current converter
Current converters are used to control currents and to convert electrical energy in terms of current, voltage or phase. Current converters are divided into rectifiers that convert AC voltage into DC voltage, inverters that convert DC voltage into AC voltage, converters that convert an AC voltage into another AC voltage with a different amplitude and frequency, and DC/DC converters that convert a DC voltage into a higher or lower DC voltage.
Depending on the type of commutation voltage, a distinction is made between line-commutated converters, self-commutated converters and load-commutated converters. Commutation refers to the transition of current from one valve branch to another.
Inself-commutated converters, the commutation voltage is provided in the converter itself. They have a great importance in power electronics.
In line-commutated converters, the commutation voltage is taken from the feeding mains. These converters play a role in high power applications, such as high voltage direct current( HVDC) transmission.
Load-sensing conver ters receive their commutation voltage from a load. They are used, for example, in synchronization machines.
An example of load-controlled converters is phase angle control. It works with thyristors and triacs and allows the converted power to be varied continuously from about 0 % to 100 % by gating the phase.