Boundary Conditions of Subharmonic Oscillations in Fixed-Switching-Frequency DC-DC Converters
arXiv:1202.4232 · doi:10.1007/s11071-014-1283-7
Abstract
Design-oriented boundary conditions for subharmonic oscillations are of great interest recently. Based on a subharmonic oscillation boundary condition reported in a PhD thesis more than a decade ago, extended new boundary conditions are derived in closed forms for general switching DC-DC converters. Sampled-data and harmonic balance analyses are applied and generate equivalent results. It is shown that equivalent series resistance causes the boundary conditions for voltage/current mode control to have similar forms. Some recently reported boundary conditions become special cases in view of the general boundary conditions derived. New Nyquist-like design-oriented plots are proposed to predict or prevent the occurrence of the subharmonic oscillation. The relation between the crossover frequency and the subharmonic oscillation is also analyzed.
Title changed. Submitted to a journal on 2/24/11, and resubmitted to IJCTA on 8/10/11. Added: S-plot to determine the required ramp slope, V2 control, a counterexample (Example 5) of the ripple index hypothesis. The key results traced back from my 1997 PhD thesis, available: http://www.lib.umd.edu/drum/. My five IJCTA papers in arXiv have two common reviewers
References in corpus (6)
- Closed-Form Critical Conditions of Saddle-Node Bifurcations for Buck Converters
- Closed-Form Critical Conditions of Subharmonic Oscillations for Buck Converters
- Using Nyquist or Nyquist-Like Plot to Predict Three Typical Instabilities in DC-DC Converters
- Saddle-Node Bifurcation Associated with Parasitic Inductor Resistance in Boost Converters
- Unified model of voltage/current mode control to predict saddle-node bifurcation
- Modeling and Instability of Average Current Control