ABSTRACT
This paper proposes a single-stage three-phase modular flyback differential inverter (MFBDI) for medium/high power solar PV grid-integrated applications. The proposed inverter structure consists of parallel modules of flyback DC-DC converters based on the required power level. The MFBDI offers many features for renewable energy applications, such as reduced components, single-stage power processing, high-power density, voltage-boosting property, improved footprint, flexibility with modular extension capability, and galvanic isolation. The proposed inverter has been modelled, designed, and scaled up to the required application rating. A new mathematical model of the proposed MFBDI is presented and analyzed with a time-varying duty-cycle, wide-range of frequency variation, and power balancing in order to display its grid current harmonic orders for grid-tied applications. In addition, an LPF-based harmonic compensation strategy is used for second-order harmonic component (SOHC) compensation. With the help of the compensation technique, the grid current THD is reduced from 36% to 4.6% by diminishing the SOHC from 51% to 0.8%. Moreover, the SOHC compensation technique eliminates third-order harmonic components from the DC input current. In addition, a 15% parameters mismatch has been applied between the flyback parallel modules to confirm the modular operation of the proposed MFBDI under modules divergence. In addition, SiC MOSFETs are used for inverter switches implementation, which decrease the inverter switching losses at high-switching frequency. The proposed MFBDI is verified by using three flyback parallel modules/phase using PSIM/Simulink software, with a rating of 5 kW, 200 V, and 50 kHz switching frequency, as well as experimental environments.
ABSTRACT
This paper describes the design and analysis of a small-sized and high thrust electromagnetic actuator. The proposed actuator is supposed to be used for application control of the hotmelt adhesive. The hotmelt has different characteristics for each material and the electromagnetic actuator is required variable characteristics. However, the problem seems to lie in the fact that it is necessary to remake another mold again to change the characteristics of the conventional electromagnetic actuator. Therefore, this paper presents small-sized electromagnetic actuator called a basic model that can stack it in the axial direction or in the radial direction. As the analysis comparison at the same size, the characteristics of conventional two serial model which stack two basic models in the axial direction and proposed three serial models have been compared by three-dimensional finite element method. In the proposed model, characteristics have been improved by reducing the core volume and increasing the number of stacks in the basic model from the viewpoint of magnetic flux density. In addition, various electromagnetic actuators that stack basic models in the axial direction or in the radial direction have been analyzed. The analysis results have been clearly shown as characteristics mapping and it has indicated that the proposed electromagnetic actuator can be constructed easily by stacking the basic model.
