Operate Power Plants in Remote Areas

Find an American design that you like and copy it?

Write a specification and get bids?

Hire a local consultant?

Sorry, that's all I have time for now, I've got to go back to work.

Thanks lyn for the reply, have been looking around but still looking around till I get something .

Regards

It's a no-brainer, all your central location needs is a Start-Stop button, Raise/Lower KW, Raise/Lower Voltage, and some meters to monitor those variables. The real "magic" takes place back at the remote location where you will need protective relaying, an autosync relay, communication/telemetry equipment, and lots of control circuitry/logic to manage the control variables. It's done all the time.

Thanks Ram, this is helpful , let me.list all the necessary information/parameters that I shall need to be sent.or monitored at the central location.

About the maintenance management, will I need condition based monitoring system for some critical equipment orthere is some other suggestion u may know?

Consider a satellite communication system if common phone and data lines are not available.

Thanks IdeaSmith, my communication idea was to suggest a dual redundancy communication system with satellite and optic fiber that runs along the transmission line.

Give us your definition of "mini-hydro" and AGC.

Whether satellite links and dual control links are worthwhile depends on the value of the power to the user and the cost of "non-availability". Also, reliability depends mostly on the quality and "de-rating" of the basic plant. Hydro power is probably the most simple, reliable generation.

You cannot get higher reliability by having more monitoring, only improve availability by avoiding major damage and repair times. Every monitoring equipment mounted on the plant will have its own maintenance and repair burden.Maintenance cannot be done from a remote place, someone has to go to site. Do you have costs for maintenance visits and time to compare with cost of monitoring equipment and communication?

Automatic Generation Control,(AGC), small hydro plant of 30MW. The maintenance visit costs are lower that the initial costs for the condition monitoring equipment, although they are more effective in the long run, but still they do have their own maintenance burdden as you have put it. We shall have routine visits for maintenace, but may require remote troubleshooting/diagnostic capabilities .

Thanks 67model for this info, it's useful to me.

OK, it is a plant of size where numerous monitoring devices are cost-effective.

I did write "mounted on the plant" - because good quality modern Programmable Logic Controllers and monitor amplifiers away from vibration and temperature of plant rarely fail, even in 20+ years. The capacity of modern PLCs and SCADA easily copes with a continuous record of every digital input/output change of state to time resolution by second - additional to specific fault alarms automatically "flagged" to the operator. If these are recorded then the "creep" of operate times from normal to alarm/shutdown points can be tracked to anticipate trouble or find the history of a developing problem.

Gauges with contacts are suggested rather than e.g. pressure switches - it can be seen that parameters are normal/not normal before alarm/shutdown limits are activated and they provide a check on electronics which can fail/"show wrong value" due to interference or software. A "back-up"/check system should not use the same technology as the primary one - think of triple computer aircraft with three same-type airspeed pitot tubes which crashed - all three iced-up and neither computers nor pilots recognised engine speed vs altitude ⇒stall speed was wrong.

Beware suppliers of site-modifiable PLC or SCADA software who want to keep it secret to themselves with passwords and non-supply of the actual "ladder/logic" file - every single necessary addition or modification to display, control or alarm can be made a slow and costly job, including after the warranty has expired. A friend went back on a project many times over years due to site problems and found time after time that the actual "ladder" did not match logic diagrams or a proper function.

It would be good for you to ask the plant suppliers to quantify their experience of failures, identifying their frequency per running hour and repair time & cost and their protection recommendations and justification.

Ask for a list of existing users of similar plant and contact each to understand their experience and views on which parts are a maintenance problem and why.

Do lake and intake need monitors for water capacity or weed/tree branch intake block: camera, lights for night-time?

thanks 67model

Sorry i have been off, Yes the water level has to be monitored, as well for production planing and not running the generators below their technical limits. Security and fire,safety monitoring is also mandatory. Your expertise has really helped.

Wish the best in 2017

The company for which I worked did try "triple processor voting" control with duplication of critical input/output on 50 MW gas turbine generators governors but over several unit years there was never a hardware fault - but a succession of software alarms and shutdowns which were never explained or resolved. The end result was that subsequent units had single controllers, less trouble at less cost.

i concur with you 100%. Actually we have been having several unexplained shutdowns originating from the governor controler. These were always software issues, all field devises being intact. After uploading a back up, everything goes back to normal. the failure can reappear after several months,this time in a different format but triggering the same governor protection. The OEM seem not to issue useful info when contacted. We have never had any similar case with the generator excitation system controllers. we are on a DCS (distributed control sytem).

The engine governor is more complex, having about 3 times the significant parameters and more calculation requirements.

There may be a cause in the different computers used.

You are probably familiar with the way, every few months, a "personnel computer" has a mystery behaviour, which is fixed by shutting down the program and restarting or occasionally the computer has to be power off/on, when everything then behaves OK again.

These PC systems have very large processing power and memory at a low price - there is a temptation to apply them to industrial systems - but have a vulnerability to software fault because the "operating system" software is very big in MByte and vulnerable to faults. I note that computers for industrial control ("now single board" and so more reliable) still come with "Windows 2000" which is thoroughly "de-bugged", does all that is needed with less memory. They are several times the price of a PC, but do not become unobtainable or fitted with a new O/S which will not run existing proven software so quickly.

The more software and memory, the more likely a fault. A PLC can happily run a plant with kilobytes of memory [static, battery maintained & EEPROM], but PC systems feed by the Gbyte!

PCs use huge amounts of "dynamic" memory [which stores data in tiny capacitors, automatically recharged many times a second to preserve their 0 or 1 state] - in fact the whole near Gbyte of O/S is kept in that memory.

Dynamic memory has a vulnerability, not much publicised, the tiny amount of charge can be removed by the effect of a "cosmic ray" particle (aside from electrical interference). In the late 1970s, it was estimated that a 64k x 8 bit dynamic memory [usual max capacity of 8 bit microprocessor then] would get a "cosmic" error once per year. Since then the memory capacity of the same area of silicon has increased enormously (charge per bit much lower too) - but the probability of a "hit" by cosmic particle is the same.

Many CPUs have internal dynamic memory also, although "static" memory (usually faster, higher power/bit) is usual. Systems, of course, have to have guards against memory fault, principally extra hardware "parity" bits on every memory word, but a parity bit can still appear "right" if two bits are corrupted. Consequently, files have checksums and check divisions which are better than parity at showing multi-bit errors - but nothing is perfect.

Whilst CPUs may report a parity error, there is no guarantee that the software they are in actually reports the fault in a usefull way, other than "him fail, boss".

As an example, the first popular PC disc O/S [8 bit, CP/M] was notorious for reporting "BDOS error on K" for any fault. But this was not the fault of the O/S, but the PC designers, who were pushed to spend programming time/effort and precious disc space on more appealing customer features than handling the error numbers of the O/S.

Unfortunately, the complex software of an industrial governor has far fewer builders & users to think about, check for, faults or find them than other applications e.g. motor cars made in millions.

You may find, on comparing the processors/memory of the generator AVR [ or PLC] with the governor that AVR has much less memory, of a "harder" form and software in EEPROM.

There is a further factor, an AVR (or PLC) is unavoidably involved with connection to high voltages and currents, including short-circuit fault currents and their radio/electromagnetic immunity has to be far better than a governor, just to survive without damage or malfunction. And you might find the AVR is still "analog".

They've been doing this in BMS. Web based monitoring and control (Iot). I do not know if your local code allows such in power utilities.

https://www.tridium.com/