Comparison between HVAC and HVDC system

Comparison between HVAC and HVDC system

There are two types of transmission system; HVAC and HVDC system. In this article, we will make comparison between HVAC and HVDC system.

Comparison between HVAC and HVDC system

Sr No

Title

HVAC system

HVDC system

1

Effect of capacitance Because of the effect of capacitance charging current produced in the line. The length of the line is limited due to the charging current. There is no effect of capacitance in the case of DC. Hence, the charging current is not produced. So, there is no restriction on the length of a line.

2

Skin effect

In the HVAC system, the skin effect produced due to the non-uniform distribution of charge in a conductor. The power loss increases due to the skin effect. There is no skin effect and power loss.

3

Supports Heavy supports needed. So the cost is more. The cost is less because of the use of lightweight support.

4

Corona effect

 

Corona effect is more in the HVAC system. Which results in the power loss and disturbance to the communication line. Less effect of the corona. Power loss is less and no disturbance to the communication line.

5

Reactive loss There is a net reactive loss. There is no reactive loss.

6

Number of line wire For bulk power transmission, six conductors used. Only two conductors required.

7

Ferranti effect In this system, the Ferranti effect produced. In this system, the Ferranti effect is absent.

8

Power factor The transmission line behaves as an inductor. Therefore, the power factor is lagging. Synchronous condenser or FACTS devices used to improve the power factor. There is no question of the power factor in the case of DC.

9

Intermediate substation Every 300km, one substation required. No requirement of intermediate substation.

10

Use of earth return It is not possible to use earth or marine as a return path. It is possible to use earth or marine as a return path.

11

Line loss Due to reactive power, line loss increases. Line loss is less in this system.

12

Stability The stability of this system is less. The length of a line is limited. This system is more stable.

13

Voltage regulation Poor Good

14

Asynchronous tie It is not possible to connect two tie line which has a different frequency. There is no question for frequency.

15

Overload capacity More Less

16

Possibility of system failure Less More

17

Volume of conductor More less

18

Power transfer and control Slightly difficult Quick control of line

19

Short circuit level Increases Fault level remains the same

20

Complexity of system Less More

21

Cost

Less More

22

Maintenance Easy to maintain Difficult to maintain and highly qualified staff need to maintain

23

Change the voltage level Possible Not possible

Leave a Reply

Your email address will not be published. Required fields are marked *