Utility power transformer monitoring

[kelechiorbiter]

Hello all,

I am new to this forum and I have found it a very exciting and resourceful place.

A little background. I am an electrical engineer and I live and work in Nigeria. We have frequent outages in my country and sometimes it takes weeks before the utilities even know the status of a transformer. This results in people being in darkness for weeks and sometimes months. I want to help solve this problem

I am working on a project that involves real-time monitoring of power transformers. The parameters I am interested in are the operating status of the transformer (on/off), temperature of the transformer, the percentage loading of the transformer and sent the results real-time on-line. I am looking at sending it via SIM module(GPRS/EDGE/HSPDA/4G) and I want two sim modules for redundancy.

Can I get any help from this forum?

I look towards having a very engaging and intensive discussion here that will result to an actual physical device.

Thanks.
​

 

[crutschow]

Can I get any help from this forum?

Yes.
You would need a temperature sensor, a current-sensor (current-transformer), a voltage sensor, and the transmitter module to start.

Can you readily buy that type of electronic equipment?
Who are the suppliers?

 

[kelechiorbiter]

Thanks everyone for the replies. You are all awesome.

crutschow, I cannot readily buy those here in my country, can I get some recommendation on the places I can buy them online?

Do you have recommended models of the sensors and the transmitter module? I would also want us to discuss in details, diagrams, methods, procedures and everything required including the casing.

We can form a small project team here and I will acknowledge everybody who participates when we succeed with the project.

Maybe we can even meet in my country and celebrate over some drinks when we succeed in this project.

Thanks, keep the replies coming.

 

[KeepItSimpleStupid]

What the US has done is upgrade the metering systems to "smart metering" where the electric meter is replaced. It's basically a zigbee network of utility meters that eventually connect to the Internet via a Cell phone Internet somewhere. The network also connects to load shedding of air-conditioning units and electric water heaters. New thermostats interface to the load shedding part without a physical device at the equipment.

If your locked out, and let's say you have a person in the house with severe asthma, you can call and have the lock removed temporarily.
There are also a few pricing tiers.

If you allow the utility to cut AC water heating, you get a reduction in your bill.

This is a form of Demand Side Management which i did extensive reseach in. I set up the system. I scientific published paper resulted.
It was actually more of using Solar panels without inverters to pre-heat water and monitoring AC Fan energy.

I'm sure that this research in co-operation with our power company led to these devices.

Power outages are easily detected. Overloads that your looking for could also be detected. 4 houses share the same transformer in my case. You don't need to monitor the transformer. You can detect overloading indirectly. Power used by those on the transformer.

So, solar power does demand side management at the right time.

Water metering has been also replaced by a battery powered wireless system. A truck has to drive through the neighborhood to gather readings. Batteries are expected to last 7 years.

 

[kelechiorbiter]

Thanks for reply KeepItSimpleStupid

We do not have the budget to do the smart metering solution for all the networks here in my country that is why I am looking for an affordable solution that will be useful to my locality.

Here in my country, more than 300 houses share one transformer!

I know we have a long way to go but I will do my part and solve the problem.

You are all very helpful. Please lets get into the practical steps to have this device built. Part lists, vendors etc

 

[crutschow]

I cannot readily buy those here in my country, can I get some recommendation on the places I can buy them online?

Do you have ready access to European suppliers such a Farnell?
Can you do an internet search of electronic suppliers in your country?

 

[kelechiorbiter]

crutschow, I do not have reliable electronic suppliers in my country. I will most likely source from outside my country.

Thanks for the tip on Farnell.

Do you have recommendations on the specific part lists, complete material list and how to assemble them into a device.

I have worked with power distribution for 10 years however when iot comes to building electronic devices I do not have experience in this. I will be needing a very good team here to assist me in developing this device. step by step.

 

[crutschow]

I can help with some of the sensor design, but I'm not familiar with what SIM modules are available for the wireless
connection.
That's probably the most complex part of the system.
What type of cell phone service do you have?

 

[kelechiorbiter]

We use GSM network for our cell phone services.

Normally, our network strength range from 3G to 4G LTE in some places.

I intend having the device send SMS in low fidelity areas to a control center for a start.

Thanks for your offer, you can start with the sensor design.

Keep the replies coming.

 

[KeepItSimpleStupid]

Don;t you have sub-stations that say distribute at around 10 kV? Then local transformers that distribute at say 240V?

So, what you care about is the substations?

Potential transformers should be easy. It's just a local transformer and transducer. You should then be looking at under-over voltage which should be easy. Temperature sensors on you transformers might be easy too. No idea how sub-stations measure current at very high voltages.

 

[kelechiorbiter]

KeepItSimpleStupid

our transformers are
33/0.415KV
11/0.415KV
33/11KV

ratings - 50KVA to 500KVA

I understand and know all the principle behind what I am looking for. What I need are recommendations and practical steps

 

[crutschow]

Need specifications.
What temperature, voltage, and current range do you need to measure?
Where exactly do you want to measure the temperature?
I assume this will be placed in some type of weatherproof box on/near the transformer(?)

 

[kelechiorbiter]

crutschow,

Yes, it will be placed in a weatherproof box.

I want to measure the oil temperature as the oil temperature rises when there is an overload or huge current flows through the internal windings of the transformer.

For this first project iteration, I just need the transformer to tell me whether it is on or off, the oil temperature and the output Volt-Amperes which will now be compared with the rated KVA output of the transformer to calculate the percentage loading on the output.

Thanks.

Which microcontroller do you suggest?

 

[crutschow]

Which microcontroller do you suggest?

Is that for the interface to the cell network?
I know the Arduino and the PIC family are popular, but I'm not that familiar with microprocessors, so someone else will need to help you with that.
I mostly do the design of analog and simple digital circuits.

 

[KeepItSimpleStupid]

Within the sub-station you might try Zigbee wireless. A wired standard is MODBUS.

The nuts an bolts should probably be an industrial PLC. PLC's can be networked. Generally, you don't do all of the work. Software such as Wonderware (PC) can manage alarms.

Work on sensors and protocol first, Voltage, current, temperature. 4-20 mA, Modbus, Profibus, industrial wireless

Zigbee is a mesh network.

 

[kelechiorbiter]

KeepItSimpleStupid thanks for your reply. I came across the zigbee solution in a paper and I have studied it.

Thanks all for the replies. On the sensors, do you have recommended sensors and vendors and other part lists.

Can we move into details.

I will appreciate more replies.

 

[kelechiorbiter]

Is that for the interface to the cell network?
I know the Arduino and the PIC family are popular, but I'm not that familiar with microprocessors, so someone else will need to help you with that.
I mostly do the design of analog and simple digital circuits.

Thanks crutschow. You can go on with the circuit design while I look up the microcontroller needed.

Thanks a lot.

 

[kelechiorbiter]

Am I allowed to share journals on what I have been able to find out on the forum? Is it allowed?

 

[KeepItSimpleStupid]

That's not what I understand 'smart' meters are for, or do, their main use is to send the readings back (saving someone coming out to read it) and to give you a real time display of consumption and cost.

It's not the meter itself, but the network. Our (USA) boxes for AC and hot water heating did work on an RF system, now they can integate to the ZIGBEE network. They we replaced when the smart meters were installed.

See this **broken link removed** thermostat for another utility in the US.

A Carrier stat is available for the Carrier Infinity system which I have.

It's also not well-known that the utility can do a remote disconnect if you don;t pay your bill.

 

[JimB]

Am I allowed to share journals on what I have been able to find out on the forum? Is it allowed?

Posting links to appropriate journals seems OK.
If there is something bad about them, I am sure that we will let you know.

JimB