Yasushi Hyakutake

Inverter improving motor efficiency of switched reluctance motor for electric vehicle

This paper proposes the new inverter topology which improves the motor efficiency of switched reluctance motor (SRM) for electric vehicle (EV). The SRMs generate the regenerating power even in motoring mode, and the regenerating power flows in both directions of battery and coils. The proposed inverter I - IV can control the flows of regenerating power to improve the motor efficiency.

Verification of operating principle of Flexible Linear Actuator

Linear motors have limitations for applications because linear motors are developed to apply for operations of rectilinear motion. Then, Flexible Linear Actuator (FLA) was proposed to enlarge the application field by giving it flexibility. The electric propulsion was small because the prototype of FLA was small, and it was difficult to compare the analytical and experimental electric propulsions. Therefore, the operating principle has not been verified. In this paper, the new experimental model is constructed to increase the electric propulsion and make the measurements easy. And, the experimental results are compared with the results calculated with the finite element method software (ANSYS) to verify the operating principle of FLA.

Improvement of efficiency of switched reluctance motor by single pulse control based on linear torque equation

The three magnetization modes in which the magnetization region is shifted according to load based on a linear torque equation are proposed. Efficiency comparison test of the proposed method and a voltage PWM control method is conducted with a real system.

Overvoltage suppression of SRM inverter for effective use of regenerative power

This paper proposes inverter circuit with snubber circuit to suppress the overvoltage of inverter circuit I which can use regenerative power effectively to improve the efficiency. And the effect of overvoltage suppression is verified. Furthermore, the influences of excitation angle and resistance are analyzed by simulation results using MATLAB Simulink. The proposed inverter suppresses the overvoltage by moving regenerative power to the battery with snubber circuit and to the coil of next excitation phase in next phase excitation. However, because of one part of regenerative power return to the battery, the efficiency of proposed circuit is lower than inverter circuit I (1). Therefore, how to suppress overvoltage and maintain improved efficiency are important for this research.

Trial manufacture of SRM drive system for electric vehicles

In past 20 years, many countries are facing the crisis of energy shortage and environment pollution problems due to the large usage of gasoline vehicles. In order to improve the present situation, the design and manufacture of pure electric vehicles have been becoming to mainstream of the development of automobile industry in the world. High efficient switched reluctance motor (SRM) for electrical vehicle (EV) has been developed, then the car body which is equipped with the high efficient SRM is manufactured. This work proposes the SRM drive system using FPGA-based controller. Also the manufactured small EV using the proposed SRM drive system is tested, and the test results are presented.

Study on Increase in Propulsion of Flexible Linear Actuator

Linear motors have limitations for applications because linear motors are developed to apply for operations of rectilinear motion. Then, The Flexible Linear Actuator (FLA) has been proposed to enlarge the application field by giving it flexibility. The electric propulsion was small because the prototype of FLA was small, and it was difficult to compare the analytical and experimental electric propulsions. Therefore, the operating principle has not been verified. In this paper, the new experimental model is constructed to increase the electric propulsion and make the measurements easy. And, the experimental results are compared with the results calculated with the finite element method software (ANSYS) to verify the operating principle of FLA.