Features of 650kVA Emergency Diesel Generator

Diesel generator is a kind of small power generation equipment, refers to the diesel fuel, diesel engine as the prime mover to drive the generator power machinery. The whole set is generally composed of diesel engine, generator, control box, fuel tank, starting and control storage battery, protection device, emergency cabinet and other components. The following is a brief introduction to the characteristics of diesel generators and matters needing attention:

First, two major characteristics of 650kVA emergency diesel generator:

The first feature is for emergency use, continuous working time is not long, generally only need to run for a few hours (≤12H);

The second feature is that 650kVA emergency generator set is in a state of shutdown and waiting in normal times. Only when the main power supply is completely blocked and cut off, the 650kVA emergency diesel generator set will start to operate and supply emergency power load. When the main power supply returns to normal, it will switch to stop immediately.

Sceond, emergency diesel generator selection points:

(1) Determination of generator capacity of emergency diesel generator

The calibrated capacity of the emergency diesel generator set is the 12h calibrated capacity corrected by the atmosphere, which should be able to meet the total calculated load of the emergency electricity, and the generator capacity should be verified according to the requirement that the generator capacity can meet the starting requirement of the single-capacity motor in the first-stage load. Emergency generators generally use three-phase AC synchronous generators, whose calibrated output voltage is 400V.

(2) Determination of the number of emergency diesel generating units

When there are more than one generator set in reserve, generally only one emergency diesel generator set is set. In view of reliability, two generator sets can be used in parallel for power supply. The number of emergency generating sets should not exceed 3. When multiple units are selected, complete sets of equipment with the same model, capacity, similar voltage regulation and speed regulation characteristics should be selected as far as possible, and the fuel properties should be consistent, so as to carry out maintenance and share spare parts. When there are two urgently needed generating sets, the self-starting device should make the two sets stand-by each other, that is, after delayed confirmation of the failure of the mains power supply, the self-starting command should be issued. If the first unit fails to self-start for three consecutive times, the alarm signal should be sent and the second diesel generator should be automatically started.

(3) The choice of emergency diesel generator

Emergency units should be diesel generators with high speed, supercharged, low fuel consumption and the same capacity. High speed supercharged diesel engine single machine has large capacity and occupies small space; Diesel engine selection with electronic or hydraulic speed regulating device, speed regulating performance is better; Generators should be equipped with brushless excitation or phase compound device synchronous motor, more reliable, low failure rate, more convenient maintenance and repair; When the capacity of a single air conditioner or motor in the first load is large, it is appropriate to choose the generator set with three harmonic excitation; The unit is mounted on a common chassis with shock absorbers; Exhaust pipe outlet should be equipped with * to reduce the impact of noise on the surrounding environment.

(4) Control of emergency diesel generator set

The control of emergency diesel generator set should have fast self-starting and automatic putting device. When the main power supply fails, the emergency unit should be able to quickly start and restore power supply. The allowable power failure time of primary load ranges from ten seconds to tens of seconds, which should be determined according to the specific situation. When the main power supply of an important project is cut off, it should first pass a definite time of 3-5S to avoid instantaneous voltage reduction and the closing time of the municipal grid or the automatic input time of the standby power supply, and then issue the command to start the emergency generator set. It takes some time from the time the command is issued, the unit starts up, and the speed is raised to full load. General large and medium-sized diesel engines also need pre-lubrication and warming process, so that the emergency loading of oil oil pressure, oil temperature, cooling water temperature in line with the provisions of the factory technical conditions; Pre-lubrication and heating process can be carried out in advance according to different conditions. For example, emergency units for military communications, important foreign activities in large hotels, large mass activities at night in public buildings, and important surgical operations in hospitals should be in pre-lubricated and warm state at peacetime, so as to quickly start at any time, as far as possible to shorten the time of failure and power failure.