IEEE Electrification Magazine - December 2017 - 31

current reference and the HP generator torque reference, the
d and q axis current references can be expressed as
2

I

)
ds1

I

)
qs1

I) -

=

=

2

2T )e1
2T )e1
I) +
k1
k1
,
2
2

I) -

-

2T )e1
k1
2

2

I) +

2T e)1
k1

(1)
(2)

,

3 P1 L 2
where k 1 = 2 2 Lm1 is the torque coefficient.
r1
To decouple the ac and dc power supply of the HP spool
generation subsystem, the two subsystem control inputs, ac
load voltage reference V )ac and dc output power reference
P dc) 1, are converted into d and q axis current commands of
the HP generator. For this conversion to be implemented the
following must occur:
xx
Given the reference line-to-line root-mean-square
(RMS) load voltage V )ac, a proportional-integral (PI)
controller is used to provide the required ac load current command I ) for regulating the voltage across
the three-phase balanced resistor (ac loads).
xx
The ac load resistance R acL is estimated as the ac load
voltage vac divided by the stator current magnitude I.
xx
Given dc power output command P dc) 1, ac load current
command I ), ac load resistance R acL, and generator
electrical frequency ~ e1, the torque reference of the
HP spool generator T )e1 is calculated.
xx
Given the torque reference of the HP spool generator
T )e1 and ac load current command I ), the d and q axis
current commands I )ds1 and I )qs1 are obtained from (1)
and (2).
Using rotor-flux orientation, two PI controllers are used
in the current control loop to regulate the d axis current i ds1
and q axis current i qs1 of the HP generator. The closed-loop

control scheme for the LP shaft generation subsystem is
shown in Figure 7. In the dc bus voltage control loop, a PI
controller is used to generate the LP generator q axis
(torque) current command I )qs2. Since the LP shaft generator has a wide-speed operating range, flux-weakening
operation is required in the LP spool generation subsystem.
The d axis (flux) current of the LP generator is inversely
proportional to the generator shaft speed to obtain a widespeed operation range. A direct flux observer is used in the
LP spool generation subsystem to provide the rotor flux
speed ~ e2 and angle i rf2 information. Similar to the current
control loop in the HP spool generation subsystem, two PI
controllers are used to regulate the d axis current i ds2 and
the q axis current i qs2 of the LP generator. Space vector
pulsewidth modulation is used to generate gating signals
for the active rectifier units.

Induction Machine-Based APU Architecture
In MEA, the traditional hydraulic flight control actuators
with a central hydraulic system are being replaced by EHAs
or EMAs. Compared to the traditional actuators, EHAs and
EMAs have lower weight and volume, increased reliability,
and reduced maintenance. However, these actuators have
a highly dynamic power profile, which includes high-peak
power demand and power regeneration.
The most widely used regenerative power management
method for EHA/EMAs on aircraft is to employ resistor
banks paralleled with the actuators, dissipating the
regenerated energy with associated cooling devices. This
solution renders the weight, volume, and efficiency of the
overall system far from optimized. Potential regenerative
power management methods include 1) using ESEs, such
as ultracapacitors and batteries, to restore and recover the
regenerative energy and 2) returning the regenerative

LP Spool Generation Subsystem
LP Generator Controller

ia2,ib2

dq
abc

∗
Vdc

+
-

∗
Voltage Iqs2 +
Controller

ωe2
vdc
θrf2

FluxWeakening
Operator
Flux
Observer 2

-

∗
Ids2
+

Current
Controller
-

Current
Controller

LP
IG

θrf2
dq

abc

SVM

... To Main
dc Bus

∗
vdc, Vabc2

HP Spool Generation Subsystem

Figure 7. The closed-loop control scheme for the LP spool generation subsystem.

IEEE Elec trific ation Magazine / D EC EM BE R 2 0 1 7

31



Table of Contents for the Digital Edition of IEEE Electrification Magazine - December 2017

IEEE Electrification Magazine - December 2017 - Cover1
IEEE Electrification Magazine - December 2017 - Cover2
IEEE Electrification Magazine - December 2017 - 1
IEEE Electrification Magazine - December 2017 - 2
IEEE Electrification Magazine - December 2017 - 3
IEEE Electrification Magazine - December 2017 - 4
IEEE Electrification Magazine - December 2017 - 5
IEEE Electrification Magazine - December 2017 - 6
IEEE Electrification Magazine - December 2017 - 7
IEEE Electrification Magazine - December 2017 - 8
IEEE Electrification Magazine - December 2017 - 9
IEEE Electrification Magazine - December 2017 - 10
IEEE Electrification Magazine - December 2017 - 11
IEEE Electrification Magazine - December 2017 - 12
IEEE Electrification Magazine - December 2017 - 13
IEEE Electrification Magazine - December 2017 - 14
IEEE Electrification Magazine - December 2017 - 15
IEEE Electrification Magazine - December 2017 - 16
IEEE Electrification Magazine - December 2017 - 17
IEEE Electrification Magazine - December 2017 - 18
IEEE Electrification Magazine - December 2017 - 19
IEEE Electrification Magazine - December 2017 - 20
IEEE Electrification Magazine - December 2017 - 21
IEEE Electrification Magazine - December 2017 - 22
IEEE Electrification Magazine - December 2017 - 23
IEEE Electrification Magazine - December 2017 - 24
IEEE Electrification Magazine - December 2017 - 25
IEEE Electrification Magazine - December 2017 - 26
IEEE Electrification Magazine - December 2017 - 27
IEEE Electrification Magazine - December 2017 - 28
IEEE Electrification Magazine - December 2017 - 29
IEEE Electrification Magazine - December 2017 - 30
IEEE Electrification Magazine - December 2017 - 31
IEEE Electrification Magazine - December 2017 - 32
IEEE Electrification Magazine - December 2017 - 33
IEEE Electrification Magazine - December 2017 - 34
IEEE Electrification Magazine - December 2017 - 35
IEEE Electrification Magazine - December 2017 - 36
IEEE Electrification Magazine - December 2017 - 37
IEEE Electrification Magazine - December 2017 - 38
IEEE Electrification Magazine - December 2017 - 39
IEEE Electrification Magazine - December 2017 - 40
IEEE Electrification Magazine - December 2017 - 41
IEEE Electrification Magazine - December 2017 - 42
IEEE Electrification Magazine - December 2017 - 43
IEEE Electrification Magazine - December 2017 - 44
IEEE Electrification Magazine - December 2017 - 45
IEEE Electrification Magazine - December 2017 - 46
IEEE Electrification Magazine - December 2017 - 47
IEEE Electrification Magazine - December 2017 - 48
IEEE Electrification Magazine - December 2017 - 49
IEEE Electrification Magazine - December 2017 - 50
IEEE Electrification Magazine - December 2017 - 51
IEEE Electrification Magazine - December 2017 - 52
IEEE Electrification Magazine - December 2017 - 53
IEEE Electrification Magazine - December 2017 - 54
IEEE Electrification Magazine - December 2017 - 55
IEEE Electrification Magazine - December 2017 - 56
IEEE Electrification Magazine - December 2017 - 57
IEEE Electrification Magazine - December 2017 - 58
IEEE Electrification Magazine - December 2017 - 59
IEEE Electrification Magazine - December 2017 - 60
IEEE Electrification Magazine - December 2017 - 61
IEEE Electrification Magazine - December 2017 - 62
IEEE Electrification Magazine - December 2017 - 63
IEEE Electrification Magazine - December 2017 - 64
IEEE Electrification Magazine - December 2017 - 65
IEEE Electrification Magazine - December 2017 - 66
IEEE Electrification Magazine - December 2017 - 67
IEEE Electrification Magazine - December 2017 - 68
IEEE Electrification Magazine - December 2017 - 69
IEEE Electrification Magazine - December 2017 - 70
IEEE Electrification Magazine - December 2017 - 71
IEEE Electrification Magazine - December 2017 - 72
IEEE Electrification Magazine - December 2017 - 73
IEEE Electrification Magazine - December 2017 - 74
IEEE Electrification Magazine - December 2017 - 75
IEEE Electrification Magazine - December 2017 - 76
IEEE Electrification Magazine - December 2017 - 77
IEEE Electrification Magazine - December 2017 - 78
IEEE Electrification Magazine - December 2017 - 79
IEEE Electrification Magazine - December 2017 - 80
IEEE Electrification Magazine - December 2017 - 81
IEEE Electrification Magazine - December 2017 - 82
IEEE Electrification Magazine - December 2017 - 83
IEEE Electrification Magazine - December 2017 - 84
IEEE Electrification Magazine - December 2017 - 85
IEEE Electrification Magazine - December 2017 - 86
IEEE Electrification Magazine - December 2017 - 87
IEEE Electrification Magazine - December 2017 - 88
IEEE Electrification Magazine - December 2017 - 89
IEEE Electrification Magazine - December 2017 - 90
IEEE Electrification Magazine - December 2017 - 91
IEEE Electrification Magazine - December 2017 - 92
IEEE Electrification Magazine - December 2017 - 93
IEEE Electrification Magazine - December 2017 - 94
IEEE Electrification Magazine - December 2017 - 95
IEEE Electrification Magazine - December 2017 - 96
IEEE Electrification Magazine - December 2017 - 97
IEEE Electrification Magazine - December 2017 - 98
IEEE Electrification Magazine - December 2017 - 99
IEEE Electrification Magazine - December 2017 - 100
IEEE Electrification Magazine - December 2017 - Cover3
IEEE Electrification Magazine - December 2017 - Cover4
http://www.nxtbook.com/nxtbooks/pes/electrification_december2019
http://www.nxtbook.com/nxtbooks/pes/electrification_september2019
http://www.nxtbook.com/nxtbooks/pes/electrification_june2019
http://www.nxtbook.com/nxtbooks/pes/electrification_march2019
http://www.nxtbook.com/nxtbooks/pes/electrification_december2018
http://www.nxtbook.com/nxtbooks/pes/electrification_september2018
http://www.nxtbook.com/nxtbooks/pes/electrification_june2018
http://www.nxtbook.com/nxtbooks/pes/electrification_december2017
http://www.nxtbook.com/nxtbooks/pes/electrification_september2017
http://www.nxtbook.com/nxtbooks/pes/electrification_march2018
http://www.nxtbook.com/nxtbooks/pes/electrification_june2017
http://www.nxtbook.com/nxtbooks/pes/electrification_march2017
http://www.nxtbook.com/nxtbooks/pes/electrification_june2016
http://www.nxtbook.com/nxtbooks/pes/electrification_december2016
http://www.nxtbook.com/nxtbooks/pes/electrification_september2016
http://www.nxtbook.com/nxtbooks/pes/electrification_december2015
http://www.nxtbook.com/nxtbooks/pes/electrification_march2016
http://www.nxtbook.com/nxtbooks/pes/electrification_march2015
http://www.nxtbook.com/nxtbooks/pes/electrification_june2015
http://www.nxtbook.com/nxtbooks/pes/electrification_september2015
http://www.nxtbook.com/nxtbooks/pes/electrification_march2014
http://www.nxtbook.com/nxtbooks/pes/electrification_june2014
http://www.nxtbook.com/nxtbooks/pes/electrification_september2014
http://www.nxtbook.com/nxtbooks/pes/electrification_december2014
http://www.nxtbook.com/nxtbooks/pes/electrification_december2013
http://www.nxtbook.com/nxtbooks/pes/electrification_september2013
http://www.nxtbookMEDIA.com