Input Current Sensorless Control for a AC-DC Converter with Unknown Load and Source Voltage Amplitude
For power electronics engineers, this method eliminates the need for input current sensors in AC-DC converters, reducing cost and hardware complexity.
This paper proposes a new filtered transformation for sensorless control of an AC-DC boost converter that globally estimates input current, input voltage amplitude, and load conductance with exponential convergence, enabling power factor compensation without input current sensors.
Input current estimation is indispensable in the sensorless control algorithms for the problem of power factor compensation (PFC) of an AC-DC boost converter. The system estimator design is challenged by the bilinear form dynamics and uncertain parameters of the system. In this paper, the system dynamics is immersed to a proper form by a new filtered transformation. Thanks to the proposed transformation, the input current, input voltage amplitude, and load conductance are globally estimated. The exponential convergent of the estimates is established in normal converter operation. An application of the proposed estimator is presented in conjunction with a well-known dynamic controller.