The state estimation of the voltage conversion process (with Kalman filtering) in a solar power system is shown in this paper. Theoretical principles of solar power systems are presented, along with the position and working principles of a DC-DC boost converter in a solar power system. Different modes of state estimation of the voltage conversion process are shown, along with a detailed explanation of the Kalman filter appliance. This approach can be applied to one of the maximum power point tracking systems (MPPT). In the practical section of this paper, the implementation of noise filtering concepts in a solar power system is shown, by using the National Instruments LabVIEW programming suite. Processes that occur in this type of system are simulated, and the basic principles of noise cancellation are explained, in order to achieve optimal working conditions.