Ultrasound diagnosis is routinely used in obstetrics and gynecology for fetal biometry, and owing to its timeconsuming process, there has been a great demand for automatic estimation. However, the automated analysis of ultrasound images is complicated because they are patient-specific, operatordependent, and machine-specific. Among various types of fetal biometry, the accurate estimation of abd...

Voltage control for AC loads can be performed by controlling phase and cycles of AC voltages reaching load end. Cycle control tends to be more beneficial, as it reduces the amount of harmonic frequency in the circuit compared to phase control circuit. When a wave is passed in cycle control circuit, then either an entire half cycle or a complete full cycle is passed, hence eliminating the sharp ...

This paper investigates the effect of temperature on a hybrid energy storage system with various energy management systems. The hybrid energy storage system consists of a fuel cell, ultracapacitor and battery with associated DC/DC and DC/AC converters. The energy management strategies employed are the state machine control strategy, fuzzy frequency/logic decoupling strategy, minimization strate...

In this paper, a new step-up/step-down AC-AC converter is designed by switched capacitor (SC) techniques. The main features of the proposed SC AC-AC converter are the symmetrical converter topology and the absence of magnetic elements. Owing to the symmetrical converter topology, the number of capacitors in the proposed AC-AC converter is fewer than that in the conventional SC AC-AC converter. ...

This article proposes a compensation method for gain and offset errors in the current sensing of three-phase AC machine drives with three sensor measurements during exact or close to standstill conditions. Errors are treated sequentially based on elliptical trajectory method, mathematical manipulation by demodulating faulted time-varying <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xm...

When power systems are expanded and connected together with weak tie lines, the low-frequency oscillations are increased and the stability margin of the power system decreases. Therefore, when designing the transmission system to be used, it is necessary to maintain the dynamic stability of the power system, and to make sure to have the most possible stability margin. SSSC is a FACTS device con...

A new method for current control of multiphase drives is presented. The proposed control method is based on a model based predictive controller which minimises a predefined function cost. A voltage vector to minimise the current error is selected. A discrete-time model of the drive is also used to generate the control signals. Simulation and experimental results are provided. These preliminary ...

This study introduces a field oriented controlled (FOC) induction machine based flywheel energy storage (FES) system fed from a 20kHz ac link and Pulse Density Modulated (PDM) Converter. The feasibilty of FES system is investigated both in software and hardware and is demonstrated succesfully in both cases. The investigated system offers a good potential as a temporary energy storage system for...

Most textbooks on electric machines present a classical five-element constant impedance equivalent circuit for modeling polyphase induction machines operating under balanced polyphase sinusoidal steady-state conditions. Yet it is known for cage rotor machines that the rotor element impedances vary significantly with rotor j-equency. Research is in progress to determine a better ac equivalent ci...