Читать книгу Practical Power Plant Engineering - Zark Bedalov - Страница 42

Let us assume, the local utility has just built a new power plant on the coast, about 120 km away from the ore deposit and have extended a 230 kV transmission line to a city 50 km away from the deposit. This is the line to which the plant will be connected to. The line passes 20 km by the proposed mining site. To further simplify the matters, we will assume that the utility has sufficient spare capacity and is happy to furnish power to the new facility. This is a fortunate situation as it makes it feasible to import the power instead of generating it on its own.

The plant load will be relatively constant with ±10% variability. Utilities love constant load, which they can supply as a base load. The base load energy is less costly to produce in $/MWh.

The plant's electrical distribution system must operate in a stable manner within the prescribed tolerances of voltage and frequency as stipulated by the standards, in spite of the load variations. The load may be subject to changes, both MW and MVAR, caused by the operating cycle and duty of the plant large motors.

The plant owner must determine, based on the history of operation of the generating plant, if the source of power is reliable enough to meet the plant requirements. The plant process can tolerate short power outages without detrimental effects, but longer outages would be a concern with respect to the economies of the plant production.

Studies will have to be made to find out if a wind farm or a solar plant could be economical and possibly developed in the vicinity to supplement the imported power.