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A linear constant current light-emitting diode (LED) driver without off-chip inductor and capacitor is presented in this paper. The proposed driver consists of one resistor, one diode bridge and one controller integrated circuits (IC). The controller IC employs four LED strings and sequences their conduction to shape the output current in proportion to the input voltage. The controller IC was designed...
This paper proposes a design of a single-switch non-isolated three-port converter for a standalone photovoltaic (PV) power system with energy storage. The three-port converter is obtained by combining the switches of two conventional cascaded DC-DC converters. Pulse-width modulation (PWM) and pulse-frequency modulation (PFM) are utilized to regulate the two converters respectively. The proposed design...
The paper summarises the business oriented approach to reinstrumentation and control improvement projects, based on the need for world class process plant profitability. The paper is illustrated with examples based on experience from a number of problems and projects.
The paper presents a method to derive an optimal parametric sensitivity controller for optimal estimation of a set of parameters in an experiment. The method is demonstrated for a fed batch bio-reactor case study for optimal estimation of the saturation constant Ks and, albeit intuitively, the parameter combination μmaxX/Y where μmax is the maximum growth rate [g/min], Y is the yield coefficient [g/g],...
Paper presents new topology of an AC boost rectifier that is used to draw the sinusoidal current from single phase overhead traction supply system through single phase transformer delivering 50 or 16.7Hz voltage depending on traction technology. The AC boost rectifier means that it operates as power factor correction. The topology of the boost rectifier system is modification of Warsaw and Vienna...
Single-inductor multiple-output (SIMO) DC-DC buck converters, which possess the advantage of compact size, are commonly implemented in portable electronics like mobile phones and tablets. However, their power efficiency is degraded considerably, as illustrated in Fig. 12.6.1, when multiple outputs are requested in a wide range, such as 1.2 to 3.3V for tablets. The use of P-MOSFET [1][2] and N-MOSFET...
Reducing the number of large external components, especially inductors, is a very important issue for Power-Management ICs (PMICs). Single-Inductor Multiple-Output (SIMO) converters are excellent candidates to meet this requirement [1-3]. However, there are several issues with SIMO converters, such as cross regulation, instability and inefficiency at light load. Under normal load conditions, comparator-based...
DC microgrids have sources such as solar power plants, battery storage systems, fuel cell power plants. DC-DC converters are used in each of these systems to interface them with DC bus of the microgrid. For economically optimized operation of microgrid, it is necessary to have a control system enabling desired load sharing between the DC-DC converters. The solution described here is incorporation...
A single stage LED driver for street-lighting application with power-factor-correction is proposed in this paper. The presented driver is the integration of PFC boost which operates in continuous conduction mode (CCM) and push-pull dc-dc converter. Both the active switches can turn on with ZVS, which results in lower switching losses. Asymmetrical pulse-width-modulation control scheme is used to control...
Nonlinear problems are very common in many industrial applications. For controlling such systems there are several conventional type of controllers intended, such as manual controller, P, PI, PID, and fuzzy controllers. In recent decade new family of intelligent controllers has been evolved because of vary complicated systems and due to requirement of accuracy in the process. The paper consists of...
Power Factor which is the ratio between the real or actual power and the apparent power is a very essential parameter in power system. It indicates how effectively the real power of the system has been utilized. In any electrical power system, a load with a low power factor draws more current than a high power factor load, for the same amount of useful power transferred. The most popular topology...
In this paper, an on-board charger for electric vehicle, with two-stage power converter, is designed. Firstly, a single-phase Boost-APFC (Active Power Factor Correction) circuit controlled by a one-cycle controller is designed as the front state converter. Compared to the traditional APFC circuit, the One-cycle controller is constructed without considering the multiplier and AC line voltage sensing...
This paper introduces a novel multiplex voltage source converter topology based on common DC bus. Except from the excellent characters of traditional VSC, the capacity of the system can be expanded. Dual mode control is proposed to stabilize DC bus voltage, when the superconducting inductor current is between the maximum and the minimum allowable value, chopper control mode is adopted; when the current...
The operation stability and robustness are usually the main criteria for the practically implemented systems. This is especially critical in LED lighting applications, where voltage regulators are used to control current of nonlinear LED load. Also the parameters of the load significantly changes with the temperature change and bin change even for the same brand LEDs. The control system of LED driver...
In the last two decades, a great part of research in the power electronics area has been involved in finding methods of improving the input current waveform while simultaneously avoiding phase displacement. The aim of the paper consists of selecting two of the most relevant single phase power factor correction (PFC) topologies currently existing for the power range of 1.5 kW up to 4 kW and to analyse...
This paper presents a moving horizon estimation (MHE) approach for estimating flow and pressure inside the annulus during managed pressure drilling (MPD). MPD is an advanced pressure control method that is used to precisely control the annular pressure throughout the wellbore in oil well drilling. The MPD model, which is a hyperbolic-type partial differential equation (PDE), is a hydraulic model based...
The algorithm of the interval observer design for a class of nonlinear systems with parametric uncertainty is considered. It is shown that the observer allows to derive an interval that contains the actual value of the state at a given time. The main condition of such a device construction deals with a cooperativity of the interval estimation error dynamics. The question of the selecting the individual...
The bidirectional isolated AC/DC converter is widely used in the past decades. Most of the topologies are based on voltage source converter. However, the performance of the voltage source based converter is significantly limited by the bulky energy storage element, the range of soft switching, the leakage inductance of the transformer and so forth. A current fed isolated AC/DC converter is studied...
This paper shows a study about circulating current of modular multilevel converter (MMC) based a high voltage direct current (HVDC) system under some unbalanced grid conditions. A basic structure of the MMC HVDC system is introduced and its system dynamics is analyzed. Based on the analysis, the modeling of circulating current and its control method under balanced or unbalanced grid condition are...
The main theme of this paper is to propose a new control method of optimizing the switching frequency to reduce the loss of phase-shifted full-bridge (PSFB) converter. The detailed loss analysis of PSFB converter is performed and the loss analysis model is given. Based on the model, the optimum switching frequency that will result in minimum total power loss under variable load conditions is studied...
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