IEEE Electrification Magazine - June 2014 - 22

Power electronics and Battery Pack
the Chevrolet spark power electronics components
include a 110-kw Pim [Figure 13(a)], a 2.2-kw dc-dc accessory power module (aPm) [Figure 13(b)], and a 3.3-kw
onboard charger [Figure 13(c)]. all of these components are
liquid cooled with a separate cooling circuit. the input for
the dc connection is on the front end of the Pim, while the
ac connection to the motor is made on the side. the
Chevrolet spark Pim is the modified version of the volt

Pim, which only drives two machines: the main propulsion motor and the oil pump motor. the aPm is the liquid
cooled version of the Chevrolet volt aPm and is housed
under the hood to share the common cooling circuit with
the Pim. the high-voltage battery charger is the reuse of
the volt charger, which runs off a 240-v supply and takes
about 7 h to fully charge the Chevrolet spark battery. however, the Chevrolet spark charger is outfitted with combination receptacle, which has the same ac interface used
for onboard charging and additional dc pins to transfer the
dc energy directly from a fast charge station. the system
is capable of completing a 50-kw off-board fast charge
(to 80% usable range) in approximately 20 min.
the Chevrolet spark lithium-ion battery has an energy
greater than 20 kwh when fully charged. the battery is liquid cooled and locally manufactured in livonia, michigan.
Figure 14 shows the spark battery module. the Chevrolet
spark du delivers a world-class performance and competitive range.

Propulsion System Performance

Mechanical Power (kW)

Mechanical Torque (Nm)

the spark ev du is efficient because of its low mechanical
losses and high electrical system efficiency. low mechanical losses are achieved by implementing the same lowspeed compact planetary gear that is used as the final drive
Figure 14. The Chevrolet Spark battery module. (Photo courtesy
of GM.)
in gm's conventional automatic transmissions. the relatively low-input speed results in low
em windage and oil drag losses. the
2013 Chevy Spark Electric
utilization of an electrical oil pump
Machine Characteristics Versus Vehicle Velocity
reduces the oil churn losses caused
120.0
600
by splash lube type designs by pro550
110.0
viding the exact amount of oil
500
100.0
required for all driving conditions.
450
90.0
the axle torque and power per400
80.0
formance of the Bev propulsion
350
70.0
system is shown in Figure 15. the
300
60.0
peak axle torque and power are list250
50.0
ed in table 1. this performance is
200
40.0
capable of meeting the zero to
150
30.0
60 mi/h acceleration in 7.6 s.
100
20.0
Shaft Torque (Nm)
the Chevrolet spark propulsion
50
10.0
Power (kW)
system is optimized, targeting spe0
0.0
cific drive cycles. the drive cycles
0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0
used during optimization are the
Vehicle Velocity (mi/h)
ePa city and highway, us06, and
Figure 15. The Chevrolet Spark axle torque and power.
la92. For each of these drive cycle

* dc Tractive In
Battery

* Tractive Mechanical Out
Inverter

* dc Regen Out

I E E E E l e c t r i f i c ati o n M agaz ine / j un e 2014

Axle
* Regen Mechanical In

Traction System

Figure 16. The Chevrolet Spark BEV energy flow.

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