H. Toodeji,
Volume 16, Issue 1 (3-2020)
Abstract
This paper proposes a hybrid switching technique for a domestic PV system with AC-module architecture. In this PV system, independent control of PV modules, which are directly connected to DC terminals of a single-phase cascaded multilevel inverter, makes module-level MPPT possible to extract maximum available solar energy, especially in partial shading conditions. As one of the main contributions, the proposed hybrid method employs a fundamental-based switching technique to decrease power losses, which directly affect the efficiency of solar energy conversion. In addition, fast dynamic response of the introduced hybrid technique lets the PV system to harvest more power in partial shading conditions. Producing a waveform with minimized THD in steady-state conditions is another advantage of the proposed switching technique. In this paper, the advantages of the proposed hybrid method are verified by the simulation of a test PV system with both conventional SPWM and proposed switching techniques in MATLAB/Simulink under various partial shading conditions.
P. Bhat Nempu, J. N. Sabhahit,
Volume 16, Issue 4 (12-2020)
Abstract
The hybrid AC-DC microgrid (HMG) architecture has the merits of both DC and AC coupled structures. Microgrids are subject to intermittence when the renewable sources are used. In the HMG, since power fluctuations occur on both subgrids due to varying load and unpredictable power generation from renewable sources, proper voltage and frequency regulation is the critical issue. This article proposes a unique method for operating a microgrid (MG) comprising of PV array, wind energy system (WES), fuel cell (FC), and battery in HMG configuration. The control scheme of the interlinking converter (ILC) regulates frequency, voltage, and power flow amongst the subgrids. Power management in the HMG is investigated under different scenarios. Proper power management is accomplished within the individual subgrids and among the subgrids by the control techniques adopted in the HMG. The system voltage and frequency deviations are found to be minimized when the FC system acts as the backup source for DC subgrid, reducing the power flow through the ILC.
M. Habibolahzadeh, A. Jalilian,
Volume 17, Issue 2 (6-2021)
Abstract
Electric traction trains are huge non-linear single-phase loads influencing adversely on power quality parameters on the grid side. Hybrid power quality conditioner (HPQC) has been utilized to compensate current unbalance, harmonics, and low power factor in the co-phase traction system simultaneously. By incrementing the traction load, the rating of the HPQC increases and may constraints its application. In this paper, a C-type filter is designed to compensate for some part of the load reactive power while the HPQC compensates the remaining part of the load reactive power. Hence, the capacity of the HPQC is reduced in full compensation (FC) mode compared to the conventional configuration. The satisfactory performance of the HPQC is associated with its DC-link operating voltage. Therefore, the Genetic algorithm (G.A) is adopted to optimize the DC-link voltage performance. Simulation verifications are performed to illustrate the usefulness of the proposed configuration. The simulation results show an 18.86% reduction in the rating of the HPQC with optimized DC-link voltage.
M. Habibzadeh, S. M. Mirimani,
Volume 17, Issue 4 (12-2021)
Abstract
The role of energy management in hybrid and electric vehicles (EVs) is an important concern to enhance operational performance and provide the defined efficiency targets in transportation. The power conversion stage as an interface between storage units and the DC-link of the three-phase inverter forms a major challenge in EVs. In this study, a control approach for DC-bus voltage, which utilizes a hybrid energy storage system (HESS) for EV applications, has been proposed. A high-energy-density battery pack and an ultra-capacitor, which owns a high-power density, form the hybrid energy storage system. The proposed approach allows full utilization of the stored energy in the storage devices, and also adds a voltage boost feature to the DC-bus. In the proposed control structure, a motor drive based on SVM-DTC is used to track the flux and torque components using regulators with the space vector modulation. The optimal DC-bus voltage can be tracked by incorporating the motor drive stage with a HESS. This integration results in less processed power. This article presents the simulation results toward confirming and verifying the effectiveness of the proposed approach.
S. Shabani, M. Asadi, A. Zakipour,
Volume 19, Issue 1 (3-2023)
Abstract
In this paper, parasitic capacitors and common mode voltage (CMV) are modeled in a delta connection multilevel cascaded STATCOM. In high frequency and high voltage applications the parasitic capacitors play important role in common mode voltages. In this paper, parasitic capacitors and CMV are modeled in a multilevel cascaded STATCOM and also parasitic currents are calculated, then a method will be proposed to reduce the effects of the parasitic capacitors. The values of parasitic capacitors are calculated by finite element software. Finally, a delta connection 13-level cascaded STATCOM with parasitic capacitors will be simulated in MATLAB Simulink and then simulation results will be presented.
P. Lakshman Naik, H. Jafari, T. Sudhakar Babu, A. Anil, S. Venkata Padmavathi, D. Nazarpour,
Volume 19, Issue 2 (6-2023)
Abstract
This paper demonstrates an enhancement of power quality in grid integrated systems with the help of the proposed control strategy for voltage source converter based active power filters. The Shunt Active Power filters (SAPF) are extensively utilized in modern grid integrated systems to diminish the power quality concerns associated with it. The SAPF is one of the various power filters, which has better dynamic performance. The SAPF requires an accurate control strategy that provides robust performance under source and loads unbalance conditions. The proposed control scheme is responsible for generating the gate signals to activate the operation of Voltage Source Converter (VSC) based Active Power Filter. Thus, the performance of mitigation of harmonics of source current principally depends on the adopted algorithm. The present paper represents a performance study of a control scheme to mitigate power quality issues in the grid integrated system. The proposed system is modelled and simulated in MATLAB-Simulink in Simpower system block set.
Abolfazl Masnabadi, Mehdi Asadi,
Volume 20, Issue 1 (3-2024)
Abstract
This paper proposed a control system for the battery charger of a solar vehicle. The battery charger has two parts, boost converter and isolated DC/AC/DC converter. The boost converter is controlled by a proposed control system based on sliding mode. In this controller, the MPPT is implemented by an extreme point of the solar cell P-V curve. Also, the control system of the DC/AC/DC converter is based on sliding mode with consideration of uncertainties of the output filter. A fast charging algorithm based on variable frequencies was carried out by the presented control system and charging of a Lithium-ion battery was done during 20 min from SOC 20% to SOC 80%. The simulation results show control system effectiveness.
Mostafa Jalalian-Ebrahimi, M. A. Shamsi-Nejad,
Volume 21, Issue 1 (3-2025)
Abstract
This paper proposes an inductive power transfer (IPT) system to maintain stable power transfer and improve efficiency for battery charging performance across a wide range of coupling coefficient variations. The proposed IPT system uses series-series (S-S) and series-inductor-capacitor-inductor (S-LCL) compensation. In both compensation configurations, the rectifier operates in half-bridge (HB) and full-bridge (FB) modes. By using the correct switching pattern between compensation networks and the rectifier, four transfer power-coupling coefficient (P-k) curves are created. A 400 W prototype simulated in MATLAB demonstrates that, with the proposed method, output power fluctuation is limited to only 3% for coupling coefficients varying from 0.1 to 0.4, with system efficiency ranging from 80% to 95.9%. Compared to other methods, the proposed structure provides stable power transfer over an ultra-wide coupling variation and does not require special coil design, clamp circuit design, or complex control.
