Hydro-Power

Hydro-Power

International Summer University

BasicsEnergy Storage

H-1

H1

Hydro-Power

Pumped Storage Power Plant

• https://www.youtube.com/watch?v=EHEqQsv8AGw

H-2Norway Energy storage for Europe Global 3000 - YouTube.URL

Hydro-Power H-3

Overview

• Motivation

• System Concepts

• Basic Equations

• System‘s Components

• Storage Effects

• System Dynamics

• Control

Hydro-Power

Motivation for Hydro-Energy

• Hydro Power

• … is renewable

• … is an established prooven technology for energy generation and storage

H-4

Hydro-Power H-5

Literature

• /Mas04/ Masters, G.M.: Renewable and Efficient Electric Power Systems, Wiley, 2004

• http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity

• http://en.wikipedia.org/wiki/Water_turbine

Hydro-Power H-6

Literature

• /Mas04/ Masters, G.M.: Renewable and Efficient Electric Power Systems, Wiley, 2004

• Bohn, Th. (Ed.): Handbuch Energie, Bd. 13, Nutzung regenerativer Energie, Technischer Verlag Resch, Köln, 1988

• Knies, W. Elektrische Anlagentechnik: Kraftwerke, Netze, Schaltanlagen, Schutztechnik, Hanser, München, 1998

• Zahoransky, R.: Energietechnik, Vieweg, Wiesbaden, 2007• Strauß, K.: Kraftwerkstechnik, Springer, Berlin, 2006• Kaltschmitt, M.: Erneuerbare Energien, Springer, Berlin, 2006• Crastan, V.: Elektrische Energieversorgung 2, Springer, Berlin, 2009

• http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity• http://en.wikipedia.org/wiki/Water_turbine

Hydro-Power H-7

Pumped Storage Power Plant Energy Line

Losses

ConvertibleHeight(Production)

Height

Energy-Line

Microplant

H6

Page Numberingduring Print

Hydro-Power

Pumped Storage Power PlantEnergy Conversion and Storage

• Energy storage during surplus of electrical energy in grid(low prices)

– Water pumps feed water into reservoir

– Conversion: Electrical Potential Energy

• Energy production during lack of energy

– Water turbine converts water running down from reservoir

• Energy Line

– Visualization of Energy Portions

H-8

Hydro-Power H-9

Power Characteristics in Northern GermanyLimitations of Storage Energy

Vattenfall-Hochspannungsnetz (Februar 2008)

Pumpspeicherin Deutschland

7000 MW40.000 MWh

Pumpspeicherin Deutschland

7000 MW40.000 MWh

IfR, TU-Braunschweig

Vattenfall-Hochspannungsnetz (Februar 2008)

Pumpspeicherin Deutschland

7000 MW40.000 MWh

Pumpspeicherin Deutschland

7000 MW40.000 MWh

IfR, TU-Braunschweig

Vattenfall Grid (1 Month)

Po

wer

in

MW

Load (red) Wind (dark green)

Wind Prognosis (light green)

Pumped Storage in Germany

7000 MW40000 MWh

Goldisthal, 1060 MW, 8500 MWh / 8 h (blue)Pumped Storage

H8

Hydro-Power

Power Characteristics in Northern GermanyLimitations of Storage Energy

Can energy storage compensate for fluctuating sources?

• Power vs. Time over 5 weeks

• Grid Load with typical patterns

– Daily fluctuation with two peaks

– Weakly fluctuations with lower load during weekends

• Wind Enery Production

– Differences between prognosis and actual production

– Longer periods of low wind-speeds

• Pumped Storage

– Energy can be visualized as area

– Energy gaps from wind cannot be filled by water storage due tolimited potentials

– Search for Alternatives in Scandinavia?

H-10

Hydro-PowerH-11

Power plant with Continuous Water Flow

TailwaterHeadwater

Crane

Turbine

Inspection Tunnel

Machine Hall

CraneHead 240 m

Low Water 229 m

Losses

ConvertibleHeight(Production)

Height

Energy-Line

H10

Hydro-Power H-12

Three Gorges Dam

Hydro-Power H-13

Pumped Storage Power Plant

System Setup

Tail-

water

UpstreamHead

Tube

Turbine

Generator

Transformer

Tube

Transformer

ElectricalPeak Load

ElectricalBase Load(Surplus input)

Energy Losses in a Pumped Storage Power Plant(3 Machine-Set: Turbine, PumpGenerator-Motor combined)

H12

Hydro-Power H-14

Basics – Bernoulli‘s Equation

TubeInlet

OHOH

OH

OH

OH g

v

g

vh

g

p

g

vh

g

p

222

22,2

22,2

22,2

22

1,21

1,2

1

Energyline

Head-Water

Tail-Water

Head (Height)

Reference

Dam

Energyline

Energy-Losses

Gain of velocity

Gain of velocity

/Masters/

Con

vert

ible

Hea

d

H13

Hydro-Power H-15

Basics

• Power (Potential Energy)

• Bernoulli‘s Equation

• Kinetic Energy

• Convertible Power

21,2

22,2212212

21,2

22,2

2

1

2

221

22,2

22

22

1,21

2

1

2

1

22

1

22

OHOHOHOH

OHOH

OHOH

TubeInlet

OH

OH

OH

OH

vvpphhg

g

v

g

v

g

p

g

phh

g

vh

g

p

g

vh

g

p

Equation-Balance of Points :2 1, Indices

Tubes) and Inlet of (Losses

TailstreamUpstreamOHOH hhVgP 22

TailstreamUpstreamOHOHkin hhVgW 22,

t

W

dt

dWP kin

Turbinekin

TurbineTurb

H14

Hydro-Power H-16

Example for Turbine Operation

• Volume Flow

• Head

• Efficiency of Turbine

• Energy

• Primary Power

• Produced Power

%80

1.3

5.33

mhs

mV

kW 85kW 1068.0

kW 106

kWs 106kNm 106

m 1.3m 5.3s

m81.9

m

kg10

2,

32

33

2,

electrical

OHkininput

OHkin

Pt

WP

E

Hydro-Power H-17

Francis-Turbine

Guide Vane

Runner

Tube

Generator(Not shown)

Hydro-Power H-18

Francis-Turbine Three-Gorges, China

Hydro-Power H-19

Francis-Turbine

Hydro-Power H-20

Francis-TurbineGuide Vane Actuators

• Guide Vanes at Minimum Flow

• Guide Vanes at Maximum Flow

Hydro-Power H-21

Pumped Storage Power Plant

Hydro-Power H-22

Pumped Storage Power Plant

Hydro-Power H-23

Characteristics of Pumped Storage Power Plant

• Pumped storage power plant in „Goldisthal“ consists of four sets ofmachines (each with generator and turbine, motor and pump)

• (Real) Power of four motors is PM = 257 MW each

• Power of four generators is PG = 269 MW each

• The reservoir contains a stored energy capacity of E = 8500 MWh

– How long does it take to complete a full storage cycle? T = 16.2 hours

• The reservoir has a volume of V=12 Mio m3.

– What is the head (height)? h = 255 m

Hydro-Power H-24

Characteristics of Pumped Storage Power Plant

• Data4 machine-sets: Power Rating PM = 257 MW, PG = 269 MW Energy E = 8500 MWhVolume V = 12 Mio m3.

• How long does it take to complete a full storage cycle?– Combination of Energy and Power

E 4 · 257 𝑀𝑊 · 𝛥𝑡 8500 MWh 𝛥𝑡 = 8.4 hours

Less for 𝛥𝑡

Complete Cycle: 𝛥𝑡 𝛥𝑡 16.2 hours

Hydro-Power H-25

Characteristics of Pumped Storage Power Plant

• Data4 machine-sets: Power Rating PM = 257 MW, PG = 269 MW Energy E = 8500 MWhVolume V = 12 Mio m3.

• What is the head (height) h?• Potential Energy

𝐸 𝜌 · 𝑔 · ℎ · 𝑉 = 8500 MWh

ℎ· ·

· /

· · · 255 m

Hydro-Power H-27

Characteristics of Pumped Storage Power Plant

PPump = 4ꞏ257 MW Power

PGenerator = 4ꞏ269 MVA

WPot = 8500 MWh Energy Capacity

up = 0.86 Efficiency

V = 12 Mio m3 Volume of upper Reservoir

A = 55 ha Area upper Res.

D = 20 m Depth of upper Reservoir

s

mq

sm

mkg

q

hg

Pq

hqgP

s

m

t

Vq

t

tPW

PumpOH

Pump

PumpOHPump

Pump

Pump

PumpPumpuppot

3

23

2

2

3

319

86.028081.91000

1020

/

343

7.986.0/1020

8500

m

MW

Approach 2nd

h MW

MWh

s

m

smkg

ms

mkg

ssmkg

sNm

q32

)()(

Unity Check

Hydro-Power H-28

Pelton-Turbine

Runner

Nozzle Deflector (Bypass)

Hydro-Power H-29

Pelton-Turbine

Hydro-Power H-30

Kaplan-Turbine

Guide Vane

Runner

Inlet

Generator

Hydro-Power H-31

Kaplan-Turbine

Hydro-Power H-32

Kaplan-Turbine

Hydro-Power H-33

Generator

• Mainly vertical axis setup

• Low speed, multiple poles

• Synchronous generators

– Island operation

– Production of reactive power

– Important: Capability to build up grit after blackout

• Energy is available, simple release (no conveyor)

• Electrical equipment (i.e. excitation): Design without externalsupply is required (self excitation or battery)

• Asynchronous Generator

– Variable speed operation for better efficiency in partial load

– Doubly fed machines

– Example: Goldisthal, Germany – 2 Synchonous Generators withfixed speed 2 Asynchronous Generator with variable speed

Hydro-Power H-34

Operating Conditions

• Running Water: Base load

• Primary Control - Bondary conditions of level control

• Secondary P-f-Control - Only in Part-Load with Valve Losses

• Pumped Storage: Peak load (Valuable)

– Fast load changes

– Grid Operations

• Primary Control

• Secondary P-f-Control - Valve Losses, Increase of Efficiency by variable speed operation

• Minute Reserve (15 Min) for Spinning Reserve –Requirement of Grid Codes, Pumped storage power plant provide most of control energy within grid.

Hydro-Power H-36

Power Density of Hydro Power Plant

PGenerator = 100 MVA Powerh = 200 m Level differenceup = 0.8 EfficiencyTDry = 30 days Period of dry daysD = 20 m Depth of upper

Reservoir

Base Load Itaipu (Brasil)

Peak Load Goldisthal

For Comparison:Assumption Goldisthal

Area of Lower / Upper reservoir: 18 Mio m3 / 12 Mio m3 = 1.5 AGoldisthal = AUpper +ALower = (1+1.5) AUpper

2

8

2

3

9.2

1065.1

107.63

km

m

s

kg

3

D

VA

TmV

hg

Pm

res

OH

Dryres

Pump

Pump

224

229

226

m

W770

m10555.2

MVA 1060

m

W3.9

m105.1

MVA 14000

m

W9.11

m104.8

MVA 100

Goldisthal

Itaipu

Example

A

P

A

P

A

P

H35

𝑃𝐴

1060 𝑀𝑉𝐴2.5 · 25 · 10 𝑚

1.7𝑘𝑊𝑚

Hydro-Power H-38

System Dynamics

• Kinetic Energy Wkin

• Power Pkin

• proportional to actuator a (vane ornozzle), Mean values before control action

• Increase of power at steady state (t ) byincrease of 10 % of actuator a

• No instantaneous change of moving mass flow, flow speed can only change after pressure drophas leveled out, i.e. traveling speed of pressure ismeasure for change in power

• Decrease of kinetic power at time t=+0 All-Passkinkin

kinkin

kin

kin

kinkin

kin

Pvm

tP

vtv

vm

mtv

vtm

tmtv

vtv

Pvm

P

Pmv

am

tvtm

dt

dtP

tWdt

dtP

tvtmtW

81.02

)0(

91.0)0(1.1

)0(

)0(

)0()0(

)0(

1.12

1.1)(

,,

~

)(2

)()(

)()(

)()(2

1)(

2

2

2

2

mFlow Mass

Hydro-Power H-39

Simulation Model

Allpass

%========================================================================

s

s+1

1

s+1Stimulus

Allpass _controlled

time

AllpassParameters and P

1s1/TI

0.8

In1 Out 1

Hydro-Power H-40

Dynamics of HydraulicsController Action

0 5 10 15-1

-0.5

0

0.5

1

1.5

Allp

ass

0 5 10 15-1

-0.5

0

0.5

1

1.5

Con

trol

led

Allp

ass

time