Question

Can transformers be used in high-voltage direct current (HVDC) systems?

Answer 1

As of my last update in September 2021, transformers are not directly used in high-voltage direct current (HVDC) systems. In HVDC systems, the conversion of alternating current (AC) to direct current (DC) and vice versa is typically achieved using electronic devices such as thyristors or insulated-gate bipolar transistors (IGBTs) in a process known as rectification and inversion, respectively.

Conventional transformers, which are widely used in alternating current (AC) systems, operate based on the principle of electromagnetic induction, where a changing magnetic field induces voltage in a secondary coil. This principle does not apply directly to direct current (DC) systems because a steady magnetic field does not produce the necessary voltage variations for induction to occur.

Instead, HVDC systems use various types of electronic converters to manage power transmission between AC and DC. These converters are capable of converting the voltage levels and adjusting the power flow direction without the need for traditional transformers.

It's important to note that technology advances continuously, and new developments might have occurred beyond my last update. However, as of 2021, transformers are not directly employed in HVDC systems, and the focus remains on electronic converters to handle the DC-AC and AC-DC conversions.