This publication describes the developed general model of the vehicle power network in MATLAB. The developed model includes most significant components of 12 V electrical network, such as alternator, rectifier, loads and battery, designed in form of sub-models. The vehicle power network model has a modular design, so single sub-models can be replaced easily. The quality of the developed model has been verified by comparison of simulation results with measurement results on the test bench. Modeling of every single component, such as the sub-model of the alternator or the sub-model of the excitation current control, as well as functioning principle of the vehicle power network and simulated automotive-typical test case will be described in detail in the following publication.