Hydro turbinepressure
monitoringsystem
Are cavitation and rough load zone
damaging your hydro turbine and reducing
efficiency? Will you be operating in newhead and flow conditions and want to knowhow your turbine will behave?

Hydro-generation plants deal with a large amount ofvariability. Hydro units today are being dispatched differently
to accommodate wind turbines and other dynamic energy
sources on the grid. At the same time, Hydro plants must
deal with extremes in reservoir and river levels. These
conditions can result in cavitation and/or rough load zone(RLZ) problems at many sites.
Even if you can’t control when these problems occur, youcan manage their effects more intelligently. Varying loads,heads, and flow rates make hydraulic disturbances a
multi-dimensional problem—one you cannot solve without
sensors and historical data. This is especially apparent

when installing air injection systems. Mapping the relevant
variables through the seasons can give you a clear
understanding of when these phenomena occur, and help
you optimize when and where to inject air.
In response to customer requests, Baker Hughes announces
the release of our hydro turbine dynamic pressure sensing
system from the Bently Nevada† product line. The systemleverages our industry-standard 3500 rack already installedat many sites, adds a new hydro dynamic pressure channel
type1 to the 3500/46M Hydro Monitor, and includes a new
Bently Nevada dynamic pressure sensor that has beentested and proven in hydro applications.
Three pressure sensor range options are available to match
the particular head characteristics of your units. The sensors
measure pulsations down to 0.2 Hz, and are typically installedon the head cover and/or draft tube. Each 3500/46M monitor
added to your 3500 rack will accept up to four dynamic
pressure signals. A unique feature of this system is that itprovides both static and dynamic pressure measurementsfrom a single sensor and channel.
The hydro turbine dynamic pressure sensing system consistsof all the hardware2 you need to retrofit your existing hydrogenerator 3500 system, or include in a new 3500 monitoring
system for your unit:• 3500/46M	Hydro monitor withmultimode positive input I/O3
• 350300

Dynamic pressure sensor• 146824	Pressure sensor cables(lengths from 10 to 1,000 ft.)

Variables and settings for the hydro dynamic pressure channel in 3500:
Direct amplitude

Direct peak (or RMS) amplitude of dynamic pressure in psi or kPa

Static pressure

Measured in psi or kPa

1X Amplitude

1X filtered peak (or RMS) amplitude of dynamic pressure in psi or kPa

1X Phase lag

1X phase lag measured in degrees

2X Amplitude

2X filtered peak (or RMS) amplitude of dynamic pressure in psi or kPa

2X Phase lag

2X phase lag measured in degrees

ModeUnique alarm setpoints for each defined mode of unit operation(when multimode feature is enabled)

Alarm latching/delays

Additional control of alarm latching and time delays, allowing for additional control ofyour alarming scheme

Timed OK channel defeat

Intelligent detection of faulty sensor/circuit, protecting you against false trips.
Now with time delay

Recorder outputs

4-20 mA outputs (one for each channel) for integration into an external recorder or display

Trip multiply

Input contact for increased Alert and Danger levels for startup and/or rough load zone operation

System 1 diagnostic plots available with the hydro dynamic pressure channel:
Trended variables

Highly customizable software pre-alarms

Direct waveforms

Visual interpretation and diagnostics

Spectrum plots

Frequencies of interest over time, speed, and load changes

X-Y plots,
performance maps

Pressure pulsations vs. machine loading (MW) or other measurements

The 3500 System provides all the benefits you have come toexpect from Baker Hughes Bently Nevada product line in termsof reliability, connectivity, and ease of use. The 3500/93 LCD or3500/94 VGA touch-screen panels provide local, configurable
display of all measurements. The 3500 system provides
total alarm control, with Alert and Danger setpoints for direct(dynamic pressure) amplitude, static pressure, and 1X and 2X
amplitude and phase.4 The 3500/32 or 3500/33 relay output
modules provide four or 16 channels of relays that can drive
alarms and annunciation when conditions worsen.

Notes

Data values can be easily mapped into Modbus registers forcommunication to your DCS or SCADA. The data can also be
streamed into System 1† diagnostic software, which can beinstalled on any desktop computer in your organization. Thisdiagnostic software provides current values and historical
trends, full dynamic analysis with waveforms and spectrum
plots, and static or dynamic pressure amplitudes vs. MW loador reservoir level. System 1 software5 can also provide email
notifications of alarms so that appropriate individuals canremain informed and up to date on the status of your hydroturbine generator units.

4. 1X and 2X amplitude and phase measurements require aKeyphasor signal.

†1. A
 vailable with 3500/01 rack configuration software
version 5.2 or later.
2. Installation-specific hardware such as isolation valves,piping and brackets not included.
3. An existing 3500/46M with multimode positive I/O module canbe reconfigured for use with the 350300 dynamic pressuresensors. Note that both channel pairs (all four channels) will
become hydro dynamic pressure channel type.

5. Available with System 1 version 6.9 or later.

 his material contains one or more registered trademarks of Baker Hughes CompanyTand its subsidiaries in one or more countries.

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