There is currently no unified calculation formula in the country for selecting the capacity of self-provided diesel generator sets, so the methods used by designers in actual work are also different: some simply determine it based on 10%-20% of the power transformer capacity; Some are added according to the capacity of fire-fighting equipment; some are selected according to the wishes of investors, which results in inaccuracy in selecting the capacity of self-provided generating units. If the capacity is selected too large, it will cause a waste of investment; if the capacity is selected too small, it will cause a waste of investment in the event of an accident. Cannot meet usage requirements. So, how to choose the capacity of self-provided generating units? After reviewing the information and referring