A "converter transformer" is typically used in high-voltage direct current (HVDC) transmission systems to facilitate the conversion of alternating current (AC) to direct current (DC) and vice versa. HVDC transmission is employed to transmit electricity over long distances with lower losses compared to traditional alternating current (AC) transmission. Converter transformers play a crucial role in this process by interfacing AC and DC systems and enabling efficient power transfer.
Here's how a converter transformer handles AC-DC conversion:
AC Input Stage (Rectification): The converter transformer takes in the high-voltage alternating current (HVAC) from the AC power source, which is typically generated by a power station. The first step is to convert this AC input into a direct current (DC) output. This process is known as rectification.
Converter Operation: The converter transformer is connected to a converter station, which houses the necessary components for the conversion process. The main components include high-power electronic devices, such as thyristors or insulated gate bipolar transistors (IGBTs), arranged in a specific configuration called a rectifier. These devices are controlled to switch on and off at precise intervals.