What is ring distributor? A distributor connected at one or more points to form a closed circuit is called a ring distributor.
With the help of a ring distributor, operation is possible with minimum amount of conductor and continuous service is obtained.
In fact, in this system, each tapping point can be considered as a fed from both ends, resulting in a much lower voltage drop. The voltage drop can be further reduced by the use of interconnectors in this system. On the other hand, supply efficiency can be increased.
To calculate the voltage drop, each part of the ring distributor is considered equivalent to a straight distributor fed from both ends.
When an interconnector is used, the current flowing through the interconnector is obtained by dividing the potential difference across its two ends by the equivalent resistance of the section.
The most common case of a ring distributor is a single feding point as shown in Fig. 13.36(ii). Here A is the feding point and tappings are taken from points B and C. For calculation purposes, this is equivalent to a simple distributor fed at both ends with equal voltage.
Ring distributor with interconnector
Sometimes a ring distributor is required to serve a large area. In this case, the voltage drop in different sections of the distributor may become excessive. To reduce the voltage drop in different sections, the distant points of the distributor are connected through a conductor called an interconnector. Fig. 13.38 shows ring distributor ABCDEA.
Points B and D of the ring distributor are joined through an interconnector BD. There are several methods for solving such networks.
However, the solution to such a network can be easily found by applying Thevenin’s theorem. The steps in the procedure are:
- Consider disconnecting the interconnector BD [see Fig. 13.39 (i)] and find the potential difference between B and D. This gives the Thevenin equivalent circuit voltage E_0.
- Next, calculate the resistance seen from points B and D of the network consisting of distribution lines only. This gives the Thevenin equivalent circuit series resistance R_0.
- If RBD is the resistance of interconnect BD, then the Thevenin equivalent circuit will be as in Fig. 13.39(ii).
Current ininterconnetor BD =frac{E_0}{R_0+R_{BD}}
Therefore, the current distribution in each section and the voltage at the load point can be calculated.
Related Article:
- Advantages and Disadvantages of AC & DC Transmission
- Limitations of AC Transmission
- Constant Voltage Transmission in Long Transmission Line