WorkShop Audace

INSA ROUEN8 juin 2012

EMC Towards a global optimization

/ Houmam MOUSSA/Houmam.moussa@hispano-suiza-sa.com

AGENDA

� CONTEXT and OBJECTIVES

� EMI modeling and simulation

� Thermal de-rating

� Conclusion

� More Electrical Aircraft but also more composite st ructure

� The generalization of embedded electrical systems contributes more and more to in the global weight of the aircraft.

� The use of static converters causes a number of major EMI issues in electrical systems, especially due to high dv/dt of switching components.

� These impediments are such as high-frequency leakage currents flowing to the ground through capacitive couplings, deterioration of motor winding insulation, radiation of power cables, network pollution, self-disturbances…

Motor

Bus-bar

Front-

end

EMI

FilterLISN

Bus-bar

EMI Noise Source

EMC in more electrical aircraft

Research topics on EMI

� EMI constraints concerns a wide range of phenomena :

� EMISSIONS

� Conducted

� Radiated

� SUSCEPTIBILITY

� Lightning, ESD

� Cross-talking

� Field coupling in cables & equipments

� Signal integrity

�EMI is addressed by all the design �processes

� functional� mechanical � thermal, etc..

�EMI concerns � signal processing� power electronics

KEY STAKES

� To participate to the global need of optimization, it is necessary totreat EMI item at the earliest stage of the electrical system designwork flow.

� Influence of the temperature on the components performances as newstandards will ask for EMC behavior with thermal testing.

� The global optimization approach is aiming to distribute and specifyEMI constraints over the entire system (converter, filters, shields ofcable, machine)

� The main objective is doing prediction of the noise source and itspropagating paths (stray elements) by an appropriated and optimizedmodeling method up to :• Today : 10MHz

• Final goal: 30MHz to 50MHz to treat radiated emissions of cable

� Establishing rules/guidelines and design tools for a predictiveapproach to optimize:• Weight

• Reliability

• Cost

• Risk

General purpose of EMI modeling

Equipment under test2kW HVDC-fed inverter

2 m and 10 m cables

Permanent Magnet Synchronous Machine

Space Vector Modulation

ground

� To be able to model and compute noise sources and the propagating path of CMand DM until 10MHz with circuit type model and standard engineering tool(SABERTM) in aeronautic

� To be able to increase frequency range up to 50 MHz, with appropriated method(frequential domain) to treat radiated emission of power cable

� To study the influence of system integration, command, cable, filters, compositeground plane...

� To build and validate an engineering methodology

AGENDA

� CONTEXT and OBJECTIVES

� EMI modeling and simulation

� Thermal de-rating

� Conclusion

Mock-up overview

INVERTER and its drivers

D0160 LISN

MOTOR

CABLE

DC FILTER

Modeling process : Inverter

InCa3D Software for, R,L, M elements

Propagating paths Improvement on Noise source

SABER Software for die element (design architect)

Measurements for C elements

Only stray capacitors are non-predictive element

InCa3D is going to adress capacitive part soon (industrialization in progress)

Other 3D tools can address capacitive part

PROGRESS: Convergence issues have been solved with Synopsys support

We are able to compute detailed physic based model of swicth component in 3 phases VSI and very low sampling time

Modeling process : Power cable

� TLM is built from Finite Elementcomputation R, L, M and C

� Matlab code developped to extract allimpedances from FEMM to fit with TLM

� Shield model : tube with section withgiven equivalent R, and L parameters

� Gain compared to analytical method

dx = λλλλ/10

Propagating pathsGeometry

consideration Finite Element Modeling & computation

Transmission Line Modeling & circuit

computation

Modeling process : Motor

� Complex geometry

� Electrostatic and magnetic coupling to treat

Zmd

Zmc

Pi Sturcture

Behavioral modeling is chosen from measurements consideration

Zmd

Matlab code is developped to fit circuit model with impedances measurements

SABER model

Overview of Simulation results

Inverter Power cablePower cable PMSML

HVDC-fed LISN

104

105

106

107

108

101

102

103

104

105

frequency (Hz)

impe

danc

e (O

hms)

Common mode impedance

Motor measurementsMotor model

104

105

106

107

108

101

102

103

104

frequency (Hz)

impe

danc

e (O

hms)

Common mode impedance

Motor measurementsMotor model

AGENDA

� CONTEXT and OBJECTIVES

� EMI modeling and simulation

� Thermal de-rating

� Conclusion

Temperature cycles

Temperature Vs Frequency

-80

-60

-40

-20

0

20

40

60

80

100

120

103

104

105

106

107

108

erreur self v0

X: 25Y: 1.024e+004Z: 0.02099

10

20

30

40

50

60

70

80

90

KHz

µ

-80

-60

-40

-20

0

20

40

60

80

100

120

103

104

105

106

107

108

erreur self v3

X: 25Y: 1.024e+004Z: 0.7672

10

20

30

40

50

60

70

80

90

-80

-60

-40

-20

0

20

40

60

80

100

120

103

104

105

106

107

108

erreur self v4

X: 25Y: 1.024e+004Z: 0.9726

10

20

30

40

50

60

70

80

90

v120*12*8 mm3

12 turns

v3 bis28*20*8 mm3

19 turns

v428*20*6 mm3

19 turns

err = |(L@25°C-L@Ti°C)|

L@25°C

Protypes performance comparision

-60

-40

-20

0

20

40

60

80

100

120

103

104

105

erreur self v4

5

10

15

20

25

30

35

-60

-40

-20

0

20

40

60

80

100

120

103

104

105

erreur self v3

5

10

15

20

25

30

35

40

-60

-40

-20

0

20

40

60

80

100

120

103

104

105

erreur self v0

5

10

15

20

25

30

35

< 10%

< 10%

< 30%

< 10%

< 15%

< 20%

< 20%

The version 4 had a wider band of relative error less than 10 %.

T°C

Hz

%T°C

Hz

%

Influence of the temperature

Power Capacitor

Power Capacitors

� Characteristics of a HT° X7R capacitor

• Capacitance vs Temperature, and vs DC Voltage

Power Capacitors

� Characteristics of a HT° X7R capacitor

• Insulation Resistance vs Temperature

Conclusion

� An HVDC-fed electrical power train (inverter, cable and motor) has been fully modeled by most of predictive method.

� EMI modeling methodology has been validated.

� Simulation results show good agreement with measurements up to 10MHz-15MHz.

�The aims of future work (in progress) are : � to obtain a frequency domain model of the EMI noise sources, trust-worthy up to 50MHz. � Improve cable modeling up to 50MHz for circuit type model� Address system level for EMI modeling with terminated and un-terminated method (frequency domain)� Adjust technology of new optimized power cable to decrease global weight of the electrical system� To take into account the EMC behavior of the component with the temperature.

THANK FOR YOUR ATTENTION