Impedance |Z| (Ohm)Impedance |Z| (Ohm)

(1)

1

Interfering signals and attenuation –

potential problems with communication via

the power grid

M.O.J Andersson

1

_{, S.K Rönnberg}

1

_{, C.M Lundmark}

1

_,

E.O.A Larsson

1

_{, M Wahlberg}

2

_{, M.H.J Bollen}

3 1

_{EMC on Site, Luleå University of Technology}

2

_{Skellefteå Kraft Elnät AB}

3

_{STRI AB}

(2)

2 Luleå tekniska universitet EMC on SITE

Three potential problems

Signals interfering with the

communication

The communication is attenuated

The communication becomes an

interfering signal

(3)

Interfering signals or noise

High-frequency fluorescent lamp UPS

(4)

Attenuation

Feeding transformer

Impedance of the power grid

(5)

The communication becomes an

interfering signal

(6)

Oscillation around the zero

crossing

(7)

7

Measurments

Pehr Högström Laboratoriet

EMC on SITE

(8)

(9)

(10)

Energy-saving lamp

(11)

Impedance of energy-saving

lamp

Impedance of low-energy lamp

0 1 2 3 4 5 6 7 8 9 10 10 30 50 70 90 110 130 150 Frequency (kHz) Im p e d an ce |Z | ( Oh m )

Impedance of low-energy lamp MD8D 4W 12/03

0 1 2 3 4 5 6 7 8 9 10 10 30 50 70 90 110 130 150 Frequency (kHz) Im p e d an ce |Z | ( Oh m )

(12)

Loads working like a shunt

(13)

Printer

Impedance of printer 0 2 4 6 8 10 12 14 16 18 20 10 30 50 70 90 110 130 150 Frequency (kHz) Im p e da nc e |Z | ( Ω ) 0m 1,8m 3,6m 7,2m 26,8m 46,8m ≈100m

(14)

Computer

0 1 2 3 4 5 6 7 8 10 30 50 70 90 110 130 150 Frequency (kHz) Im p e d ace | Z | ( O h m ) 0m 1,8m 11,8m 21,8m 30m 40m 50m 60m 70m 80m 90m 100m 110m

(15)

Computer & printer

0 1 2 3 4 5 6 7 10 30 50 70 90 110 130 150 Frequency (kHz) Im pe da nc e |Z | ( O hm )

(16)

16 Luleå tekniska universitet EMC on SITE 0 1 2 3 4 5 6 10 30 50 70 90 110 130 15 Frequency (kHz) Im pe da nc e |Z | (O h m )

(17)

Conclusion

With the increasing use of energy-saving

equipment, the magnitud of signals in the

communication channel increases

Interfering signals can be reduced by using

filters

The use of filters will lead to attenuation

The way that EMC-filters are designed today and

the way that we want to use the power grid for

communication are not compatible

(18)

Impedance |Z| (Ohm)Impedance |Z| (Ohm)

Interfering signals and attenuation –

potential problems with communication via

the power grid

M.O.J Andersson

, S.K Rönnberg

, C.M Lundmark

,

E.O.A Larsson

, M Wahlberg

, M.H.J Bollen

EMC on Site, Luleå University of Technology

Skellefteå Kraft Elnät AB

STRI AB

Three potential problems



Signals interfering with the

communication



The communication is attenuated



The communication becomes an

interfering signal

Interfering signals or noise

Attenuation



Feeding transformer



Impedance of the power grid

The communication becomes an

interfering signal

Oscillation around the zero

crossing

Measurments

Pehr Högström Laboratoriet

EMC on SITE

Energy-saving lamp

Impedance of energy-saving

lamp

Loads working like a shunt

Printer

Computer

Computer & printer

Conclusion



With the increasing use of energy-saving

equipment, the magnitud of signals in the

communication channel increases



Interfering signals can be reduced by using

filters



The use of filters will lead to attenuation



The way that EMC-filters are designed today and

the way that we want to use the power grid for

communication are not compatible



Sarah Rönnberg

•

sarah.ronnberg@ltu.se



EMC on SITE

•

http://emconsite.tt.ltu.se/



Acknowledgement

•

Skellefteå Kraft Elnät AB

•

ELFORSK

•

Skellefteå Kommun

_{, S.K Rönnberg}

_{, C.M Lundmark}

_,

_{, M Wahlberg}

_{, M.H.J Bollen}

_{EMC on Site, Luleå University of Technology}

_{Skellefteå Kraft Elnät AB}

_{STRI AB}