This paper presents a control scheme for the Modular Multilevel Converter (MMC) to drive a variablespeed AC machine, especially focusing on improving dynamic performance. Theoretically, the energy balance in the MMC cell capacitors is prone to be unstable at start-up and at low frequency operations. Additionally, the MMC topology essentially requires advanced control strategies to balance energ...

This study was carried out to obtain optimum operation conditions for X-ray machines. We investigated some factors affecting on quality assurance of conventional Siemen X-ray machine, inone of Mansoura Hospitals such as reproducibility of dose output, time and applied high voltage, Kilo-voltage accuracy, mA accuracy, time accuracy, and linearity. We measured these factors using Non-Invasive kil...

An optimal design of a low energy ~300 MeV! proton synchrotron for medical applications is addressed. The machine has the following properties: ~1! The transition energy is higher than the targets final proton beam energy of 300 MeV; ~2! the betatron tunes are chosen such that the machine is free of systematic resonances; ~3! the machine can accommodate both slow and fast extraction systems; an...

torque, speed, and power as mechanical variables are associated with the functional performance of any rotating machinery. the real-time performance and the efficiency of a machine can be determined with on-line measurement of these parameters. in this investigation a rotary torque meter (transducer) was constructed from strain gauge sensors for measuring the torque of rotating shafts. the syst...

Solar photovoltaics is one of the most promising technologies for the non-carbon based electricity production. Power electronics is therefore necessary. In this paper a converter is analyzed which makes it possible to control the mean value of the output voltage, this is e.g. the voltage across a DC machine (and therefore the speed) from zero up to three times of the input voltage. The converte...

This paper presents voltage fed current regulated rotor-side and grid-side control of doubly-fed induction generator (DFIG) under steady and transient conditions. The vector control of grid-side is made to control the active and reactive power flow from the utility grid to the grid side converter independently and also maintain the dc-link voltage constant. Machine-side control regulates the sp...

The proposed paper deals with steady state estimation of a electromagnetic torque ripples and a current waveform of a two-phase induction motor (IM), which is supplied by an three-leg voltage source IGBT bridge connected inverter (VSI). The complex Fourier series analysis of the inverter’s output voltage was made, to obtain an analytical formula of supply voltage waveform. The space phasor theo...

The most common cause of high voltage electric machine malfunction is an electrical failure of the insulation system due to extreme partial discharges activity. The paper discusses the methodology for the construction of a low-pass high voltage filter for partial discharge measurement. It focuses mainly on the shape optimization, using an analytical approach with subsequent verification using t...

Indirect field orientation (IFO) induction machine drives are increasingly employed in industrial drive systems, but the drive performance is often degrades. Motor works on best performance at certain voltage and frequency for certain loads. In this paper artificial neural network is used to predict the operating voltage and frequency when the load torque and speed going changed so motor effici...

In this paper, the voltage sag ride-through capabilities of the line-connected electrically excited synchronous machine with damper windings (EESM) is investigated. We will design an algorithm for voltage sag ride through by controlling the flux. Two aspects are investigated, first the capability to keep the nominal speed and second the damping of speed oscillations. We will show through simula...