Back: Kawamura Lab

Train's Adhesive Control
There exists a slip phenomena between the rail and train's wheel caused by friction. The speed difference between driving wheel and train is called slip speed. In general, the train's tractive force (or saying adhesive force) reaches peak at one slip speed.
This characteristic is used to keep the adhesive force to be maximum with motor control. This approach is called the maximum adhesive force control. As a result, the train can run faster.
(Click here for detail)

Line-Current Detection Type Active Filter
Current and voltage harmonics ithat have component frequency of the signal that is an integral multiple of the fundamental frequencyj generated in power electronics systems may cause serious damages to any electrical equipment.

AF (Active Filter) is a device that eliminate (or saying compensate) the harmonics. With it, the supply of clean electric power is possible.
Line-Current Detection Type Active Filter is being studied that is independent from the load's number. (Click here for detail)

(Click here for movie)

Traction Control
The slip is very easily happened and therefore it is difficult to start and accelerate a car on the low friction road such as wet road. Traction control is to depress the slip and make the car be able to be accelerated fastly.
Since EV has the high torque responsibility, traction control can be implemented with low cost but high performance.

This EV is reconstructed based on JIMNY. Inverter and control devices are in its bonnet; batteries are in its rear part; the motor is directly connected with center shaft. The car is 4WD.
Since ADTR-Motor is used, there is no center differential gear. (Click here for detail)

ADTR Motor (Anti-Directional-Twin-Rotatory Motor)
This kind motor has two rotors, an inner rotor and an outer rotor. Two rotors rotate in inverse direction but with same torque by "action and reaction". The motor can be used for EV without differential gear.
(Click here for detail)

Stepping Motor
This kind motor is widely used for position control. The research objective is to enhance the motor's high reliability and stability.

New Concept Motor
This motor has multiple rotors and is driven by compound multi-phase AC. It can be considered to have good transmission efficiency, therefore it is expected to be used to HEV (Hybrid EV) in a near future.
The research is focused on theoretical analysis and developing new control method.

Independent Control of UPS
UPS is a device that is inserted between a primary power source, such as a commercial utility, and the primary power input of equipment to be protected, e.g., a computer system, for the purpose of eliminating the effects of transient anomalies or temporary outages.
Independent control is being studied , in which, different from the conventional master-slave control mode, multiple UPS are independent from each other and work stably.
(Click here for detail)

Estimation of Battery Remaining Capacity
The remaining capacity estimation method of batteries used for EV is being studied.