To improve the matching between standby generators and UPS equipment, as far as possible to select excellent performance generators, the main focus should be on improving the input characteristics of UPS and improving the connection between the two.
(1) Influence of different power outputs on diesel generator sets
According to UPS capacity, the capacity of the general generator set is the UPS capacity of 2~ times. In fact, UPS generally work at the rated capacity of 50%~80%, while the power generation for the generators may be about 30%% of the rated capacity. This not only causes the capacity of the generator set not fully utilized, increase the investment of equipment, resulting in the "big horse" phenomenon, and make the generation unit more prone to malfunction, increased maintenance, reduce the work reliability of the generator set, the reason is:
① according to the characteristics of the diesel engine, if the long-term work under the small load, the cylinder temperature is lower, the normal entry into the cylinder oil can not be completely burned, and fuel can not be fully burned, resulting in the piston rings, nozzle coke is serious, the cylinder wear intensified, so that the above-mentioned parts of the accelerated failure to produce the diesel engine performance decreased, exhaust fumes.
② diesel engine at 30% rated load below, economic variation.
Combined with various factors, the generator set requires that the load must be more than 60%% rated load in the case of work, the diesel engine is more favorable.
(2) The influence of different excitation modes of modern synchronous alternator on the load is also different
In fact, the power ratio of ups and generators can be matched in 1: (1~), the key is to consider the excitation mode of modern synchronous alternator in generator set. When using the self-excited synchronous alternator, its UPS power and the power generation unit ratio should at least 1: (2~), but still cannot exclude the generator set not by UPS, when the use of Permanent magnet generator, power ratio 1: (~5), can ensure that the generator set normal work.