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 resonant controllers (RCs) are commonly used in the current control of grid-tied converters with LCL filter due to their advantages, such as zero steady-state error at both fundamental sequences, easy design process, and straightforward implementation. Nevertheless, these traditional solutions do not permit to place the closed-loop poles of the system in convenient locations when dealing...
In this work it is presented a two-phase open-end winding induction motor (IM) driven by an improved current source inverter (CSI). The proposed inverter has independent full quadrant operation, lower DC-link current value, high magnetics power density, 25% more efficient and high AC output voltage waveform quality compared to conventional CSI solutions. A back-to-back AC-DC-AC current source converter...
Distributed diode rectifier units have been proposed as a robust and cost efficient solution for the connection of large off-shore wind farms to HVDC links. However, since the diode rectifier platforms are connected in series with cables of varying distances, their dc-side voltage might not be the same in all diode rectifier platforms. This paper introduces a diode rectifier platform dc-voltage balancing...
With the increase of the load and the growth of length of the line, it is not available to get the voltage rating by the conventional droop control. As a result, an improved control strategy based on dynamic virtual resistance is proposed in low-voltage DC microgrids. The designed dynamic virtual resistance is changed with the load current and the drop of voltage amplitude. The value of virtual resistance...
Formation of microgrids have been proposed as a solution to improve grid reliability, and enable smoother integration of renewables into the grid. Microgrids are sections of the grid that can operate in isolation from the main power system. Maintaining power balance within an islanded microgrid is a challenging task, due to the low system inertia, which requires complex control to maintain stable...
The authors solve the problem of effective use of renewable energy sources for autonomous electric consumers. A new device for coupling heterogeneous energy sources has been developed. The universal coupling device (UCD) allows to connect diverse AC and DC sources to a 220/380VAC consumer. A 30 kVA UCD prototype is created. The article gives a UCD brief description and presents the results of the...
In order to strengthen the framework structure of distribution network, promote the agility of its control methods, and improve its intelligent and automation level, Soft Normally-Open Point (SNOP) as a novel power electronic device is installed in distribution network, which can provide accurate control of real and reactive power flow. This paper proposed the dynamic mathematical model of three-port...
DC voltage droop control is seen as the preferred control structure for primary voltage control of future multi-terminal HVDC systems. Different droop control structures have been proposed in literature which can be classified in eight categories. This paper contributes to an analysis of the disturbance rejection of these droop control structures. The approach is based on multi-variable frequency...
Multiple-pickup wireless power transfer (WPT) systems are popular in electric vehicles (EV) and other charging applications. Currently, these systems use all the pickups to provide power at any load demands. However, it causes some unnecessary power loss. This paper proposes an output control strategy for an efficient power supply according to the power demand while enhancing overall power transfer...
Solar-energy utilization is growing in demand since the past decade due to the increase in energy needs and depletion of non-renewable sources. But the problem with solar energy is that it's not constant; it keeps on fluctuating depending upon the weather conditions such as, solar irradiation, temperature, thus a battery is always connected between the load and the solar panel so as to act as a secondary...
Boost converters are widely used in several applications such as solar PV systems, energy storage systems, etc. In order to improve its dynamic performance, several model predictive control (MPC) strategies have been proposed to govern this DC-DC converter. However, in general, they require long prediction horizons to achieve a stable closed-loop due to its well-known non-minimum phase behavior. A...
This paper presents a new modulation for modular multilevel converters (MMC) based on a simple idea, which is very easy to implement. It consists of playing with the relative behaviour of each phase in order to obtain the desired AC voltage. This method also assures that the voltage capacitor in each sub-module remains constant. Moreover, this converter allows the operation of the system under unbalanced...
The article recommends the principle of commutative programming scan of the comparison signal. This principle allows linearization of transient characteristics «regulating pilot — output voltage» of pulse-width convertors. In the article obtained the expressions for determining the sequence of discrete samples, forming a functional scan reference signal. The functional scan is necessary for the linearization...
Measurement of lightning and switching transient overvoltage in power system is significant to the research that guides the protection of power system. This study presented a new type of sensor for the measurement of lightning and switching transient overvoltage based on the capacitive coupling and Pockels effects. Its advantages include high accuracy and sensitivity of measurement, non-contact with...
This paper proposes an energy and dc-bus voltage control strategy for the MMC converter, connected to HVDC link, using online quadratic optimization. The proposed approach leads to regulate simultaneously the energy sum and difference in “abc” frame and to maintain the DC voltage level around the operating point. The aim of this paper concerns the development of a reliable strategy based on optimization...
The modular multilevel converter (MMC) with cascaded full bridge cells is available for an AC/AC transmission system without transformers in high voltage line. When it is interconnected with power line, it is possible to control the active power flow in order to supply the power to the power line. This research applied the MMC to grid connection system of distributed generator for single phase AC/AC...
Variation of wind power affects the stability of a multi-terminal HVDC (MT-HVDC) system installed in the purpose of integrating offshore wind farms and supplying an offshore constant power load in oil and gas plat form. This paper investigates the stability of such MT-HVDC system. In order to determine the stability, an impedance-based stability method is adopted. The stability is determined by checking...
This work describes a symmetrical transformation approach for the state of charge control of a mixed-type energy storage system based on the modular multilevel converter. By decoupling of external and internal arm power flows the transformation offers a comprehensible insight into the state of the system. Storage unit current limitations are taken into account in the described control structure.
The paper is dedicated to problem of current sharing of paralleled DC-DC converters in order to provide balanced loading of DC-DC converters with common DC bus. Cascaded control system structure is considered where, at first, an inner multivariable current proportional controller is designed and then, at second, an outer voltage integral controller is constructed in order to keep the desired output...
In the context of microgrids, most of the research has concentrated on developing new control strategies for integration of DG sources into the power grid and seamless transition techniques between grid-connected and islanded modes. However, a few research work has focused on the power control at the point of common coupling (PCC) between utility grid and microgrid. This paper presents alternative...
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.