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Conversion of Petrochemical Plant from 60 Hz to 50 Hz
Our Petroleum company is designed for 60hz and feeding from in-house 60 HZ 11KV Gas Turbines. We wish to go for the 50HZ Government supply. Please suggest how to manage.
By Siva Kumar on 16 August, 2017 - 3:32 am

I am working in Gulf. We have 12 MW Petroleum Production Plant. All the equipment in this plant is designed for 60 HZ. At present 4 Nos. of 4 MW Gas Turbines, 11KV,60 HZ are feeding the plant and the plant is running for the last 10 years. Now we are in the plan to stop the Gas Turbines and to feed the Power from Government Power Supply which is 50 HZ...

How to utilise the Government power which is 50 HZ to feed all the loads inside the Plant? The total load in the plant is 12 Mega watt. Requesting you all to give the suggestions.

My email id :

This should be the 'easy' fix: data acquisition for HMI/SCADA/DCS which is usually filtered and sampled with respect to the AC power frequency to minimize AC frequency noise on low level signals. Whatever is sampling the data should have its AC line frequency setting be changed from 60Hz to 50Hz. It's usually setup setting. Allen Bradley 1756 cards have a 'notch filter' setting for this purpose.

Depending on firmware/hardware, the minimum sampling time might be affected when going from 60Hz to 50Hz.

By Bob Peterson on 16 August, 2017 - 2:00 pm

I can't imagine this is a simple problem nor one that can be done inexpensively, or very quickly.

The simplest solution might be to replace the turbines with big electric motors and just use the existing generating equipment.

Otherwise you are going to have to go through the plant and look at every load and figure out what you can do. Some loads might not care if fed 50 Hz power so you might not have to do anything to them other than feed them the right voltage.

Some places you might get by with adding a VFD.

Some things might be scrap and start over.

First thing to do is make a survey of all your loads.

Fixed speed pumps may be a problem.

They will run 20% slower so the head will be different unless you up the impeller size or add a VFD to bump up the frequency.

It shouldn't affect too many instruments, most of them will be on DC.

Interesting project.