a. chowdhury

Bi-directional power converters are utilized for effective management of available electrical energy associated with renewable energy systems with the use of an energy storage system. Improved hybrid three quasi z source converter (IHTQZSC) is proposed in this paper which has been providing a higher voltage gain without any switched capacitor or charge pump cells. IHTQZSC has been intended for bi-directional power transfer and control applications in this paper. The converter ensures a widespread voltage gain in a single stage DC↔AC power conversion system with lesser shoot-through time instants. The competence of the converter is acclaimed with voltage stress, current stress, peak switching device power and power losses compared with the other high voltage gain converters. Impact of voltage gain and power drawn by the converter on the efficiency has been explained. The four-quadrant power control is achieved with the constant switching frequency predictive controller. The DC-link voltage of the converter is controlled with a PI controller, and a predictive controller is used for the grid current tracking. The bi-directional working of the converter is illustrated with MATLAB/Simulink software

The power system in upcoming years will face issues of power frequency instability due to an increase in the share of Renewable Energy Sources (RES). The RESs are integrated into the power system through the power electronic converters. The operation and control of RES are drastically different than the conventional energy sources. This paper is focused on the effect of a rise in the share of RES on power system frequency stability and its possible solutions. The RESs are not taking part in the frequency regulation process in case of disturbance. Despite this, they generate disturbances in the power system caused by the intermittent nature of input energy. The RES doesn’t have extra active power for the frequency regulation as they already operate at their maximum power point. These power electronic-based generators don’t contain inertia like conventional generators. The inertia-less systems adversely affect the Rate of Change of Frequency (RoCoF) and frequency nadir. This is demonstrated on IEEE 9-bus system with different scenarios. According to that analysis, the RES should provide an inertial response during disturbances. In this paper, the proposed Modified Virtual Inertia Control (M-VIC) technique emulates inertia like conventional generators by using external Energy Storage Systems (ESS). In M-VIC the inertial response is replicated by controlling the rate and duration of power provided by ESS. The proposed technique is more effective to reduce the frequency nadir and RoCoF with better utilization of ESS. To demonstrate this, the PV integrated single-area power system model is simulated in MATLAB R2019a.

Energy efficiency is an essential aspect of motor technologies. The replacement of conventional Single Phase Induction Motor (SPIM) by Permanent Magnet Synchronous Motor (PMSM), Synchronous Reluctance Motor (SynRM), or Switched Reluctance Motor (SRM) for energy-efficient operation leads to high capital expenses. This paper presents a cost-effective design method to improve the efficiency of the existing SPIM. It implements a novel idea by transforming it to Line Start Synchronous Reluctance Motor (LS-SynRM). A rotor of 0.5 HP, SPIM is successfully redesigned using finite element analysis (FEA). A comprehensive parametric sensitivity analysis in terms of barrier position and width focused on the work. Moreover, introducing a permanent magnet in the rotor barrier has also been investigated. Parametric analysis determines the optimum size of the permanent magnet. However, the best-fit significant rotor parameters have been estimated. Results revealed substantial improvement in the performance of derived LS-SynRM and Permanent Magnet Assisted LS-SynRM (PMaLS-SynRM).