High voltage products require an interesting mix of science and engineering in order to withstand the forces that that are applied to them. When moving very high voltage electricity around the country, it is vital to have equipment that can withstand the rigors that are placed upon them. There is a range of high voltage products that are worth mentioning here. However, this is merely a brief summary as each individual component is certainly worth discussing in a greater amount of detail.
There are a number of switchgear units which are designed to be able to cope with very high voltages.
These include air-insulated switchgears, gas-insulated switchgears, as well as other hybrid switchgears which are designed for specific purposes. Other items worth mentioning include generator circuit breakers, disconnectors, and instrument transformers.
Surge arrestors are a crucial piece of equipment when dealing with high voltage electricity. Because the levels in a cable can vary at certain times, a surge can actually cause a huge amount of damage to other electrical equipment, and can result in whole circuits having to shut down. Surge arrestors are able to control the surge in order to prevent the damage that might have occurred. Instrument transformers are utilized for a variety of applications, including revenue metering, insulation, as well as protection and control services.
When dealing with insulation, long-rod insulators, made of silicone, have been used on certain 550kV overhead power lines. Disconnectors also have a range of applications, and can be utilized on lines anywhere from 72.5kV up to a massive 800kV. There are a range of coil products that are manufactured by the electrical manufacturing companies, in addition to the variety of other smaller components that are manufactured specifically to deal with high voltages.
For electrical engineers, a direct current voltage test is something that must be performed from time to time.
In essence, these are pressure tests that are conducted on high voltage cables. While many cables operate on AC, for numerous reasons the AC testing is not possible, which is why DC testing must take place. More often than not, a DC test will be comprised of half wave rectification, and will typically make use of HV selenium rectifiers. You might have heard about doubling and multiplier circuits. These types of circuits are used in some simple household appliances, like in television sets, but also have high voltage applications.