Many types of models have been developed for the voltage source inverter taking into account non-ideal effects, such as voltage drops over the semiconductors, non-ideal switching characteristics and turn-on delay times. However, uncertainties caused by measurement errors during the identification and during the operation of the model have been neglected so far. Nevertheless, the consideration of these uncertainties is necessary in the context of guaranteed state estimation, especially for safety-critical systems. In this paper, a modelling and identification approach is proposed, which considers the most important non-ideal effects and uncertainties. The uncertainties are described by intervals yielding a guaranteed inclusion of the voltage source inverter's output voltages. The guaranteed inclusion of the output voltages is proven by simulations and experiments.