wind farm protection

Wind Farm Protection

Automation, Lattes

Schneider Electric 2- Marketing - Guilhen – Oct 2010

PES system

PES system

81U/O

27/59

59N

df/dt

dV

Frequency

Voltage

Residual Voltage

81U/O

27/59

59NIslanded load fed unearthed

AR?

O/C & E/F50/51N

df/dt

dV

ROCOF

Voltage Vector Shift

Co-generation/Embedded Machines

NPS Voltage

NPS O/C

47/46


50N51N

64

5051

67dfdt

dV81O81U

59N

2759

67N

R,LF,O

32

P341 Interconnection Protection

46

47


33kV Transformer feeder extension to windfarm - <10MVA,11kV collection


33kV ring network with embedded generation, 2 wind farms with collection voltage at 33 kV


Comprehensive Protection


Windfarm Protection Relays

Models

● P341 G59 Interconnection Protection Relay

● P12x/P13x/P14x Feeder Protection (OC, EF and AR)

● P92x Voltage/Frequency protection


ER G59 Protection Requirements for Connection of Distributed Generators<5MW to Systems <20kV


- MiCOM P341 Generator Protection -- MiCOM P341 Generator Protection -

MiCOM P341 ApplicationsG59 Protection Equipment



●To inhibit connection of the generating equipment to the REC’s supply unless all phases of the REC’s supply are energised and operating within the agreed protection settings

●To disconnect the generator from the system when a system abnormality occurs that results in an unacceptable deviation of the voltage or frequency at the point of supply

General Requirements Protective Equipment




●To disconnect the generator from the REC’s system in the event of loss of one or more phases of the REC’s supply to the installation

●To ensure that either the automatic disconnection of the generating plant, or where there is component supervision of an installation, the operation of an alarm with audible and visual indication, in the event of a failure of any supplies to the protective equipment that would inhibit its correct operation

General Requirements Protective Equipment




Protection required for

Electricity Board Network

Under & Over Volt & Frequency

Loss of Mains (1)

Overcurrent

Earth Fault

Reverse Power

Directional Overcurrent (3)

Neutral Volt Displacement (4)

Parallel Limit Timer

Protection Requirements for Private Generator Operating in Parallel with Electricity Board Network

Permanent Parallel Operation

HV Generators LV Generators

NoExport

Small <150kV

Medium 150-250kVA

Large >250kVA

Export

Protection required

(2) (3) (3)

Notes: (1) Protection for generators(2) Sensitive Relay(3) Optional(4) Application dependant


Notes: (1) Protection for generators(2) Sensitive Relay(3) Optional(4) Application dependant


Protection Requirements for Private Generator Operating in Parallel with Electricity Board Network

Short Term ‘Test’ Parallel Operation (5 min max)

HV Generators LV Generators

NoExport

Small <150kV

Medium 150-250kVA

Large >250kVA

Protection required

Protection required for

Electricity Board Network

Under & Over Voltage & Frequency

Loss of Mains (1)OvercurrentEarth Fault

Reverse Power

Directional Overcurrent (3)

Neutral Voltage Displacement (4)

Parallel Limit Timer



Protection

Under Voltage

Over Voltage

Under Frequency

Over frequency

Protective Equipment and Recommended Setting for LV Supply Arrangements

Phases

All

All

One

One

Trip Setting

-10% (Phase neutral)

+10% (Phase neutral)

-6%

+1%

Total*

Tripping Time

0.5s

0.5s

0.5s

0.5s

* The total tripping time includes any intrergration or timing period of the protection relay as well as relay circuit-breaker operating time

For all other arrangements the settings of the relays should be agreed with the REC



An expression for a sinusoidal mains voltage waveform is generally given by the following:

V = Vp sin (wt) or V = Vp sin (t)

where (t) = wt = 2ft

If the frequency is changing at constant rate Rf from a frequency fo then the variation in the angle (t) is given by:

(t) = 2f dt, (F = Fo + Rf t)

which gives (t) = 2{fo t + t Rf t/2}

and V = V sin {2(fo + t Rf/2)t}

Hence the angle change (t) after time t is given by:

(t) = Rf t2

Voltage Vector Shift Protection

Schneider Electric 16- Marketing - Guilhen – Oct 2010- MiCOM P341 Generator Protection -- MiCOM P341 Generator Protection -


Single phase line diagram showing generator parameters

E

R

T

jX

VIL



Vector Diagram Representing Steady State Condition

E

I XL

II R

LVT

L



Transient voltage vector change due to change in load current IL

L

L

E

I

I XI RV

L

L

I X”

VT

L

T

I



The rate of change of speed, or frequency, following a power disturbance can be approximated by:

df/dt =

where P = Change in power output between synchronised and islanded operation

f = Rated frequency

G = Machine rate MVA

H = Inertia constant

df/dt

P.f

2GH



df/dt =

Two consecutive calculations must give a result above the setting threshold before a trip decision can be initiated

P341 df/dt calculation

F - f

3 cycle

n n - 3 cycle



df/dt+t: Time Delayed ROCOF

t

f

df/dt Setting

Start

Trip Pick up cycles

Time delay


wind farm protection

Documents

mains supply

external load

main supply network

generator sizes

small generator

connected load

sole protection

frequency element