The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The utilization rate of the power conditioner in the grid-tied solar power system is low because the operation of photovoltaic (PV) cell depends on the sunlight. Adding the small scale wind power generating system to the existing solar power system can increase the utilization rate of the power conditioner. In this paper, we propose a novel design method by which the small scale wind power generating...
This paper proposes an advanced configuration of power converter in heliostat system. The traditional converter with four switches is replaced by the NPC converter. A modulation algorithm of NPC converter is also introduced. This replacement help the system works with many low-level voltage sources and the output voltage is more flexible. Therefore, the system efficiency increases and the dimension...
Integration of wind and solar within dc microgrids into buildings is presented. First, a cache control method is applied to utilize a hybrid energy storage which combines diverse but complementary storage technologies. Second, an adaptive droop scheme is proposed to provide coordination control of a battery in real-time and long-term operation. Compared with other existing droop controls, it is distinguished...
This paper introduces a predictive voltage controller for multilevel inverter used in Dynamic Voltage Restorer, which is able to protect a sensitive load against grid voltage sags dynamically. The compensated voltages are obtained by using Phase-Lock Loop to detect the phase and the magnitude of the grid voltage then compare to the load reference voltage. A three-phase NPC inverter with output LC...
This paper concerns the design of a Solid-State Transformer (SST) based grid integrated battery charger with an isolated bi-directional dc-dc converter to maintain the overall system competitiveness. The proposed full bridge DC-DC converter exploits the shoot through mode in the V2G mode for the boosting purpose, which is the uniqueness of the proposed topology. The inclusion of SST in the design...
Doubly-Fed Induction Generator (DFIG) Wind Turbine (WT) is rather sensitive to power system faults and requires specific power converter protection, namely a crowbar. When the crowbar is triggered, the rotor is short circuited over the crowbar impedance, the rotor-side converter (RSC) is incapacitated and therefore the DFIG operates as a squirrel-cage induction generator (SCIG) that tends to drain...
In this paper, an AC/DC converter with a small DC-link capacitor for EV chargers is proposed, where a bridgeless PFC (power factor correction) boost rectifier and a full-bridge phase-shifted-modulated DC-DC converter are employed to transfer power from the grid to the electric vehicle. In order to solve the inherent problem of the second-order ripple power in a single-phase AC/DC converter, an auxiliary...
This paper reviews the existing structures for converter stages in renewable energy and motor drive systems that offer high voltage gain at the input of an inverter. The inverter may also connect the DC supply to the utility grid. For traction motor drives in vehicle and rail transport and in high-frequency transformer connected grids, bi-directional power flow capability is also required. Cascaded...
This paper proposes a Discontinuous current mode (DCM) feedback current control for the grid-connected inverter in order to achieve the low THD of the grid current at wide load range. In the DCM operation, the nonlinearity between the duty ratio and the current occurs in the current command response, whereas another nonlinearity between the disturbance voltage and the current occurs in the disturbance...
Direct current (DC) connection of the large-scale wind generations with high voltage levels and long distance has been widely developed. Meanwhile, medium voltage direct current (MVDC) can also offer similar benefits compared to high voltage direct current connection of wind generations. This study presents a comparison study of MVDC and MVAC for the integration of distributed wind generations. The...
Electric spring is a new smart grid technology which can regulate voltage fluctuations caused due to integration of intermittent renewable energy sources. So far electric springs have been studied mostly with resistive loads which are ON all the time. This paper analyses the performance of electric spring when connected with different types of variable loads. The electric spring circuit was simulated...
This work develops a systematic state-space approach to modeling of an improved buck-boost DC-DC converters. The averaged model of the converters is analyzed. Based on this model, a control law is design to keep the output voltage stable when the input is unstable. The simulation results are presented to confirm the capability of the converter to keep the output voltage stable. The proposed converter...
This paper proposes an application of multi objective optimization method in a smart grid. Recently, smart gird problems has become more diversified and complex which cannot be solved by single objective optimization method. Technical, economical, and placement problems of control devices should also be considered as required. The technical and economical problems are treated as ordinal multi objective...
Multi-output chargers are widely used in various electronic devices due to their benefit in terms of cost, efficiency and space for installation. On the other hand, Inductive Power Transfer (IPT) has been applied increasingly in electric vehicle (EV) since it is more convenient and safer as compared to conductive chargers. However, researches on multiple output chargers using IPT system for EV charging...
This paper proposes an enhanced distributed generation (DG) unit with an adaptive virtual impedance control approach in order to solve the inaccurate reactive power sharing problem. The proposed method can adaptively regulate DG units with the aid of the equivalent impedance, and the mismatching problem of the feeder impedance is compensated by sharing the reactive power accurately. The proposed control...
This paper presents modified Stator Flux Oriented Control (SFOC) for Doubly Fed Induction Generator (DFIG) in wind turbines to reduce torque pulsation during unbalanced voltage dips, and current waveform is also improved with the decreasing of harmonics. The proposed schemes utilize multiple PI with Fuzzy plus Resonant controllers (PI-F+R) to obtain commanded rotor currents and also introduce extra...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.