DC Constant Current Electronic Load: Stability Analysis

Teaching modeling and control of switched DC-DC converters consists of converter design concerning specifications, converter modeling, and choosing and designing a controller to ensure the converter system works appropriately. Besides the power supply, a load should be carefully chosen. To test with several DC-DC converters where the load current is constant and varies, a known control bandwidth of the electronic load should be used to get the correct results—the control bandwidth links to the poles of the load system, which interact with the tested converter. A switching boost power converter is proposed for a load with a nonlinear current controller where the controlled bandwidth can be changed. To reduce ripple current drawn from the tested converter, two sets of cascade LC filters are used. These filters exhibit in poles of the system, which interacts to the converter. An average model has developed to investigate the system's stability, and its eigenvalues are evaluated. Simulation results are given to verify the model and highlight its suitability to use as a load for the switching converter.