i want to buy a generator for our company i want to know how to calculate current for 1000kva capacity generator. and also want to know control and protection are required for the same generator please explain.
Depends what the voltage is. If it is a 1 Volt generator then it puts out 1000000 Amps. Use the energy equation to find out the current, - voltage relationship. PowerVolts * Amps. You may need to synchronise this with other electricity sources so there needs to be a system that does this and only connects them when they are in phase, and that disconnects it if the phases start to drift apart. Otherwise the generator will destroy itself.
OK - You have elaborated - At that voltage you will have about 2400 Amperes. I P/E You have a generator putting out about 1 million watts. Divide that by the voltage and you get the usable amperes at rated voltage. Drop that to 380 3 phase Y would transformer. With loss through this you will have about 2352 amps. But the voltage has dropped from 415 to 380 so the amperes will go up. You will have about 2500 amps available at the output side of the transformer. Remember this is TOTAL amperes across all 3 legs of the windings. Remember that The Power is ALWAYS equal to the VOltage X the Amperage. If one goes up the other goes down. That will NOT change. Transformers are 98% efficient so you must calculate the initial loss through the primary transformet before you calculate the oiwer available for your main buss. If you have 1000 KVA before the transformer you will have 980 KVA at the out side. At 380 V, 3 phase you will have 2578 Amps. 980,000VA/380V 2578.94A OK So far? For safety you have to derate the system by 20% to prevent overload and burnout of the Generator or transformer. you have 2000 amps at 380 volts. That is on your main buss in the master control panel. You have a master breaker there feeling smaller buss lines. On each of these is one breaker per machine OR you can take sub feeder lines to sub panels throughout the factory. From these sub panels you can distribute 3 phase for motors and secondary panels for 110 or 200 single phase for lighting and hand tools. This is so complex and I want to tell you so much. How about I go there and do it.
Depends on the use of the generator. Power and current are related. Divide the rated power of the generator( I assume is diesel driven) by the voltage of the area where you operate (Europe is 240) so 1000000 VA: 2404,166 ampere in the most favourable conditions (Power factor 1) usually the current value is multiplied by .7(Minimum Power Factor acceptable) which will give you a maximum continuous current of circa 3500 ampere. If you are using the generator for emergency you require an automatic starting system and a priority circuit together the standard protection panel which include: 1 Over and Under voltage protection 2 Over and Under frequency protection 3 Phase sequence 4 Overload. Most of these panels have other functions as well. If you require more information than what I have written, I suggest you look at some of the leaflets provided by manufactures
