Kaz Furmanczyk

Latest Solutions

to meet Power Conversion Needs

on the Electric Aircraft

Aerospace Electrical Systems Expo 2014

Long Beach, California, April 1-3, 2014

Kaz Furmanczyk

Crane Aerospace & Electronics

2013 Crane Aerospace & Electronics

Background

Increase in Power Needs on the More Electric Aircraft

Adaptation of 230 Vac on New Aircraft

Solving Power Conversion New Challenges

Design Considerations

Conventional ATRU Approach

New ATRU Topologies for Converting 230 Vac Into 270 Vdc

Design Example

Summary and Conclusions

Presentation Outline

2


Background

New generation of aircraft are becoming More Electric

Traditional pneumatic and hydraulic systems on airplanes are being replaced with electrical devices

More electrical equipment is being added to airplanes

Higher power needs to be generated and distributed

Wire weight and power losses are increasing with

distribution of higher power

To mitigate wire weight and distribution loss issues, new

aircraft have adopted 230 Vac as the main power bus

voltage

3


Background

This presents a new challenge to power conversion

Existing aircraft equipment (actuators, pumps, etc) have been designed to use 270 Vdc obtained by direct rectification of 115 Vac

270 Vdc can not be simply produced from 230 Vac

There is a need for reliable, low weight and simple power equipment converting 230 Vac to 270 Vdc

This presentation addresses options for such equipment and new solutions

4


Design Considerations

The following power conversion technologies are capable of converting 3-phase, 230 Vac into 270 Vdc in addition to meeting aerospace power quality requirements:

Multiphase power conversion (passive conversion)

High frequency switch mode conversion (active conversion)

Multiphase power conversion become attractive in aerospace applications due to simplicity, low weight and low cost

5


Multiphase Power Conversion

3-phase to n-phase autotransformer

3-phase n-phase

Three-

Phase AC

Input

DC

Output1 2 n

Output Voltage: 270 Vdc nominal

(with 115 Vac input); passive regulation

Meets Input Current Harmonic Limits

Power Factor: 0.980-0.990

Efficiency: 96-98%

Simplicity: low parts count; no need for energy storage components (C or L)

Design

Approach

Output Voltage Ripple

[% p-p]

Input Current THD

[%]

6-pulse

14 28-33

12-pulse

3.4 9-14

18-pulse

1.52 6-9

30-pulse

0.55 2.5-3.5

EA.I [A]

t [s ]

8 .0 0

-8 . 0 0

0

-6 . 0 0

-4 . 0 0

-2 . 0 0

2 .0 0

4 .0 0

6 .0 0

2 .5 0 m 5 .0 0 m2 .8 0 m 3 .0 0 m 3 .2 0 m 3 .4 0 m 3 .6 0 m 3 .8 0 m 4 .0 0 m 4 .2 0 m 4 .4 0 m 4 .6 0 m

V_Aux.V [V] R_Aux.I [A]

t [s ]

3 0

2 5

2 6

2 7

2 8

2 9

2 .5 m 5 m2 .8 m 3 m 3 .2 m 3 .4 m 3 .6 m 3 .8 m 4 m 4 .2 m 4 .4 m 4 .6 m 4 .8 m

VM_Rload1.V [V] Rload1.I [A]

t [s ]

3 0

2 5

2 6

2 7

2 8

2 9

2 .5 m 5 m2 .8 m 3 m 3 .2 m 3 .4 m 3 .6 m 3 .8 m 4 m 4 .2 m 4 .4 m 4 .6 m 4 .8 m

EA.I [A]

t [s ]

5 0

-5 0

0

-4 0

-2 0

2 0

4 0

2 .5 m 5 m2 .8 m 3 m 3 .2 m 3 .4 m 3 .6 m 3 .8 m 4 m 4 .2 m 4 .4 m 4 .6 m 4 .8 m

VM_Rload1.V [V] Rload1.I [A]

t [s ]

3 0

2 5

2 6

2 7

2 8

2 9

2 .5 m 5 m2 .8 m 3 m 3 .2 m 3 .4 m 3 .6 m 3 .8 m 4 m 4 .2 m 4 .4 m 4 .6 m 4 .8 m

EA.I [A]

t [s ]

5 0

-5 0

0

-4 0

-2 0

2 0

4 0

2 .5 m 5 m2 .8 m 3 m 3 .2 m 3 .4 m 3 .6 m 3 .8 m 4 m 4 .2 m 4 .4 m 4 .6 m 4 .8 m

V_Load.V [V] Rload1.I [A]

t [s ]

3 0

2 5

2 6

2 7

2 8

2 9

2 .5 m 5 m2 .8 m 3 m 3 .2 m 3 .4 m 3 .6 m 3 .8 m 4 m 4 .2 m 4 .4 m 4 .6 m 4 .8 m

EA.I [A]

t [s ]

5 0

-5 0

0

-4 0

-2 0

2 0

4 0

2 .5 m 5 m2 .8 m 3 m 3 .2 m 3 .4 m 3 .6 m 3 .8 m 4 m 4 .2 m 4 .4 m 4 .6 m 4 .8 m

Effects of design approach on output voltage ripple and input current THD

6

ATRU


Conventional ATRU Designs

Most commercial aerospace power quality requirements

can be satisfied with 12-pulse or 18-pulse ATRUs, when

converting 3-phase 115 Vac into 270 Vdc

Typical 12-pulse ATRU:

BC

12

3

4 5

6

b

c

a

1

2

3

A

B

C

Input

115 V AC

Output

270 V DC

A

1

2

3

e

f

e

f

AUTOTRANSFORMER RECTIFIERS

IPT #1

IPT #2

7


Conventional ATRU Designs

To convert 230 Vac into 270 Vdc scaling windings need to

be added to an autotransformer

B

C

12

3

4 5

6

b

c

d

a

1

2

3

A

B

C

Input

230 V AC

A

1

2

3

e

f

e

f

AUTOTRANSFORMER RECTIFIERS

IPT #1

IPT #2

Output

270 V DC

5 kW Load

8

Total Power Processed = 8,245 VA


New ATRU* 12-Pulse Topology

B

A

C

1

2

3

4 5

6

b

c

d

a

1

2

3

4

5

6

A

B

C

Input

230 V AC

Output

270 V DC

5 kW Load

AUTOTRANSFORMER

RECTIFIER

*Covered by US patent No. 7,796,413

Conventional ATRU design comparison: 6065/8245 * 100% = 73.6%

9

Total Power Processed = 6,065 VA

The same conversion of 230 Vac to 270 Vdc New technology

26.4% Improvement


New ATRU* 18-Pulse Topology

B

A

C

12

3

4

5

67

8

9

b

c

d

e

f

a

1

2

3

4

5

6

7

8

9

A

B

C

Input

230 V AC

Output

270 V DC

AUTOTRANSFORMER

RECTIFIER

For applications where higher power quality is required

ATRU optimized for conversion of 230 Vac into 270 Vdc

Output voltages shifted 40 degree (9 output phases)

Six outputs taken directly from taps on delta windings

Only three short stud windings added

Weight reduced by 26% compared to existing ATRU topologies

*Covered by US patent No. 7,796,413

10


New ATRU Design Example

5 kW ATRU, 12-pulse Topology Design Example

Parameter Value

Power Rating 5 kW continuous

7.5 kW (150%) overload for 2 min.

Input Voltage 230 V ac, 360-800 Hz, 3-phase,

DO-160G characteristics

Output

Voltage 270 V dc nominal at full load

Power Factor 0.98 minimum, 50% to 100% load

Efficiency 95% minimum, 50% to 100% load

Power Quality Meets DO-160G individual current

harmonic limits

EMI

Conducted

Emission

Meets DO-160G, Section 21,

Level B emissions on AC input

Weight 7.2 lb maximum

Size 9 x 3.7 x 3.1 (L x W X H)

Operating

Temperature -40 deg. C to 85 deg. C at base plate

Cooling Conduction through base plate

11


Summary and Conclusions

Demands for electrical power on todays aircraft are increasing

Latest commercial aircraft have adopted 230 Vac as main power bus voltage

Many of the existing aircraft equipment use 270 Vdc power

270 Vdc can not be simply produced from 230 Vac thereby presenting a challenge to the power conversion equipment

This paper addressed new ATRU design topologies for converting 230 Vac into 270 Vdc

Comparison analyses showed substantial improvements (26%) of these new topologies over traditional solutions

Hardware test results confirmed the analyses

12

New ATRU topologies fulfilled the challenge of generating 270 Vdc on aircraft with a 230 Vac bus

Lower weight Higher power quality


The Crane Advantage!

For more information please visit CraneAE.com Technical Assistance

Kaz Furmanczyk, Principal Engineer Tel. +1 425.743.8106

Email: [email protected]

13

Kaz Furmanczyk

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