ENGINEERING ARTICLES

 Introduction Electrostatic fields play a crucial role in high voltage engineering, influencing the design and performance of power systems. Understanding these fields helps in the effective insulation and protection of electrical components. This article delves into the fundamental concepts of electrostatic fields, their behavior, and applications in high voltage systems. Uniform and Non-Uniform Fields Electrostatic fields can be classified into uniform and non-uniform fields based on the distribution of electric charge and the resulting electric field intensity. Uniform Fields: These fields have a constant electric field intensity throughout the space. They are typically created between two parallel plates with a uniform charge distribution. Uniform fields are used in applications requiring predictable and stable electric field conditions. Non-Uniform Fields: These fields have varying electric field intensity, often resulting from irregular charge distributions or geometries. Non...

HVDC links may be broadly classified into the following categories: Monopolar Links Bipolar Links Homopolar Links The basic configuration of a monopolar link is shown in figure. It uses one conductor, usually of negative polarity. The return path is provided by ground or water. Cost considerations often lead to the use of such systems, particularly for cable transmission. This type of configuration may also be the first stage in the development of a bipolar system. Instead of ground return, a metallic return may be used in situation where the earth resistivity is too high or possible interference with underground/ under water metallic structures is objectionable. The conductor forming the metallic return is at low voltage.

For voltages higher than about 300 to 500 kV, the cascading of transformers is a big advantage, as the weight of a whole testing set can be subdivided into single units and therefore transport and erection becomes easier. Also, with this, the transformer cost for a given voltage may be reduced, since cascaded units need not individually possess the expensive and heavy insulation required in single stage transformers for high voltages exceeding 345 kV.It is found that the cost of insulation for such voltages for a single unit becomes proportional to square of operating voltage. The low voltage. supply is connected to the primary winding ‘l’ of transformer I, designed for an high voltage output of V as are the other two transformers. The exciting winding ‘3’ supplies the primary of the second transformer unit II; both windings are dimensioned for the same low voltage, and the potential is fixed to the high potential V. The high voltage or secondary windings ‘2’ of both units are se...