Parasitics and voltage collapse of the DC-DC boost converter

The nonlinearity arising from parasitic parameters in a boost converter is investigated in this paper. It is shown that this nonlinearity can cause a serious instability problem for boost converter control. The nonlinearity makes robust controller design difficult due to sensitivity to disturbances. Static and dynamic voltage collapse is studied. Non-iterative formulae are derived using the bilinear averaged model to calculate the voltage collapse point due to the parasitic parameters. Using these simple formulae boost converter operating region and disturbance limits can be calculated in the design phase. The use of these formulae in the design of the boost converter control system is studied. Boost converter disturbance and operating limits calculated using the derived formulae are verified using switched nonlinear circuit model based simulations.