Abstract: An alternating current rotating machine control device that shares information among power conversion devices and instruments. A power conversion system has a top level control device, a master station, multiple power conversion devices, instruments (such as a temperature sensor and a pressure sensor), and the like. The top level control device is connected to two of the power conversion devices by a first communication line. These power conversion devices have two or more communication functions, and are connected to a remaining power conversion device, a temperature sensor, and a pressure sensor by a second communication line.

Abstract: An inverter is capable of converting a direct current from a direct current power supply into an alternating current and supplying it to an armature winding. A rectifier circuit is capable of rectifying the current, that has been converted to an alternating current by the inverter, into a direct current and supplying it to the field winding. The amount of the alternating current supplied to the armature winding and the amount of the direct current supplied to the field winding are in a proportional relationship, and implementation of switching control of the inverter controls both the amount of the alternating current supplied to the armature winding and the amount of the direct current supplied to the field winding while this proportional relationship therebetween is maintained.

Abstract: An active reactive induction motor is provided. The motor comprises two sets of three-phase windings. One set of windings carries the active power and is called the power windings. The second set of windings carries the reactive power and is called the flux windings. The power windings carrying the active power provides more power to the induction motor than the flux windings carrying the reactive power. A driver circuit for driving the active reactive induction motor and the corresponding modes of operation is also provided.

Abstract: After the power source to the control substrate is turned on, power is supplied to the compressor driver and the fan driver. Then, when it is determined that an indoor unit is in operation, the compressor driver and the fan driver are operated. Meanwhile, when it is determined that the indoor unit is not in operation, after the lapse of ten minutes or twenty minutes under a predetermined setting, the power to the compressor driver and the fan driver is cut. When the operation of the indoor unit is started again, power is supplied to the compressor driver and the fan driver.

Abstract: A system and method for generating a magnetic field in a rotating machine. In one embodiment, a primary winding assembly is configured to generate a rotatable magnetic field. The assembly is connected to receive multiple signals of different phases to effect field rotation. A set of secondary windings is positioned for generation of current based on magnetic coupling during the field rotation. The secondary windings include conductor capable of supporting superconducting current flow. A rotatable machine includes a stator and a rotor winding coupled for rotation with respect to the stator. The secondary windings are formed in a circuit for providing superconducting current through the rotor winding.

Abstract: An active reactive induction motor is provided. The motor comprises two sets of three-phase windings. One set of windings carries the active power and is called the power windings. The second set of windings carries the reactive power and is called the flux windings. The power windings carrying the active power provides more power to the induction motor than the flux windings carrying the reactive power. A driver circuit for driving the active reactive induction motor and the corresponding modes of operation is also provided.

Abstract: A control apparatus for an electric car, including a power converter which feeds AC power of variable voltage and variable frequency to a primary side member of a linear electromagnetic actuator, voltage command means for giving a command of a voltage which is fed to the linear electromagnetic actuator, current detection means for detecting current information which flows between the power converter and the linear electromagnetic actuator, and motor constant calculation means for calculating a motor constant of the linear electromagnetic actuator on the basis of the voltage information Vu given by the voltage command means and the current information Iu detected by the current detection means.

Abstract: A permanent magnet (PM) dynamoelectric machine with directly controllable field excitation control comprises: a drive shaft; a PM rotor assembly with multiple PMs arranged around an outer axial periphery of the rotor assembly; a stator assembly comprising a ferromagnetic stator yoke, multiple ferromagnetic stator teeth mounted to the stator yoke with distal ends proximate the outer axial periphery of the rotor assembly separated by an air gap and multiple stator coils mounted between the stator teeth; multiple saturable ferromagnetic shunts, each shunt coupling adjacent distal ends of the stator teeth to shunt air gap magnetic flux ?g generated by the PMs across the air gap through the distal ends of the stator teeth; and multiple saturation control coils, each saturation control coil wrapped about a saturable region of an associated one of the shunts; wherein application of a control current Ic to the control coils at least partially magnetically saturates the shunts to reduce shunting of air gap magnetic fl

Abstract: A system and method for generating a magnetic field in a rotating machine. In one embodiment, a primary winding assembly is configured to generate a rotatable magnetic field. The assembly is connected to receive multiple signals of different phases to effect field rotation. A set of secondary windings is positioned for generation of current based on magnetic coupling during the field rotation. The secondary windings include conductor capable of supporting superconducting current flow. A rotatable machine includes a stator and a rotor winding coupled for rotation with respect to the stator. The secondary windings are formed in a circuit for providing superconducting current through the rotor winding.

Abstract: A frequency converter for outputting a power to drive a motor, having: an inverter unit for inverting a d.c. power to an a.c. power; a control unit for controlling the inverter unit; and a housing for supporting at least the inverter unit and control unit, wherein a rise time change unit is provided in the housing, the rise time change unit changes a rise time of a waveform of a voltage output from the inverter unit.

Abstract: A frequency converter for outputting a power to drive a motor, having: an inverter unit for inverting a d.c. power to an a.c. power; a control unit for controlling the inverter unit; and a housing for supporting at least the inverter unit and control unit, wherein a rise time change unit is provided in the housing, the rise time change unit changes a rise time of a waveform of a voltage output from the inverter unit.

Abstract: A controller is provided for transitioning a drive signal to a single phase motor between a square wave and pulse width modulation modes, wherein the drive signal is in square wave mode at low motor frequencies and in pulse width modulation mode during normal operation. The transitioning includes using a real time motor model to effectuate transition of the drive signal between the modes, and a sampling rate for sampling the real time motor model during the transitioning. The sampling rate is automatically modified during the transitioning, wherein acceleration of the motor includes transitioning the drive signal from square wave mode to pulse width modulation mode, including periodically increasing the sampling rate during the transitioning. Conversely, when transitioning from pulse width modulation mode to square wave mode, the controller automatically deaccelerates the sampling rate during the transitioning.

Abstract: An induction machine includes a rotor having rotor flux and a rotor resistance. The induction machine outputs first and second reference current values. A control system includes a first controller that outputs first and second reference voltage values to the induction machine and that generates an estimated rotor flux magnitude value based on a rotor resistance parameter. A computation circuit receives the first and second reference current values from the induction machine and the first and second voltage reference values from the first controller and calculates an actual rotor flux magnitude. A rotor resistance adjustor that updates the rotor resistance parameter based on the actual and estimated rotor flux magnitudes.

Abstract: A three phase AC motor which rotates at the synchronous speed determined by the number of poles of its main stator winding and the frequency of the AC input to it, which does not need any exciter machine or brushes to provide its DC field current, but has an internal, but independently adjustable excitation system to supply its field current. The internal excitation system consists of an auxiliary winding on the stator which is additional to the main power winding, another auxiliary winding on the rotor besides the main DC field winding, a diode rectifier circuit on the rotor from which the DC field current is supplied by rectification of the induced currents in the rotor auxiliary field. The field current adjustment can be made by adjustment of the input to the stator auxiliary winding. This can be done independently by eliminating any magnetic coupling between the main and auxiliary circuits.

Abstract: Digital device to regulate the speed of an electric motor having a commutating element mounted in series with the motor at the terminals of an A.C. distribution network. A duration of an on-state of the commutating element defines values corresponding to desired reference speeds. The digital device includes a tachometer sensor connected with the motor which emits pulses indicative of the speed of the motor, a microcontroller having an oscillator, a first counter whose count is tied to at least one period of the pulses to calculate an actual speed of the motor, a memory containing desired reference speed values, a comparator to compare the desired reference speed with the actual speed of the motor, and an interface to control the on-state of the commutating element.

Abstract: The purpose of this invention is to provide secondary resistance low temperature compensation in vector speed control at values that are close to the actual secondary time constant even at startup of the motor wherein the secondary time constant operation is not carried out.The invention consists of vector speed control devices 1 to 5 of the induction motor IM, with secondary resistance low temperature compensation of the electric motor being carried out by installing a secondary time constant operator (6) which detects the secondary time constant of an electric motor; a comparator/register (7) which holds and outputs low temperature data .tau..sub.2 from a comparison of register data and the output .tau..sub.2 of the aforementioned operator (6); and a damping unit (8) which, during operation, carries out replacement of sequential data with the output .tau..sub.2 of the operator (6), and, during shutdown, which turns to the output values .tau..sub.

Abstract: This invention provides a vector control method for controlling an induction motor that is used to drive an elevator based on secondary time constants, wherein the secondary time constants, which have been corrected for temperature, are determined in a short amount of time and the precision of the determination is improved, by passing a constant current of the same phase as during a similar operation to the excitation side of the induction motor while the elevator is mechanically stopped and then determining the secondary time constants.

Abstract: A system and method for controlling the speed of an electric motor compares the actual speed of the motor with the desired speed of the motor. A digital comparison of the desired speed of the electric motor with the actual speed of the electric motor provides an error signal indicative of the error between the desired speed and the actual speed. A large timing current from a programmed timing control will cause an increase in the speed of the motor, while a smaller timing current from the programmed timing control will cause a decrease in the speed of the motor. In this manner, the programmed timing control affects the actual speed of the motor 12 to approach the desired speed. The programmed timing control can also provide a ramping acceleration or deceleration as the motor speed changes to approach the desired speed. The speed control system can also include a programmed stall detector which can cause the operation of the electric motor to be ceased when a stalled motor condition is detected.

Abstract: An a.c. variable speed drive system which can switch between a driving operation and regenerative operation of an inverter in accordance with the operation speed.

Abstract: A control system for controlling the load of an AC motor/generator of secondary AC excitation type connected to a power system in parallel to at least a synchronous machine. The AC motor/generator has the secondary excitation winding thereof controlled in the amount of excitation so as to generate an output in accordance with an external output command. In the case of variation of power flow between the power system and the synchronous machine, the output command is corrected in accordance with the variation, and the amount of the secondary excitation is controlled by the corrected output command, whereby the variation of power flow between the power system and the synchronous machine is absorbed by the AC motor/generator thereby to prevent the synchronous machine from stepping out.

Abstract: An induction motor circuit which effectively prevents voltage spikes caused by leakage inductance of the induction motor stator windings without otherwise interfering with the overall operation of the induction motor. The circuit incorporates two windings between a common point and the positive supply and two other windings between the common point and the negative supply. Voltage spikes are suppressed by diodes connecting directly from the ends of each of the windings to the supply terminals oriented to the opposite end of the respective windings.