Mitsubishi Denki Kabushiki Kaisha

Renesas Electronics Corporation

Kiyoshi Ishikawa

Naohiko Aoki

Tatsuya Kunikiyo

Katsumi Eikyu

Kenichiro Sonoda

Masato Fujinaga

Norihiko Kotani

A drive apparatus for a motor having a stator and a rotor, the drive apparatus including a current detection unit configured to detect, when the motor is rotating, each of multi-phase currents flowing through coils of the stator, and a control unit for controlling the motor by sensor-less control configured to convert the detected multi-phase currents into a d-axis current Id and a q-axis current Iq in a d-q coordinate system, calculate a phase error between an actual rotational position of the rotor and an imaginary rotational position thereof by comparing the d-axis current Id with a d-axis current command value Idref and comparing the q-axis current Iq with the d-axis current command value Idref, perform control so that the phase error gets closer to zero, and output voltage command values to a motor drive circuit.

Drive apparatus for oil-pump motor and drive control method for oil-pump motor

An oil-pump motor drive apparatus includes a current detection unit for detecting each of multi-phase currents flowing through coils of a stator, a control unit for converting the detected multi-phase currents into a d-axis current Id and a q-axis current Iq, calculating a phase error between an actual rotational position of the rotor and an imaginary rotational position by comparing the d-axis current Id with a d-axis current command value Idref and comparing the q-axis current Iq with the d-axis current command value Idref, performing control so that the phase error gets closer to zero, and outputting voltage command values indicating voltages to be applied to respective phases of the brushless motor, to a motor drive circuit, in which the control unit sets the d-axis current command value Idref to a value larger than zero when the number of revolutions of the motor is smaller than a predetermined number.

A physical quantity at a given position in an analysis space is expressed by using a Poisson's equation, a Green's function and the Green's theorem. The equation thus obtained is substituted into an unknown parameter in the equation, to be expanded into infinite series. Stopping the expansion when the equation is expanded to some degree, the equation can be expressed only with known parameters such as boundary conditions. Through calculating the respective values of integrations included in terms of the series by the Monte Carlo method and adding them up, a physical quantity at a given position can be thereby obtained. Further, by the same method, a parasitic element constant at a given position in the analysis space can be also obtained. With this method, a simulation is achieved for obtaining a physical quantity and a parasitic element constant at a given position in an analysis space, without solving a matrix equation.

Simulation method

A method of manufacturing a semiconductor device wherein the device is manufactured according to extracted process parameters. The process parameters are extracted as a set of optimum process parameters which satisfy an intended specification using process functions. The process functions describe a characteristic of the semiconductor device, and are determined using experimental values and/or simulated values. The process parameters may then be transmitted online to a factory.

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Tokyo, Japan

Kiyoshi Ishikawa