Computer aided optimal design of high power density EMI filters

Power density of power converter systems is becoming an increasing crucial design constraint for a wide range of technical applications. Size reduction of EMI filter in power converters is an important challenge due to its significant impact on the overall converter volume and weight. In order to take on this issue, a computer aided procedure for a fast selection of optimal discrete EMI filter components and layout is described in this paper. The proposed technique is a rule-based automatic procedure based on a suitable database that considers the commercially available data sheets of passive components (e.g. magnetic cores, capacitors). It allows the minimization of the filter’s volume and therefore the improvement of the converter’s power density. The size and the performance of an EMI filter designed by using the proposed procedure, have been compared with those of a conventionally designed one. The comparison demonstrates the effectiveness of the proposed method

ODEF: an interactive tool for optimized design of EMI filters

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 improves a previously validated EMI filter design procedure that extends the conventional filter design method in order to achieve optimal power density. Features and operation of ODEF tool are illustrated. Moreover, the experimental assessment of an input EMI filter, designed according to the optimized procedure for an inverter-fed induction motor drive, is performed

In-flight maintenance study Final report

Sample system analysis, MF requirements, redesign, and packaging desig

Fully Analog Laser Driver With Robust Active Feedback Control

The objective of this project was to go through a real life engineering development cycle, document and justify the design choices, and use background experience in electronic design and control systems to implement the best design possible. The laser driver implemented in this project is designed for the general use of a large variety of diodes in continuous wave mode, much like off the shelf laser drivers. The design goals included improving upon off the shelf laser drivers by decreasing steady state error, setting time, response time, and overshoot. Many different feedback control systems were evaluated, and a modified PID controller was chosen which was designed to overcome the operational behavior of real-life electronics. The system was designed from the ground up, the electronics were simulated in the time domain, the entire system derived into the Laplace Domain and simulated using Matlab/Simulink. A printed circuit board was designed and assembled to verify performance in a real system

Development of an Ion Thruster and Power Processor for New Millennium's Deep Space 1 Mission

The NASA Solar Electric Propulsion Technology Applications Readiness Program (NSTAR) will provide a single-string primary propulsion system to NASA's New Millennium Deep Space 1 Mission which will perform comet and asteroid flybys in the years 1999 and 2000. The propulsion system includes a 30-cm diameter ion thruster, a xenon feed system, a power processing unit, and a digital control and interface unit. A total of four engineering model ion thrusters, three breadboard power processors, and a controller have been built, integrated, and tested. An extensive set of development tests has been completed along with thruster design verification tests of 2000 h and 1000 h. An 8000 h Life Demonstration Test is ongoing and has successfully demonstrated more than 6000 h of operation. In situ measurements of accelerator grid wear are consistent with grid lifetimes well in excess of the 12,000 h qualification test requirement. Flight hardware is now being assembled in preparation for integration, functional, and acceptance tests

Design of robust controllers for telecom power supplies

A Telecom power supply is studied and analyzed from control system viewpoint. It consists of three stages: AC/DC rectifier, a backup battery, and a Telecom load. The AC/DC rectifier stage can be composed of paralleled DC/DC converters preceded by paralleled AC/DC converters. However, paralleled DC/DC converters are only considered in this thesis because they constitute the main dynamics in practice. A system of paralleled DC/DC converters operating in continuous inductor current mode with either voltage mode control or peak current mode control are modeled and analyzed using state-space representation. The H∞ control design is used in order to guarantee the robust stability and robust performance of the system in spite of different uncertainties. Also the H∞ loop-shaping design is used to design robust controllers in the presence of uncertainties. μ-analysis is used to evaluate the robustness of the system. Simulation results are presented to demonstrate the control design procedure and to compare between the two approaches presented. A Telecom power system can be composed of voltage-loop and current-loop subsystems. The multi-input-multi-output proportional-integral-derivative (PID) controller is first designed achieving robust stability and robust performance of the voltage-loop. Then, the multi-input-multi-output proportional-integral (PI) controller for current-loop is designed to achieve robust stability and robust performance of the overall system. μ-analysis is used to evaluate the robustness of PID and PI controllers. Simulation results are also presented to demonstrate and validate the control design. The required output characteristic of a Telecom power system contains three modes of operation: constant-voltage, modified constant-power, and constant-current modes. This nonlinear operation can be achieved by using the fuzzy-logic approach. A fuzzy PID-like controller is implemented to achieve the robust output voltage in spite of load disturbances. A fuzzy PI-like controller is implemented to ensure the overload protection reaching the optimal output characteristic of a Telecom power system. Also the internal-model control (IMC) method is applied to basic DC/DC converters: buck, boost, and buck-boost converters. IMC scheme is used to improve the dynamic performance of basic converters by achieving a robust output voltage against line and load disturbances. Simulations show good dynamic performance of the IMC controller.reviewe

The design and application of power line carrier communication and remote meter reading for use in integrated services and broadband - integrated services digital networks

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN009939 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Performance Improvement of AC-DC Power Factor Correction Converters For Distributed Power System

In present situation, the increase in the utilization of computers, laptops,uninterruptable power supplies, telecom and bio-medical equipments has become uncontrollable as its growth is rising exponentially. Hence, increase in functionality of such equipments leads to the higher power consumption and low power density which provided a large market to distributed power systems (DPS). The development of these DPS posed challenges to power engineers for an efficient power delivery with stringent regulating standards; this is the motivation and driving force of this research work. The objective is to minimize the switching losses of front-end converters employed in DPS, with the primary aim of achieving nearly unity power factor operation of converters.Single-phase and three-phase rectifiers are increasingly used in the field of alternating current – direct current (AC-DC) power converters as front-end converters in DPS. For power factor correction (PFC) stage, conventional single-phase AC-DC PFC boost converter is the most suitable topology because of its inherent advantages. These PFC boost converters exhibit poor dynamic regulation of output voltage owing to low pass filter in the voltage feedback loop. Research effort has been made to mitigate this problem of AC-DC PFC boost converters. An extended pulse width modulation switching technique has been investigated and proposed especially for single-phase and three-phase AC-DC PFC boost converters to improve the dynamic response of output voltage during transient periods

Measurements, Models, Systems and Design

531 s.

ANALYZING EFFICIENCY OF SWITCH-MODE WELDING POWER SUPPLY

esearches and studies have indicated that many of the welding quality issues are related to the weld schedule or power supply. During a weld, a certain amount of energy is lost which can be reduced to improve the efficiency of the power supply. This thesis presents a DC/DC buck converter power supply for small scale resistance spot welding (SSRSW), which can provide a testing platform for studies of different control modes, and at the end implement the results of the experiments and research done with this power supply. In this thesis, a model of the small scale resistance spot welding power supply has been implemented. The power supply uses pulse width modulation technique with MOSFETs to convert the power of a 12V battery to the weld current up to 1000A. Various measurements of voltage and current were taken at the respective terminals to calculate the energy losses. Capacitances were added with gradually increased values and again measurements were taken to calculate and analyze the energy losses in presence of the capacitances based on their numerical values. It was noted that the energy losses were reduced appreciably by this technique. So, the efficiency of the converters can be improved