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Novel Capabilities of Power Quality Monitoring at the Smart Grid

Netzah Calamaro, Yuval Beck, Doron ShmilovitzIsrael Electric Company , TAU energy conversion

lab, HIT

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Grid event location Existing array of power quality monitors

and meters

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innovative software tools for smart grid diagnostics and control

• Software that analyzes grid through waveform monitoring.

• Modern electric energy transport theories significantly contribute to this

• Periodic averaged theories, instantaneous theories re-investigated

Hardware infrastructure already exists

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Current’s Physical Components theoryThe way it’s done

• Current decomposition into physical components

• Power decomposition into physical components

• All components are orthogonal

• Orthogonal = independent = separate

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Current’s Physical Components theory

( ) ( ) ( ) ( ) ( ) ( )a r s u Bi t i t i t i t i t i t ( ) ( ) ( ) ( ) ( ) ( )a r s u Bi t i t i t i t i t i t

Advantages• Energy measurement• active/reactive load characterization • grid monitoring and control• load identification

Disadvantages• requires Fast Fourier Transform (FFT) X 8

channels • Minimal response time: half a cycle• For active filter requires storage components

(explain what is a filter)

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Current’s Physical Components theory

( ) ( ) ( ) ( ) ( ) ( )a r s u Bi t i t i t i t i t i t ( ) ( ) ( ) ( ) ( ) ( )a r s u Bi t i t i t i t i t i t

( ) ( ) ( ) ( ) ( ) ( )a r s u Bi t i t i t i t i t i t

2 2 22 2 2a s r u Bi( t ) i ( t ) i ( t ) i ( t ) i ( t ) i ( t )

Components:ActiveReactiveScatteredUnbalanced Backward

Orthogonality:

Physical decomposition:

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Current’s Physical Components theory

( ) ( ) ( ) ( ) ( ) ( )a r s u Bi t i t i t i t i t i t ( ) ( ) ( ) ( ) ( ) ( )a r s u Bi t i t i t i t i t i t

0jn to n

n N

v( t ) U 2 Re V e

0jn to n

n N

i( t ) I 2 Re I e

Voltage and current harmonic representation

(FFT)

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Current’s Physical Components theoryDecomposition Algorithm

Feature generation(FG)

Admittance

Transfer function

FFT and Normalizing

CPC and Z- transform

i(t),v(t)

ia(Z) ir(Z) is(Z) iu(Z) iB(Z)

Ya(Z) Yr(Z) Ys(Z) Yu(Z) YB(Z)

θ (Z) |A(Z)| Phase delay vgroup(Z) Zero-

Pole

In,Vn

FG

V(Z)

FG FG FG

Back to grid monitoring and control

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Instantaneous p-q theory

• p – active, q- reactive

• Significantly different from periodic averaged theories (CPC)

• Instead of periodic averaged powers, it’s instantaneous powers

• Power components are completely different physical meaning than CPC

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Instantaneous p-q theory

Advantages• Grid monitoring and control• Active filtering, power conditioning• Not require storage components• Latency: instantaneous, immediate

Disadvantages• Not characterize active/reactive load

correctlyWhy? Recognition of active/reactive requires a period and not an instant.

• Less suitable for energy measurement

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Instantaneous p-q theoryThe way it’s done

Physical meaning of powers

Back to grid monitoring and control

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Instantaneous p-q theoryDecomposition algorithm

To filter

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Instantaneous p-q theoryClark Transformation

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Grid monitoring and control application - CPC

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Grid monitoring and control application – p-q

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Instantaneous p-q theoryNovel application: Microscope

, telescope

To microscope

To telescope

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Instantaneous p-q theoryNovel application: Microscope,

telescope

2 2 2

, ,

,

T

p q

T

p q T

p u i u i q u i u i i s u i

u i upu pu q u q u q ui i

u u u u uuu u u

Telescope:

1 2

1 2

( ) ( ), ( ),..., ( ) ,

( ) ( ), ( ),..., ( )

M

M

L L L

L L L

v t v t v t v t

i t i t i t i t

To schematic

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Instantaneous p-q theoryMicroscope, telescope

Microscope:

2, 2 2

( ) ( ) ( ) ( )( ) ( ) ( ) ( )

( ) ( )( )

T

np n n n

n nn n

v t i t v t p ti t v t p t v t

v t v tv t

21 1

2

1

( , )

1 1,( , )2 2

2 2

1 1

( ) ( ) ( ) ( )( ) ( )

( )

( )1 ( ) ( )( )

( )( ) ( )

N N

n k k nj k j

Nq

nn

n kn kq n k

N N

n nn n

v t i t v t i ti t i t

v t

q tv t i ti t

i tv t v t

To slide 16

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Instantaneous p-q theoryActive Power quality through active filtering

To schematic

To constant power

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Instantaneous p-q theoryActive Power quality through active

filtering – constant powerTo slide 11

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0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08500

1000

1500

Time (sec)

ph

ase

volt

age (

V)

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

6

8

10x 104

Time (sec)

ph

ase

cu

rren

t (A

)

0 0.2 0.4 0.6 0.8

-15

-10

-5

0

Normalized Frequency ( rad/sample)

Ph

ase

(rad

ian

s)

-3 -2 -1 0 1 2-1.5

-1

-0.5

0

0.5

1

1.5

Real Part

Imag

inar

y P

art

0 0.2 0.4 0.6 0.8

10

20

30

40

50

Normalized Frequency ( rad/sample)

Gro

up

del

ay (

in s

amp

les)

0 0.2 0.4 0.6 0.8

3

4

5

6

7

Normalized Frequency ( rad/sample)

Ph

ase

Del

ay (

sam

ple

s)

0 0.2 0.4 0.6 0.8-20

-15

-10

-5

0

5

Normalized Frequency ( rad/sample)

Mag

nit

ud

e (d

B)

Current’s Physical Components theory PC farm

Load identification

To flow diagram

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0 0.2 0.4 0.6 0.8

-15

-10

-5

0

Normalized Frequency ( rad/sample)

Ph

ase

(rad

ian

s)

Current’s Physical Components theory AC motor

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08500

1000

1500

Time (sec)

Vo

ltag

e p

hase R

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.080

5

10x 10

4

Time (sec)

Cu

rren

t p

hase R

0 0.2 0.4 0.6 0.8-0.2

-0.1

0

0.1

0.2

Normalized Frequency ( rad/sample)

Gro

up

del

ay (

in s

amp

les)

Group delay

0 0.2 0.4 0.6 0.8-0.2

-0.15

-0.1

-0.05

0

Normalized Frequency ( rad/sample)

Ph

ase

Del

ay (

sam

ple

s)

0 0.2 0.4 0.6 0.8

-0.04

-0.02

0

0.02

0.04

Normalized Frequency ( rad/sample)

Ph

ase

(rad

ian

s)

-0.5 0 0.5-0.6

-0.4

-0.2

0

0.2

0.4

0.6

Real Part

Imagin

ary

Pa

rt

Load identification

To flow diagram

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Current’s Physical Components theory - dimmer

Load identification

To flow diagram

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Feature generation(FG)

Admittance

Transfer function

FFT and Normalizing

CPC and Z- transform

i(t),v(t)

ia(Z) ir(Z) is(Z) iu(Z) iB(Z)

Ya(Z) Yr(Z) Ys(Z) Yu(Z) YB(Z)

θ (Z) |A(Z)| Phase delay vgroup(Z) Zero-

Pole

In,Vn

FG

V(Z)

FG FG FG

Current’s Physical Components theoryalgorithm

To pc farm

To AC motor

To dimmer

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Conclusion:

• Over existing infrastructure of power quality monitors

• Using only software located at the MDM(Meter Data Management)

• Additional grid power quality data is obtained over EN 50160 is obtained

• It requires modern electric energy transport theories knowledge

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Conclusion:

• Novel applications presented:Telescope, microscope – for grid movement between branches

• Grid monitoring and control

• Grid active filtering

• Power flow –energy flow optimization

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Questions