IEEJ Journal of Industry Applications

Vol.1 No.3 pp.132–140 DOI: 10.1541/ieejjia.1.132

Paper

Innovative Application Technologies of AC Motor Drive Systems

Keiichiro Kondo∗a) Senior Member, Hisao Kubota∗∗ Senior Member

(Manuscript received March 13, 2012, revised June 20, 2012)

This paper deals with the innovative application technologies on variable speed AC motor drive systems. These
application technologies are categorized on the basis of the advantages of the AC variable speed motor drive systems,
such as downsizing, packaging with high density, energy savings, better availability and maintenancebility, higher
controllability of the torque and speed, load leveling. Various component technologies such as the power conver-
sion technology, control technology, and motor technology are also mentioned along with their related application
technologies. Future perspectives of the ac drive application technologies are discussed in the conclusion of the paper.

Keywords: AC variable speed dive, PMSM drive, IM drive, power converter, motor control

ac motor drive systems ontheir applications. Technical bene-

1. Introduction fits of the applications of ac motor drive systems are,
Electrical and mechanical energy conversion system has • more downsizing and more packaging,
many advantages against the other measures to obtain the • more precise control of the torque and the speed,
mechanical force, such as internal combustion engines and • higher availability and higher maintenancebility,
hydraulic actuators. In the electrical motor drive, variable • energy savings,
speed ac motor drive system has been developed thanks to • and load leveling with the energy storage devices.
the progress of the power electronics technologies. Inverter- After the progress of the ac drive systems themselves in-
driven induction motors can be controlled more precisely cluding power electronics technologies, they are combined
than dc motor drive system thanks to the field-oriented con- with the energy storage devices such as batteries or capaci-
trol. Inverter-driven permanent magnet synchronous motors tors to carry out bidirectional energy conversion between the
can increase their efficiency and can reduce their mass and electric energy and the mechanical energy. ac drive systems
dimensions, compared with induction motors. Brushes and play new role as an essentialcomponents of sub-system in the
commutaters in dc motors require the periodical inspection emerging applications to save the energy. This fact indicates
and replacement, and limit current change ratio against time. one of the directions of future progress of ac motor variable
Variable speed ac motor drive systems are free from the any speed drive technologies. This paper aims at revealing the
technical problems with the brushes and commutaters. The direction of the development of the ac drive systems, through
wider speed operation range than the dc motor and regen- the reviewing the recent innovative ac drive applications.
erative brake operation with unity power factor at the front In the first part of this paper, innovative ac drive applica-
end are other advantages of the ac motor drive system. In tions are categorized by the benefits of the applications as
early 1990’s, the rare earth magnet released in the market mentioned above. Some of the examples of the application
and started to apply permanent magnet synchronous motors in the each technical benefit are introduced and reviewed in
(PMSMs) to the various power range up to around 1 MW. each section. In addition, some of the essential technologies
PMSMs play important roles in the application field where in the motor itself, power conversion circuit and motor con-
the higher efficiency and/or the downsizing are preferred or trol are mentioned in each section. Through the review of the
required. Thanks to the progress of the power semiconduc- recent innovative applications, future progress of the ac mo-
tor devices technologies in these 20 years, such as the IGBTs tor variable drive system is discussed in the last part of the
in 1990’s and SiC devices in 2000’s, power electronics tech- paper.
nologies have been expanding their application fields. The
2. Applications for More Precise Torque and
progress of the power electronics also promotes the applica-
Speed Control
tion or variable speed ac motor drive technologies.
Ac drive systems provide the various engineering benefits 2.1 Principal of More Precise Torque and Speed Con-
compared with the other measures to obtain the mechanical trol of the AC Drive System Torque of electrical mo-
force. Figure 1 shows that technical features and benefits of tors principally can be controlled more precisely than the one
of internal combustion engines can be done because the cur-
a) Correspondence to: Keiichiro Kondo. E-mail: kkondo@faculty. rent and flux is easier to control. Thanks to the field-oriented
chiba-u.jp control and the brush less structure, ac motor drive systems
∗
Engineering Dept., Graduate School of Chiba University
1-33, Yayoi-cho, Inage-ku, Chiba 258-8540, Japan can provide higher torque response than dc motor drive sys-
∗∗ tems. The higher torque control capability can improve the
School of Science and Technology, Meiji University
1-1-1, Higashi-mita, Tama-ku, Kawasaki 214-8571, Japan speed control capability and can provide additional technical


c 2012 The Institute of Electrical Engineers of Japan. 132
 Innovative Application Technologies of AC Motor Drive Systems（Keiichiro Kondo et al.）

Fig. 1. Technical features of variable speed AC motor drive systems and their applications

Fig. 3. Electric active stabilizer suspension system (5)

Fig. 2. Configuration of electric variable valve timing

control system (2)
drive can open and close the intake and exhaust valves at the
optimal timing for each, independent from the engine crank
benefits. shaft angle and speed. Thus, the engine output power is en-
2.2 Large Scale Servo Drive for Electric Press Ma- hanced in wider speed range than the one of the conventional
chines Large scale electric press machines, for instance mechanical variable valve timing system. These functions
for producing automobile parts, can enhance the press force are achieved by the feature of the higher power density of
and improve their controllability by applying a 100 kW class the electric motor and higher controllability of the ac servo
servo drive system and a wheel with high inertia. The electric system.
press machines are able to control the press force and speed An electric active stabilizer suspension as shown in
more precisely than the hydraulic press machines. These fea- Fig. 3 (3) , is another application of servo controllers for the
ture enable to reduce the noise and vibration during the press automobile. The torsion torque is controlled by an ac servo
process with precisely controlling the press force (1) . By com- motor to reduce the roll angle of the vehicle body, which
bining with a wheel with higher inertia, the electric press ma- enhances the drivability and improve the stability of the car
chine can process the material which is hard to be processed body during the vehicle’s curving.
with higher precision. Test benches such as the dynamometers (4) are examples of
2.3 Servo Controls and Precise Torque Controls for precise torque control for the automobile. In the applications,
Automobile Applications In addition to the electrical the current control system has a dynamic range of 1500 Hz
propulsion system of the pure electrical vehicles or hybrid by compensating the time lag in the current regulator (5) . This
electric vehicles, ac motor servo controls are applied to the feature enables to emulate the engine motion caused by the
auxiliary equipments of the conventional type automobiles combustion.
with internal combustion engine. One of the examples is 2.4 Torque Control Method under the Limited Cur-
an electric variable valve timing control system, as shown rent and Voltage In the application field of ac variable
in Fig. 2, for an internal combustion engines (2) . A down sized speed drive, their operational ranges are enlarged in higher
IPMSM is installed on the axle of the cam shaft. The ac servo torque and higher speed both. Thus, more torque is required

133 IEEJ Journal IA, Vol.1, No.3, 2012

 Innovative Application Technologies of AC Motor Drive Systems（Keiichiro Kondo et al.）

Fig. 4. Voltage waveform of PWM and single-pulse

modes (7)

even in higher speed range. Higher inverter output voltage

and optimized field weakening control are effective to en-
hance the torque performance in the higher speed range. As Fig. 5. System configuration of the propulsion system
for an icebreaker ship (11)
an example of the former case, single-pulse mode has been
applied to the railway vehicle traction inverters to drive both
induction motors and PMSMs for the sake of reducing the
switching loss (6) . Though this is originated from the railway
vehicle traction application, the single plus mode (rectangu-
lar wave mode) is applied to a hybrid automobile traction,
as shown in Fig. 4 (7) , mainly to enhance the output voltage
of the inverter. As examples of the latter cases to enhance
the torque in higher speed range, several methods have been
proposed, mainly for the PMSM drive systems (8)–(10) . In all
methods, the induced voltage of the amateur reaction is con-
trolled in principal to maximize the reluctance torque under
the limited voltage condition.
Fig. 6. System configuration of the electrical power
3. Applications for Downsizing and Higher steering (14)
Power Density
3.1 Principal of the Downsizing and Higher Power the reliable ac motor drive system is much benefit on the ap-
Density of the AC Motor Drive System The electrical plications.
motor principally can generate mechanical power by the in- 3.3 Electric Power Steering For automobile steering
teraction between the current and the flux. The energy con- systems, the hydraulic power steering are utilized for con-
version is carried out in more narrow space than internal com- ventional power steering systems. Electric pumps are ap-
bustion engines. The density of the transmitted power by plied to some hydraulic power steering systems to obtain the
electric wires is much higher than the hydraulic or pneumatic pressured oil (13) . In electric power steering (EPS) systems,
hoses can transmit. In addition, the arrangement of the drive steering angle is amplified by brushless dc motors (14) . The
shafts limits the construction of drive trains and the transmit- EPS features more down sized and more energy efficient than
ted power is limited either by the hydraulic or mechanical the conventional hydraulic power steering systems. Figure 6
transmission. Electrical drive system provides more freedom shows a column assist type EPS, which does not need any
of the arrangement of the drive train thanks to the flexible additional equipment such as an oil pump or a pressured oil
power transmission by the electric cables and higher power supply hose. Recently developed EPS does not performs only
density of the electric motors. Especially, ac motor drive sys- a steering torque booster but an actuator to stabilize the ve-
tems have the more benefits than the dc drive system thanks hicle motion and assist car’s following the running lane (15) .
to the brushless structure and three phases ac power feeding. As for stabilization of the car body motion, variable gear ra-
3.2 Electric Ship Propulsions The arrangement of tio function can changes the steering angle of front wheels
the ship propulsion equipments onboard becomes more flexi- against the steering wheel angle for the further more stable
ble by the electrical propulsion system. Figure 5 shows a sys- motion of car body. Steering assist control is studiedto se-
tem configuration of the propulsion system for an icebreaker cure the safely steering even if a motor cable fails in some
ship (11) . ac drive system enables more precise torque control phase (16) . The motor torque ripple and the cogging torque are
and can avoid the rush current at the ship starting by the field- evaluatedon EPSs design because drivers’ feeling of steering
oriented control in the whole speed range (12) . This results in is important (17) .
cutting the power margin for the rush current of the main mo- 3.4 Elevator Applications Small-sized elevators are
tor and optimize the rated power of the traction equipment in- increasingly installed for residential homes, train passengers
cluding the generator, traction circuit and main motors. In the at stations, and pedestrians in midtown. In some cases, el-
case of the ship for the special mission such as an icebreaker evators are additionally installed while the facilities are in
for the southern polar observatory trip, high redundancy with services. Some buildings do not have enough space to make

134 IEEJ Journal IA, Vol.1, No.3, 2012

 Innovative Application Technologies of AC Motor Drive Systems（Keiichiro Kondo et al.）

Fig. 8. Configuration of a diesel engineand Litium-ion

battery hybrid traction system for rail car (19)

Fig. 7. Down sized PMSM drive system installed at el-

evator

machine rooms for the motors and inverters. In such cases,

PMSMs drive system is preferable to be designed very thin Fig. 9. Traction and auxiliary equipments onboard a hy-
and small and is installed in the same room of the moving brid diesel railcar
cage, as shown in Fig. 7 which is an elevator for pedestrians
in midtown. PMSMs can increase the current density in the The hybrid traction system is so-called series hybrid system
stator winding, compared with induction motors under the as shown in Fig. 8 (19) . Series hybrid system has advantages
same thermal design. PMSMs can be designed with less vol- against the parallel hybrid system (20) such as more regener-
ume of the iron core by reducing the flux. More torque is ative brake and less maintenance work due to eliminating a
expected in interior permanent magnet synchronous motors hydraulic transmission and a reduction gear. As shown in
(IPMSMs) than surface permanent magnet synchronous mo- Fig. 9, the series hybrid rail car installs more traction and aux-
tor (SPMSMs), because of the reluctance torque in addition iliary equipments under floor than conventional rail cars with
to the PM torque. These result in increasing the efficiency of diesel motive units. Compact and light variable speed ac mo-
the PMSM and inverter both, by reducing current of IPMSM tor and generator system contributes the critical installation
at the same torque as SPMSM. By utilizing the reluctance of the equipments in the limited space.
torque of IPMSM, the size of the system including control 4.3 Large Scale Industrial Drive System In natural
board, inverter and PMSM is reduced with 42% of their vol- gas plants, compressors are originally driven by gas turbine
ume (18) . engines, which requires more space to be installed, and fre-
quent and long maintenance work. Large scale induction mo-
4. Applications for Higher Availability and Main-
tor drive systems, for instance 100 MW class, are recently ap-
tenancebility
plied to drive compressors to cope with these problems with
4.1 Principal of the Higher Availability and Mainte- the gas turbine engines (21)–(24). Voltage source inverters are
nancebility with AC Drive Systems Mechanical energy introduced to drive such size motors, instead of load com-
conversion system including internal combustion engines, muted type inverters. Figure 10 shows a circuit configuration
hydraulic motors, hydraulic transmissions, and pneumatic ac- of large scale five-level inverter drive system, with three sets
tuators, sometimes needs periodical inspection and mainte- of star connected full bridge single phase 3 level inverters
nance because they have frictional moving parts which are with GCTs, which works as a nine-level inverter across the
easy to be worn and oil seal parts which are easy to leak line-to-line voltage. The specifications of a single inverter
for oil. Electrical drive systems including variable speed ac are 7200 V-2400 A-30 MVA and three of the inverters with
motor drive systems require almost no inspections and less 120 VA are for a motor. Water cooled system is applied to
maintenance. Therefore, they can be more reliable or less the inverter and its efficiency is 98.6%. The power density
chance of failure. This is originated from the principal that reaches 1 MW/m3 . Wave forms of a line to line voltage and a
the contactless electro-magneto force is utilized for electrical phase current is shown in Fig. 11. Almost perfect sinusoidal
and mechanical energy conversion. Thus, internal combus- current wave is achieved, which contributes significantly to
tion engines or hydraulic actuators are replaced by ac motor reduce the harmonics loss and EMC problems, and leakage
drive systems in some application fields to reduce the main- current. This kind of motor drive system is achieved thanks to
tenance work and to increase the reliability. With the recent the evolution of power electronics and provides more reliable
improvement of reliability of the power electronics, thanks large power scale motor drive system.
to IGBTs with the less loss and the simple drive circuit for Another variation of large scale motor drive system is
instance, ac variable speed drive systems expand their appli- the modular multi level (MMC) converter to drive fan or
cation field up to 100 MW class power range. pump (25) . Figure 12 shows a MMC circuit configuration,
4.2 Hybrid Diesel Rail Cars For the quite same sake which is originally applied to high voltage dc power trans-
of hybrid automobiles, a fleet of diesel engine and lithium- mission system. Each cell output zero voltage or vcu j and
ion battery railway cars are utilized for non-electrified lines. each phase voltage is 9 level output in this circuit. Lower

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 Innovative Application Technologies of AC Motor Drive Systems（Keiichiro Kondo et al.）

Fig. 12. Circuit configurations of MMC (25)

Fig. 10. Circuit configuration of 5 level inverter for

large scale drive in gas and oil industry (22)

Fig. 13. A experimental test result to start induction mo-

tor with MMC (26)

torque in the ultra-lower speed range including zero speed

and even in the reverse rotational condition. However, the
induced voltage of the fundamental frequency is very low or
zero in the speed region. Any additional information is re-
quired to estimate the angle or speed based on the current or
Fig. 11. Output voltage and motor current of 5 level in- voltage information. For induction motor, a mechanical sim-
verter for large scale drive in gas and oil industry (23)
ulator which calculates the rotor frequency based on the me-
chanical rotational equations is proposed to start the railway
ac voltage with lower frequency, including dc voltage is im- vehicle at zero speed (27) . The equivalent V/f ratio is regulated
possible or hard to output in this circuit because the capacity along with the inertia and motor calculated torque based on
of a capacitor in each cell is limited. To cope with the such the torque current. As shown in Fig. 14, an experimental test
problem in variable speed ac motor drive, a method to start result is presented in which a railway vehicle can start even
induction motor with reducing the capacitor voltage to out- under the 200% of the rated load condition (28) .
put lower phase voltage as shown in Fig. 13 (26) . AC variable As of IPMSMs, harmonics current or voltage injection is
motor drive system with this circuit configuration promotes utilized for traction application for instance (29) . However the
reliability and availability in large scale industrial drive sys- noisy sound due to the injected harmonics current comes a
tems. problem to deteriorate the comfort of passengers. In addition
4.4 Sensorless Motor Drive for Traction Applications to the harmonics injection, a method to estimate pole posi-
In railway vehicle and automobile traction applications, tion without harmonics voltage or current injection is pro-
speed or angle sensorless drive system can provide more reli- posed for IPMSMs at lower speed range (30) . In this method,
able and less maintenance systems. In addition the sensorless differentiated stator current is detected while inverter output
drive systems can be more down sized in the limited motor the zero voltage vector (31) . Utilizing the change of current is
installation spaces. To drive inertial loads requires the higher principally reasonable to detect the rotor angle information at

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 Innovative Application Technologies of AC Motor Drive Systems（Keiichiro Kondo et al.）

Fig. 16. An experimental tests result of IM starting at

acoasting condition (33)

Fig. 14. An experimental result of IM starting with the

mechanical simulator. (28)

Fig. 17. An experimental test result of PMSM starting

at a coasting condition (34)

Fig. 15. An experimental test result of PMSM drive

rotor speed information is required to establish the rotor flux.
with lower noise harmonics injection (32)
Initial rotor speed estimation method with the punctual lin-
earized method is introduced to design the controller system-
lower speed range because the current of the fundamental fre- atically (33) . Figure 16 shows an experimental test result with
quency component reflect any rotor information. In the case a 1.5 kW rated induction motor to estimate the initial rotor
of injecting the harmonics current, less injected current can speed. In the case of PMSMs, the inverter output voltage vec-
prevent the noisy sound, but deteriorate the stable rotor angel tor must be close to the PM induced voltage vector to avoid
estimation, especially at the transient of the motor current. A over current at the gate start under the rotor rotating condi-
method to control the injected voltage to the IPMSM is pro- tion. Three phase short circuit current vector is utilized to
posed to reduce the noise (32) . The harmonics voltage is con- estimate the induced voltage vector angle to output the cor-
trolled according to the fundamental frequency component of rect inverter voltage vector. The short circuit current vector is
stator current error and amplitude of the harmonics injected generated by outputting zero voltage vector of the inverter in
current. In Fig. 15, the proposed method successfully reduces several ms duration (33) . Detected short circuit current vector
the noisy sound and the angle estimation properly work. has error due to the delay of the control period. To compen-
The inverter starts switching operation in the motor rotat- sate the error, rotor speed is calculated by the two intervals
ing condition without any initial rotor speed or angle infor- of short circuit vector angles. When the short circuit current
mation, because the inverter operation halts during the ve- vector 1, 2, and 3 are generated in Fig. 17, differences among
hicles coasting to save the inverter and the motor loses. As their angles are detected to estimate the induced voltage vec-
of induction motors, rotor speed can be principally estimated tor angle and the estimated rotor speed Nest can follow real
with the rotor flux induced voltage. On the other hand, the rotor speed Nreal properly.

137 IEEJ Journal IA, Vol.1, No.3, 2012

 Innovative Application Technologies of AC Motor Drive Systems（Keiichiro Kondo et al.）

Fig. 18. Cut model of a 160 kW rating IPMSM for a Fig. 19. A system configuration of a hybrid excava-
HEV tor (35)

5. Energy Savings and Load Leveling Applica-

tions
5.1 Principal of Energy Savings and Load Leveling by
Application of AC Drive Systems Regenerative opera-
tion is one the most advantage of the electrical and mechan-
ical energy conversion by electric motors. This feature con-
tributes to save the consuming energy and to reduce the main-
tenance work of mechanical drive system, especially when
driving inertial loads, such as automobiles, railway vehicles
Fig. 20. Hybrid shunter locomotive type HD300
and elevators. In addition, recent enhancement of energy
storage devices, such as batteries and electro double layer ca-
pacitors (EDLCs), increases the effect of the energy savings EDLC is connected to dc link circuit. This is a quite similar
and of leveling peaky load powers. Variable speed ac mo- configuration of the ones for rail cars shown in Fig. 8. This
tor drive systems are most increasingly applied to the fields configuration in the hybrid loader can improve the power
which are driven by internal combustion engines such as au- conversion efficiency from the engine output power to the
tomobiles, diesel locomotives and ships. The downsized and wheel output power by eliminating the hydraulic transmis-
higher power density features of ac motor drive systems also sion. EDLCs charge the kinetic energy of the loader by the
promote their application in these filed. regenerative brake. The changed energy in EDLCs assists
5.2 Automobile Traction and Other Ground Vehicles the output power of the engine generator to save both the fuel
Applications For traction motors of the plug-in elec- consumption and engine output power. The replacement of
tric vehicles (PEVs) and hybrid electric vehicles (HEVs), the hydraulic drive system by a variable speed ac motor drive
IPMSM, as shown in Fig. 18, is mainly utilized due to their system can improve the energy efficiency and save the fuel
down sized and high efficiency features. The field weaken- consumption.
ing ratio is as three times high as the rated speed. The field 5.3 Railway Shunter Locomotives Application In
weakening control and single pulse mode is applied as men- addition to the hybrid rail car described in section 4.1, series
tioned in section 2.4. Basic control strategy is same as the one diesel engine and battery hybrid traction system is applied to
for the railway vehicle traction with starting by the constant a shunter locomotive too, as shown in Fig. 20, which switches
torque and field weakening control in the middle and higher freight cars at freight train stations (36) . The system configura-
speed range. The load profiles for automobile are more un- tion is quite same as the one for the rail car in Fig. 8, besides
predictable and the dc voltage of the batteries changes wider the engine output power and the battery energy. This sys-
than the case of the railway vehicle traction. These must be tem aims at load leveling for the diesel engines including the
considered to determine the electrical and mechanical speci- idle stop, because the load profile of the shunter locomotives
fications of the motors for electric vehicles. is unpredictable and sometime the shunter locomotive must
Similar applications are hybrid excavators and hybrid keep a stand by status for the possible work load. Thus, the
wheel loader. Hybrid excavators recover the kinetic energy load leveling contributes to cut much fuel consumption and
of the turning upper structure by the generator and EDLCs, much emission, and reduce the noise to start the locomotive.
as shown in Fig. 19. The regenerated energy is used to as- 5.4 Hybrid Turbo Charger for Ship Propulsion A
sist the engine output power. This results in cutting 25–41% hybrid turbocharger is applied to the large scale ship propul-
of fuel consumption compared to conventional hydraulic ex- sion application. A permanent magnet synchronous gener-
cavators (35) . A hybrid wheel loader is equipped with a se- ator (PMSG) is directly mounted on the turbine axle of the
ries hybrid traction system, in which output power of diesel turbo charger, as shown in Fig. 21. The generator is driven
engine generator converted to dc power by a diode rectifier by the exhaust gas energy of the diesel engine. The PMSG is
and the dc power is used to drive ac motors by a inverter. a water cooled type 745 kW-9000 min−1 rating. The PMSG

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 Innovative Application Technologies of AC Motor Drive Systems（Keiichiro Kondo et al.）

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ac motor drive systems are increasingly applied to the field verter for the elevator driveL1000A”, Yasukawa Technical Review, Vol.73,
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by the evolution of the structural aspect itself for instance ( 19 ) M. Shiraki, H. Sato, and S. Arai: “A hybrid system for diesel railcar se-
ries Ki-Ha E200”, Proceedings of International Power Electronics Confer-
higher power density and lower loss of ac motors and invert- ence (IPEC), 2010, pp.2853–2858 (2010)
ers. In addition, the restriction of the electrical power feed- ( 20 ) H. Ihara, H. Kakinuma, I. Sato, T. Inaba, K. Anada, M. Moromoto, T. Oda,
ing is released than before thanks to the higher performance S. Kobayashi, T. Ono, and R. Karasawa: “Development of Motor-Assisted
Hybrid Traction System”, Record of World congress of Railway Research
of energy storage devices for instance, Lithium-ion batteries.
(WCRR) 2006 (2008-5)
From these facts, variable speed ac motor drive systems must ( 21 ) H. Hosoda and S. Peak: “Multi-Level Converter for Large Capacity Motor
be enhanced in the simple structure, the cost reduction, and Drive”, IPEC2010, pp.516–522 (2010)
the higher performance to be an essential components as sub- ( 22 ) D. Yoshizawa, K. Takao, M. Mukunoki, and Y. Shimomura: “The large Ca-
pacity 5 level GCT Inverter for OIL & GAS plant application”, Proceedings
system in the application systems in near future. on JIASC 2008, No.1-79 (2008) (in Japanese)
( 23 ) M. Nakamura, M. Tsukakoshi, and K. Hashimura: “Redundancy System for
Continuous Driving Large Motor Drive Equipment”, Proceedings of Interna-
tional Power Electronics Conference (IPEC), pp.2527–2530 (2010)
( 24 ) M. Tsukakoshi, M.A. Mamun, K. Hashimura, H. Hosoda, and S.C. Peak:

139 IEEJ Journal IA, Vol.1, No.3, 2012

 Innovative Application Technologies of AC Motor Drive Systems（Keiichiro Kondo et al.）

“Introduction of a Large Scale High Efficiency 5-level IEGT Inverter for Oil Excavator: Hybrid Evolution Plan for Construction Equipment”, http://www.
and Gas Industry”, ECCE 2010, pp.4313–4320 komatsu.com/CompanyInfo/press/2008051315113604588.html (2012-2)
( 25 ) M. Hagiwara, K. Nishimura, and H. Akagi: “A Medium-Voltage Motor Drive ( 36 ) T. Soeda, N. Terauchi, H. Nitta, G. Sugiyama, and T. Ogawa: “Development
with a Modular Multilevel PWM Inverter Part.I Experimental Verification of a Hybrid Shunting Locmotive”, The Proceedings on the 17th United Sym-
by a 400-V, 15-kW Down scaled Model”, IEEJ Trans. IA, Vol.130. No.4, posium on Railway Technologies (J-RAIL2010), No.SS3-2-2, pp.401–404
pp.544–551 (2010) (2010-12) (in Japanese)
( 26 ) M. Hagiwara, K. Nishimura, and H. Akagi: “A Medium-Voltage Motor Drive ( 37 ) K. Shiraishi, Y. Ono, and K. Sugishita: “Development of Large Marine Hy-
with a Modular Multilevel PWM Inverter Part.II Startup Method and Perfor- brid Turbochargerfor Electric Power Generation by Exhaust Gas from Main
mance”, IEEJ Trans. IA, Vol.130, No.4, pp.552–559 (2010-4) Engine”, Mitsubishi Heavy Industries Technical Review, Vol.47, No.3
( 27 ) T. Homma, S. Wakao, H. Shibuya, K. Kondo, Y. Sato, and T. Furuya:
“A Stability Analysis of the Mechanical Simulatorfor Induction Motor
Speed Sensor-less Controlin Ultra Lower Speed Range”, Proceedings of the Keiichiro Kondo (Senior Member) received B.S. and Ph.D. in the fac-
Eleventh IEEE Workshop on Control and Modeling for Power Electronics
ulty of electrical engineering, department of science
(COMPEL 2008), (USB Memory), COM220 (2008)
and technology, of Waseda University in 1991. He
( 28 ) K. Kondo and K. Yuki: “Study on an Application of Induction Motor Speed
entered Railway Technical Research Institute in 1991
Sensor less Controlto Railway Vehicle Traction”, IEEJ Trans. IA, Vol.125-D,
No.1, pp.1–8 (2005) (in Japanese) and 2000 respectively. Since 2007, Dr. Kondo is an
( 29 ) H. Kawai, T. Sunohara, Y. Tasaka, and S. Fukasawa: “Permanent-Magnet associate professor of electrical and electronic engi-
Synchronous Motor Propulsion System for Tookyo Metro Ginza Line neering course of graduate school of Chiba Univer-
Trains”, Toshiba Review, Vol.63, No.6, pp.46–49 (2009) sity. His research interest is power electronics, AC
( 30 ) Y. Shibano and H. Kubota: “Pole Position Estimation Method of IPMSM at motor drive, and their application to the railway vehi-
Low Speed without High Frequency Components Injection”, The IEEE Ap- cle traction. Dr. Kondo is a member of the Institute
plied Power Electronics Conference and Exposition (APEC 2009) of Electrical Engineers of Japan. He is also a member of the IEEE Industry
( 31 ) Y. Hosogaya and H. Kubota: “Consideration about Zero-Speed of Pole Po- Applications, Industrial Electronics, and. He is a Dr.Eng. and Professional
sition Estimation Method of IPMSM without High Frequency Components Engineer Japan (Mechanical Engineering, Technical Management).
Injection”, Proceedings on JIASC 2009, pp.I-605–606 (2009) (in Japanese)
( 32 ) S. Taniguchi, T. Honma, S. Wakao, K. Kondo, and T. Yoneyama: “Con-
trol Method for Harmonics Voltage Injection to Achieve Noise Reduction in Hisao Kubota (Senior Member) received the B.E., M.E., and Ph.D.
Position—Sensorless Control of Permanent-Magnet Synchronous Motors at degrees in electrical engineering from Meiji Univer-
Low Speeds”, IEEJ Trans. IA, Vol.129-D, No.4, pp.382–388 (2009)
sity, Japan, in 1982, 1984, and 1989, respectively.
( 33 ) S. Taniguchi, S. Mochiduki, T. Yamakawa, S. Wakao, K. Kondo, and T.
Since 1984, he has been a member of the faculty at
Yoneyama: “Starting Procedure of Rotational Sensorless PMSM in the Ro-
tating Condition”, IEEE Trans. IA, Vol.45, pp.194–202 (2009)
Meiji University, where he is currently a Professor.
( 34 ) S. Taniguchi, K. Yasui, K. Yuki, and Y. Nakazawa: “A Free-run Startup His research interests are in motor drives. Dr. Kubota
Method for Position Sensorless PMSM”, Proceedings on Technical Meeting is a member of the Institute of Electrical Engineers
of Motor Drive, Rotating Machineryand Semiconductor Power Conversion, of Japan. He is also a member of the IEEE Industry
RM-10-057. SPC-10-070. MD-10-002, pp.7–12 (2010) Applications, Industrial Electronics, and Power Elec-
( 35 ) Komatsu News release: “Komatsu Introduces the World’s First Hydraulic tronics Societies.

140 IEEJ Journal IA, Vol.1, No.3, 2012