managing flexibility in the operation of your turbines

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Managing Flexibility in the Operation of Your TurbinesWaterpower Week 2021 | Atkinson / Foust / Ort | 2021-04-27

Voith Hydro North America Contributors

Thomas Ort

(contributor)

Mechanical Design Engineer

Voith Hydro, Inc.

Jason Foust

(contributor)

Lead Hydraulic Design Engineer

Voith Hydro, Inc..

Carl Atkinson

(contributor and presenter)

Director, Sales and Marketing

Voith Hydro, Inc.

Managing Flexibility in the Operation of your Turbines | Waterpower Week 2021 | 2021-04-27 2

Grid FlexibilityWhat is it?

The shift to a greater fraction of renewable

energy sources for electricity generation and the

evolution of grid operations and electricity use

trends are redefining the needs from the electric

generation fleet.

Grid operators are modifying the regulatory

structures and revenue mechanisms for

generators to address these changing needs.

Source: Argonne National Lab Report ANL/DIS-14/7 “Modeling and Analysis of Value of

advanced Pumped Storage Hydropower in the United States”


Generation flexibilityHydropower


Hydropower units are uniquely capable

of addressing many grid flexibility needs.

• Regulation

• Ability to cycle without notification

• Black start

• Inertial support

• Reactive power support

However, not all units are equally

capable of providing these capabilities.

Age and design make a difference.

Source: PJM’s Evolving Resource Mix and System Reliability, March 2017

Hydro power basicsSite characteristics

5

Storage Run-of-river

Managing Flexibility in the Operation of your Turbines | Waterpower Week 2021 | 2021-04-27

Energy Conversion

Francis and Kaplan unitsTraditional design characteristics

6

Focus Francis Kaplan

Storage: Upper Reservoir Run-of-River

Application: Med Head/ Low Flow Low Head/High Flow

Runner Type: Fixed Adjustable

Traditional Operation: Peak/Full Load Power Control/Flow Control (Flexible)


Age of generating facilitiesDesign limitations


• Units designed before 1980

likely had not fatigue design

guidelines or parameters

defined.

• Significant cyclic loading was

not expected in the course of

typical operation.

Source: U.S. Energy Information Administration, Preliminary Monthly Electric Generator Inventory

http://www.eia.gov/electricity/data/eia860M/

Modernization of Francis and Kaplan unitsBest opportunity to address flexibility

8

Operation

• Power uprate

• Efficiency improvements

• Improved cavitation performance

• Lifecycle extension

• Improved reliability

• Operating range



Modernization – other considerationsEnvironmental mitigations

Modernization presents an

opportunity to address

environmental issues that

may limit future flexibility:

• Water Quality

• Oil and grease

• Fish Passage

Modernization – other considerationsIntegration of intermittent renewables

10

With increased wind and solar

integration, flexible generation is a

necessity

• Modernization projects often target

a wider range of continuous

discharges for Francis machines

• Kaplan machines are being

operated in Automatic Generation

Control (AGC) and Primary

Frequency Control (PFC)

Operational Flexibility


Source: https://www.powermag.com/developments-in-energy-

storage-could-spell-the-end-of-the-duck-curve/

Hydro turbines - areas of concern Cavitation, noise and vibration


Off-design operation results in excess

cavitation, noise and vibration. Francis


Hydro turbines - areas of concern Increased stress and fatigue

Rapid operational changes

increases stress and fatigue.

Francis

Francis and Kaplan unitsFlexible design

13

Natural Aeration Robust Runner Quantizer Filter

Application: Francis/Kaplan Application: Francis/Kaplan Application: Kaplan

Improves hydraulics and

addresses source of dynamic

loads at off-design conditions

Allows runner to withstand

increased dynamic

off-design conditions

Reduces blade movements

by defining discrete blade

position set points


Flexible operationFrancis trailing edge aeration

14Managing Flexibility in the Operation of your Turbines | Waterpower Week 2021 | 2021-04-27

• Trailing edge aeration has been used in the field for 25+ years with

focus on a typical turbine operating range (Q/Qopt ≥ 60%)

• Trailing edge aeration has a large impact during off-design

operation

– reduced pressure fluctuation, noise and vibration

– significant efficiency improvement at low loads

• Trailing edge aeration is a comprehensive solution for wide

operation, offering several advantages over traditional solutions

(vacuum breaker aeration, compressed air systems or robust

runner design)

Flexible operationKaplan frequency control


F(1) Intelligent, non-linear filter for measurement of grid frequency

F(2) Quantization of runner blade setpoint

HyConTM – Quantizer available with the Voith standard governor (patent pending)

Grid frequency

Wicket gates

Runner blades

Governor

_ +F(1)

F(2)

Controller

Turbine designRequirements and their interaction


Component Stresses

Bearing Pressures

Max Output

Pressure Pulsations

Servomotor Capacity

Mode of Control

Governor Capacity

Blade Timing

Environmental Aspects

Cavitation

Blade Opening Tendency

Efficiency

Operating RangeDependencies between requirements

creates a tangled mess

Hyd

rau

licG

ove

rno

r/HP

UM

echanic

al

Reuse of Geometry

Runaway Speed

Managing FlexibilityHydropower turbines


Hydropower is absolutely capable of

addressing grid flexibility needs.

Newer units can be designed to meet high

capability demands for cycling, rapid start, wide

operating range and other key characteristics.

Rehabilitation of older units requires additional

care and design verification to confirm the

entire machine is capable of the increased

loading factors.

Failure may be accelerated by using older

designs in newer applications without

confirmation of these capabilities.


Thank you!


Contact:

Carl Atkinson

Director, Sales (US)

Phone 717.792.7891

[email protected]

managing flexibility in the operation of your turbines

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