IEEE Electrification Magazine - December 2017 - 28

advanced more electric architecture. A PM generator has
been investigated for this twin-spool twin-generator
architecture due to its high power density and self-excited capability. As shown in Figure 2, a high-speed starter/
generator and a low-speed generator are placed directly
on the HP and LP spool of the engine, respectively. In the
engine starting process, the PM starter/generator on the
HP spool can operate as a motor to start the engine using
ground power supply. During flight mission, the power
generated from the two generators is rectified and transmitted to a ±270-Vdc power bus. However, the amount of
electrical power consumption of frequency-insensitive ac
loads is still significant. In a Boeing 787, the power
consumption of frequency-insensitive ac loads under
cruising condition is close to 50%. This amount of ac
power is supplied through a two-stage ac-dc-ac conversion, which adds extra losses and additional hardware to
the system.
The induction generator-based ac/dc hybrid generation
system is shown in Figure 3. In this system, a high-speed
open-end winding squirrel-cage induction starter/generator and a low-speed conventional wye-connected squirrelcage induction generator are attached to the HP and LP
spools of the engine, respectively. In the generating mode
of operation, the HP generator is in charge of all the CVVF
power, while the dc power demand is shared by both the

Gas Turbine
HP Spool

HP and LP generators. The ac/dc hybrid generation architecture can supply CVVF power directly from one side of
the generator winding terminals without an external
exciter, and it can generate dc power on the other side of
the generator winding terminals through an inverter/
rectifier unit (IRU). As a result, the overall hardware
requirement of the system is reduced compared to the dc
primary generation systems, while the electrical loadsharing capability between the HP and LP spools is
still maintained.
A more detailed electrical system configuration is
shown in Figure 4. An IRU and frequency-insensitive ac
loads are connected to each end of the HP spool open-end
winding induction generator terminals. An active rectifier
unit is connected to the LP spool wye-connected induction
generator. The dc output end of the IRU and the active rectifier unit are parallel to the dc bus.
In this generation system, all of the CVVF power is generated by the HP generator only, while the power demand
of the dc loads is shared between both the HP and LP generators. The generation subsystem on the HP spool
includes a high-speed generator, an IRU, a CVVF distribution bus, and a shared CV dc distribution bus. The generation subsystem on the LP spool consists of a low-speed
generator, an active rectifier unit, and the shared CV dc
distribution bus.

HP PM
Starter/
Generator

LP PM
Generator

Active Rectifier
Unit

Active Rectifier
Unit

Gas Turbine
LP Spool

±270-Vdc Distribution

PWM Inverter Unit

Auto Transformer or
PWM Inverter Unit

dc/dc Converter
Unit

230-Vac Distribution

115-Vac Distribution

28-Vdc Bus

Figure 2. The system configuration of the PM generator-based dc primary generation system. PWM: pulsewidth modulation.

28

I E E E E l e c t r i f i cati o n M a gaz ine / DECEMBER 2017



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