Design of a Teaching Tool for Stability Analysis of DC-DC Converters

This paper describes the design of a virtual instrument (VI) to analyze stability in control systems implemented in LabVIEW virtual instrumentation software. The VI generates a Routh-Hurwitz array for analyzing system stability based on obtaining the characteristic D (s) equation and is able to identify situations where there is a space or row of zeros within the array. Furthermore, the VI shows the graphical location of the poles and zeros of the transfer function in closed loop, the graphical system response to a unitary step input and peak time, overshoot, settling time and peak value of the step response. Finally a case study on a DC-DC buck type converter operating in continuous and discontinuous conduction is reviewed.