Diesel Generator

DG Set is rated by KVA only and hence how much KVA we can take from DG set is the focus point now.The PF of the electrical system depends upon the nature of characteristics of the load.

In our DG set, only one third of the Diesel input as fuel in KCal(Kilo Calories) to the DG set is converted to Electrical output as Kwh and so the efficiency of generation of DG set is around 35% only. But it is very user friendly and instantly performs. That is why we pay Rs.7 to EB per unit where as the cost of 1 Kwh unit through our
DG is nearing Rs.20 now.

We have to look in to the five systems in the DG set. The four inputs to function at their maximum efficiency are :

  1. Air Intake and Ventilation
  2. Diesel
  3. Cooling Circuit
  4. Lubrication function – To get Maximum output per litre
  5. Nature of load and loading of DG set.

DG Engine can be start by two methods:

  1. Using Battery
  2. Using Dynamo

In generator,If load increases fuel consumption decreases to supply towards combustion system and vice versa.

Droop Speed Control“- Parallel running generator through load sharing is achieved by controlled frequency at system

Auto Synchronizer will read Voltage,Frequency and Phase angle parameter from generator and also busbar voltage ,while regulating the speed through the engine governor or Engine Control Module(ECM).

Battery range in particle work:

  1. 12.0V produce approximately 8.0V and it is to be used less than 125KVA DG Set
  2. 24.0V produce approximately 18.0V and it is to be used more than 125KVA DG Set

From 5 or 8KVA to 30KVA is Single DG Set and need to be useful only for home and small shops.

From 10KVA to 2500KVA is Three Phase DG Set and need to be useful for Industrials.

Note: 250KVA is used in Power Grid for Emergency Power.

Generator Size:

  1. Based upon electrical load like motor starting current,non-linear load,environmental condition(altitude,temperature exhaust emission regulation).
  2. Acceptable maximum Voltage Drop.

Generator can be electrically connected through the process of synchronization (Votlage,Frequency,Phase) before connecting to the system.

Failure of synchronization will lead to Short Circuit Current,Damage Switch gears etc..

Generator Installation Guidelines:

  1. Size and Selection : Toatal load,Peak load
  2. Electrical Factor : Peak load vs Steady load
  3. Cooling : Engine cooling during process on
  4. Ventilation : Allowing air flow during the cooling process(design)
  5. Fuel Storage : How long generator run at specific usage rate
  6. Noise : DB levels to expected model
  7. Exhaust : PPM(Part Per Million) level of certain element, CO2 emissions,RoHS
  8. Starting System : Keys start,Pull start, Button Start etc..

The Tests required to be conducted on transformer as per IS2026 :

Transformer Testing

  1. Ratio measurement test on all taps.
  2. HV & LV Winding resistance.
  3. Insulation Resistance Test.
  4. Vector Group Test.
  5. Load Loss & Impedance Voltage Measurement at principal tap.
  6. No load Loss & current measurement.
  7. Separate Source Withstand Voltage test.
  8. Induced Over voltage Test.
  9. BDV Test.
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