How to increase surge capacity ?

How to Increase surge capacity of an inveter ?
I have a 2kva inverter for a photostat machine with 1800 watts ,The inverter output is flickering when it running ?.

Hi. Can you elaborate a bit more. What is the source, and the capability of source? Have you measured the source voltage (assuming DC batteries) to see if thy keep the voltage constant?

The source is 24 volts 150 Ah (new battery), serially connected with two 150 Ah battery . it keep constantly works other devices like fridge etc .But it flickering whenever works with the above said photostat mechine .

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what is the theory behind the surge capacity increasing?

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Some of the Inverter has High surge capability (up to 300%) . how to attain these basic theory ?

Just increasing surge capacity may not solve your problem. 1800VA UPS may be an offline UPS almost all offline UPS's have a slow voltage correction in inverter mode which will result in to flickering kind of issues when high surge is coming. You may have to manage with the flickering or go for a smaller capacity for your lighting load.

I hope your inverter power not sufficient to deliver power to Photostat machine.
1. 2KVA inverter may not deliver exact 2KVA due to aging it will reduce up to 1.8KVA
2. Your Photostat machine have rated 1800W true power, what is the apparent power
3. Photostat machine are inductive load so reactive power will be avilable
4. So apparent power will be more than 2KVA
5. If you operate other electrical equipment, make situation miserable
6. Passive power factor correction is the solution
Calculate power factor and add capacitor to increase PF
https://www.wikihow.com/Calculate-Power-Factor-Correction

Hope the post will help you !!!

The maximum power that the inverter can supply is what we used to call as Surge, but it is usually for only a short time - may be for a few seconds up to 15 minutes. For few electrical appliances, especially with electric motors will be needed much higher surge. even Pumps could be considered along with the refrigerators (compressors) as an examples.

In Your case:
Check for the actual surge rating of your 2kva inverter. I have considered 2kva is the surge rating, which means it can carry 2kva for around 15 seconds before it gets trips off.

Photostat machine may be rated with 1800 watts and the surge could be even more. That means when started using the Photostat machine, it will use up more than 1800W[surge] for a few seconds then drops to 1800W[continuous] for steady operation.

So which is leading to the flickering problem. So Increase the surge rating will not serve you as a permanent solution. So its better to use another inverter with higher surge rating. Generally Inverters are available in different Size ratings from 50va to 50kva. Inverters larger than 11kva are not often used for household applications.

P.S. Different brands of inverters have different surge capacity

Is there any ready by adding two 5fard capacitor across the output.

Your MOSFET will get heated up

I have been checked the same inverter with another low watts laser printer below 800 watt . The same problem is there .but flickering amount was reduced .

The question is still remaining for me .
I am asking How to design Inrush current for a particular power circuits ?