Measurement of energy quantity and quality

plantationscarfΤεχνίτη Νοημοσύνη και Ρομποτική

25 Νοε 2013 (πριν από 3 χρόνια και 8 μήνες)

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Měřící Energetické Aparáty, a.s.

www.e
-
mega.cz


Měřící Energetické Aparáty, a.s.

www.e
-
mega.cz

Measurement

of

voltage

quality


in
electricity

meter



Technicaly

possible


Price

of

realisation
?


Interrest

of

custommers
?


Feasibility

is

time

and

financialy

demanding


Contribution

for

distribution

companies
?


Contribution

for

society?

Měřící Energetické Aparáty, a.s.

www.e
-
mega.cz

Measurement

of

energy

quantity

and

quality



Energy meters are set gauges, measuring functions

are

stable and consistent


The meter is perceived by society as an unchanging, certified device

and

even technically

well
-
meaning development can lead to discussion and consequently
to
distrust


Power Quality Measurement currently goes through a dynamic development


Implementation in the new networks and

in already constructed and operated networks


Unification

of

standards


Time

factor
:
price

+ performance ↔
time

Měřící Energetické Aparáty, a.s.

www.e
-
mega.cz

parameter

quantity

measurement

quality

measurement

evaluation

methods

deterministic

statistic

evaluation

period

continuous

10
periods

/

1
week

number

of

values

3

×

6
registers

91
values

measurement

V, I, PF

V, (in
future

I)

precision

requirements

comparable

analog

circuits

equal

comm
.
requirements

comparable

comm
.
security

required

not

for

now

computing

power

/

consumtion

normal

high

Měřící Energetické Aparáty, a.s.

www.e
-
mega.cz

Questions

for

decision

about

joint
measurement


of

electric

energy

quantity

and

quality




Delivery

point
for

measurement

of

quality

of

electric

energy

is

point

in public
distribution

network,
where

energy

is

exchanged

between

contracting

parties
.

This

point
may

vary
from

point
of

measurement

of

electric

energy

quantity



Class

A


for

contracting

relationships


Class

S


for

statistical

evaluation

(
two

tendencies

of

measuring

methods
)


Měřící Energetické Aparáty, a.s.


Linearity
range

of

voltage

measurement

circuits
: 1.75 U
NOM

class

S


3
rd

testing

state

1.52U
NOM
, 20%
harmonics
, 0.723%
flicker
, 1%
interharmonics



Evaluation

period:


energy

quantity

/

15min


quality

/

10min

aggregation



Data transfer
security
:


energy

quantity

/

billing


quality

/

informative

www.e
-
mega.cz

Měřící Energetické Aparáty, a.s.

www.e
-
mega.cz

Continuous

phenomena


(
flagged

10
minute

evaluations
)



Frequency

evaluation
, 10s
average

value

of

harmonics

basic
component


Flicker

evaluation
,
for

changes

∆U
/
U
from

1

change
/min
.

upto

4000
ch.
/min
.


Voltage

unbalance


Harmonic

analysis
,
frequency

of

calculation

(10
periods
/1s,
without

gaps
)


Voltage

phenomena


(U
RMS1

or

U
RMS1
/
2
,
hysteresis
,
clustering

algorithms
)


For

flagging


Secured

power

supply

(
measurement

uncertainity

1%
U
nom

and

20ms
during

1
minute
)

Měřící Energetické Aparáty, a.s.

www.e
-
mega.cz

Expected

development

in
votage

quality

measurement



Changes

of

indicative

values

​​
for

voltage

and

continuous

phenomena


Rapid
voltage

changes


Record

of

RMS
values


Oscilographic

record


Phase

angle

during

inception

of

rapid
change


Short

change

of

voltage

unbalance


Phase

shift

caused

by rapid
change


Measurement

of

harmonics

and

interharmonics

(40. H, 50.H, 100.H)


Transient

voltage

Měřící Energetické Aparáty, a.s.

www.e
-
mega.cz

Conclusions



Intended association of operational measurements and the measurement

of quantity and quality of el. energy is in place


The solution can only be assessed on the basis of operational experience



V
erification

of measurement in substations which is easily accessible is offering


It is needed to respect different meanings of measurement in substation

and on interface between distribution and
custommer


Other solutions in case of already constructed and operated networks

and
an
other in new networks or in networks with a refurbished power equipment