A vector controller for a permanent magnet synchronous motor uses current command values and detected currents of the d-axis and q-axis, a calculated frequency, and motor constant settings to control the output voltage of a power converter; the motor constants are identified by use of active or reactive power obtained from the output voltage and detected current of the power converter, the calculated frequency, and the detected current immediately before or during an actual operation.

A power factor improving system for a power supply system, comprising an AC power supply, a rectifier circuit connected to the AC power supply, a smoothing circuit for smoothing the output current of the rectifier circuit and supplying DC power to the load, an inductance element inserted in series between the power supply and the rectifier circuit, switching means including a switching element and a rectifier element inserted between the AC input terminal of the rectifier circuit and one of the ...

A vector controller for a permanent magnet synchronous motor according to the present invention has a motor constant identifying unit for identifying motor constants of the permanent magnet synchronous motor, which is connected to an electric power converter in the vector controller, by using a second d-axis current command value, a second q-axis current command value, a detected output current of the electric power converter, and motor constant settings. The vector controller uses the motor con...

A magnetic field source movable type phantom head has a vessel filled with physiologic saline. The vessel preferably has an inner contour corresponding to an outer contour of a cerebrum of a patient to be tested. An electrode support tube has electrodes at one end. The electrodes are arranged within the vessel and movable at least in a vertical direction toward a center of the vessel as guided by a guiding and fixing device which guides the electrode support tube in a liquid tight fashion and fi...

An apparatus includes the position determining members for determining the relative position between the reference frame and the head utilizing at least the teeth or external acoustic meatuses and the nose of the head, and the placement members for placing the magnetic field generating elements for MEG and the markers for MRI measurement at the predetermined reference positions on the head by operating the positioning mechanism movably provided on the reference frame. Thus, the reference points ...

A field weakening vector controller is disclosed which calculates a d-axis current command value for a power converter to drive a permanent magnet synchronous motor. The field weakening vector controller includes a stabilization calculator, a d-axis current command calculator, a q-axis current command calculator, and a phase calculator. The d-axis current command calculator corrects the d-axis current command value, while the stabilization calculator calculates a product of the phase error and t...

Objects of the present invention are to provide an inverter apparatus in which the specification thereof can be readily changed without changing an inverter basic unit, and to provide an inverter apparatus in which an inverter basic unit and an I/O block unit can be readily separated and the number of degrees of freedom of installation can be increased. An inverter apparatus of the present invention is constituted by an inverter basic unit and an I/O block unit which is connected to the inverter...

An inverter corrects an output voltage in accordance with the magnitude of output voltage error due to a dead time and an ON-state voltage drop in power elements so as to energize an AC motor in a manner of single phase alternating current excitation, by calculating an active component of current Iq and a reactive component of current Id from the phase .theta. of an excitation voltage vector and a detected instantaneous current value iu, and by measuring characteristic constants of the motor, in...

A torque control apparatus for a compressor driven by a motor through a main shaft, in which variations of the rotation speed of the main shaft due to torque variations are detected at selected angular positions of rotation of the main shaft. Current values to be supplied to the motor for eliminating the rotation speed variations depending on the angular positions of rotation of the main shaft are computed and stored during at least one revolution of the main shaft, and, in the next revolution o...

A power source apparatus has a power factor improving circuit which uses switching elements (4) as buildup transistors. According to the power source apparatus of the present invention, a current carrying ratio of the switching elements is decided to be a value which is obtained by subtracting a number of proportional value of the power source current waveform from the maximum current carrying ratio. Since the device of the present invention does not necessitate a detecting circuit of the power ...