Commonly generators continue to work for a long time, the load curve changes greatly, the unit capacity, the number of units, the type of choice and the unit control mode and emergency units.
(1) to determine the capacity: the unit long-term continuous operation of the output power to meet the maximum load calculation of the whole project, and should be based on the importance of the load to determine the capacity of generating units standby unit. The continuous output power of the diesel engine is typically 0.9 times the rated power.(2) to determine the number of units: the general set is usually more than 2 to ensure the continuity of power supply and adapt to changes in electricity load curve. The number of units in order to be based on changes in electricity load to determine the number of units into the generating units, so that diesel engines are often running under the economic load to reduce fuel consumption and reduce power generation costs. The best economic operating status of the diesel engine is between 75% and 90% of the rated power. In order to ensure the continuity of power supply, the common unit itself should consider setting up standby units.
(3) to determine the speed: the general civilian should use the speed of 1000 to 1500 r / min high-speed unit, and the speed of 300 to 350 r / min low-speed unit for marine host.
(4) to determine the voltage: generator output voltage to determine the same with the emergency generating units, generally 400V, individual electricity consumption, transmission distance of the project can choose high-voltage generating units.