Abstract: A three region control strategy for a permanent magnet motor is presented. In a first control region, the permanent magnet motor is operated at, a 120° conduction square wave mode at reduced phase current, and below a no-load speed. The motor phase current commutation causes eddy current losses in the rotor magnets and core which are insignificant due to the low phase currents and relatively low rotor speed. Meanwhile, the inverter switching losses are kept low as two switches are in use (on/off) for each current commutation during the 120° conduction mode. In a second control region, the permanent magnet motor is operated at a 180° conduction sinusoidal wave mode with high phase currents. The 180° conduction sinusoidal wave mode minimizes the commutation loss. In a third control region, the permanent magnet motor is operated above its no-load speed or in a field weakening mode.

Abstract: A method of regulating a rotating electrical machine includes a preparatory step of determining a discrete voltage control law for the machine. The discrete control voltage to be applied at each sampling time is determined in the form of a first term corresponding to free evolution of the state of the machine in the absence of control, between the preceding sampling time and the current sampling time, and a second term dependent on the set point torque and a set point for the magnetic energy consumed by the machine. The method further includes, at each sampling time, a step of determining, with the aid of the discrete control law, the control voltage to be applied to the machine for the torque of the machine to reach the set point torque and the magnetic energy consumed by the machine to correspond to the set point magnetic energy.

Abstract: A low noise synchronous motor including a permanent-magnet rotor and a stator with at least two pairs of stator poles and corresponding windings further includes an electronic power supply comprising a capacitor that is serially connected to one winding of only one pair of poles to act as a 90° phase shifter and a static switch that is driven by an output of said electronic power device and connected to drive another winding of said two pairs. The static switch is controlled by a sensor detecting the position of the rotor.

Abstract: A plurality of magnetic sensors are provided in a magneto motor to sense variations of rotating poles of rotor magnets. One of the magnetic sensors is provided to let the exciting current of stator coils and the rotating poles of the rotor interchange orthogonally, and the others are provided to let the exciting current of the stator coils and the rotating poles of the rotor interchange non-orthogonally. The magnetic sensor letting the stator coils and the rotor magnets orthogonally excite each other will let the magnetic flux density of the armature gap be highest, and the others letting the stator coils and the rotor magnets non-orthogonally excite each other will generate an effect similar to weak magnetic control.

Abstract: A method for position-sensorless motor control is provided, wherein a rotor-position estimation current signal is superimposed on the &ggr;-axis direction component of a target current vector representing target currents of stator windings. The period of the current signal is an even multiple of a PWM carrier period and varies at random. The amplitude of the current signal increases with the amplitudes of the target currents. An even number of samples are obtained from the &dgr;-axis direction component of a current vector representing detected currents of the stator windings in each period of the current signal. A discrete Fourier integration of the samples determines the amplitude of a current response to the current signal in the &dgr;-axis direction. The &ggr;-axis direction is corrected so that the current response substantially shrinks to zero in the &dgr;-axis direction.

Abstract: A pulse synchronized with the period of PWM of inverter and depending on the inferred value of the position of the motor rotor is applied as a PWM pattern to the motor and as a result the difference of magnetic resistance of the motor rotor, which can be inferred by observing the rate of change with time of the d axis current and q axis current on the d and q axis co-ordinates of the current flowing through the motor winding is detected and the position of the motor rotor can be thereby inferred. Thus the position of the motor rotor can be ascertained with high precision by a straightforward device construction without employing a rotor position sensor and reduction in size, reduction in costs and facilitation of maintenance can be achieved.

Abstract: The invention relates to a system for the electronic commutation of a brushless DC motor (1) having three phase windings (u, v, w) which are electrically displaced by 120°, comprising a semiconductor bridge (4) consisting of six power semiconductors (S1 to S6), which drives the phase windings (u, v, w) for generating a rotating magnetic stator field, a control unit (6) which correspondingly drives the power semiconductors (S1 to S6), and a device for detecting the respective rotational position of a rotor exhibiting a permanent-magnetic magnet wheel, the device for detecting the rotor position being constructed as sensor-less evaluating unit (8), for evaluating the voltage induced by the rotating magnet wheel which can be measured at the winding terminal (U, V, W) of the motor which is not currently driven. It is the object of the present invention to achieve a reduction of running and commutation noises whilst maintaining the inexpensive and fault-insensitive sensorless rotor position detection.

Abstract: An exemplary embodiment of the invention is a method for torque control of a PM synchronous machine. The method includes obtaining a torque command signal and a machine speed and determining an operating mode in response to the torque command signal and the machine speed. The operating mode includes a first operating mode and a second operating mode. In the first operating mode, a stator phase voltage magnitude is computed and an angle between the stator phase voltage and a stator phase back emf is determined in response to the stator phase voltage magnitude. In the second operating mode, the stator phase voltage is set to a predetermined magnitude and the angle between the stator phase voltage and the stator phase back emf is determined in response to the predetermined magnitude.

Abstract: In an arrangement having an electric power inverter 2 which applies a voltage to an AC motor 1 and a control unit 4 which calculates a voltage command value applied in PWM signals, detection use voltages Vup, Vvp and Vwp are applied in synchronism with PWM signal generation use carrier waves in the control unit 4 as well as motor currents iv and iv are detected in response to current detection pulses Pd in synchronism therewith. In a magnetic pole position detection unit 12, counter electromotive forces of the synchronous motor 1 are estimated from a relationship between the detection use voltages Vup, Vvp and Vwp and current difference vectors of the motor current to determine a magnetic pole position &thgr; through calculation. The determined magnetic pole position &thgr; is inputted to coordinate conversion units 8 and 11 and a motor speed detection unit 13.

Abstract: An inverter for use in a switched reluctance (SR) motor drive is provided. The inverter comprises a first and second transistor for selectively providing current to an SR motor winding. A resonant-type snubber circuit is connected to the transistors to reduce turn-off loss. The snubber circuit includes a pair of diodes, a capacitor, and an inductor. The snubber circuit is reset during switch-on time of the transistors. At transistor turn-off time, the snubber circuit uses the capacitor to effectively limit the rate of change of voltage across the transistors. This allows the transistors to turn off with lower losses, and can also reduce the acoustical noise generated by the motor drive.

Abstract: The present invention relates to a current limit circuit of an inverter refrigerator. The present invention comprises a current limit unit for outputting a current limit signal by comparing an excess current generation due to load change with a limit current level set in advance. Accordingly, the present invention can extend life span of a compressor by protecting a BLDC motor from the excess current and reducing permanent magnet demagnetization due to the excess current. In addition, the present invention can improve a mobility of a motor by maintaining uniform torque with stable current in the operation, and can operate a compressor stably without turning off by a momentary excess current in the compressor operation.

Abstract: A Switched Reluctance Motor or SRM is controlled by detecting signals indicating the angular position of the rotor of the motor and energizing the motor depending on these signals. The periods of the abovementioned signals are discretized into a given number of time windows, defining a table with a plurality of positions each corresponding to one of said time windows. A respective power supply configuration of the motor is associated with each of said positions of the table. The positions in the table undergo cyclical scanning and the motor is energized with the power supply configuration associated with the position identified in each case during the scanning movement. The scanning movement is performed from a reference position identifying the energization advance of the motor and preferably determined using a logic of the fuzzy type based on the speed of rotation and the load of the said motor.

Abstract: A control scheme for an surface-mounted permanent-magnet synchronous (SMPMS) drive uses a combination of an open-loop magnetizing current reference calculation and a stabilizing feedback term, which speeds-up the torque transient response. The feedback term increases the stability margin during torque transients by increasing the available voltage margin for current control. The magnetizing current reference calculation takes into account the saturation effects in the SMPMS drive, which occur at peak torque points, and compensates for them. By taking into account saturation effects, stable operation at high speed is achieved, thereby increasing the speed range of the SMPMS drive.

Abstract: A digital motor controller circuit including a an energy storage device, a bus protection circuit, an input signal selector, a combiner, a calibration device for altering parameters for different applications, a compensator, a motor driver circuit, and feedback circuitry for controlling a motor with a minimum of cost and space requirements.

Abstract: A digital calculation apparatus 4 including a position-detection means 14 for detecting the magnetic pole position, based on the detected current difference values of the synchronous motor 1 in a two-phase short-circuit state, takes in current flowing in the synchronous motor by generating an interruption trigger signal in synchronization with the PWM signals for driving an inverter 3, and driving an A/D converter with the generated trigger signal.

Abstract: A method for starting an open-loop vector control of a synchronous machine by determining a stator inductance model of the machine; measuring the stator iductance in a plurality of directions; arranging the measured inductances in the model to form model parameters resulting in minimum error; checking the polarity of rotor magnetization to verify the direction thereof; initializing flux linkages of the open-loop vector control according to the model parameters and the direction of rotor magnetization; and starting the machine by the open-loop vector control method.

Abstract: The energization control system for a motor equalizes the power loss of switching elements energizing coils of each phase of the motor in order to maintain a balance of heat development. The energization control system for a motor includes a plurality of phase coils and two switching elements. The energization control system of a motor supplies an electric current from the power source line to the coil when two switching elements are simultaneously conducted. Two switching elements are controlled under a first condition that one of the switching elements is switched every predetermined time while the other of the switching elements is conducted. Two switching elements are also controlled under a second condition that the other of the switching elements is switched every predetermined time while one of the switching elements is conducted. The first condition and the second conditions are repeated and synchronized to the predetermined time every predetermined period.

Abstract: A method for monitoring the speed of a synchronous motor, the synchronous motor having a permanent magnet rotor (3) and coils (1, 2), sinusoidal currents being applied to the coils (1, 2). Also a device for monitoring the speed of such a motor, wherein in at least one of the coils (1, 2) the power supply is disconnected and one or more voltage characteristics (U1, U2) are evaluated which are induced by the permanent magnet rotor (3) in one or more of the coils (1, 2) disconnected from the power supply, the minimum duration of the interruption of the power supply of the coils (1, 2) and the evaluation of the voltage characteristic (U1, U2) being equal to the temporal spacing between two consecutive zero crossings of the respectively induced voltage characteristics (U1, U2).

Abstract: A method to operate an electronically commutated DC motor driving a centrifugal pump and comprising a stator fitted with at least one winding and a rotor fitted with permanent magnets, said method including a monitored stepping operation within which one full revolution of the rotor is constituted by a sequence of distinct individual steps, the rotor being accelerated by applying a stator field and being decelerated to a stop before the stator field is commutated.

Abstract: There is provided a brushless motor and a driving control device therefor both of which can restrain the occurrence of current variations, torque variations and noise in the brushless motor, thereby constructing an electrically-operated power steering system of low noise and good steering feeling. In the driving control device for the brushless motor having a current variation rate control part which controls a current variation rate during commutation, and having plural excitation phases, the current variation rate control part terminates commutation transient time which is the time for which phase currents are in a transient state during a commutation operation, within ½ of commutation interval time which is the time required from the starting time of a certain commutation until the starting time of the next commutation.

Abstract: Systems and methods for controlling a polyphase brushless direct current (DC) motor (12) are described. One system includes a meter (14) coupled to a motor terminal (A, B, C) and adapted to produce a range of digital output values (44) representative of a motor terminal signal from which a back EMF signal is derivable. The system (10) also may include a controller (16) that is coupled to the meter (14, 42) and is operable to monitor the range of meter output values and to compute a motor commutation time based upon a monitored local minimum meter output value and a monitored local maximum meter output value. A pulse width modulation (PWM) circuit (26) may be provided, and the meter (14, 42) may be synchronized with the PWM circuit (26). Zero crossings in the back EMF signals are identified based upon direct measurements of the signals at the motor terminals (A, B, C).

Abstract: There is provided a control method capable of stably rotating a synchronous motor synchronously with an output frequency even when a phase error between a real rotary axis and a control rotary axis is large. In a phase error operating unit, from the magnitude of the motor current, the magnitude of the motor voltage, the phase difference between the motor current and the motor voltage, and the motor constants, the phase difference between the motor current and the real rotary axis is determined as the first phase difference, and the phase difference between the motor current and the virtual rotary axis is determined as the second phase difference. The difference between the first and second phase differences is defined as the phase error, and the estimation position is so modified as to make the phase error zero.

Abstract: A position sensorless motor control apparatus is provided that achieves high resolution and high accuracy angle estimation, achieves angle estimation even in the presence of phase voltage saturation, and achieves high accuracy angle estimation even when a back electromotive force constant changes. An angle estimating unit which generates estimated rotor angle comprises: an estimation phase selecting unit for selecting an estimation phase designating the stator winding phase to be used for the generation of the estimated angle; a deviation generating unit for generating, based on the estimated angle and phase voltage value, a deviation relative to a model expressed by a phase voltage equation of the estimation phase; an angle correcting unit for correcting the estimated angle so that the deviation converges to zero; and an estimated coefficient value correcting unit for correcting an estimated coefficient value which is the estimated value of a coefficient in the phase voltage equation.

Abstract: Method and system for estimating rotor position of a switched reluctance machine is provided. The method allows for estimating flux linkage across a respective phase of the machine. The method allows for measuring of magnetization curves at aligned and unaligned positions of the machine. The method further allows for computing magnetization reference data between the aligned and unaligned positions. A storing step allows for storing rotor position data based on the magnetization reference data. The stored rotor position data is indicative of rotor position variation as a function of phase current. A relating step allows to relate the estimated flux linkage to the magnetization reference data to determine, for a respective phase current, correspondence of the estimated flux linkage relative to the magnetization reference data. A retrieving step allows for retrieving stored rotor position data when said correspondence is determined.

Abstract: Method for controlling a permanent magnet synchronous motor, wherein an equivalent circuit describing the characteristics of the permanent magnet synchronous motor is formed, and via calculations based on. the equivalent circuit, a vectorial representation of the control quantities is produced, in which the horizontal axis of the co-ordinate system used represents the magnetisation, the vertical axis represents the torque and the vectors used are stator voltage (Us), supply voltage (e) and current (I), which is at a distance of 90° from the horizontal axis. In the vectorial representation, a correction vector (dU) is formed via inference based on the equivalent circuit and the correction vector is summed with the electromotive force, giving the stator voltage (Us) as a result.

Abstract: A method to control a switched reluctance motor (SRM) with a first phase (1) and a second phase (2) comprises: aligning the rotor with the second phase (2); at a first time point (t1), energizing the first phase (1) with a phase voltage that is substantially constant; monitoring an increase of the phase current (I1) in the first phase (1) until the phase current reaches a maximum (302); monitoring a decrease (303) of the first current (I1) until at a second time point (t2) the phase current (I1) reaches a minimum (304) and starts to increase again (305); de-energizing the first phase (1) at a third time point (t3) that follows the second time point at (t2) at a predetermined time interval; and repeating energizing, monitoring and de-energizing for the second phase (2) instead of the first phase (1).

Abstract: An apparatus for detecting a rotor position in a brushless direct current (BLDC) motor, in which a rotor position can be detected by a virtual neutral point voltage and current of one phase in a motor. The number of circuits required for the rotor position detection is reduced to save the production cost and reduce the space occupied by a position detecting circuit.

Abstract: The teachings herein comprise a method and apparatus for determining the position of a rotor by applying a voltage across a pair of phases of a motor and using a voltage measurement responsive to the applied voltage and indicative of the distribution of the phase inductances within the phase pair to which a test voltage is applied to determine the rotor position.

Abstract: Hall ICs 23u, 23v and 23w are provided to detect the magnetic fields of magnetic regions 8 of a rotor 9 and are offset in position by an electrical angle of 30° from central positions of a U-phase stator pole 1, V-phase stator pole 6 and W-phase stator pole 2. A driving circuit 21 controls the timing of rotor driving signals that are supplied to respective stator coils for respective phases based upon rotor position signals outputted from the Hall ICs 23u through 23w. For example, in order to rotate the rotor in a forward direction, the driving circuit 21 controls the timing of the rotor driving signals according to a first logic. Similarly, in order to rotate the rotor in a reverse direction, the driving circuit 21 controls the timing of the rotor driving signals according to a second logic.

Abstract: A small synchronous motor with high reliability so devised that transition from start operation to synchronous operation is ensured. A microcomputer 22 switching-controls the current application range to a range where the rectified current flowing through a rectifying bridge circuit 20 and an A-coil alternately is inverted during one turn of a permanent magnet rotor 5 to suppress the input on the inverted side with respect to the non-inverted side and thereby to start a synchronous motor, turns off first to fourth transistors 16-19 when the rotational speed of the permanent magnet rotor regulated by the power source frequency and measured by a power source frequency measuring section 24, and turns on triacs SW1 and SW2, thereby making a switch to the synchronous operation circuit 21.

Abstract: In order to reduce undesired sound caused by circular ring oscillation in the diametric direction of the stator by an electromagnetic force, electromagnetic force drift memory stores a drift information of the electromagnetic force causing the circular ring oscillation of the stator. This electromagnetic force drift information is read out according to the position information &thgr; and is supplied to a correction coefficient generating circuitry. Correction coefficient generating circuitry corrects the amplitude component of the activation current wave from by forming correction coefficient &bgr; (t) of the activation current so as to cancel the electromagnetic force harmonic component in the diametric direction which component is the component of the circular ring oscillation of the stator.

Abstract: A circuit for the measurement of time intervals includes a generator providing primary periodic pulses, a frequency divider capable of transmitting secondary periodic pulses for scaling down the frequency of the primary periodic pulses, and a counter for counting the secondary periodic pulses transmitted during the measured time interval. The frequency divider is programmable by a digital factor which determines the frequency division. The circuit further includes a self-calibration circuit for modifying the digital factor as a function of the number of pulses counted by the counter during a previous time interval measurement.

Abstract: A magnetic-pole position detecting apparatus for a synchronous motor includes an arithmetic section outputting six voltage vectors having equal amplitudes and equal-interval phases to a circuit section as a voltage vector command. The circuit section applies the voltage vectors to a synchronous motor, outputs a trigger signal to a detection section each time after finishing the application of each voltage vector, and detects each phase. Thereafter, the arithmetic section calculates and outputs magnetic-pole positions at every 60/(2k) degrees (where k is a natural number based on the detection current. Each voltage vector is applied for a time period sufficient for each phase winding to be magnetically saturated in an order so that the phases of each voltage vector either increase monotonically or decrease monotonically.

Abstract: The present invention concerns an electronically commutated motor, in which for commutation, the output signals of a number of correspondingly arranged Hall sensors are initially evaluated to generate a multiple-figure digital code and in which, after startup of the motor, only one figure of the code is still generated by evaluation of the output signal of a single Hall sensor, while the remaining figures of the digital code are taken from a table stored in an electronic logic component as bit pattern or determined by means of a corresponding algorithm. The advantage of this expedient is that commutation no longer depends on the position-tolerance arrangement of several Hall sensors, but occurs at the best possible time.

Abstract: A method of minimizing errors in a rotor angle estimate in a synchronous machine the method comprising the steps of determining the stator flux (&PSgr;ssest) of the synchronous machine on the basis of the current model of the synchronous machine, determining the stator flux (&PSgr;ssu′) on the basis of the voltage integral and initial value (&PSgr;ssu(n-1)) of the stator flux, and determining the rotor angle (&thgr;est(n)) of the synchronous machine. The method also comprises the steps of determining an angle correction term (&thgr;k(n)) on the basis of the determined stator fluxes (&PSgr;ssest, &PSgr;ssu′), and adding the angle correction term (&thgr;k(n)) to the determined rotor angle (&thgr;est(n)) of the synchronous machine to obtain a rotor angle estimate (&thgr;(n)).

Abstract: In a method of accurately estimating the rotor position of a synchronous motor having saliency from observable quantities, a control system for adjusting an output frequency of an inverter on the basis of a value of axis shift of the synchronous motor to operate the motor synchronously with the output frequency is provided with an induced voltage estimating/axis shift operating unit. Currents resulting from conversion of detection currents on a control axis, voltage commands to be inputted to an inverse converter and a speed command are inputted to the operating unit to estimate an induced voltage of the motor 2 and determine the axis shift from a phase of the estimated induced voltage. By using an electrical constant Lq of inductance, a voltage drop across the inductance is determined by the product of a motor speed command and magnitude of motor current. The voltage drop is a virtual quantity that does not depend on the motor rotor position.

Abstract: A motor current detection amplifier detects a motor current's areas in two phase periods with reference to a motor voltage. A controlling microcomputer computed the ratio of the motor current areas of the two phase periods and provides the same as phase difference information which is in turn used to control a motor drive voltage to apply a sine wave of a predetermined period to the motor's coil to allow 180°-driving including a sine wave conduction resistant to noise and achieving a reduced cost hike.

Abstract: The brushless electric motor (M) is provided with switching means (Q1-Q6) for selectively supplying current to the armature windings (U, V, W) of the motor (M) from a DC-power supply (1) The switching means (Q1-Q6) are controlled by measuring the back-electromotive forces developed in the windings (U, V, W) during operation and comparing these measurements with a high and low reference voltage, in such a way that each time a measured back-electromotive force with positive slope crosses the high reference voltage or a measured back-electromotive force with negative slope crosses the low reference voltage, a commutation signal is generated to commutate the switching means (Q1-Q6), this provides a highly simplified control of the switching means.

Abstract: A method and apparatus for controlling the speed of a voltage-controlled fan by locking the pulse-width modulated speed control voltage to a tachometer signal of the fan is presented. By triggering the off time of the PWM pulse to the detection of the tachometer signal and ensuring the off time is less than one tachometer period, no phase and frequency information is lost.

Abstract: To provide a control circuit or the like of a brush-less motor capable of properly controlling current of motor windings by detecting positions of magnetic poles of a rotor at a rotational frequency of the rotor from low rotation which cannot lock a PLL circuit to steady-state rotation for rotating at high speed. Positions of magnetic poles are detected by a change in a magnetic flux (magnetic flux signal) of motor windings caused by rotating a rotor having the magnetic poles, thereby, a synchronizing signal (ROT signal) in synchronism with rotation of the rotor is generated.

Abstract: A synchronous motor controller comprises speed control means for calculating an active current reference value on a basis of a deviation of a speed sensed value from a speed reference value of the synchronous motor, three-phase PQ conversion means for calculating an active current value and reactive current value on a basis of an armature current of the synchronous motor and a voltage phase reference value active current control means for calculating a voltage phase compensating value on a basis of a deviation of the active current value from the active current reference value, voltage phase computing means for calculating the voltage phase reference value and polar-coordinate three-phase conversion means for calculating a three-phase voltage reference value on a basis of the voltage phase reference value and a voltage amplitude reference value.

Abstract: An electrical rotary drive, designed as a bearingless motor, has a magnetically journalled rotor (3) and a stator (2) which comprises a drive winding (6) having at least two loops (61, 62) for producing a magnetic drive field which produces a torque on the rotor (3), and has a control winding (7) having at least three loops (71, 72, 73, 74) for producing a magnetic control field by means of which the position of the rotor (3) with respect to the stator (2) can be regulated, with each loop (61, 62) of the drive winding (6) belonging to a different electrical drive phase and each loop (71-74) of the control winding (7) belonging to a different electrical control phase, and having a setting device (4) which supplies each loop (61, 62) of the drive winding (6) and each loop (71-74) of the control winding (7) with a phase current or a phase voltage as a setting parameter, with the setting device (4) being designed in such a manner that the setting parameter for each loop (61, 62) of the drive winding (6) and for e

Abstract: The present invention concerns a device (20) for controlling an electric motor (1) including a rotor (6) and at least three stator coils (2, 3, 4) connected between three connection terminals, means (5) for providing three control signals (Ua, Ub, Uc) to said connection terminals, and means (22) for dectecting said rotor angular postion. Said dectecting means include measuring means (24) designed to be connected to the motor, such that the means form with said coils at least two oscillating circuits supplying two respective signals (U1, U2) at two measurement frequencies respectively which are themselves periodic functions of said rotor angular position, and means (26) for calculating a single value corresponding to the two measurement frequencies, this value being the desired angular position.

Abstract: The present invention relates to a brushless motor system. The brushless motor system has a brushless motor, a motor driver, and at least one sensing circuit. The brushless motor has a rotor, and the sensing circuit is used to detect the rotor position. The sensing circuit has a Hall sensor and two capacitor devices. The Hall sensor has two output ports. As the rotor rotates, the Hall sensor will generate a sensing signal at each of the two output ports. Each of the capacitor devices is connected in series to one of the two output ports of the Hall sensor, and the two capacitor devices are used to filter out DC biases in the two sensing signals. The motor driver is connected to the two capacitor devices for driving the rotor of the brushless motor according to the two sensing signals from the two capacitor devices.

Abstract: An apparatus for executing field weakening control comprises a means for computing a start rotational speed of field weakening control based on a ratio of a battery voltage used in a normal operation to a detected battery voltage in execution of only field weakening control without generating a torque, and an interpolation means for carrying out linear interpolation on at least two values selectively fetched from a plurality of current tables in accordance with a battery voltage to find a field weakening current. The apparatus provided by the present invention is further characterized in that, in addition to correction of a start rotational speed of the field weakening control, a field weakening current is corrected in accordance with a ratio of a rated battery voltage used in a normal operation to a detected battery voltage.

Abstract: 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 &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.

Abstract: A method is for decoding three logic signals produced by three Hall effect sensors installed in an electronically-switched three-phase brushless motor according to a sequence of six driving phases to be switched synchronously with a rotor position. The method includes determining a real phasing of the three Hall effect sensors at 60, 120, 300 or 240 electrical degrees. The determining is accomplished by decoding a whole set of eight possible combinations of the three logic signals produced by the three Hall effect sensors. The real phasing of the three Hall effect sensors is discriminated based upon two dissimilar combinations from among six valid combinations, the six valid combinations from among the eight possible combinations. The method further includes determining the rotor position based upon the real phasing of the three Hall effect sensors and generating logic driving signals synchronous with the rotor position.

Abstract: An energization control device for an electric motor includes: a rotor angle sensor for detecting a motor rotational angle; a current sensor for detecting a current flowing through a phase coil; a control data storage device for storing therein a plurality of control data items in map format which correspond to rotational conditions of the rotor; and a control device for controlling the energization of the phase coil. The control device obtains first control data items for deriving a first torque from the motor and second control data items for a second torque, when a target torque is intended to be derived from the motor which is smaller and larger than the first torque and the second torque, respectively.

Abstract: The specification discloses a braking method for a single-phase motor, which is applied to a single-phase DC brushless motor driven by a three-phase motor driving IC. The invention uses a control unit to compute the rotational speed of the single-phase motor according to a rotation number signal generated by the motor rotational axis. When the rotational speed is below a threshold, the motor driving IC is controlled to stop rotating the single-phase motor. Through the single-phase motor braking method disclosed herein, the problem of unable to determine the rotational direction of a single-phase motor within a three-phase motor driving IC existing in the prior art can be solved by merely modifying the program in the control unit without adding system elements.

Abstract: A rotating flux vector is set up in a motor or generator's rotor by simultaneously energizing two phase windings while the rotor remains stationary, wherein each phase winding may be energized by the same or different excitation voltages. Respective tap voltages are then recorded at this first flux position. Thereafter, the two phase windings are simultaneously energized by another voltage excitation, wherein each phase is energized at the same or different voltages, causing a new flux position to occur. Once again, respective tap voltages are recorded. This process may be repeated for various rotations of the motor's flux. The measured tap voltages are evaluated to determine the location of the rotor, without actually moving it. The present invention is applicable to SR and non-SR machines having a plurality of phases and pole configurations.