transient response
- variable inductance circuit
- voltage 12 V to 3.3 V
- voltage overshoot
- Inductors
- Buck converters
- capacitor-charge balance principle
- control systems
- equivalent inductance
- fast transient regulation
- fast unloading transient event
- fast unloading transient recovery
- Inductance
- buck converter
- load transient response
- low-voltage high-current synchronous buck converter
- output current ripple reduction
- power convertors
- pubcrawl
- resilience
- Resiliency