IEEE Electrification Magazine - June 2014 - 53

provide the propulsion power when
needed and also have full regeneration energy capture capability. The
power of the electric motor is of the
order of 40-80 kW.
There is no particular standard for
the dc bus voltage in electric and
hybrid vehicles. The dc bus voltage in
hybrid vehicles is of the order of 144-
650 Vdc. The dc bus voltages in some of
the familiar EVs/HEVs are as follows:
xx
Toyota Prius: 500 Vdc with a 202-V
nickel-metal hydride (NiMH) battery (202 V is boosted to 500 V; it is
650 V in the 2010 Prius)
xx
Lexus RX400 hybrid: 650 Vdc with
a 288-V NiMH battery (288 V is
boosted to 650 V)
xx
Hybrid Honda Accord: 188 Vdc
(NiMH battery)
xx
Tesla Roadster electric car: 375 Vdc
(lithium-ion battery)
xx
Chevy Volt: 325 Vdc (lithium-ion
battery).

More Electric Aircraft

Conventional

Toyota Crown

Micro Hybrid
Engine

Mild Hybrid
Honda Insight

Parallel
Full Hybrid
Battery

Electric
Motor

Toyota Prius
Electric Vehicle

Battery

Series

Engine

Electric
Motor

Range Extender

Nissan Leaf

Series Hybrid
Chevy Volt with
Plug-in Capability
Fuel Cell Vehicle

Generator

Fuel Cell

Honda FCX
Figure 2. Hybrid vehicle architectures (K. Rajashekara, "Converging Technologies for Electric/
Hybrid Vehicles and MEA Systems," in Proc. SAE Power Systems Conf., Fort Worth, TX, Nov. 2-4,
2010, Paper No. 2010-01-1757).

CF/IDG System
CSD

Engine

Gen

CF ac Bus
400 Hz

In an MEA, the thrust for aircraft propulsion is provided fully by the jet
VSCF System
engine. In addition, the jet engine
CF ac Bus
Gen
Cycloconverter
Engine
driving a generator is responsible for
400 Hz
proving the required power for all of
VSCF with
the electrical loads. The different
dc Link System
dc
types of electrical power generation
CF ac Bus
Gen
Engine
Converter
Inverter
systems currently being used in air400 Hz
planes are shown in Figure 3:
xx
the constant frequency (CF) 115-Vac,
VF System
three-phase, 400-Hz generation
VF ac Bus
Gen
Engine
types typified by the integrated
(380-760 Hz)
drive generator (IDG); the IDG is
VF/270-Vdc System
used for powering the majority of
270 Vdc
Converter
Gen
civil transport aircraft today
Engine
xx
variable speed CF (VSCF) cycloconverter
dc Emergency Power
xx
VSCF with an intermediate dc
28 Vdc
Converter
PMG
link
Engine
xx
variable-frequency (VF) 115-V
and 230-V, three-phase power Figure 3. Electrical power generation strategies in aircraft (K. Rajashekara, "Converging
generation (380-760 Hz)
technologies for electric/hybrid vehicles and More Electric Aircraft systems," in Proc. SAE Power
xx
VF at 115 V and then converted Systems Conf., Fort Worth, TX, Nov. 2-4, 2010, Paper No. 2010-01-1757).
to 270-Vdc bus voltage
xx
permanent magnet (PM) generators used for generatused for pressurizing and cooling the cabin, starting the
ing 28-Vdc emergency electrical power for highmain engines, and de-icing the wings. The hydraulic power
integrity systems.
is used mainly for flight control actuators. The electrical
In a traditional airplane, the jet engine is designed to propower is used for supplying the power to all of the electrical
duce thrust and to power the pneumatic, hydraulic, and elecloads, including the computers and avionics systems. In
trical systems, as shown in Figure 4. The pneumatic power is
addition, the engines drive the gearbox-mounted units,

IEEE Electrific ation Magazine / j une 2 0 1 4

Table of Contents for the Digital Edition of IEEE Electrification Magazine - June 2014