Backup Batteries for Stations and Sub-Stations

Not down here it isn't (110V DC is one of the common substation battery voltages).

What country and standard are you talking about specifically (like most things electrically and standards related, it varies between countries).

I would guess I'm talking about IEEE standards. I've worked in stations and found that 250 VDC is quite common in the U.S. but I'm not sure who decided that ould be best.

250 VDC is also used in Australia but I don't know how common it is.

I am over here in an refining industry in India.

here, we do use 250Vdc as standard for backup batteries in substations.

Dear Guest,

We are an ISO 9001-2000 certified manufacturer of battery chargers for substations, power plants, T&D network etc., in India. Most of our installations are 110 V systems. In Mahul refinery of Bharat Petroleum, we have 28 installations all of 110 V ( direct and through M/s Engineers India Ltd., also ). In Hindustan petroleum Visakh refinery we have supplied 1 No. 220 V system apart from 2 Nos. 110 V system. 110 & 220 V mentioned above are nominal voltages and depending on the type of battery, Float & boost charging voltage is decided.

Could you please let me know in which refining industry you are?

Thanks and regards

Ashok Toshniwal, Bangalore India.

ashoktoshniwal@ yahoo.com

Depending on the capacity of the substation, even 24 V DC or 30 V DC is used e.g. a small 5 MVA substation at 11 or 33 kV incoming supply feeding a commercial building. Otherwise most of the systems are 110 V and few of 220 V. Above details are for India though we have supplied 110 V & 30 V systems in 12 other countries also.

Thanks and regards

Ashok Toshniwal, Bangalore, India.

In India its mostly 110V DC.

Selection of station/sub-stations backup batteries basically should be based on your requirements, i.e., voltage ratings of the circuit breaker's trip coils and charging motors, indicating lights, protective relays, control relays, etc.

Based on my previous work experience, 125 VDC battery voltage is common in large power stations and for small sub-stations, some batteries are rated are 48 VDC.

Regards.

Rudy C. Fernando

There are several standard voltages for utility battery systems, depending on the installed equipment. Smaller stations with just a transformer, voltage regulators and micro-processor based control systems may be 24 or 48 VDC. Larger stations with switchgear and other heavy loads will often be 125 VDC. 250 VDC was originally reserved power plants, or for starting distributed generation, such as diesel generators or the starting engine of a combustion turbine. Some utilities have now standardized on 250 VDC for all major substations. Section 5 of NEMA Standard PE 5-1997, Utility Type Battery Chargers, includes tables listing standard voltage ratings.

All the standards for batteries I know of must be purchased, but the charger standard is free once you register on the NEMA website. If you intend to manufacture or supply electrical equipment for the US market, I strongly recommend that you subscribe to the applicable NEMA, ANSI and IEEE standards. They provide all the information needed to design and test compatible products.