Load Allocation Among Various Types of Power Stations
- When a interconnected system makes use of hydroelectric plant, steam power plants and other types of power stations it is necessary to draw the annual load duration curve of the total system and fit the various types of plants into the area under the curve.
- The next consideration is the annual load factor of the hydro-electric stations. First of all annual load factor and average load factor should be taken into account.
- The optimum installed capacity of the hydro-plant in relation to the total system load should be decided taking into account the system load curves and load demand at the present time as well as estimated for the near future.
- The hydro-electric station with ample storage i.e. with large catchment area has more firm power. The secondary power is available for short periods, such a plant can be worked as either a base-load plant or a peak-load plant depending upon the load demand and there is comparatively more flexibility for its use on the load curve.
- The steam station would be working at different load factors during the year. The capacities of hydro-station and steam station have to be so chosen which justifies the final economy in the production of electrical energy at the cheaper rate.
- The final economy is effected by a proper choice of generator loadings in each type of station considering the fuel and operational economy of steam stations and the storage position of the hydro-plant.
- Figure represents a typical allocation of load to various plants. The allocation may change depending upon the availability of water, working load factor of thermal plants etc.