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Author

Ikuo Yasuoka

Bio: Ikuo Yasuoka is an academic researcher from Toshiba. The author has contributed to research in topics: Inverter & Induction motor. The author has an hindex of 9, co-authored 41 publications receiving 367 citations.

Papers
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Patent
08 Feb 2006
TL;DR: In this paper, a variable voltage variable frequency inverter is used to suppress the sudden change of motor torque at short circuiting of a resistor, and minimizing the power consumption in the resistor, thereby suppressing the drop of regeneration percentage, and reducing the capacity of the resistor.
Abstract: PROBLEM TO BE SOLVED: To make an electric vehicle controller advantageous in terms of space and cost, by suppressing the sudden change of motor torque at short circuiting of a resistor, and minimizing the power consumption in the resistor, thereby suppressing the drop of regeneration percentage, and reducing the capacity of the resistor. SOLUTION: This electric vehicle controller is equipped with a variable voltage variable frequency inverter 3, which converts DC into AC of optional frequency, at least one induction motor 5 for drive of a vehicle which is connected in parallel with the side of the DC of the variable voltage variable frequency inverter 3; a resistor 6 which is connected in series between the variable voltage variable frequency inverter 3 and the induction motor 5; and a chopper 9, which is connected in parallel with the resistor 6 and has a switching function. When the voltage between the terminals of the induction motor 5 is higher than the output voltage of the variable voltage variable frequency inverter 3 at power regenerative brake or at power generating brake, this makes the circulation percentage of the chopper a first conduction ratio; and when it is lower than the output voltage, this makes the conduction ratio a second circulation percentage higher than the first conduction ratio. COPYRIGHT: (C)2004,JPO

109 citations

Proceedings ArticleDOI
03 Aug 1997
TL;DR: In this paper, the authors developed a re-adhesion control algorithm for a traction inverter system with vector control for commuter train applications, which consists of creep control, estimated traction force control, oscillation suppression control and all wheel slip suppression control.
Abstract: The authors developed a re-adhesion control algorithm for a traction inverter system with vector control for commuter train applications. The re-adhesion algorithm consists of creep control, estimated traction force control, oscillation suppression control and all wheel slip suppression control. As the result of the running tests with new control, the adhesion performance was improved by more than 20% and passenger comfort was greatly improved, regardless of the conditions of the rail, gradient and kind of rolling stock.

28 citations

Patent
21 Jun 2011
TL;DR: In this paper, a system and method for a vehicle control system is described, which includes an inverter circuit, a permanent magnet synchronous motor, and a crossover connected between the inverter and the motor.
Abstract: A system and method for a vehicle control system is disclosed herein. The system includes an inverter circuit, a permanent magnet synchronous motor, and a crossover connected between the inverter circuit and the permanent magnet synchronous motor. The system may also include at least one current sensor installed between the inverter circuit and the permanent magnet synchronous motor. A contactor may also be connected between the inverter circuit and the permanent magnet synchronous motor and may pass or shut off electricity between the inverter circuit and the permanent magnet synchronous motor. The system may also include a control unit connected to the contactor and the current sensor. The control unit may detect a current abnormality using information from the current sensor and open the contactor if an abnormality is detected.

27 citations

Patent
14 Oct 2003
TL;DR: In this paper, the authors proposed a gate command calculator for reducing the noise generated by a main electric motor while the car is running at high speed, which is made up of an inverter 1 that converts DC into AC, the main electric motors 3 connected to the AC side of the Inverter 1, inverter output frequency calculating portions 11, 13, 14 that calculate the output frequency of a voltage that is outputted by the inverter, an output voltage calculating portion 5 that calculates the value of the voltage outputting by the Inverster 1.
Abstract: PROBLEM TO BE SOLVED: To provide an electric car controlling device capable of reducing noise that arises from a main electric motor while the car is running at high speed. SOLUTION: This electric car controlling device is made up of an inverter 1 that converts DC into AC; the main electric motor 3 connected to the AC side of the Inverter 1, inverter output frequency calculating portions 11, 13, 14 that calculate the output frequency of a voltage that is outputted by the inverter 1, an inverter output voltage calculating portion 5 that calculates the value of the voltage outputted by the inverter 1, and a gate command calculator 9 that generates a gate command of the inverter 1 based on the frequency and the value of the voltage outputted by the inverter 1. In this device, the gate command calculator 9 is provided at least with one-pulse control unit 25 that outputs one pulse every half cycle of sine waves, and comprises a one-pulse control limiting means (a control mode selecting portion 29) that prohibits the execution of the one-pulse control under a prescribed condition. COPYRIGHT: (C)2005,JPO&NCIPI

22 citations

Patent
27 Nov 2001
TL;DR: In this article, an electric rolling stock controller performs adhesion control which regulates torque if detecting slipping or skidding of a drive shaft wheel, and later restores the torque by calculating the maximum value of slipping velocity of the wheel relative to a rail based on the vehicle velocity estimated from the rotational-speed signal of a motor.
Abstract: PROBLEM TO BE SOLVED: To improve acceleration of a vehicle and comfortableness in ride by reducing frequency of occurrence of slipping/skidding of a drive shaft wheel. SOLUTION: The electric rolling stock controller performs adhesion control which regulates torque if detecting slipping or skidding of an electric rolling stock, and later restores the torque. It monitors slipping or skidding of the drive shaft wheel, and if it detects the slipping or skidding, it calculates the maximum value of slipping velocity of the drive shaft wheel relative to a rail based on the vehicle velocity estimated from the rotational-speed signal of a motor and the rotational-speed signal of the motor. The adhesion factor is acquired from a pre-set function Y=-AX+B (A and B are constants) in which X is maximum slipping velocity and Y is adhesion factor. A drive torque is regulated if slipping or skidding is detected. When calculating a target value to which the drive torque is later restored, the target value to which a torque is restored is raised if the adhesion factor is large, while the target value to which the torque is restored is made smaller if it is small. COPYRIGHT: (C)2003,JPO

21 citations


Cited by
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Patent
09 Feb 2011
TL;DR: In this article, a power conversion device includes a power switching circuit that supplies AC voltages generated between switching elements operating as upper and lower arms, and a control circuit that generates and supplies to the driver circuit signals for controlling the switching operation of the switching elements by a PWM method in a first operational region in which frequency of an AC power to be outputted is low.
Abstract: A power conversion device includes a power switching circuit that supplies AC voltages generated between switching elements operating as upper arms and switching elements operating as lower arms, and a control circuit that generates and supplies to the driver circuit signals for controlling the switching operation of the switching elements by a PWM method in a first operational region in which frequency of an AC power to be outputted is low, and that generates and supplies to the driver circuit signals for controlling the switching operation of the switching elements at timings based upon the phase of the AC power to be outputted in an operational region in which the frequency of the AC power to be outputted is higher than in the first operational region.

124 citations

Patent
28 Jul 2009
TL;DR: In this paper, a vehicle control apparatus according to the present invention includes a calculation section configured to calculate a first risk level present on the left of a vehicle and a second risk level presented on the right of the vehicle.
Abstract: According to conventional art, if there is an obstacle on the left of a vehicle, a control threshold value is set so as to avoid the obstacle If the control threshold value is exceeded, the vehicle is controlled in accordance with a deviation quantity so as to return to a position where the control threshold avoids being exceeded However, even if a risky oncoming vehicle is approaching the vehicle on the right, the vehicle is controllably moved toward the oncoming vehicle Thus, disadvantageously, a driver has a sense of fear or discomfort A vehicle control apparatus according to the present invention includes a calculation section configured to calculate a first risk level present on the left of the vehicle and a second risk level present on the right of the vehicle, a setting section configured to set a first control threshold for the left of the vehicle based on the first risk level and to set a second control threshold for the right of the vehicle based on the second risk level, a change section configured to change at least one of the first and second control thresholds based on the first and second risk levels, and a control section configured to control the vehicle based on the changed control threshold

94 citations

Journal ArticleDOI
TL;DR: In this paper, a model-based design method of voltage phase controller for IPMSM was proposed by linearizing the relationship between torque and voltage phase, and the analysis of the proposed model describes that the plant is a non-minimum phase system.
Abstract: This paper presents a model-based design method of voltage phase controller for IPMSM. The voltage phase controller controls the torque with the output voltage phase only in high-speed region where the inverter output voltage amplitude is saturated. However, voltage phase control cannot achieve quick torque response because it is designed in defiance of transient characteristic. Due to the nonlinear characteristic between torque and voltage phase, a model-based design has not yet been carried out. In this paper, a model-based design is proposed by linearizing the relationship between torque and voltage phase. The analysis of the proposed model describes that the plant is a nonminimum phase system. Simulation results and experimental results show the effectiveness of the model-based design method which uses the proposed model. Furthermore, the stable analysis shows that the conventional design method has low bandwidth due to an unstable zero of the plant.

58 citations

Patent
28 Jun 2007
TL;DR: In this paper, the lower arm of V-phase is turned on, and a route of motor current passing through an IGBT element from a V phase coil is formed, and therefore, the motor current returning to the short-circuited phase decreases.
Abstract: When an upper arm of U-phase has failed because of short-circuit, lower arms of V-phase and W-phase as the opposite arms are switching-operated. When only the lower arm of V-phase is turned on, a route of motor current passing through an IGBT element from a V-phase coil is formed, and therefore, the motor current returning to the short-circuited phase decreases. Further, by the switching operation of the arm opposite to the short-circuited arm, an AC current is induced in a motor generator. Therefore, it is possible to continuously drive the motor generator while preventing increase in the current passing through the short-circuited phase, without adding a new device structure. This ensures running of the vehicle in the limp mode.

58 citations

Patent
19 Oct 2006
TL;DR: In this article, the authors provided an electric power converter in which commonmode noise is suppressed without causing enlargement of components, increase in the number of components and a cost hike, and the like.
Abstract: There are provided an electric power converter in which common-mode noise is suppressed without causing enlargement of components, increase in the number of components, a cost hike, and the like The electric power converter is provided with a capacitor ( 12 ) connected with the input terminal of the inverter circuit ( 13 a ), a noise suppression means ( 10 a, 10 b ) that is provided around at least one of input-side conductors connected with the input terminals of the inverter circuit ( 13 a ) and output-side conductors connected with the output terminals of the inverter circuit ( 13 a ), an electric quantity detector ( 11, 19 a, 19 b, 19 c ) that is provided in the input-side conductors or the output-side conductors at a position opposite to the inverter circuit with respect to the noise suppression means ( 10 a, 10 b ), and a control unit ( 20 ) that controls the inverter circuit ( 13 b ), based on an electric quantity detection signal from the electric quantity detector

55 citations