Hitachi, Ltd.

Other

Hitachi Automotive Engineering Co., Ltd.

Yuusuke Takamoto

Ryoso Masaki

Sanshiro Obara

Satoru Kaneko

Taizou Miyazaki

Hiroyuki Yamada

Yutaka Nishimura

Seiji Suda

Hirohisa Yamamura

Hiroshi Katada

Junichi Makino

Tomoji Inui

Fumio Tajima

Seiji Ishida

Takashi Ikimi

Tsutomu Ohmae

Eiichi Ohtsu

Hironori Ohashi

A power corresponding to an A/C voltage command id,* is applied in the d-axis direction of rotational coordinates of a stopped synchronous motor via a current control unit, a three-phase converting unit, and a power converter. Further, by using &ldquo;an amplitude value of a current iq&prime; in the q-axis direction of the rotational coordinates generated in response to the A/C voltage command id,*&rdquo; which is fed back and detected via a current detector and a dq converting unit, a field pole position estimation value &thgr;{circumflex over ( )} is converged. The field pole position is estimated by using the converged field pole position estimation value &thgr;{circumflex over ( )} as a true value of the field pole position &thgr; of the synchronous motor.

Method of estimating field pole position of synchronous motor, motor controller, and electric vehicle

A more compact and light-weight drive unit is required for an electric vehicle in order to improve its mileage per charge, acceleration performance and overall efficiency. A control apparatus which generates drive signals to drive power devices in the power converter includes: a current reference generator calculates from a torque reference value a d-axis exciting current reference value on the basis of which the ac motor generates a magnetic flux, and a q-axis torque current reference value, the d-axis and the q-axis being orthogonal to each other; a current control circuit generates ac voltage reference values Vu*, Vv* and Vw* from the d-axis exciting current reference value and the q-axis torque current reference value; and a drive signal generator generates drive signals to drive power devices from the ac voltage reference values. Both the current reference generator and the current control circuit are processed digitally by the same arithmetic unit.

Control apparatus for electric vehicle

A motor control device for an AC motor driven by a power converter with a maximum output frequency more than 500 Hz has a digital arithmetic unit which performs current-feed back control of the AC motor up to a maximum output frequency of the power converter, and outputs an AC voltage command to the power converter. The digital arithmetic unit includes a voltage control signal calculating unit for calculating a vector sum of the d-axis current deviation from a first subtracting unit and the q-axis current deviation from a second subtracting unit based on the d-axis and q-axis phases from a phase calculating unit as well as for calculating a d-axis voltage control signal and a q-axis voltage control signal according to the calculated vector sum, and performs current integration control for the d-axis and q-axis using the calculated vector sum as an input value. The AC voltage command is calculated based on the d-axis voltage control signal and the q-axis voltage control signals.

Motor control device for high frequency AC driven motor

A power corresponding to an A/C voltage command id1* is applied in the d-axis direction of rotational coordinates of a stopped synchronous motor via a current control unit, a three-phase converting unit, and a power converter. Further, by using 'an amplitude value of a current iq' in the q-axis direction of the rotational coordinates generated in response to the A/C voltage command id1*' which is fed back and detected via a current detector and a dq converting unit, a field pole position estimation value .theta. is converged. The field pole position is estimated by using the converged field pole position estimation value .theta. as a true value of the field pole position .theta. of the synchronous motor.

Method of estimating field pole position of synchronous motor, motor

An inverter system providing both an improvement in the voltage utilization factor and a reduction in the switching loss uses a two-phase switching method. In the inverter system, an .alpha.-axis voltage command value; v.sub..alpha.r and a .beta.-axis voltage command value v.sub..beta.r are input to a stop phase selection means. Six sections are judged based on the values v.sub..alpha.r and v.sub..beta.r to select phases for which it is allowable to stop pulse width modulation control in a two-phase switching method. Then, a phase having the largest absolute value of current is selected among the phases for which it is allowable to stop pulse width modulation control using a U-phase current i.sub.u and a V-phase current i.sub.v. This information is a control mode S. Based on these, two-phase switching calculations are performed by a dead-time compensation calculation means and a pulse width modulation generating means. By doing so, the switching loss can be reduced.

Inverter system and control system for electric vehicle

A permanent magnet synchronous motor controller includes an inverter for supplying an alternating current power converted from a direct current power to a three-phase permanent magnet synchronous motor, having a pair of switching elements for each of said three phases of the motor; a smoothing capacitor for smoothing the direct current power connected to the inverter in parallel; and a control unit for controlling the motor by ON-OFF controlling each of the switching elements of the inverter, which further including a short circuit transition processing portion for changing control to 3-phase short circuit after performing precursory ON-OFF control of each of the switching elements so as to avoid occurrence of over current at an initial period of performing the 3-phase short circuit while the motor is being rotated.

Permanent magnet synchronous motor controller and electric vehicle

In a controller for an electric vehicle, a voltage current phase difference calculating circuit calculates a vector phase .theta..sub.c from a voltage command value and the primary current of an alternating current motor. The vector phase .theta..sub.c is input to a second voltage command circuit which calculates a second d-axis voltage command value and a second q-axis voltage command value using the vector phase .theta..sub.c and d-axis and q-axis current differences. By correcting the voltage command value using the second d-axis and second q-axis voltage command values, the stability of the current control system is improved. By controlling the electric vehicle using such a system, a stable current control can be attained even when the electric vehicle is driven under a regenerative running state or a weak magnetic field control state.

Electric motor controller capable of performing stable current control

In a method and apparatus for motor control in an electric vehicle, current feedback control from an AC motor is performed using a digital arithmetic unit. The motor control equipment includes a power converter having a maximum output frequency of at least 500 Hz for driving the AC motor, and the digital arithmetic unit outputs an AC voltage command to the power converter based on current feedback from the AC motor up to the maximum output frequency of the power converter. The digital arithmetic unit includes a first subtractor for calculating the deviation between a detected value and a command value for the d-axis current, and a second subtractor for calculating the deviation between a detected value and a command value for the q-axis current. A phase calculator calculates a d-axis phase corresponding to the resistance and reactance components of the impedance of the d-axis, and a q-axis phase corresponding to the resistance components of the impedance of the q-axis. A voltage control calculator calculates control signals for the d- and q-axis voltages, due to the d-axis current deviation and the q-axis current deviation, based on the d-axis phase and the q-axis phase. The AC voltage command is output to the power converter based on the d- and q- axis voltage control signals.

Frequency dependent current control system for an AC motor

An electric vehicle control unit capable of position control so that the vehicle can be held in its stop position without vibration, even if an operator does not keep the brake pressed. The control circuit of the electric vehicle comprises a speed/torque instruction generation circuit, a position control selection circuit, a position instruction generation circuit and a motor control circuit. When the vehicle stops, control of the motor is changed from speed or torque control to position control.

The invention provides an electric power converter system which uses a standard low-priced control processor and is suitable for improving the voltage utilization factor in the output voltage. D-axis and q-axis voltage commands and a rotation angle .theta. defining a voltage command vector on a rotating coordinate system are input to a voltage calculation circuit. The voltage command vector is transformed in a rotating coordinate transformation unit into a .alpha. axis and .beta. axis voltage commands to be defined relative to stationary coordinate system. A judgment unit determines which section contains the voltage command vector, from among three sections on the stationary coordinate system having one axis thereof (.alpha.-axis for example) coinciding with one axis of the three phases. A three phase voltage generation unit then selects a method of calculation on the basis of a result of the section determination, and calculates three phase voltage command values respectively utilizing the .alpha. axis and .beta. axis voltage command values. Since calculation requires only a simple add/subtract and shift operation, a high performance economical power converter system which improves the voltage utilization factor substantially can be realized.

Power converter

An electric vehicle control system, according to the present invention, comprises at least two electric motors for independently driving left and right wheels of the vehicle, power supply unit for supplying power to the motors, unit for detecting command entered by a driver of the vehicle and driving operational amount provided for the vehicle, unit for detecting output torques of the two motors, unit for calculating a motor speed difference command signal for making the two output torques consistent with each other, unit for calculating a vehicle speed command signal for the vehicle on the basis of detected command and the driving operational amount, unit for calculating motor speed command signals for respective of the motors on the basis of calculated motor speed difference command signal and the vehicle speed command signal, unit for detecting actual speeds of the two motors, and control unit for voltage controlling supply power from the power supply unit to the motors so that the detected actual speeds of the motors become consistent with the motor speed commands for respective motors.

Control system for electric vehicle

An electric vehicle control device is disclosed, which includes an AC motor for driving a vehicle; a main electric power conversion unit for supplying an AC voltage to the AC motor; a battery for supplying a DC voltage to the main electric power conversion unit; an auxiliary electric power conversion unit connected to the battery and adapted to be connected to a load or a power supply; a controller for controlling the main and auxiliary electric power conversion units so as to act selectively as an inverter or a converter; and a switching unit for giving selectively the AC motor the AC voltage from the main and auxiliary electric power conversion units under control of the controller. In the running mode of the electric vehicle, the controller described above makes the main electric power conversion unit act as an inverter and controls the switching unit so that the AC voltage from the main electric power conversion unit is given to the AC motor. Further, responding to detection of a failure of the main electric power conversion unit, the controller makes the auxiliary electric power conversion unit act as an inverter and controls the switching unit so that the AC voltage from the auxiliary electric power conversion unit is given to the AC motor.

Electric vehicle control device

Analog circuit of a thermal type intake air flow sensor for detecting a quantity of air drawn into an automotive engine is formed as a part of the input hardware of a microcomputer for control of the engine, and the analog circuit is used for operations which need to be performed at high speed, while adjustment, an output process, etc. are executed under the same operating system as is used for engine control.

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Hitachi, Japan

Yuusuke Takamoto