Homework Coursework Example | Topics and Well Written Essays - 1000 words

Homework - Coursework Example 1964). Understanding of electrical stress and electrical strength help avoid discharges in electrical appliances which cause insulation failure. The discharges result from high working voltage and can be reduced by reducing the working voltages. For optimum design of electrical appliances, knowledge on the tendency to increase voltage stress is necessary. Proper selection of insulation material for reliability and economic purposes is done in relation to corona discharges and dielectric strength. High voltage engineers must know the field intensities in different media that are under electric stress. This helps in economical and efficient choosing of insulators to ensure reliable operation of the equipment and the correct electrode configurations. Thickness of the insulating material. A material’s electric strength increases at a rate less than that of a linear increase in its thickness. This means the electric strength for a thicker sample is lower than for a thin sample. Therefore increasing the thickness will greatly affect the electric strength of the insulating material (Malik et al 1998). Duration of voltage transients and operation frequency. When operating frequency increases, the electric strength is reduced. The electric strength of a solid material increases fast and nearly reaches its intrinsic breakdown strength if voltages are applied for short periods, in the order of 10 nS. Humidity. Humidity can reduce the electrical strength of an insulating material. The failures are accelerated if there is a difference in the humidity of the testing environment and that of the environment of operation. Temperature. dielectric constant property of an insulating material can be greatly affected by temperature changes. This will in turn interfere with the signal integrity and result to unstable performance For insulators, for example, polyimide, their electrical