Frequency Response Measurement of the Loop Gains of Digitally Controlled Power Converters by Disturbing Digital Circuits

To design stable controller of the DC-DC converter or other power electronics converter used method is frequency loop measurement. The methods to measure analog controller-based loops are well known. More and more digital controllers are used and by using traditional methods not all of the loops can be measured. The paper presents a practical approach to measure Bode plots of digital controller, plant and whole loop with traditional measurement device, but supplying disturbance signal into the digital system. Practical results are shown, and instructions given to implement such measurement method into conventional microcontroller. Achieved measurement results fits well with theoretical ones and simulations.