Sensorless Voltage Observer for a Current-Fed High Step-Up DC-DC Converter Using Extended Kalman Filter

Abstract

In high voltage applications, sensorless voltage control techniques can reduce the cost and increase the reliability of DC-DC converters. In this paper, a sensorless voltage observer for a current fed Cockcroft-Walton voltage multiplier is designed. The first step is to derive the converter model. Since any inaccuracy in the derived model can result in a discrepancy between the observed voltage and the actual output voltage, an accurate model is derived, which incorporates the influential elements. Then, two voltage observers based on the extended Kalman filter (EKF) are designed and used to estimate the output voltage, transformer magnetizing current and inductor current for two different configurations of the high step-up DC-DC converter. Experimental and simulation results of the system show the efficiency of the observers. The proposed observers represent good precision as the main parasitic parameters are considered in the converter model.

Steady‐state hybrid extended Kalman filter based sensorless voltage controller for a phase‐shifted full‐bridge converter

“…sensorless voltage control). For example, Haadi et al [15] proposed a sensorless voltage observer for a step-up DC/DC converter using extended Kalman filter (EKF). As they mentioned in their study, the major limitation of their method is the high computational burden and it is not suitable for low-power embedded systems.…”

“…Arranging the expressions we end up with the augmented model in Equation (15). Linearising it around the nominal conditions (V O , V S , G load , d nom ) as in Equation ( 14) we obtain the linearised discrete-time dynamic model in matrix form of Equation (16).…”

“…FIGURE15 Experimental results for percentage error of load resistance estimation and percentage error of output voltage estimation and regulation with respect to load resistance (R load )…”