Search results for "Converter"
showing 10 items of 275 documents
Effect of the non-linearity of demagnetization curves on the torque of hybrid stepping motors with permanent magnets in slots
1998
The recent achievements in electronic control as well as the higher performance of advanced permanent magnets have brought about a change in the general strategy for design and development of new types of small electrical machines. A special application of permanent magnets (PM) is represented by hybrid stepping motors (HSM). The latter are a sort of combination of variable reluctance‐motors and permanent magnet‐motors. The influence of various PM inserts into the magnetic circuits of electromechanical converters on field and force distribution has been already investigated by the authors (1996). Promising results for HSM have been reported, especially when rare‐earth PMs are used. The main…
Decoupled control scheme of the grid-connected split-source inverter for renewable energy sources
2016
Grid-connected power conversion systems for renewable energy sources must fulfill several requirements, including high efficiency, reduced cost and complexity, and, quite often, also boost capabilities from the dc sources to the ac power grid. For such applications, single-stage power converters with boost capabilities offer some potential advantages. Among several proposed options, split-source inverter (SSI) has been recently investigated. This paper proposes a decoupled control scheme for the SSIs, where the common mode term of the ac modulation signals is used to control the dc input current. Thus, the dc input current and ac output current can be controlled independently. The proposed …
Grid integration of PEM fuel cell with multiphase switching for maximum power operation
2016
Energy storage in the form of electrolytic Hydrogen can play an important role for integration of intermittent renewable energy sources in the smart grid environment. Electrolytic Hydrogen can be used as a fuel in proton exchange membrane (PEM) fuel cell. In this work, a technique for multiphase switching of a DC-DC converter associated with grid integration of a PEM fuel cell stack for maximum power operation in non-dispatchable mode is proposed. The presented system consists of a PEM fuel cell stack which is operating in non-dispatchable mode of operation, DC-DC multiphase switching boost converter for maximum power operation and a grid tied three phase voltage source inverter (VSI). VSI …
Achieving maximum power transfer in a multi-source renewable system
2014
In this paper, a multi-source DC-DC power system is proposed for renewable applications. A multi-input, single inductor power converter controlled by two interacting control loops is designed. The steady-state and small-signal analysis of the designed system is carried out. A battery-photovoltaic system is designed as an application example. Both the output voltage and maximum power point of solar panels are properly controlled to achieve high performances of the whole system. Experimental results on a 48 V laboratory prototype are presented to discuss system performances.
Optical Fibre Control-Measurement Systems Of Compound HV/HP Electrical Equipment
1988
Responsible electrical equipment should be controlled during the work in care of their high reliability. Traditional control measurement systems cannot fulfil the task because of the hard conditions in which the equipment may operate (various electrical potentials, electromagnetic interferences, changes of temperature, etc.). The development of fibre optic transmission media and fibre optic sensors allows the construction of new control measurement systems for cooperation with such electrical equipment as: converters, generators, treLnsforniens, switch bays, busbards, etc. Those optical fibre structures, composed of bu-ses and sensors are subject of this paper. The main attention is paid to…
ODEF: An interactive tool for optimized design of EMI filters
2016
The impact of EMI filters on volume and weight of power converters is significant. For this reason, filter's size optimization is a strategic step towards the improvement of the power converter's power density. An EMI filter design that follows a conventional procedure does not guarantee the selection of components/configuration leading to the best power density. Therefore, in order to help EMI engineers and scientists in pursuing a fast and effective choice of optimal discrete EMI filter components and configuration, a novel tool is proposed in this paper, namely ODEF (Optimized Design of EMI Filters). ODEF is an interactive software application running in Matlab® environment. It suitably …
On the design of observers robust to load variations for synchronous converters
2015
Due to the ever growing concern on energy efficiency issues, synchronous rectification gained increasing attention in recent years. In the semiconductor industry fast controllers developed for DC-DC converters are typically based on inductor current measures. In this context system costs and performances strictly depend on the current sensor and its proper design. In this paper we present a sensorless synchronous approach based on a current observer. The same observer formulation is valid for the three standard DC-DC converters, simplifying its design for different configurations. Furthermore the designed observers are proven to be robust against load variations, the most uncertain paramete…
Non-linear digital control improving transient response: Design and test on a multiphase VRM
2010
Multiphase interleaved buck converters are widely used for point of load applications, especially for VRMs. Performance optimization issue often clashes with size and cost requirements thus leading the industrial and academic research to focus on advanced solutions. This paper presents a control technique for multiphase VRMs including two interacting sections: the linear loop implements a PWM peak current mode control and the nonlinear subsystem modifies few linear loop parameters under load transients only. Steady-state performances are affected by the linear control only while dynamic performance optimization is a non-linear algorithm issue. The proposed control system improves the dynami…
Optimized design of high power density EMI filters for power electronic converters
2016
Nowadays, power density of power converters and related EMI filters is gaining more and more attention. This severely impacts on the design constraints in several application domains. A conventional design of the EMI filter does not guarantee the selection of components/configuration leading to the best power density. For this reason, an optimized design procedure of discrete EMI filters in terms of power density is proposed in this paper. It is based on a previously developed rule-based design procedure, introducing here additional features to obtain a more effective optimization of EMI filter's power density. The proposed approach has been validated in terms of EMI filter's performance an…
Dynamic performance enhancement of AC/DC PFC boost converters by means of MRAS observers
2015
Controlling a Power Factor Corrected (PFC) boost converter is not a trivial task, because the higher the dynamic performance, the higher is the input current distortion. On the other hand, recent applications of these converters require fast transients in response to disturbances, such as sudden variations of load power, reference voltage and input voltage. Better performance can be obtained adding a feedforward action to the traditional control scheme, using observers to estimate the input voltage and the output current. However, the actual improvement depends on the dynamic performance of the chosen observers. This paper aims at evaluating the applicability and the performance of differen…