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.
Conventional photovoltaic (PV) power system connects hundreds and thousands of solar cells to form the PV array to match the power and voltage rating. It has been reported that any mismatch among cells results in significant power loss. PV modular level parallel inverter (MLPI) has attracted significant research attention in order to address the issue and improve system reliability. The MLPI requires...
In cascaded-type microgrid, the synchronization and power sharing of distributed generators (DGs) become two new issues that needs to be addressed urgently. In this paper, a unified droop control is proposed and its stability is analyzed in the islanded mode. The proposed scheme can ensure the system stability and accurate power sharing without communication in four-quadrant operations. Finally, simulation...
A novel discrete sinusoidal signal integrator (DSSI) structure is proposed in this paper for single grid-tied inverters. The DSSI provides an adjustable gain and bandwidth at the expected frequency and a highly attenuated gain at other frequencies which make the DSSI based controllers obtain the zero steady-state error tracking performance of arbitrary frequencies. The performance of the conventional...
The linear vernier permanent-magnet (LVPM) motor incorporates the merits of high efficiency and low cost, which is very suitable for long stroke applications. This paper proposed a new direct thrust force control for dual inverter fed open-end winding LVPM motor to reduce force ripple. First, the topology and structural characteristics of the LVPM motor are briefly presented. Second, the mathematic...
Aalborg Inverter is a kind of high efficient Buck-Boost inverter. Since it may work in “Buck-Boost” mode, the control bandwidth should be high enough to ensure a good performance under any grid condition. However, during the “Boost” operation, the control bandwidth depends much on the grid impedance if the crossover frequency is traditionally chosen lower than the characteristic frequency of system...
In this paper, three control strategies for a wide band-gap bidirectional DC-DC converter (BDC) are introduced and combined to improve the vehicle traction system performance. A feed-forward control algorithm is proposed to reduce the voltage ripple of DC-link capacitor located between the BDC and traction inverter. Through voltage control of the BDC, both three-phase short and uncontrolled generator...
Inverters are widely applied in industrial fields. To acquire the analytical solution of sinusoidal pulse width modulation (SPWM) Single-phase inverters, a traditional harmonic balance based method is extended, in which the double Fourier transform is used to describe the nonlinear switching function of the converter. Thus the steady-state periodic solution of the inverter can be obtained by our approach...
A key objective to be fulfilled by distributed voltage source inverters working in parallel in islanded MicroGrids (MGs) is to ensure active power sharing while keeping the frequency at a desired setpoint. Recently, consensus-based control techniques have been applied at the secondary control level for active power sharing while correcting the frequency deviation that the droop control implemented...
Uninterruptible Power Supplies (UPS) have several closed loop control topologies for control of Voltage Source Inverter (VSI). The topologies vary mainly due to choice of control/feedback variable. This paper attempts to categorize different control topologies and highlights the similarities/differences between them. Further, an analytical study on the basis of steady-state and transient performance,...
With increased penetration of renewable energy sources in the bulk electricity system, it is important for power system planners and operators to maintain grid stability and carry out system impact studies for identifying reliability-related problems. Adequate models have been developed by the industry to represent positive sequence response of solar PV plants for grid interconnection studies. In...
In this work, a Lyapunov-function based control method for three-phase grid-tied LCL-filtered quasi-z-source source inverters (qZSIs) is proposed. The mathematical model of grid-tied qZSI is modeled in the synchronously rotating dq-frame. Motivated from the energy distribution in qZSI, an energylike function (referred to as Lyapunov-function) is formed. Then, using Lyapunov's direct method a Lyapunov-function...
Module-Integrated Converters (MICs) are becoming an interesting option for residential photovoltaic (PV) applications because the PV modules are enabled s to work as plug and play devices. Reducing the costs and increasing the lifetime of the MICs are the main challenges for large-scale adoption of MIC technology. Particularly, current spikes during the connection of the MICs with the grid cause unnecessary...
Fault detection in induction motors in non-stationary regimes managed by inverters is an existing industrialized demand. Inverter-fed machines have being used due to their adjustable velocity and quick dynamic response, although the injection of objectionable frequency components. The condition monitoring of these motors can significantly reduce the cost of maintenance in the early detection of faults...
In this paper, an advanced droop control using a multinomial model for operating the parallel-connected uninterruptible power supply (UPS) inverters is proposed. To control the parallel inverters without any physical communications, the control method using a P/Q droops is conventionally used. The conventional method droops voltage and frequency using the monomial model. In conventional droop control,...
Distributed renewable energy generations bring to attention the grid-connected inverter with LCL filter, whose control performance can be largely influenced by filter parameter variations. This paper has proposed a “comprehensive-loop-search, pattern-recognition, key-parameter-scan” method to evaluate the parameter variation influence, especially grid-side inductance and filter capacitance variation,...
For three-phase four-leg inverter, symmetrical component method and double closed-loop control is a traditional method to sustain the symmetry of three-phase output voltage in steady-state under unbalanced load, but asymmetrical output voltage is still generated in transient process. By analyzing the transient process after sudden load change, this paper illustrates the change law of the output voltage...
The huge, ever growing demand for electrical energy has hitherto been primarily met through the combustion of fossil fuels, and conversion of heat liberated therefrom. The relentless exploitation of these resources has raised questions regarding emission of green house gases, particulate pollution, and their harmful effects on environment. It also brings into focus the sustainability of generation...
This paper proposes a high-efficiency single-phase three-level bidirectional inverter. The proposed inverter has a three-level power switching circuit. It can reduce switch voltage stresses with low harmonic components. It has common-mode capacitors at the ac-filter to suppress the ground leakage current for high power quality. Its circuit operation and control strategy are described. Its common-mode...
A filter-based control scheme is developed for buck-type converters. This approach relies only on a single output voltage measurement. The benefits of this approach are reducing the system cost as well as measurement noise and disturbance injected by output current and/or inductor current measurements. A Lyapunov stability analysis is utilized to demonstrate system stability. Experimental results...
Secondary frequency control, i.e., the task of restoring the network frequency to its nominal value following a disturbance, is an important control objective in microgrids. In the present paper, we compare distributed secondary control strategies with regard to their behaviour under the explicit consideration of clock drifts. In particular we show that, if not considered in the tuning procedure,...
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.