IEEE Electrification Magazine - September 2013 - 16

noise caused by the pantograph was one of the most serious noise sources of the Shinkansen train set. Therefore,
a pantograph shield was developed as an effective countermeasure against aerodynamic noise of the pantograph [Figure 7(c)]. It was installed around the pantograph to reduce flow velocity around the pantograph,
resulting in effective reduction in aerodynamic noise, as
the energy of aerodynamic noise is proportional to the
sixth power of the flow velocity.
The pantograph shield was very effective in reducing
wayside noise emitted from the pantograph; it helped the
improvement of the maximum speed of Shinkansen
trains to 270 km/h in 1992. However, since the Japanese
noise regulations for wayside noise of high-speed trains
are very strict, the combination of the pantograph shield
with the conventional diamond-type pantograph was not
enough to achieve further speed-up. A low-noise pantograph was developed, consisting of a
single-membered and smoothshaped pantograph head and a
simple articulated frame. This pantograph, with an insulator cover or
low-noise insulators, achieves a
reduction of aerodynamic noise.
Since 1997, all new Shinkansen
trains operating at speeds over
240 km/h have been equipped with
low-noise pantographs. The low-noise
pantograph has contributed to the
further speed-up of Shinkansen
trains while keeping within the noise regulations. Today,
the maximum speed has increased to 320 km/h as of
March 2013.
Although the low-noise pantograph is very effective at
reducing aerodynamic noise, an improvement of its
contact performance has to be exchanged. Smoothing the

pantograph members makes the pantograph heavy, and
it is difficult to use a long stroke spring for a pantograph
head suspension because a large plunger generates significant aerodynamic noise. Since a speed-up of
Shinkansen trains without assuring compliance with the
noise regulation cannot be implemented, pantograph
design must give high priority to noise reduction in Japan.

Design policy of the pantograph/Catenary
system for shinkansen
Changeover Switches
There are about 30 substations and 30 sectioning posts in
the Tokaido Shinkansen. If Shinkansen trains had to coast
in front of each substation and sectioning post to change
electric phase, they would lose much time. JNR engineers
installed changeover switches to reduce the coasting time
to only 0.3 s. A pair of changeover
switches, a neutral section, and a track
circuit constitute the equipment. At
the beginning, in 1964, air-blast circuit
breakers and then vacuum circuit
breakers were introduced and have
been used until now. Figure 8 shows
the arrangement of a changeover
switch. The circuit breakers have to
work for each passing train. Therefore,
on the Tokaido Shinkansen, they have
to be replaced every five years.
Currently, the Central Japan Railway
Company is developing solid-state thyristor switches.
Since any pantograph only shunts sections in the same
feeding area in the case of the changeover section,
electrical connection between operating pantographs can
be permitted. Furthermore, trains can pass through the
changeover section without coasting.

The high speed and
larger bodies needed
high power, and ac
traction was suitable
to supply the
Shinkansen.

(a)
Figure 6. (a) A compound catenary for the Shinkansen and (b) CS and PHC simple contact lines.

I E E E E l e c t r i f i c atio n Magaz ine / september 2013

(b)

Table of Contents for the Digital Edition of IEEE Electrification Magazine - September 2013