some power quality and electromagnetic compatibility...
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47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
Belgrade, Sava Centre, 30th November – 2nd December 2016
Some Power Quality and Electromagnetic Compatibility Issues in HVAC Equipment
Mircea Ion Buzdugan
Faculty of Building Services EngineeringTechnical University of Cluj-Napoca, Romania
47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
Belgrade, Sava Centre, 30th November – 2nd December 2016
Motto: Think EMC!
Are Electromagnetic Compatibility and Power Quality dichotomous?
A system is electromagnetically compatible with its environment if it satisfies three criteria:1. It does not cause interference with other systems.2. It is not susceptible to emissions from other systems.3. It does not cause interference with itself.
But what does Power Quality mean?
Two relevant case studies!
47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
Belgrade, Sava Centre, 30th November – 2nd December 2016
Case study no. 1: An air handling unit using two fans driven by brushless DC motors
Schematic diagram of an air handling unit Hardware block diagram Input stage of the drive circuit
47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
Belgrade, Sava Centre, 30th November – 2nd December 2016
Supply voltage and current drawn by the AHU The FFT chart of the harmonic limits of the AHU
47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
Belgrade, Sava Centre, 30th November – 2nd December 2016
Harmonic limits check
Harmonic limits test report for one centrifugal fan
Harmonic limits test report for the air handling unit
47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
Belgrade, Sava Centre, 30th November – 2nd December 2016
The schematic test setup for conducted interference
Conducted interferences of a single BLDC drive in linear scale
Conducted interferences of the AHU in linear scale
47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
Belgrade, Sava Centre, 30th November – 2nd December 2016
Case study no. 2: A residential heating gas central 24 kW
EMI filter of the gas home heating system
The transfer characteristics of the filter indifferential mode
The transfer characteristics of the filter incommon mode
1
2
C D
C D
I I II I I= += −
( )
( )
1 2
1 2
1212
D
C
I I I
I I I
= − = +
47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
Belgrade, Sava Centre, 30th November – 2nd December 2016
RF conducted emissions induced in the public low voltage network by a nearby AM radio broadcasting station
Linear scaleLogarithmic scale
47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
Belgrade, Sava Centre, 30th November – 2nd December 2016
The topology of the power EMI filter
The equivalent circuit of the differential mode filter
The equivalent circuit of the common mode filter
The ferrites obey to the concept of complex magnetic permeability: j′ ′′µ = µ − ⋅µ
0X L ′= ω⋅ ⋅µ 0R L ′′= ω⋅ ⋅µ 2 2Z R X= + tan /′′ ′δ = µ µ
47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
Belgrade, Sava Centre, 30th November – 2nd December 2016
The reactive component of different ferrite materials
The resistive component of different ferrite materials
THE NON-IDEAL BEHAVIOR OF LUMPED COMPONENTS
RESISTORSTransfer function: ( )
2 1
1
ssR EPC ESL EPCH s ESL
sR EPC
+ +⋅ ⋅=+
⋅
Hidden schematics:a. b.
Theoretical Bode plots of the impedance variation with frequency
11
2f
R ECPπ=
⋅first cut-off frequency
12Sf ESL EPCπ
=⋅
self resonant frequency
( ) 2 1s ESL RH s
s ESL EPC sR EPC⋅ +
=⋅ ⋅ + ⋅ +
Belgrade, Sava Centre, 30th November – 2nd December 2016
47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
Magn
itude
(dB)
-50
0
50
100
150
10 4 10 6 10 8 10 10
Phas
e (de
g)
-90
-45
0
45
90
Bode plot of the impedance variation
Frequency (Hz)
Bode plots of the transfer function for a resistor.
Magn
itude
(dB)
-50
0
50
100
150
10 3 10 4 10 5 10 6 10 7
Phas
e (de
g)
-90
-45
0
45
90
Bode plot of the impedance variation
Frequency (Hz)
Bode plots of the model from Fig. a. in the relevant range for conducted emissions
Magn
itude
(dB)
-50
0
50
100
10 4 10 5 10 6
Phas
e (de
g)
-90
-45
0
Bode plot of the impedance variation
Frequency (Hz)
Bode plots of the model from Fig. b in the relevant range for conducted emissions
Belgrade, Sava Centre, 30th November – 2nd December 2016
47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
CAPACITORSTransfer function: ( )
2 1s ESRsESL ESL CH s ESL
s
⋅+ +
⋅=
Hidden schematics:
a.
Theoretical Bode plots of the impedance variation with frequency
self resonant frequency1
2Sf ESL Cπ=
⋅
b.
( ) 1
11
H ss EPC ESR s ESL
sC
−= ⋅ + + ⋅ +
Belgrade, Sava Centre, 30th November – 2nd December 2016
47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
Magn
itude
(dB)
-50
0
50
100
10 3 10 4 10 5 10 6 10 7
Phas
e (de
g)
-90
-45
0
45
90
Bode Diagram
Frequency (Hz)
System: sys
Frequency (Hz): 2.01e+04
Magnitude (dB): -20
Bode plots of the impedance variation with frequency of thecapacitor from Fig. a
Magn
itude
(dB)
-50
0
50
100
150
200
10 3 10 4 10 5 10 6 10 7
Phas
e (de
g)
-90
-45
0
45
90
Bode plot of the impedance variation
Frequency (Hz)
System: sys
Frequency (Hz): 7.09e+06
Magnitude (dB): 191
Bode plots of the impedance variation with frequency of thecapacitor from Fig. b
series resonance frequency 1
ss
ESLC
ωω
⋅ =
parallel resonance frequency1
pp
ESLEPC
ωω
⋅ =⋅
Belgrade, Sava Centre, 30th November – 2nd December 2016
47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
INDUCTORS
Transfer function: ( ) 2
1
1L
sLESRH s ESR
s L EPC s ESR EPC
+=
⋅ + ⋅ ⋅ +( )
11LH s s EPC ESR
sL
− = ⋅ + +
Hidden schematics:a. b.
Theoretical Bode plots of the impedance variation with frequency
cut-off frequency 1 2ESRf
Lπ=
self resonant frequency
Belgrade, Sava Centre, 30th November – 2nd December 2016
1p
p
LEPC
ωω
⋅ =⋅
47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
Bode plots of the impedance variation with frequency of theinductor from Fig. a
Magn
itude
(dB)
-50
0
50
100
150
200
10 2 10 4 10 6 10 8 10 10 10 12
Phas
e (de
g)
-135
-90
-45
0
45
90
Bode plot of the impedance variation
Frequency (Hz)
System: sys
Frequency (Hz): 1.84e+07
Magnitude (dB): 150
Bode plots of the impedance variation with frequency of theinductor from Fig. b
Magn
itude
(dB)
0
50
100
150
200
250
10 2 10 4 10 6 10 8 10 10 10 12
Phas
e (de
g)
-90
-45
0
45
90
Bode plot of impedance variation
Frequency (Hz)
System: sys
Frequency (Hz): 1.84e+07
Magnitude (dB): 236
Belgrade, Sava Centre, 30th November – 2nd December 2016
47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
Equivalent schematics of the common mode choke Equivalent schematics of an EMI filtering cell
The interest in the components’ behavior was focused on the high frequencies where they are to be used to reduceconducted and/or radiated emissions.In order to obtain consistent results, apart from the conventional parameters and stress de-rating factors (powerdissipation, limiting voltage and current, operating temperature range, etc.), one should think also in terms ofnonideal behaviour of the circuit elements in the equivalent model.
Belgrade, Sava Centre, 30th November – 2nd December 2016
47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
Belgrade, Sava Centre, 30th November – 2nd December 2016
EMI filter transfer characteristics in differential mode
EMI filter transfer characteristics in common mode
47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
Belgrade, Sava Centre, 30th November – 2nd December 2016
Final spectrum of RF emissions of the AHU Final spectrum of RF emissions of the gas heating central
Conclusions!
47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
Belgrade, Sava Centre, 30th November – 2nd December 2016
Thank you for your attention!
47th International Congress and Exhibition on Heating, Refrigeration and Air-Conditioning
Belgrade, Sava Centre, 30th November – 2nd December 2016
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