September 17th

Problems of Practical Diagnostics of Induction Machines in Industry

There are many problems in practical diagnostics of high-power, quirrel-cage induction machines, operated in industrial conditions. These problems make the diagnostics a difficult matter. The problems appear already at the stage of gathering diagnostic signals. The only practically accessible signals are the currents on secondary sides of current transformers monitoring supply currents of separate machines.

Read full article

An Improved Model of a Three phase Induction Motor Incorporating the Parameter Variations

A great deal of work is being done on the improvement of control through simulation of the electric drives used for various high-power purposes. The authenticity of the simulated results is based on the accurate modeling of the various parts of the electric drive system.

Read full article

September 15th

A New Closed Loop Speed Control Strategy for a Vector Controlled Three- Phase Induction Motor Drive

This paper presents a model based mathematical equations for control of torque and speed of a three-phase indirect vector controlled VSD-fed induction-cage motor that is controlled through the space vector modulated method. This enables a wide range of acceptability of the model for various values of load and various types and ratings of induction motors.

Read full article

Fuzzy System for the Detection of Power Quality Performance on Induction Motor

Sensitive equipment and non-linear loads are now more common in both the industrial/commercial sectors and the domestic environment. Because of this a heightened awareness of power quality is developing amongst electricity users. Therefore, power quality is an issue that is becoming increasingly important to electricity consumers at all levels of usage. This article presents the fuzzy system to determine the power quality.

Read full article

September 11th

Effects of Source Voltage Harmonics on Power Factor Compensation in AC Chopper Circuits

In recent years, the detailed modelling of power electronic devices and their behaviours on various system conditions are a great concern of the power industries and customers. One of the widely proliferated such devices is the triac controlled ac choppers. Although these types of devices have important application areas, their poor power factor is the main obstacle for the large scale implementation in power systems.

Read full article

Transfiguration of supplied-by-HV/MV transformer network to the supply radius

A HV/MV transformer supplies a few power lines of known parameters and loads. These power lines can be substituted with the supply radius, at the end of which there is the equivalent load-receiver representing the entire load being transmitted by the transformer. The R and X parameters of this substitute supply radius are needed to calculate adjusting parameters of the voltage regulator which controls the HV/MV transformer. The presented method enables simple determining of the supply radius parameters R and X.

Read full article

September 9th

Voltage quality improvement using DVR

The problem of voltage sags and Swells and its severe impact on sensitive loads is well known. To solve this problem, custom power devices are used. One of those devices is the Dynamic Voltage Restorer (DVR), which is the most efficient and effective modern custom power device used in power distribution networks. Its appeal includes lower cost, smaller size, and its fast dynamic response to the disturbance. This paper describes DVR principles and voltage restoration methods at the point of common coupling (PCC ).

Read full article

September 8th

Computer-Based Voltage Dip Assessment in Transmission and Distribution Networks

Digital simulation is a powerful mean to predict the voltage dip performance of a power network. Voltage dip characteristics can be accurately reproduced using present simulation tools and a stochastic prediction procedure that could incorporate the random nature of the voltage dip causes and the behaviour of sensitive equipment during this type of events.

Read full article

September 6th

Active Earthing System to Optimise Power Quality in MV Networks

Neutral treatment is a key issue when a MV network is designed. Requirements of insulation and safety have to be met whilst guaranteeing rapid fault detection, location, arc suppression and tripping -if necessary- within a proper timing. The values of overvoltages and fault currents expected in the network are crucial, since they affect Power Quality parameters, namely interruptions and voltage dips.

Read full article

Development of a Photovoltaic Array Emulator System based on a Full-Bridge Structure

Nowadays solar photovoltaic technology is becoming more and more important every day. Manufacturers and laboratories dedicated to photovoltaic (PV) equipment research and development are arising continuously, and so are their needs of having appropriate test equipments.

Read full article