Areas of Activity of Distribution Planning

The principal areas of activities related along with distribution planning are as follows:

1. Existing Load Data Study: The study of the existing system forms a critical input to distribution planning and involves activities such as

1. Updating all distribution system statistics;
2. Evaluating changes in technical and economic planning criteria; and
3. Evaluating and updating voltages, load forecasts, and consumers category-wise with a time horizon of 10 to 15 years.

2. Future Load Growth Study: Load forecasts are extremely significant in Distribution Planning. These are mainly used for:

1. Power purchases;
2. Reinforcement of distribution system expansion planning;
3. Demand side management;
4. Tariff application; and
5. Monitoring of loss reduction programme.

The forecasts might be completed on a short-term, medium-term or long-term basis. These have to be carried out systematically and rigorously to be of any help in distribution planning. Or else, they could lead to wrong estimates and the planning can go awry.

The steps includes in the load forecasting process are:

1. Data collection;
2. Data validation;
3. Selection of methodologies;
4. Development of assumptions;
5. Development of energy and demand forecasts; and
6. Comparison with the historical load growth data.

3. Power Factor/Reactive Load Study: A study of loading pattern and voltage drops requires to be carried out to ascertain the reactive power compensation that is needed to be provided at different points of the distribution system so as to maintain voltages within specified limits. You can study about power factor and reactive compensation in Appendix 1 given at the end of this unit.

4. Study of Thermal Capability of Conductors (Capacity of Feeders/ Circuits): The thermal capacity of line circuit is dependent on the size of the conductor and type of environmental factors that is ambient temperature, wind speed and solar radiation. A study of peak loadings for the conductors needs to be carried out to figure out overloaded feeders with the help of standard tables giving rated currents for each type of conductor. Accordingly, a proper action plan for bifurcation or replacement of feeder needs to be chalked out.

5. Economic Impact Study: A study of the economic impact of the implementation of the distribution system plan needs to be carried out. Cost-benefit analysis needs to be done to ascertain whether the investments in implementation of distribution plan lead to long term savings and improvement in supply quality.