Masayuki Terashima

Novel motors and controllers for high-performance electric vehicle with four in-wheel motors

We have, in accordance with new concepts, undertaken the development of a high-performance electric motor vehicle, designated as the IZA. The main performance features of the IZA are a maximum speed of 176 km/h, a range of 548 km per charge at a constant speed of 30 km/h, and acceleration from 0 to 400 m in 18 s. We have developed a direct driving in-wheel motor and controller in order to achieve high performance characteristics. The in-wheel motor is composed of an outer rotor with a rare earth permanent magnet (Sm-Co) and an inner stator. The motor drive controller consists of a three-phase inverter and a microprocessor-based controller. The maximum output and maximum torque of each total drive system, including motor and inverter, are 25 kW and 42.5 kg/spl middot/m, respectively, and the total efficiency of the drive system is over 90% at the rated speed. The performance of the motor, controller, and drive system have been confirmed by numerous simplex and vehicle transit tests. This paper describes the design concepts, configuration, and performance of the motor, controller, and drive system developed for this high-performance electric vehicle.

Decoupling Control of Secondary Flux and Secondary Current in Induction Motor Drive with Controlled Voltage Source and Its Comparison with Volts/Hertz Control

A concept of decoupling control in the strategy of the speed regulation of the squirrel cage induction motor with controlled voltage source is represented. The decoupling control intends to cancel out the cross terms between the secondary flux and the secondary current. Three necessary and sufficient conditions for the decoupling control are offered that correspond to taking into account the effect of the primary impedance in the control strategy. Phase lead compensation with the slip frequency control allows the realization of the decoupling control, which is found to be an extension of both the conventional vector control and the constant volts/hertz control. Numerical and experimental results are also shown.

A high response induction motor control system with compensation for secondary resistance variation

A high response digital speed control system for the induction motor drive, which is based on the decoupled control method, has been developed. This control system can compensate the error of the time constant caused by the variation of temperature in the secondary circuit of the induction motor. This paper presents the principle of the control system and experimental results and discusses the compensation for the error of the secondary time constant.

Decoupling torque control system for automotive engine tester

This paper presents a novel decoupling control method for the engine torque control of an automobile engine tester. The engine tester is mainly composed of a dynamometer control system and an engine control system. The conventional engine tester has the problem that the performance of the engine torque control system is deteriorated by the influences of the interference between the dynamometer speed control system and the engine torque control system. The authors proposed the practical engine torque control system based on an observer and an identification system to eliminate the interference of the dynamometer speed control system. The effect of observers parameter error on the engine torque estimation response was analyzed. According to the result of this analysis, a practical method is proposed to identify the engine inertia moment and the shaft spring coefficient that are parameters of the observer. The authors confirmed through simulation and experiments that the proposed decoupling engine torque control system realizes a robust control system from the interference with the dynamometer speed control system.

Velocity measurement using phase orthogonal spatial filters

The authors developed a velocity measurement system based on a spatial filtering method. A charge coupled device (CCD) line sensor was used to detect the object pattern, and a DSP (TMS32025) performed the spatial filtering calculations. Because the selectivity of the spatial filter was fixed, the measurement accuracy of this approach is generally influenced by the condition of the object pattern. A method that improves the accuracy of the velocity measurement by using two pairs of spatial filters with phases orthogonal spatial weighing functions was developed. The new method of velocity measurement is described with some experimental results. >

High-performance automotive engine control in engine tester

This paper presents a novel decoupling control method on the engine torque control for the automotive engine tester. The engine tester is mainly composed of a dynamometer control system and an engine control system. The conventional engine tester has the problem that the performance of the engine torque control system is deteriorated by the influences of the interference between the dynamometer speed control system and the engine torque control system. The authors proposed the practical engine torque control system based on an observer and an identification system to eliminate the inference of dynamometer speed control system. The effect of observers parameters error on the engine torque estimation response was analyzed. According to the result of this analysis, a practical method is proposed to identify the engine inertia moment and the shaft spring coefficient that are parameters of the observer. The authors confirmed that the proposed decoupling engine torque control system realized a robust control system from the interference with the dynamometer speed control system through simulation and experiments.

Novel motors and controllers for high performance electric vehicle with 4 in-wheel motors

The authors have, in accordance with new concepts, undertaken the development of a high-performance electric motor vehicle, designated as the IZA. The main performance features of the IZA are a maximum speed of 176 km/h, a range of 548 km per charge at a constant speed of 40 km/h, and acceleration from 0 to 400 m in 18 seconds have developed a direct driving in-wheel motor and controller in order to achieve high performance characteristics. The in-wheel motor is composed of an outer rotor with a rare earth permanent magnet (Sm-Co) and an inner stator. The motor drive controller consists of a 3-phase inverter and a microprocessor-based controller. The maximum output and maximum torque of each total drive system, including motor and invertor, are 25 kW and 42.5 kgm, respectively and the total efficiency of the drive system is over 90% at the rated speed. The performance of the motor, controller and drive system have been confirmed by numerous simplex and vehicle transit tests. This paper describes the design concepts, configuration, and performance of the motor, controller and drive system developed for this high performance electric vehicle.

Inertia-lowering control of motors

An inertia-lowering control system that uses a disturbance observer to apparently reduce inertia was developed. In order to realize this control with induction motors, vector-controlled induction motors and DC motors are compared, then equations and machine constants needed for designing systems were clarified. A digital signal processor and a microprocessor were adopted for induction motor control, and good results are obtained for the inertia-lowering experiment.<<ETX>>