Introduction:
Electronic devices, as we all know, run on low-voltage DC supplies such as 5-volt DC. We also know that high-voltage AC voltage is used in transmission lines. But apart from these, there is a HVDC (high voltage direct current) transmission system. in which we use high-voltage DC supplies to transmit the power.
HVDC transmission system
when the bulk power is transmitted by high-voltage DC supplies, called an HVDC transmission system. But this system is not used everywhere, as a HVAC transmission system is.
Advantages of HVDC transmission systems
In HVAC transmission systems, there are many types of effects and phenomena that affect the line and also increase power loss. Some effects affect the line, which is given below.
- Skin effect
- Corona effect
- Ferranti effect
- Proximity effect
- The charging current increased.
- High insulation required.
- Reactive power required
- Power flow is not easy.
- Stability limit
But in the case of the HVDC transmission system, there is not a single effect that affects the line, which is given above.
But the question still remains: why do we not use HVDC transmission systems everywhere?
Limitations of HVDC transmission systems
Apart from these benefits, there are some limitations to this system that prevent it from being used everywhere.
- We can’t step down the HVDC voltage like the HVAC voltage. because a transformer runs only on an AC supply. So, this is a big challenge for the HVDC transmission system.
- Because of the low efficiency of this system
- This system has a low overload capacity.
- This system’s equipment, such as converters and circuit breakers, is very expensive.
Some important parts of the HVDC system
- Rectifiers
- Inverter
- Filter
- DC circuit breaker, etc.
Applications of HVDC transmission systems
Some applications for this system.
- If we have to transmit a bulk amount of power, we use this system.
- If we have to transmit the power across the sea through cable, we use this system.
Types of this systems
- Monopolar HVDC link
- Bipolar HVDC link
- Homopolar HVDC link