An HVDC transmission station or converter station is a specially operated electrical substation which converts AC power supply into DC supply and DC supply into AC supply. The system forms a terminal line for a high-voltage direct current (HVDC) transmission line. The terminal used for converting AC to DC is called the rectifier terminal and the terminal that converts DC to AC is called inverter terminal. Typically they are called converter terminals because they can work in both the rectifier and inverter mode. An HVDC transmission station requires very high-quality HVDC equipment to operate efficiently.
AC transmission systems are widely used for short-distance power transmission, but when it comes to transmitting power supply for long-distance, HVDC transmission systems have their technical and economical advantages over AC transmission lines. Here’re some basic advantages of HVDC system over AC transmission systems:
- An HVDC system makes it possible to transmit bulk power supply over very long distances with higher efficiency and lower loss than an HVAC transmission system of the same capacity. Higher efficiency and lower electrical loss mean more power supply is reaching to the final station.
- An HVDC system offers more controllability with instant and precise control of the active power flow in the link. HVDC systems’ high controllability is due to the constant power transfer through the transmission lines.
- High short circuit currents are one of the problems across many cities because of the current HVAC system. An HVDC system can help in this cause as it doesn’t contribute to the short circuit current of the connected AC system.
- Even an HVDC transmission system has some added expenses at the station in comparison to the existing HVAC system, but it cost less in its overall performance.
- An HVDC system causes lower environmental impact because they use fewer overhead lines to deliver the same amount of power.
Usually, at each end of an HVDC transmission line, we find an HVDC link that comprises an ac substation and conversion substation and the supply conversion is done using a combination of converter-transformers and converter valves. For the whole operation, the high quality electrical equipment is used that includes AC current switchgear, DC current switchgear, converter transformer, harmonic filtering equipment, DC reactor, and converter valves. Converter transformers are key components of HVDC-stations used for converting AC power into DC power and vice versa.
If you are looking to purchase high-quality HDVC equipment, always prefer a reputed and world-class manufacturer and supplier for your need. Always prefer the products that have standard ratings and certification needed in this business. Make sure to consult with an expert to decide the right kind of HVDC equipment for your requirements. An HVDC system requires a highly engineered product for efficient operation with lower power loss. Many manufacturers also offer the highest quality customized engineered equipment depending on the client’s requirement. An HVDC system has economical, technical, functional, and operational advantages over an HVAC system and they are also future proof in the long run.