Prediction of Inductance Current in UPS Based on Kalman Filter Estimator

Abstract

In this paper, Kalman Filter (KF) estimator is used to predict inductance current in the Push-Pull circuit in Uninterruptible Power Supply (UPS). At first, the model of Push-Pull circuit is built with two state variables. One is the voltage of capacitance, which can be measured by sensors, and the other one is the current of inductance, which is predicted by KF estimator. Then, the derivation of using KF estimator to predict inductance current is given. At last, the simulation and experiment studies are carried out to show the predicted inductance current with KF estimator is available to be used in the voltage control loop as compensation. The results show the predicted inductance current is closed to the true value and has good stability in noisy environment and good dynamic performance for abnormal mutation of other control values.