Often the form of energy most readily available is not the most useful form. Coal can be burned to provide heat, but converting the chemical energy stored in coal into electrical energy requires a series of intermediate steps. In each step of the conversion process, some energy is wasted. ELECTRICAL
Year: 2014
Although there are many ways to classify energy, we will discuss eleven forms of energy. The first three forms of energy are related to the energy of motion associated with moving objects, atoms, and molecules. MECHANICAL ENERGY OF MOTION: Moving objects exhibit mechanical energy of motion, also called kinetic energy.
In a HV test field, the HV components of test systems are designed with an external indoor insulation usually. When internal insulation shall be tested, the test voltage must be connected to the internal part of the apparatus to be tested. This is usually done by bushings which have an
From a practical standpoint, we define the optimization task as follows: given a system or process, find the best solution to this process within constraints. This task requires the following elements: • An OBJECTIVE FUNCTION is needed that provides a scalar quantitative performance measure that needs to be minimized or
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
For voltages higher than 400 KV, it is desired to cascade two or more transformers depending upon the voltage requirements. With this, the weight of the whole unit is subdivided into single units and, therefore, transport and erection becomes easier. Also, with this, the transformer cost for a given voltage
Voltage sags may cause lamps to extinguish. Light bulbs will just twinkle; that will likely not be considered to be a serious effect. High pressure lamps may extinguish; it takes several minutes for them to re-ignite. All lamps, except incandescent lamps, require high voltage across the lamp electrodes during starting.
A rotating machine is less exposed to lightning surge as compared to transformers. Because of the limited space available, the insulation on the windings of rotating machines is kept to a minimum. The main difference between the winding of rotating machine and transformer is that in case of rotating machines
It has been observed that in case of very small gaps of less than a mm and the gas pressure between the gap lies in the range 10–9 to 10–2 torr, there is no change in the breakdown voltage i.e, if the gap length is small a variation of gas pressure in the range given above
The vacuum breakdown mechanism based on this theory makes following assumption: (i) A loosely bound particle known as clump exists on one of the electrode surfaces. (ii) When a high voltage is applied between the two electrodes, this clump gets charged and subsequently gets detached from the mother electrode and
