Hydro governor development in PLC; experience?


Thread Starter

Donald Vaughan

We are in the early stages of developing a PLC based governor for hydro
generators, using AB PLC's.
We would be interested in hearing from others who have attempted a similar
successfully or not!

Donald Vaughan
Hydro Electric Corporation
Tasmania, Australia

Prof. Luis Alberto Gomez

unless you are not concern with power and frequency stability and you are trying a very small turbine (<10MW) don’t do it.

R A Peterson

In a message dated 11/18/99 2:42:22 PM Central Standard Time,
[email protected] writes:

> unless you are not concern with power and frequency stability and you are trying a very small turbine (<10MW) don't do it.<

Why? An answer like that without some reasons/experience behind it doesn't
have a whole lot of credibility to it. It may be a good answer, but it needs
some filling out.
I believe that Voith hydro (USA) has developed such S/W on the A-B PLC5
platform some time ago.



Keith Curtin

I know for certain that Russ Electric has done many such installations using GE
Fanuc PLCs (and probably AB PLCs as well.)

The scope for their implementation of PLC control went well beyond governor control.
The PLCs performed startup sequencing (including a provision to pass through a
regime of turbine cavitation), normal operation (turbine speed, synchronization to the
station bus, generator loading... including constraining a unit to its nameplate ratings,
power factor control, river-flow/reservoir-level management, etc.) and shutdown sequencing.

As I recall, the generators could be set for isochronous or droop mode. In
isochronous mode, system frequency was maintained to approximately the accuracy
of the clock crystal in a high-speed counter. This probably would not be accurate
enough for long periods of operation as an island (i.e., the system is isolated from
the power grid.) However, I'm certain that a system could be constructed that would
maintain longterm accuracy using the 1 pps reference from a GPS time receiver.

Also, Russ was quite successful in converting low-pressure, water-based hydraulic
actuators to high-pressure, synthetic oil-based actuators. In many cases, this is
necessary to speed up the response time of the governor circuits.

Keith Curtin
Trimation, Inc.
Meridian Energy www.meridianenergy.co.nz use many hydro controllers based on
a AB PLC 5-40's with controlnet or RIO for field devices, it comes with
Voith Hydro developed power and speed control software implemented in ladder
logic and provides what seems to be good control of hydro generators.