Nina Baimel

Novel optimized method for maximum power point tracking in PV systems using Fractional Open Circuit Voltage technique

The paper proposes new improved MPPT measurement method based on the conventional Fractional Open Circuit Voltage (FOCV) method, where the maximum power point voltage is estimated by continuous measuring of PV panels open circuit voltage and calculation of the voltage factor. In the proposed Semi-Pilot Cell (SPC-FOCV) the measurements of the open circuit voltage are performed on one PV cell which is located at the edge of PV panel. When there is no measurement of the open circuit voltage, the PV panel configuration is unchanged and all PV cells inside the panel supply power to the load. During the measurement, the semi-pilot cell is disconnected from the panel by a pair of transistors and bypassed by the bypass diode in order to ensure proper operation of other cells in the panel. This method is intended for application in small PV systems. The proposed method was analyzed and validated by extensive simulation results. It was proved that it can precisely estimate maximum power point voltage. The SPC-FOCV method overcomes the disadvantages of the conventional FOCV and pilot cell FOCV methods. By implementing the proposed method, more power can be supplied to the load with higher efficiency than by the conventional FOCV and pilot cell methods.

New capacitive synchronous AC machine

The paper proposes a new type of the synchronous AC machine operated on a principle of the electric field effect. The proposed machine has smaller size and lighter weight than the standard electromagnetic synchronous machines with the same rated parameters. Another important advantage is a simple structure of the machine, which simplifies the production process and reduces the costs of the motor. The paper also presents extensive simulation results of the proposed capacitive machine. The simulation results show that the proposed machine has high industrial potential and able to develop relatively high power output.

Analysis of hybrid thirteen level cascaded H-bridge inverter operated under different PWM methods

The paper presents an extended analysis of a hybrid 13-level inverter operated under different modulation methods and different conditions. The proposed approach can be extended to any desired number of levels. Extensive simulation results of the proposed inverter are presented. The simulations are validated by hardware-in-the-loop experimental results.

Phase-shifted Discontinuous Pulse-Width Modulation Methods for Multi-level Inverters Operated in Over-modulation Range

Abstract This article presents combinations of the generic phase-shifted pulse-width modulation method with conventional discontinuous pulse-width modulation methods operated in the over-modulation range. The treated discontinuous methods are the third harmonic injection, Depenbrocks DPWM1, and Ogasawaras DPWM2. The significant advantage of the present approach over the conventional phase disposition pulse-width modulation method is the equal power flow between the H-bridges and the improved distribution of the switching operations number between them. Furthermore, they provide improved linearity in the over-modulation range. The proposed pulse-width modulation methods are analyzed by extensive simulation results. Several aspects, such as the total harmonic distortion factor of the inverter output currents and voltages, harmonic content, frequency spectrum distribution, and switchings number, are studied.