Generators As Prime Power Systems

Prime power generation is the continuous supply of power from a generating set for a long period and as the primary source of power. This will typically apply to installations that have decided to generate their own power and go ‘Off-The-Grid’. Sometimes this can occur in remote locations and rural areas of the developing world. It can also be used within city centre locations where the local utility supply is already oversubscribed or the user has identified that it is cheaper to generate their own local power. In addition some operations such as mining, oil and gas exploration or on-board ship have no other alternative to prime power generation.

It may also be cheaper and more cost-effective in some parts of the world for users to generate their own power, in certain parts of the world, than to buy electric power from the grid – such as in parts of China, for example, where energy costs are far higher than fuel costs and it is cheaper to install generators than to buy grid power.

Unlike standby generators (designed to operate for short durations), prime power generators need to be especially designed to operate constantly. They are similar to continuous power generators, which are also required to operate constantly but at a consistent load. Prime power generators are designed to operate continuously, for long periods, but at variable load.

Prime power generators have several features that differentiate them from standby generators. They have to be more robust to withstand the constant movement and vibration that results from continuous operation. A few other design factors enable them to function efficiently over longer periods:

• Cooling systems: for the engine and alternator: prime power generation generators typically have a large cooling system. Continued fuel combustion in the engine causes heat, which if not cooled could cause overheating. Engine jackets are often used to cool it by circulating cold water. The circulating water absorbs heat and is in turn cooled by a radiator fitted with a fan. A cooling system is also required for lubricating oil. In very large industrial prime power generators, a cooling tower or other elaborate system may be required.
• Alternators: are also subject to temperature rise due to continuous flow of current through the windings. The alternator operates continually to provide uninterrupted power supply and so never gets a chance to cool down. This being the case, alternators require heavy-duty windings.

ECO Power Supplies provides a complete design service for generating set installations.