Analysis of the dynamic characteristics in the overcurrent limited mode of the DC-DC converter

The steady-state and dynamic characteristics in the overcurrent-limited mode of a DC-DC converter are analyzed theoretically and experimentally. The circuit conditions are defined for foldback current limiting, constant current, and voltage drooping characteristics, which are realized when the DC voltage gain of the overcurrent limiting control loop is larger than, equal to, and less than unity, respectively. It is shown that the stability in the overcurrent-limited mode, as well as the transient response from the load point in the constant voltage-regulated mode to that in the current-limited mode, can be improved by using a relatively large DC voltage gain and by approximately adjusting the rate time and reset time in the derivative and integral compensators, respectively