Perancangan Prototipe Turbin Angin Sumbu Horizontal Skala Laboratorium Dengan Inverter

A horizontal axis wind turbine design research has been carried out using an inverter. This study aims to generate the output power generated by the generator through an inverter. So that the use of an inverter can turn on the 10 watt lamp. From the research results obtained turbine rotation varied between 1357 rpm to 2415 rpm producing a generator voltage of 3.05 volts to 4.61 volts and generator currents 32mA up to 49 mA. The inverter produces a voltage of 16.57 volts up to 20.46 volts and an inverter current of 0.60 amperes up to 0.48 amperes. The greater the rotation of the wind turbine turbine, the greater the generator voltage generated and so is the voltage of the inverter. While the current will increase as the turbine rotation increases and the inverse of the inverter current will decrease as the turbine rotation increases.

Transient Analysis of the Self Excited Induction Generator Subjected to Grid Disturbances

The present paper analyzes the consequences of short grid voltages interruptions on grid-connected self-induction generator, particularly, on the currents and electromagnetic torque of the generator. These effects depend on several variables such as the phase difference between the grid voltages and those of the generator, the magnitude of the grid voltage and the generator currents at the instant of reconnection to the grid. The approach has been used for studying the effects of these grid disturbances on the self-excited induction generator; is a numerical approach. In the numerical approach, which is based on the dynamic d-q model of the induction generator, the effect of magnetic saturation is accurately accounted for. This numerical model has been validated by experimental measurements taken from an induction generator test bench. The analysis focuses on the amplitudes of the peaks of the currents and torque during short interruptions especially at the reconnection of the grid voltage. The results obtained from the numerical model are compared to the measured ones.

Control methods for PWM rectifier cooperating with variable speed PM generator

The paper deals with cooperation between pulse width modulation (PWM) rectifier and variable speed synchronous generator which is applied especially in small water or wind plants. In such applications, the synchronous generator, which is usually permanent magnet (PM) generator, rotates at a variable speed which depends on water or wind energy. Therefore, this energy should be converted to the parameters of the three-phase power grid with the use of a power electronic unit. The main aim of the control strategy is to transfer a maximum possible amount of energy produced by the water turbine or the wind turbine connected to a synchronous generator. The second purpose of the control method is to decrease the amount of higher harmonics of generator currents. The paper describes two basic methods which are used in control systems of the PWM rectifiers. The first one is the sinusoidal PWM method, and the second method relates to the hysteresis switching of the PWM rectifier transistors. A significant part of the paper is devoted to control principles of the PWM rectifier which cooperates with a variable speed PM synchronous generator. Special attention is paid to higher harmonics of PM generator currents with respect to individual methods.

Staged pinch for controlled thermonuclear fusion

Staged pinch implosions provide a means to couple energy to a small-diameter fibre on an extremely fast time scale, circumventing the limitations of conventional pinches. In this scheme the generator current initially traverses an intermediate hollow plasma shell, which compresses onto the fibre placed coaxially and transfers the current to the fibre with a significantly reduced risetime. The results are impressive, since the delivered peak power is increased by several orders of magnitude, the coupling efficiency improves, and the most dangerous plasma instabilities that commonly plague high-density/high-temperature pinches are eliminated. This technique can be fielded on both fast and slow generators (i.e. tens of nanoseconds to microseconds), making it feasible to extend the concept to a wide range of presently assembled systems. Staging may therefore present a dramatically new means of pulsed-energy conversion, which could find many applications. In addressing the requirements for thermonuclear fusion in a staged Z pinch, our preliminary calculations based on zero-D models suggest the potential for a significant thermonuclear burn with generator currents of the order of a few megaamperes and one microsecond risetime. Studies are actively underway at various places around the world (England, France, Germany and Russia) as well as in the USA (UCI/UCR) to investigate different aspects of staged pinching and its applications, particularly those leading to controlled thermonuclear fusion.