Abstract: A power converter having a first switch and a first unidirectional current device that conducts current unidirectionally. The first switch and first unidirectional current device are interconnected such that when interconnected with a dc voltage supply, battery, and first phase winding of an electrical machine: (1) a first operational state exists in which a conductive state of the first switch causes the dc voltage supply to conduct current through the first switch and first phase winding, so as to store energy within the first phase winding and (2) a second operational state exists in which a non-conductive state of the first switch causes the first phase winding to discharge its stored energy by conducting current through the first unidirectional current device and battery, so as to store energy in the battery.

Abstract: An AC machine control system for an AC machine (motor, generator, transformer, etc.) having open-ended windings, the control system comprising a drive circuit configured to transfer AC power between a first set of voltages and each end of the open-ended windings without the use of a substantial energy storage device, while eliminating common mode voltage and/or injecting zero sequence voltages.

Abstract: A brushless, synchronous machine is provided. A brushless, synchronous motor includes a rotor, a stator extending around at least a portion of the rotor and separated from the rotor by an air gap, a first stator winding, a second stator winding, a third stator winding, a drive circuit, a first rotor winding, a second rotor winding, and a diode bridge. The first stator winding, the second stator winding, and the third stator winding are mounted to the stator to generate square waves. The drive circuit is configured to provide a current to the first stator winding, the second stator winding, and the third stator winding, wherein the current includes an alternating current (AC) component and a direct current (DC) component. The first rotor winding is mounted to the rotor to form a plurality of third harmonic coils. The second rotor winding is mounted to the rotor.

Abstract: When a rectangular wave voltage control mode is selected, a control apparatus estimates the output torque of an alternating-current motor based on the outputs of a current sensor and a rotation angle sensor, and executes torque feedback control by adjusting the phase of rectangular wave voltage based on the difference between the torque estimated value and a torque command value. The control apparatus executes a switching interruption that outputs a control command to a switching element of an inverter every 60 degrees of electrical angle, and executes an angle interruption that samples the phase currents of the alternating-current motor based on the output of the current sensor and converts those phase currents into a d-axis current and a q-axis current every predetermined electrical angle that is set beforehand.

Abstract: A method for driving a brushless motor including a first coil and a second coil for two phases but does not include a coil for one of three phases. A three-phase inverter circuit is connected to the first coil and the second coil. Currents having a phase difference corresponding to an electrical angle of 60 degrees are applied to the first coil and the second coil to generate a circular rotating magnetic field.

Abstract: An inverter control apparatus that controls a three-phase inverter which transforms a direct-current voltage into an alternating three-phase voltage, the inverter control apparatus includes: a voltage command vector generation portion that generates a first voltage command vector for specifying a vector of a voltage to be applied to a three-phase load that is connected to the inverter; a voltage command vector correction portion that in performing overmodulation with the inverter, corrects the first voltage command vector by setting a limit onto a coordinate-axis component of the first voltage command vector on an ab coordinate system to generate a second voltage command vector, wherein the inverter is so controlled that a voltage depending on the second voltage command vector is applied to the load, and the ab coordinate system is a coordinated system that depending on a phase of the first voltage command vector with respect to a predetermined fixed axis on a two-dimensional fixed coordinate system, rotates

Abstract: A control system is designed to use a plurality of voltage vectors expressing a switching mode for a switching circuit to thereby control a difference between a current actually flowing through a multiphase rotary machine and a command current value therefor within an allowable range. The plurality of voltage vectors include a zero vector that allows line-to-line voltages in the multiphase rotary machine to be all zero, and a plurality of non-zero vectors that allow at least one of line-to-line voltage in the multiphase rotary machine to be nonzero. A drive unit is configured to switch only one phase of the switching element for each shift of the switching mode to thereby shift, in accordance with a preset switching pattern, the switching mode from a specified one of the plurality of non-zero vectors to the specified one of the plurality of non-zero vectors via the zero vector.

Abstract: Systems and methods are provided for charging energy sources with a rectifier using a double-ended inverter system. An apparatus is provided for an electric drive system for a vehicle. The electric drive system comprises an electric motor configured to provide traction power to the vehicle. A first inverter is coupled to the electric motor and is configured to provide alternating current to the electric motor. A first energy source is coupled to the first inverter, wherein the first inverter is configured to provide power flow between the first energy source and the electric motor. A second inverter is coupled to the electric motor and is configured to provide alternating current to the electric motor. A rectifier is coupled to the second inverter and configured to produce a direct current output. The second inverter is configured to provide power from the rectifier to the electric motor.

Abstract: The invention relates to a vehicle drive system, comprising an electromechanical converter, in particular an electric variable transmission. The converter is provided with a primary shaft having a rotor mounted thereon, a secondary shaft having an interrotor mounted thereon and a stator, fixedly mounted to a housing of the electromechanical converter. Viewed from the primary shaft in radial direction, the rotor, the interrotor and the stator are arranged concentrically relative to each other. Further, the primary shaft is arranged for being driven by an output shaft of an engine and the secondary shaft is arranged for driving an input shaft of a transmission unit.

Abstract: The synchronous motor driving apparatus including position sensors provided in the synchronous motor, a current polarity detection circuit for detecting the polarities of the currents in the respective phase windings of the synchronous motor, an inverter driving the synchronous motor, a motor speed calculation unit calculating the rotational speed of the synchronous motor depending on the output signals from the position sensors, a speed control unit outputting a first voltage adjusting component (q-axis current command value Iq*) to cause the rotational speed of the synchronous motor to approach a speed command value and a phase control unit outputting a second voltage adjusting component (d-axis current command value Id*) to cause the phase differences between the phases of the position sensor signals and of the currents in the respective phase windings of the synchronous motor to become a predetermined value.

Abstract: An AC/DC converting circuit, has a full-bridge rectifier having two input terminals and two output terminals, a first capacitor, a second capacitor, an electronic switch having a control terminal, a trigger circuit having an input terminal and an output terminal, and a detecting circuit having an input terminal and an output terminal.

Abstract: Methods and apparatus are provided for aligning a control reference axis with a magnetic north of a permanent magnet motor. The method includes the steps of injecting a predetermined stator current on an estimated reference axis of the permanent magnet motor and introducing predetermined error on the estimated reference axis. The method further includes the steps of determining if a speed of the permanent magnet motor is greater than a predetermined threshold speed and setting the control reference axis to 180° added to the estimated reference axis if the speed of the permanent magnet motor is greater than the predetermined threshold speed or setting the control reference axis to the estimated reference axis if the speed of the permanent magnet motor is less than or equal to the predetermined threshold speed.

Abstract: A device for controlling a polyphase rotating machine comprising a stator, a rotor, and sensors, the device being capable of receiving at least one first sensing signal (V, W, U) representing a position of the rotor relative to the stator and outputted from a first sensor (16; 18; 14), and a second sensing signal representing the position and phase-shifted relative to the first signal (V, W, U). The second signal is outputted from a second sensor. The control device comprises: means (K, R) for combining the first and the second sensing signals (U, V, W) into a combined signal (Ku; Kv; Kw) including at least one controlled switching signal with a variable cyclic ratio. The combined signal (Ku; Kv; Kw) is based on the cyclic ratio and enables the machine to be controlled.

Abstract: A motor drive apparatus drives a motor by a first motor drive part and a second motor drive part. The first motor drive part includes a first inverter for supplying current to a first winding set. The second motor drive part includes a second inverter for supplying current to a second winding set. A control unit starts to supply currents to the first winding set and the second winding set at the same time after waiting for completion of all failure detection processing with respect to each of the first motor drive part and the second motor drive part.

Abstract: A method for starting a motor (14) with a bidirectional rotation direction, to rotate a fluid circulation centrifugal pump (10) having a predetermined optimum hydraulic efficiency depending on the starting rotation direction thereof. The method provides an initial motor (14) starting in either rotation direction, with subsequent pump (10) rotation in the same direction and, subsequently, a periodical interruption and restoration of the motor (14) power feeding as many times (N, N?) as to ensure the motor (14) starting, at least one or more times within a predetermined time interval (Ttot, Ts), in the rotation direction which corresponds to the predetermined pump (10) optimum hydraulic speed.

Abstract: An example power management arrangement includes a motor controller configured to communicate power to a motor drive bridge to drive a motor. The motor controller is configurable to selectively receive power from each of a first power supply and a second power supply. The voltage of the power from the first power supply is different than a voltage of the power from the second power supply. An example power adjusting method includes receiving power at a motor controller, adjusting a voltage of the received power using the motor controller, communicating the power with the adjusted voltage from the motor controller to a motor drive bridge to drive a motor.

Abstract: The present invention aims to provide a synchronous motor drive system that is capable of suppressing ripples in current while reducing switching loss. The system includes three-phase inverters 201-203, a control circuit 400 for controlling the operations of the three-phase inverters and a synchronous motor 300 including a plurality of three-phase coils. To control the operations of the three-phase inverters, the control circuit 400 causes the three-phase inverters 201 and 203 and the three-phase inverter 202 to use different carrier frequencies to generate three-phase AC power, and each of the three-phase inverters supplies a different one of the three-phase coils with three-phase AC power.

Abstract: A device for controlling a polyphase rotating machine, the machine comprising a stator, a rotor, and sensors, the device being capable of receiving: at least one first sensing signal (U; V; W) representing a position of the rotor relative to the stator and output by a first sensor; and a second sensing signal (V; W; U) representing the position and phase-shifted relative to the first signal and output by a second sensor. The control device comprises: means (K, R) for combining the first and second sensing signals into a combined signal, the means including at least one controlled switching element capable adopting at least in two states, the combined signal being based on a state of the first element and enabling the machine to be controlled.

Abstract: Systems and methods are disclosed to provide torque linearity in the field-weakening region for an electric (e.g., IPM) machine. The systems and methods implement a field weakening and a torque linearity control loop for linearizing torque generated by an electric machine. As a result, torque linearity is maintained when the electric machine operates in the field weakening region.

Abstract: A semiconductor power converter includes a power converter for converting direct current to three-phase alternating current or vice versa; a means for detecting a current in an alternating current side of the power converter; a means for providing a current reference in the alternating current side of the power converter; a current controller for calculating a voltage reference in the alternating current side of the power converter to match the current reference and a value of the detected current; and a pulse width modulation means for controlling the power converter through pulse width modulation based on the voltage reference, wherein the current reference is used in place of the value of the detected current for at least one phase current among three phase currents in the alternating current side.

Abstract: A combined device for instantaneous control of power transfer between two cores of a direct current network and for powering an alternating current engine. The device includes: an assembly of two three-phase inverters, each including three switching cells connected to the engine, which engine includes three stator windings connected to the two three-phase inverters, and a module for controlling the assembly, which ensures both an adjustable direct current power transfer and enables stabilization of the direct current voltage of one of the two cores if it is not connected, and the control of the engine.

Abstract: A method and circuit arrangement for determining position of the rotor of an electronically commutated motor, wherein the rotor has magnetic axes having different permeances. Voltage is applied to stator phases, and resultant phase currents are monitored for purpose of determining rotor position in the standstill state of the motor. First and second rise times of phase currents are determined until predetermined limit values are reached in unsaturated state. The assignment of a magnetic axis to a stator phase is determined from first rise times of the currents in unsaturated state of the rotor core, and the polarization of the rotor is determined from second rise times of currents upon energization with saturation effects. After run-up of the motor, initial energization of the stator can be determined comparing levels of the magnet wheel voltages and corrected by changing the commutation of stator energization.

Abstract: In various embodiments, an electric motor drive system (400, FIG. 4) and a motor vehicle (1000, FIG. 10) include an inverter (404, FIG. 4) adapted to generate (604, FIG. 6), based on inverter control inputs, a number, N, of phase current waveforms (118, FIG. 1), and a phase current sampling apparatus (408, FIG. 4) having a same number, N, of current sensors (502, 503, 504, FIG. 5). Each of the current sensors is adapted to receive one of the phase current waveforms, and the current sensors are adapted simultaneously to sample the phase current waveforms and to generate digital values representing amplitudes of the phase current waveforms. The system and motor vehicle also include a controller (410, FIG. 4) adapted to receive the digital values, to perform an evaluation of the digital values, and to generate the inverter control inputs (462, FIG. 4) based on the evaluation.

Abstract: In a motor controller, in the case that occurrence of a failure of electric current flow is detected in any phase of a motor, a phase electric current command value changing in accordance with a secant curve or a cosecant curve with an asymptotic line at a predetermined rotation angle corresponding to the phase in which the failure of electric current flow has occurred is calculated. The calculated phase electric current command value is limited in such a manner as to become within a predetermined range. In the case that a rotation angle of the motor exists in a range in which the phase electric current command value is limited, the execution of an anomaly detection of a control system utilizing an electric current deviation of a d/q coordinate system is inhibited.

Abstract: A motor controller and an electric power steering system including the motor controller are provided. The motor controller has a microcomputer. When the on time of one of the lower potential-side FETs corresponding to the respective phases in a drive circuit becomes shorter than the detection time for detecting the phase current value, the microcomputer estimates the phase current value of the electric current undetectable phase based on the phase current values of the two phases other than the electric current undetectable phase corresponding to the relevant FET (blind estimation). When electric current detection is performed in the blind estimation, motor control signals are output, by which the switching state of the switching arm of the electric current undetectable phase is maintained and the power loss caused by the switching operation of the FETs in the two phases other than the electric current undetectable phase is compensated for.

Abstract: A motor driving apparatus comprises a charge/discharge control circuit for controlling charge to or discharge from a capacitor connected in parallel in a link section between a converter and an inverter, and a current control means for controlling discharge current from the charge/discharge control circuit. The current control means controls discharge current from the charge/discharge control circuit based on input current to the inverter or output current from the converter so that output current from the converter is equal to a prescribed value.

Abstract: A cleaner that can have the sufficient capability of collecting pollutant particles by a battery voltage as well as a AC voltage. The cleaner uses a switched reluctance motor to rotate a collecting fan. The switched reluctance motor is driven by a motor driver in one of a PWM mode or a pulse trigger mode. The motor driver drives the switched reluctance motor using one of the battery voltage and a DC voltage converted from the AC voltage, depending on whether the AC voltage is received. The PWM mode and the trigger mode are switched depending on whether the AC voltage is received. Accordingly, the cleaner makes it possible to reduce the time taken to clean up pollutant particles using the battery voltage to the time taken to clean up the pollutant particles using the AC voltage.

Abstract: A heat dissipation system for an electronic device comprises a base, a fan, a pulse width modulation speed control circuit controlling the speed of the fan, a converter outputting a voltage signal, a selection switch connected to the motor, and a control element provided on the base, connected to the switch and to the converter. When the control element is operated, the switch selectively enables the motor be connected to the output of the pulse width modulation speed control circuit or to the output of the converter, and when the motor is electrically connected to the converter, the control element can modify the output voltage of the converter.

Abstract: A system and method for starting and regulating a wound rotor motor (120) including a phase-controlled SCR converter (150) and a drive circuit (130, 140) having a voltage source inverter (140) and a voltage source converter (130). The SCR converter (150) regulates power transmitted to the drive circuit from the rotor of the motor (120) so that the ratings of the drive circuit are not exceeded.

Abstract: A motor controller includes an output voltage modulator that outputs sinusoidally-modulated voltage for driving a motor; a modulation factor specifier allowing specification of a modulation factor greater than 1.0 for the output voltage; a current detector that detects current flowing in the motor; and a field-oriented controller that divides the current detected by the current detector into a d-axis current component and a q-axis current component and that conforms each of the components to a command current produced based on a command rotational speed; a rotational position estimator that estimates motor rotational speed and rotor rotational position for use by the field-oriented controller; wherein the position estimator includes a filter that smoothes a d-axis induced voltage obtained during the estimation, and the motor rotational speed and the rotor rotational position are estimated based on the d-axis induced voltage smoothed by the filter.

Abstract: Methods and systems are provided for operating an electric motor having at least one winding coupled to first and second power supplies. A torque command for the electric motor is received. A present power reserve for the first and second power supplies is determined based at least in part on the torque command. An operating voltage for the second power supply is determined based on the present power reserve. The operating voltage for the second power supply is applied to the at least one winding. The application of the operating voltage allowing the present power reserve to flow between the first and second power supplies and the motor.

Abstract: A control apparatus for an AC rotary machine, including first voltage command calculation means for calculating first voltage commands from current commands, an angular frequency, and constant set values of the AC rotary machine, second voltage command calculation means for calculating second voltage commands on the basis of difference currents between the current commands and current detection values, so that the difference currents may converge into zero, third voltage command calculation means for calculating third voltage commands by adding the first voltage commands and the second voltage commands, voltage application means for applying voltages to the AC rotary machine on the basis of the third voltage commands, and constant measurement means for calculating the constant set values on the basis of the second voltage commands.

Abstract: A hand-held power tool has a device housing and at least one grip disposed on the device housing. An electric drive motor is arranged in the device housing for operating a working tool. A battery pack provides electric energy for operating the electric drive motor. An electronic control unit is connected to the electric drive motor and the battery pack. An operating element disposed on the grip controls the electric drive motor. An electric actuator is acted upon by the operating element and the output signal of the electric actuator is supplied to the electronic control unit. Electric energy is applied to the electric drive motor by the electronic control unit as a function of a position of the operating element, wherein in a first dead travel range of the operating element that adjoins an inoperative position of the operating element the supplied electric energy is zero.

Abstract: The invention relates to a method and an arrangement for braking a synchronous motor (4) used with a frequency converter (2). The braking current of the motor (4) is controlled by connecting only the negative changeover contacts (10) of the inverter (16) of the frequency converter (2) or alternatively by connecting only the positive changeover contacts (17) of the inverter (16) of the frequency converter. The arrangement comprises a control (3), which is arranged to control in a braking situation only the negative changeover contacts (10) of the frequency converter (2) or alternatively only the positive changeover contacts (17) of the frequency converter (2).

Abstract: An electric compressor control device includes: an inverter for electric compressor motor; a communication microcontroller arranged in a low-voltage region for transmission of an instruction signal via a high-speed communication bus; and a control microcontroller arranged in a high-voltage region and connected to the communication microcontroller via an insulation element for transmitting the instruction signal from the communication microcomputer as an inverter control signal to the inverter. The power voltage of the communication microcomputer is supplied from a low-voltage power source. The voltage from the low-voltage power source is transformed via a transformer and supplied as a power voltage of the control microcontroller.

Abstract: Systems and methods are disclosed to provide torque linearity in the field-weakening region for an IPM machine. The systems and methods adjust the q-axis and the d-axis components of the stator current commands of the IPM machine using a flux weakening and a torque linearity control loop respectively. Thereby, torque linearity is maintained during the field weakening region of operation of the IPM machine.

Abstract: A power converter includes a PWM active rectifier and controller that minimize harmonic ripple currents on the DC link during an engine start mode (first stage) in which power is provided to an AC starter motor. The PWM active rectifier and controller also minimize harmonic currents on AC input lines during a second stage (active filter mode). The power converter also includes a PWM inverter and corresponding inverter controller that controls the performance of the AC starter motor during the first stage based on mode selection input received. The power converter system further includes pre-charge circuitry that charges a DC link capacitor located within the power converter system to a desired level prior to providing the power converter system with AC power.

Abstract: A low-cost sine-wave drive for a 3-phase permanent magnet synchronous AC machines (PMSM) in open-loop control is based on the measurements of two linear Hall sensors. The two Hall sensors are excited by a magnetic ring with the same pole number as the PMSM rotor magnet and sinusoidal flux distributions. The output signals of the Hall sensors are unified through a two-phase-type phase-lock-loop in order to reduce the impact of the sensor mounting non-uniformity during mass production. The peak torque and speed of motor is simply controlled by adjusting the amplitude of pulse-width-modulation carrier. Smooth torque control is achieved due to sinusoidal 3-phase currents. Such a simple sine-wave drive can be achieved with or without the assistance of a micro-controller unit (MCU). No current sensor is required for the motor phase current detection. This motor can be used in industrial applications where there is no strict requirement on torque response and constant speed control of PMSM machines.

Abstract: In an AC motor driving circuit from an AC power supply and a DC power supply, a matrix converter and a power conversion circuit are provided. The matrix converter is connected between an output of the AC power supply and an input of the AC motor. In the power conversion circuit, switches back-to-back connected to diodes, and bidirectional switches are series-connected, respectively. Connection junctions between the switches and the bidirectional switches are connected to the input phases of the AC motor, respectively. The other terminal of each switch is connected to one terminal of the DC power supply while the other terminal of each bidirectional switch is connected to the other terminal of the DC power supply. In this manner, the number of switches through which electric power passes at the time of operation is reduced so that loss can be reduced. Accordingly, power conversion efficiency can be improved.

Abstract: The invention relates to a power supply appliance (14) of a transport system, which power supply appliance comprises a power rectifier (1) of the motor, an AC voltage circuit (8), control voltage circuit (13), a power supply circuit (7) of the safety devices (10), an AC/DC transformer (9) fitted between the AC voltage circuit and the control voltage circuit, which is fitted to supply power from the AC voltage circuit (8) to the control voltage circuit (13), as well as a power shaping circuit (4).

Abstract: A multi-phase electric motor comprises a stator comprising a plurality of wire coils surrounding a non-magnetizable core; a rotor with permanent magnets embedded therein, the rotor being disposed adjacent to the stator, the rotor being mounted on a rotatable drive shaft; a power source; a position sensor operably connected to the rotor; and a control circuit operably connected to the power source, the position sensor, and the wire coils, for controlling distribution of electrical energy to the wire coils. In this motor the control mechanism transfers electrical charge from a first coil to a second coil.

Abstract: An inexpensive, productivity-enhanced single-phase AC synchronous motor in which stabilized synchronous pull-in can be carried out by suppressing generation of counter torque during a starting operation. Starting operation is performed while the energizing range of motor current is suppressed such that the energizing direction of motor current waveform lagging in a phase behind the output waveform from a detection sensor (17) is switched at at least the zero cross point of the output waveform from the sensor when the number of revolutions of a permanent magnet rotor (1) reaches a predetermined number of revolutions in the vicinity of the synchronous number of revolutions.

Abstract: A motor controller (101) according to the invention comprises an inverter circuit (3) for driving a brushless motor (4) and a control unit for controlling the rotational speed of the brushless motor (4) by controlling the phase of the motor current of the brushless motor (4) through the inverter circuit (3).

Abstract: A delta type inverter is used in conjunction with a closed-loop motor controller to provide a control device for driving a three phase brushless direct current motor. The delta inverter has one-half of the solid state switching devices and diodes required by conventional bridge type inventers, thereby improved reliability, and enabling the motor control device to have reduced size, cost and weight. The closed-loop motor controller may include a torque loop for reducing torque ripple during operation of the motor.

Abstract: A first duty ratio of a drive command signal is computed by comparing a level of the drive command signal with a first threshold value at a motor controller of a blower motor apparatus. A second duty ratio of the drive command signal is computed by comparing the level of the drive command signal with a second threshold value at the motor controller. A control signal is generated based on the first duty ratio and the second duty ratio in the motor controller and is used to drive a blower motor of the blower motor apparatus.

Abstract: Methods and apparatus are provided for discharging a direct current (DC) bus providing power to a motor control circuit in an electric motor system. The method includes the steps of detecting a predetermined discharge signal and generating operational control signals comprising phase currents for dissipating energy from the DC bus through a passive load in response to detecting the predetermined discharge signal, wherein the passive load includes motor windings of an electric motor of the electric motor system. The method also includes the step of providing the operational control signals to the motor control circuit for discharging the DC bus through the motor control circuit and the motor windings of the electric motor.

Abstract: Methods and apparatus are provided for improved discharge of a DC bus which provides power to an inverter. An electric motor system provided with the improved discharge method for discharge of the DC bus includes an electric motor, the inverter which provides electric control for the permanent magnet electric motor, the direct current (DC) bus which provides power to the inverter, and a processor. The processor generates operational control signals and provides such operational control signals to the inverter. In response to detecting a predetermined discharge signal, the processor generates operational control signals for generating a ripple current in motor windings of the electric motor to dissipate energy from the DC bus through a passive load, the passive load including the motor windings of the electric motor.

Abstract: The present invention provides a power module, power converter, and vehicular electric machine system capable of reducing inductance of a peripheral section of an output terminal in a power module, and additionally, reducing a surge voltage. A positive emitter conductor 3 connected to an emitter electrode of a positive power semiconductor element Mpu and an output terminal U are electrically interconnected by using a plurality of aluminum wires 7, a negative collector conductor 4 connected to a collector electrode of a negative power semiconductor element Mnu and the output terminal U are electrically interconnected by using a plurality of aluminum wires 9, and the positive emitter conductor 3 connected to the emitter electrode of the positive power semiconductor element Mpu and the negative collector conductor 4 connected to the collector electrode of the negative power semiconductor element Mnu are further electrically interconnected by using a plurality of aluminum wires 8.

Abstract: Two apparatuses are disclosed for providing a dynamically varying water surge in a salt-water reef aquarium. The first apparatus is a micro-controller based variable frequency reef surge drive 100 for an AC permanent magnet synchronous motor (PMSM) submersible aquarium pump. Drive 100 comprises voltage conversion circuitry 105, xmicro-controller 110, reef-surge generation program 115, variable frequency drive 118, mode switch 130 and tidal cycle switch 135. Three user-selectable modes of operation are provided: a random frequency mode, a fixed-program mode and a tidal mode. A second apparatus comprises a novel submersible AC PMSM pump with dual impeller assemblies and dual input and output chambers for supporting forward and reverse flow through an AC PMSM pump.

Abstract: A brushless synchronous motor is provided in a simple configuration and at a low cost. The brushless synchronous motor comprises a rotor having salient magnets arranged in a circumferential direction, a stator having driving magnetic poles arranged in the circumferential direction, and an exciting coil wound around each driving magnetic pole, where the rotor is made in a non-circular profile. For example, the rotor may comprise a cylindrical body which has at least one flat surface perpendicular to one magnetic pole direction of the rotor, or a cylindrical body having an elliptic profile with a longer diameter in one magnetic pole direction of the rotor. A detector circuit is associated with each of a predetermined number of exciting coils for outputting a detection signal indicative of the impedance of the exciting coil in accordance with the distance between the driving magnetic pole and rotor, to detect a rotating angle of the rotor.