WO1997018617A1 - Procede et appareil permettant d'accroitre le rendement d'un moteur a aimant permanent - Google Patents

Procede et appareil permettant d'accroitre le rendement d'un moteur a aimant permanent Download PDF

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Publication number
WO1997018617A1
WO1997018617A1 PCT/US1996/018446 US9618446W WO9718617A1 WO 1997018617 A1 WO1997018617 A1 WO 1997018617A1 US 9618446 W US9618446 W US 9618446W WO 9718617 A1 WO9718617 A1 WO 9718617A1
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WO
WIPO (PCT)
Prior art keywords
switch
motor
motor coil
power source
electrical energy
Prior art date
Application number
PCT/US1996/018446
Other languages
English (en)
Inventor
Denis L. Palmer
Robert A. Palmer, Jr.
Robert A. Palmer, Sr.
David Ng
Original Assignee
Palmer, Charles, L.
Palmer, Douglas, L.
Palmer, Stanley, B.
Staker, Lynn, L.
Cline, Keith, W.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Palmer, Charles, L., Palmer, Douglas, L., Palmer, Stanley, B., Staker, Lynn, L., Cline, Keith, W. filed Critical Palmer, Charles, L.
Publication of WO1997018617A1 publication Critical patent/WO1997018617A1/fr

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Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
    • H02P6/08—Arrangements for controlling the speed or torque of a single motor
    • H02P6/085—Arrangements for controlling the speed or torque of a single motor in a bridge configuration
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
    • H02K11/30—Structural association with control circuits or drive circuits
    • H02K11/33—Drive circuits, e.g. power electronics
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K25/00—DC interrupter motors or generators
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K29/00—Motors or generators having non-mechanical commutating devices, e.g. discharge tubes or semiconductor devices
    • H02K29/06—Motors or generators having non-mechanical commutating devices, e.g. discharge tubes or semiconductor devices with position sensing devices
    • H02K29/10—Motors or generators having non-mechanical commutating devices, e.g. discharge tubes or semiconductor devices with position sensing devices using light effect devices

Definitions

  • This invention pertains to direct current electric motors using permanent magnets, and more particularly, to methods and apparatus for improving the efficiency of direct current electric motors
  • Prior art electric motors are powered by a power source connected to electromagnetic coils
  • the magnetic field produced by each motor coil repels a magnetic field produced by an adjacent permanent magnet on a rotor, which causes a motor shaft affixed to the rotor to rotate
  • the power is removed from the motor coils
  • the magnetic field in each motor coil collapses and thereby generates electrical energy in the coil where it is dissipated as heat Accordingly, the energy remaining in the motor coils when the power is removed is simply wasted
  • the invention is directed to an electric motor for rotating a motor shaft in response to electrical energy
  • the electric motor includes a motor coil that, in 9- response to electrical energy, produced a magnetic field that is used to rotate the motor shaft
  • the electric motor also includes a power source that produces the electrical energy used to cause the motor coil to produce the magnetic field Coupled between the power source and the motor coil is a first switch that forms a first closed circuit between the power source and the motor coil when the first switch is closed
  • the electrical motor also includes a storage element such as a capacitor, that is coupled to the motor coil When the first switch is opened, the magnetic field in the motor coil collapses which converts the magnetic energy in the magnetic field to electrical energy which is transmitted to the storage element for storage The stored energy can be returned to the power source or used directly to power the motor coil when the first switch is closed
  • an apparatus provides bi-directional control of a motor coil
  • the apparatus includes a motor controller that provides a first control signal for causing the motor coil to form a magnetic field of a first polarity
  • the motor coil also provides a second control signal for causing the motor coil to form a magnetic field of a second polarity
  • the motor coil causes a motor shaft to rotate in a first rotational direction when the magnetic field is ofthe first polarity and causes the motor shaft to continue to rotate in the rotational direction when the magnetic field is ofthe second polarity
  • a first switch coupled between the power source and the motor coil receives the first control signal from the motor controller and, in response, closes to form a first closed circuit
  • the first closed circuit enables electrical current to flow from the power source through the first switch and the motor coil in a first direction such that the motor coil forms the magnetic field of the first polar orientation
  • a second switch coupled between the power source and the motor coil receives the second control signal from the motor controller and, in response, closes to form a second closed circuit
  • the second closed circuit enables electrical energy to flow through the second switch and the motor coil in a second direction such that the motor coil forms the magnetic field of the second polar orientation
  • the apparatus includes a first counter voltage protection element that is connected and structured to prevent the electrical energy from flowing through the first switch in the second direction
  • the apparatus includes a second counter voltage protection element that is connected and structured to prevent the electrical energy from flowing through the second switch in the first direction
  • the apparatus preferably includes a first spike protection element coupled and structured to protect the first switch against power spikes from the power source
  • the invention is directed to a method for operating an electric motor having a motor coil coupled to a power source.
  • the method energizes the motor coil in a manner that causes the motor coil to produce a magnetic field that stores magnetic energy.
  • the method switches off power to the motor coil such that the magnetic field collapses and the magnetic energy is converted to electrical energy
  • the method stores the electrical energy for subsequent use in operating the electric motor
  • the switching step is performed by an electronic switch and the method includes protecting the electronic switch against power spikes from the power source and from the power generated by collapsing fields of same coil and other coils While energizing the motor coil, electrical energy flows through the electronic switch in a first direction.
  • the method preferably includes preventing the electrical energy from flowing through the electronic switch in an opposite direction when power to the motor coil is switched off.
  • Figure 1 is an axial section through a first embodiment of a motor according to the prior art
  • Figure 2 is a Section A-A from Figure 1 showing the stator ofthe prior art.
  • Figure 3 is an axial section through a second embodiment of a motor according to the prior art.
  • Figure 4 is Section B-B from Figure 3 showing the stator ofthe motor.
  • Figure 5 is Section C-C from Figure 3 showing an end view of a rotor of the motor
  • Figure 6 is a linear projection of a circumference through two rotors and a stator ofthe motor of Figures 3-5.
  • Figure 7 is the view of Figure 6 after 15 degrees of rotor rotation.
  • Figure 8 is the view of Figure 6 after 30 degrees of rotor rotation.
  • Figure 9 is the view of Figure 6 after 45 degrees of rotor rotation
  • Figure 10 is a schematic of a distributor circuit in the prior art for determining the cycling sequence
  • Figure 1 1 is a transverse section illustrating one embodiment of a distributor means in the prior art
  • Figure 12 is a transverse section illustrating a second embodiment of a distributor in the prior art
  • Figure 13 is a transverse section illustrating a third embodiment of a distributor means in the prior art
  • Figure 14 is a schematic diagram of a first circuit for controlling and improving the efficiency of an electric motor
  • Figure 15 is a schematic diagram of a second circuit for controlling and improving the efficiency of an electric motor.
  • Figure 16 is a schematic diagram of a third circuit for controlling and improving the efficiency of an electric motor
  • Figure 17 is an elevational view of a mechanism for controlling the efficiency of an electric motor
  • Figure 18 is a cross-sectional view of a first mechanism for controlling the efficiency of an electric motor
  • Figure 19 is a cross-sectional view of a second mechanism for controlling the efficiency of an electric motor.
  • Figure 20 is a cross-sectional view of a third mechanism for controlling the efficiency of an electric motor.
  • Figure 21 is a timing diagram of an electric motor according to the present invention, where the electric motor is running at full output
  • Figure 22 is a timing diagram of an electric motor according to a first aspect of the present invention, where the electric motor is running at reduced output
  • Figure 23 is a timing diagram of an electric motor according to a second aspect ofthe present invention, where the electric motor is running at reduced output
  • Figure 24 is a timing diagram of an electric motor according to the present invention, showing the effect of an improved aspect of the present invention
  • Figure 25 is a timing diagram of an electric motor according to the present invention, showing the method of causing the motor to change rotational direction
  • Figure 26 is a timing diagram of an electric motor according to the present invention, showing the method of causing the motor to stop in a desired position
  • Figure 27 is a schematic diagram of a drive circuit for bi-directional control of a motor coil according to the present invention
  • Figure 28 is a timing diagram of an electric motor employing the drive circuit of Figure 27
  • Figure 29 is a schematic diagram of an alternate drive circuit according to the present inventioin
  • Figure 30 is a second alternate drive circuit according to the present invention.
  • Figure 31 is a timing diagram of an electric motor employing the drive circuit of Figure 30
  • Figures 1 and 3 the prior art includes a magnetic motor 1 containing stator 2, rotors 3, a central shaft 4, a distributor means 5 and a housing 6 Said stators 2, rotors 3 and housing 6 are made of nonmagnetic material
  • Each stator 2 has a plurality of solenoid coils 7 disposed with equal radial spacing around a circumference near the outside circumference of said stators 2
  • the number of said solenoid coils 7 in each stator 2 is always an integral multiple of four
  • the cylindrical axis of each said solenoid coil 7 is parallel to the axis of the central shaft 4
  • the solenoid coils 7 are wound on cores with varying magnetic reluctance depending on desired output, RPM and torque ofthe motor
  • Each rotor 3 has a plurahty of permanent magnets 8 disposed at equal radial spacing around the same circumference at which said solenoid coils 7 are disposed
  • the number of permanent magnets 8 in each rotor 3 is always one and one-half times the number of solenoid coils 7 in each stator 2
  • the magnetic poles of each permanent magnet 8 are axially aligned with said central shaft 4
  • the relative locations of the stator coils 9 through 12 and the rotor magnets 13 through 18 are such that at least two-thirds of said rotor magnets 0
  • coils 19, 21, 23 and 25 have become progressively more misaligned with magnets 38/27, 29/30, 32/33 and 35/36, respectively, and their primes As the progressive misalignment becomes about half of that shown, coils 19 and 23 are magnetized in the opposite direction as magnets 27 and 33 and their primes, while coils 21 and 25 are magnetized in the opposite direction as coils 19 and 23 This results in rotational forces similar to those described above in explaining Figure 6
  • magnets and coils used in the preferred embodiment aie cylindrical, other shapes may be used
  • coils and/or magnets with square or rectangular cross-sections may be used in this motor in the prior art
  • Distributor means 5 is provided to properly cycle the magnetizing current from a direct current source to the stator coils
  • the cycling sequence for the number of poles in the embodiment of Figures 6-9 can be seen by reference to the circuit shown in Figure 10 wherein the poles of a battery or other direct current source are connected to a pair of switches 43, 43' repeatedly cycling together from contacts 44 to 47 and 44' and 47', respectively Magnetic coils 19, 21, 23 and 25 are in a first bank to be charged simultaneously while the other coils 20, 22, 24 and 26 are in a second bank to be charged as a group alternately with the first bank
  • Non-conductive rotor 42 is fixed on shaft 4 in a housing 48 and has a series of six equally spaced cam lobes on its periphery arranged to sequentially engage spring contacts 44-47 and close them against a stationary contact 43 leading to the positive pole of the direct current source
  • a second cam rotor like rotor 42 is located directly behind it and operates contacts 44 -47' simultaneously to connect them with the negative pole of the direct current source
  • FIG. 12 A second, more preferred distributor arrangement, involving brushes rather than spring contacts, is shown in Figure 12
  • the cam rotors are replaced by electrically conductive rings 142, 142' separated by an insulating ring 143 and each having an insulating core 150 coupled to the shaft 4
  • Spring-loaded brush units 44-47, 15 degrees apart from center to center are mounted in a carrier 151 to move radially inward against the periphery of the ring 142
  • This ring has circumferential cutouts filled with insulating sections 152 leaving conductive lobes therebetween which extend circumferentially preferably slightly more than 15 degrees so that at least one of the brushes will engage one of the conductive lobes
  • lobe 142a is coming into engagement with brush 44 before lobe 142b leaves brush 47.
  • the other conductive ring 142' is arranged in the same manner with respect to a second set of brushes corresponding to contacts 44'-47' in Figure 10 Power to the conductive rings 142, 142' may be by way of brushes 243, 243' engaging their outer faces
  • a photoelectric distributor control can also be used and is preferred for many applications
  • Figure 13 illustrates such a control for the Figure 1 embodiment
  • a disc 242 is mounted on the shaft and has three equally spaced light passage holes 143
  • a plurality of photoelectric cells are arranged so that their light beams 144-147 are spaced apart 30 degrees, center to center, in an arc centered at the axis of the shaft 4
  • the holes 143 in the disc 242 have a diameter corresponding to a chord connecting two of the centers of adjoining of the light beams 144-147 and the beams have a width so that there will always be the passage IB through the disc 242 of at least one ofthe beams.
  • the amount of overlap in which two of the light beams pass simultaneously through the disc can be varied by varying the size of the light passage holes or by varying the width ofthe light beams at the disc, as for example, by varying the distance of the light emitters of the photoelectric cells from the disc
  • the photoelectric cells operate in a suitable circuit to close control switches 44-47 and 44 -47' sequentially as explained with respect to Figure 10
  • Other systems such as current sensing systems or magnetic switches operating in a similar manner as discussed above, can also be used for a distributor control system
  • the motor of the present invention has improved efficiency because of more efficient use of the magnetic energy within the motor and its simple configuration
  • the motor also provides a modular design which allows components to be disassembled, replaced, and reassembled in a matter of minutes
  • the motor also provides high torque start without high startup current draw, as required of present motors This is expected to substantially extend battery charge life in battery powered motors.
  • a high torque at a wide variety of rotational speeds will eliminate the need for transmissions, thereby eliminating the attendant mechanical power loss inherent in transmissions and also the increased vehicle weight caused by the transmission
  • battery recharging is accomplished when decelerating by returning the current generated within the motor to the storage batteries
  • the motor generates only small fractions of the heat caused by // present-day high torque motors, thereby eliminating a major loss of potential energy which instead is captured and utilized subsequently in the motor
  • the materials used in the motor core can be of many different types depending upon the application of the motor and the operating speed and the torque requirements
  • the core materials for less loss in the core should be essentially a nonmagnetic and nonconductive material such as air, plastic, ceramics, and so forth.
  • the core material can be a high inductive loss materials such as steel iron, or other alloys
  • the size, shape and volume of the materials also has an effect on the output power of the motor and the response time of the motor to input power changes
  • other stationary components of the motor such the case, end plates, stators, and the like are preferably non ⁇ magnetic and non-conductive materials to substantially eliminate any hysteresis effect from occurring in any ofthe motor parts
  • the material in the core may have to be air or a material with similar electromagnetic properties
  • a high torque and/or a low speed motor may require a larger core of a high magnetic density, such as steel, iron, and so forth, to obtain the required output.
  • a motor having a combination of these properties can be created by employing a core selected from several of the magnetic specialty cores available for high density and low electrical loss The ability to change the motor functions by changing core material is unique to this design
  • a change in core material enables the same motor to be changed from high to low speed and low to high torque without the need to rewind the motor.
  • a motor that needs to put out constant torque from an unstable power source could be designed to be very slow to react to power level changes and therefore effectively smooth out power transients
  • the motor will be more immune to variable input power than present-day motors
  • One aspect of the invention eliminates a majority of these losses by cutting the inductive losses by removal of all substantially conductive and magnetically inductive materials from the proximity ofthe coils. It also works by increasing the number of turns on the coils to obtain a high DC electrical resistance in comparison to a typical motor Because of the decreased inductive resistance ofthe resulting motor, a majority of the heat loss is eliminated, thereby increasing the efficiency ofthe motor
  • the present invention also includes a circuit to capture the energy left in each motor coil after the required motion in the rotor has been accomplished When the power source powering the motor coil is switched off, the electromagnetic field in the coil collapses The energy is recaptured by bleeding off the electrical energy from collapsing field in the coil and directing the energy from the coil through diodes or other mechanical and electronic means to a storage device, such as a capacitor or battery or combination of these and other storage devices.
  • the storage device stores the electrical energy bled off from the coil until needed for the next coil or until it can be returned to the power source.
  • the recapture of the excess coil energy in a storage device for re-use in powering the motor greatly increases the efficiency ofthe resulting motor
  • one cycle of this process is accomplished by energizing one or more coils through a commutator and/or control circuit
  • the energy from the control circuit produces a magnetic field which reacts with the magnetic fields of the nearby permanent magnets in the rotor which causes a net force on the rotor
  • the commutator and/or control circuit de-energizes or removes the applied voltage from the coil With no voltage, the field produced by the coil begins to collapse and reverts the unused energy in the magnetic field to a voltage
  • the voltage activates an energy return circuit and channels the energy from the coil through one or more diodes or other devices, where it is stored in a storage capacitor or storage device until it is needed or can be returned slowly back to the power source through the power source's intemal resistance
  • prior art motors simply electrically ground the coils or create an open circuit and lose the excess energy in the coils as heat
  • FIG 14 is a schematic diagram of a first drive circuit for controlling and improving the efficiency of an electric motor. Portions of this first drive circuit are very similar to that shown in Figure 10, except that two additional banks, comprising coils 319, 321, 323 and 325 (bank 2) and coils 320, 322, 324 and 326 (bank 4) have been added to allow for four-phase operation of the motor Also additional contacts 300, 301, 302, 303, 300', 301', 302' and 303' have been added to the contacts 43 and 43', respectively.
  • each of the sets of coils is connected to a rectifier and a capacitor, which in turn are connected to the power source (here a battery 400)
  • the coils 19, 21, 23 and 25 in bank 1 (which receives phase A of the voltage waveform applied to the motor) are connected to a conventional rectifier 402 and a capacitor 404
  • the coils 319, 321 , 323 and 325 in bank 2 (which receives phase B of the voltage waveform applied to the motor) are connected
  • each of the collapsing fields When the battery 400 is switched off, the electromagnetic fields in the coils collapse
  • the electric energy produced by each of the collapsing fields is transmitted to a respective one of the rectifiers 402, 406, 410, 414
  • Each rectifier rectifies the energy received from one ofthe coils and transmits a rectified voltage to the corresponding capacitor 404, 408, 412, 416
  • Each capacitor stores the rectified voltage received from its corresponding rectifier and transmits the stored voltage to the battery 400 to recharge the battery or returns the stored voltage to the appropriate coil to re-energize the coil as needed
  • FIG. 15 is a schematic diagram of a second drive circuit for controlling and improving the efficiency of an electric motor
  • any conventional commutation and control circuit 421 supplies the four phases of the motor's voltages through the motor coils 422, 424, 426 and 428
  • the inductance of each of these coils can be controlled to optimize the return of the energy stored in the internal coils of the motor to a storage device or to the power supply, such as the battery 430
  • the motor coils 422, 424, 426 and 428 respectively apply voltages to conventional rectifiers 432, 434, 436 and 438 when the electromagnetic fields in the coils collapse
  • the respective rectifiers rectify the voltages and then apply the rectified voltages to transfer capacitors 440, 442, 444 and 446, which are connected in parall nel to a storage capacitor 448 and the battery 430.
  • Energy which is returned to the storage capacitor 448 can be used to recharge the battery 430 or returned to the commutation and control circuit 421 for application to the motor being controlled.
  • Figure 16 is a schematic diagram of a third drive circuit for controlling and improving the efficiency of an electric motor.
  • two of four phases applied to the motor are controlled by a conventional first commutator and control circuit (not shown) similar to that shown in Figure 15 and the two remaining phases are controlled by a second similar commutator and control circuit (not shown).
  • the drive circuit includes two independent power sources 450, 452. Because of the increased complexity of the two power source arrangements, the single power source motor is generally favored over the two power source motor. Persons skilled in the art of motor design will appreciate that other modifications of this concept can be applied.
  • the drive circuit shown in Figure 16 operates similar to the drive circuit shown in Figure 15 in that the energy from the coils 422, 424, 426, 428 is recaptured in transfer capacitors 454, 456, 458, 460, 462, 464, 466, 468 connected to storage capacitor 470.
  • Each of the transfer capacitors 454-468 is connected in parallel with one of the two power sources 450-452 while the storage capacitor 470 is connected in parallel with the series combination of the two power sources.
  • the diodes 472, 474, 476, 478 are connected to form a first rectifier 480 and the diodes 482, 484, 486, 488 are connected to form a second rectifier 490
  • Electrical energy produced by the collapsing magnetic fields of coils 422-424 is transmitted via the first rectifier 480 to the transfer capacitors 454-468 and the storage capacitor 470
  • electrical energy produced by the collapsing magnetic fields of coils 426-428 is transmitted via the second rectifier 490 to the transfer capacitors 454-468 and the storage capacitor 470.
  • the energy stored in the transfer capacitors 454-468 and the storage capacitor 470 can be returned to the power sources 450, 452 or directly to the coils 422-428 as needed
  • Figure 17 is an elevational view of an electric motor 500 employing an alternate mechanism for controlling the efficiency of the electric motor.
  • the motor 500 includes a motor shaft 502 coupled to a rotor 504 having a plurality of permanent magnets. Further, the motor 500 includes a stator 506 with one or more of the motor coils 422-428 shown in Figures 15 and 16 Connected to the motor coil 422 is the rectifier 432 and the storage capacitor 448 which stores the energy from the collapsing magnetic field on the motor coil
  • the efficiency ofthe motor 500 is controlled by changing the inductance of the motor coils 422-428 shown in Figures 15 and 16 Increasing the inductance by inserting a slug of a magnetically permeable material at least partially within the motor coil 422 will increase the strength ofthe magnetic field produced by the coil, thereby increasing the torque imparted to the motor shaft Similarly, decreasing the inductance by removing the amount of the slug that is within the motor coil will decrease the strength of the magnetic field produced by the coil and decrease the torque imparted to the motor shaft Accordingly, by changing the position of the slugs within the coil, the timing and effectiveness of both the generation of rotational energy and braking effect of the motor can be determined as conditions warrant The efficiency of the motor can be improved further by employing an energy recapture circuit such as the circuit shown in Figure 15, including the rectifier 432 and the corresponding capacitor 440 coupled to a power source (not shown)
  • FIG 18 is a cross-sectional view of a first embodiment of the alternate mechanism for controlling the efficiency of an electric motor
  • the stator 506 includes motor coils 422, 424, 426 electrically connected to a control circuit such as that shown in Figure 15
  • a rack 508, having a plurality of magnetically permeable slugs 510, 512, 514 is mechanically coupled to the stator 506
  • Each of the slugs 510-514 is inserted in a respective one of the motor coils 422-426 to increase the inductance of the motor coils
  • both the coils 422-426 and the rack 508 of magnetic slugs 510-514 move together away from and toward the permanent magnets in the rotor 504 This changes the magnetic coupling between the rotor 504 and the stator magnetic rack assembly which changes the motor torque as described above with respect to Figure 17
  • FIG 19 is a cross-sectional view of a second embodiment of the alternate mechanism for controlling the efficiency of the electric motor 500
  • the stator 506 including the motor coils 422-428
  • the stator 506 is spaced away from the rotor 504 by a fixed distance and the position of the rack 508 of magnetic slugs 510-514 is moved with respect to the stator and rotor
  • each magnetic slug of the rack 508 is inserted into and removed from a corresponding coil of the stator 506
  • Figure 20 is a cross-sectional t view of a third embodiment of the alternate mechanism for controlling the efficiency of the electric motor 500.
  • each coil preferably is coupled via a rectifier to a storage capacitor to capture the energy from the coil when its magnetic field collapses.
  • Figure 21 is a timing diagram of an electric motor according to the present invention, where the electric motor is running at full output. It shows that two adjacent coils in a motor are driven at the full voltage and in phase quadrature with respect to one another. Driving the motor in phase quadrature enables the coils in each bank of coils to drive the motor rather than the four coils per bank of coils shown in Figures 14-16.
  • Figure 22 is a timing diagram of an electric motor according to a first aspect of the present invention, where the electric motor is running at reduced output Like the two adjacent coils depicted in Figure 21, the two adjacent coils of Figure 22 are driven in phase quadrature. However, a reduced output is achieved by reducing the voltage of the waveforms applied to the coils
  • Figure 23 is a timing diagram of an electric motor according to a second aspect of the present invention, where the electric motor is running at reduced output Figure 23 shows that the reduced output can be achieved by running one coil with a full voltage waveform while applying a reduced or zero voltage waveform to the other coil. Any coil can be off for as long as necessary to reduce output.
  • Figure 24 is a timing diagram of a motor coil according to the present invention contrasted with a timing diagram of a prior art motor coils (a) (b).
  • the voltage waveform applied to the prior art motor coil as shown in timing diagram (a) includes a voltage spike at each direction transition.
  • employing a recapture circuit, such as the recapture circuit shown in Figure 15 reduces the undesirable spiking of the voltage waveforms that are applied to the motor coil.
  • a spike protection element such as a diode, can be employed to further reduce the voltage spike, as discussed below with respect to Figure 27. /?
  • Figure 25 is a timing diagram of an electric motor according to the present invention where the rotation of the motor shaft changes direction
  • Figure 25 shows that changing the time-order of the phasing of the waveforms applied to the adjacent coils in the motor, the motor can be made to reverse rotational direction. That is, changing the voltage waveform applied to a second coil from one-quarter wavelength behind the voltage waveform applied to a first coil to one-quarter wavelength ahead ofthe voltage waveform ofthe first coil causes the rotation ofthe motor shaft to reverse direction
  • Figure 26 is a timing diagram of an electric motor according to the present invention, in which the motor is caused to stop Figure 26 shows that by gradually deenergizing the coils in the motor, the motor can be brought to a stop at a desired rotational position If the motor overshoots the rotational position desired, then the motor can be re ⁇ energized briefly to cause the motor to reverse direction until the desired rotational position is reached.
  • the circuit 600 includes a motor coil 602 that preferably is part of a stator ofthe electric motor.
  • the motor coil 602 is one of many motor coils on the stator that each interact with permanent magnets on an adjacent rotor to cause the rotor to rotate as discussed above.
  • the rotor is coupled to the motor shaft of the motor such that the energization ofthe motor coil causes the motor shaft to rotate
  • the circuit drive 600 includes a power source 604 that supplies electrical energy to the motor coil 602 which causes the motor coil to create a magnetic field
  • the magnetic field repels one permanent magnet of the rotor and attracts another permanent magnet ofthe rotor to rotate the motor shaft as discussed above.
  • the electrical energy from the power source 604 is directed through the motor coil 602 in a first direction which is left to right as shown in Figure 27
  • a motor controller (not shown) provides a first control signal (A) to a first switch 606 and a second switch 608.
  • the first and second switches 606, 608 preferably are field effect transistors for high speed switching at high power and low cost.
  • the first and second switches 606, 608 each close to form a first closed circuit between the motor coil 602 and the power source 604 Electrical current flows from the power source 604 through a first spike protection diode 610 and through the first switch 606 to the motor coil 602 From the motor coil 602, the electrical energy flows through a second spike protection diode 612 and through the second switch 608 back to the ground terminal of the power source 604
  • the first closed circuit formed by the motor coil 602, power source 604, first and second switches 606, 608, and first and second spike protection diodes 610, 612 causes the motor coil to form a magnetic field of a first polarity which rotates the motor shaft in the first rotational direction
  • the motor controller switches off the first and second switches 606, 608 Switching off the first and second switches 606, 608 causes the first closed circuit to open, which causes the magnetic field in the motor coil 602 to collapse
  • the magnetic energy in the magnetic field of the motor coil 602 is thereby converted into electrical energy which is transmitted via recapture diodes 614, 616 to a storage capacitor 618
  • the storage capacitor 618 stores the energy received from the motor coil 602 for subsequent use in powering the motor coil
  • the stored energy can be used to recharge the power supply 604 if a rechargeable battery is employed While the motor coil 602 is de-energized, another motor coil is energized to keep the motor shaft turning in the first rotational direction as described above with respect to Figures 6-9
  • the power supply 604 drives electrical energy through the motor coil 602 in a second direction (right to left in Figure 27), which reverses the polarity of the motor coil
  • the third and fourth switches 620, 622 preferably are field effect transistors or other high speed, high power switches
  • the second control signal causes the third and fourth switches 620, 622 to close and thereby form a second closed circuit between the power source 604 and the motor coil 602.
  • the electrical energy flows from the power source 604 through a third power spike protection diode 624 and through the third switch 620 to the motor coil 602
  • the electrical energy flows from the motor coil 602 through a fourth power spike protection diode 626 and through the fourth switch 622 back to the power source 604
  • the second closed circuit formed by the motor coil 602, power source 604, third and fourth switches 620, 622, and third and fourth spike protection diodes 624, 626 causes the motor coil to form a magnetic field of a second polarity
  • the second polarity of the motor coil / 6?02 continues to rotate the motor shaft in the first rotational direction because the previous rotation of the motor shaft and rotor has reversed the relative polarity of the permanent magnets adjacent the motor coil That is, the rotor rotation has positioned adjacent the motor coil 602 permanent magnets of a polarity opposite to that of the permanent magnets positioned adjacent the motor coil when the first control signal closed the first or second switches 606, 608
  • the motor controller opens the third and fourth switches 620, 622 Opening the third and fourth switches causes the second closed circuit to open, which causes the magnetic field in the motor coil to collapse
  • the magnetic energy from the collapsing magnetic field of the motor coil 602 is converted to electrical energy and transmitted via third and fourth recapture diodes 628, 630 to the storage capacitor 618
  • the storage capacitor 618 stores the electrical energy for subsequent use in energizing the motor coil 602 or recharging the power source 604
  • the recapture diodes 614, 616, 628, 630 form a rectifier similar to those shown above in Figures 14-17
  • the circuit 600 also includes first through fourth counter voltage protection diodes 632, 634, 636, 638 parallel-connected to the first through fourth switches 606, 608, 620, 622, respectively.
  • Each of the first through fourth counter voltage protection diodes 632-638 prevent electrical energy from flowing through the respective switches in an opposite direction from that intended
  • the counter voltage protection diodes 632-638 prevent current from flowing from the drain to the source of each of the switches 606, 608, 620, 622
  • Such counter voltage protection diodes are particularly effective when the first through fourth switches are field effect transistors that can be severely damaged by excessive reverse voltage
  • a second drive circuit identical to the drive circuit 600 shown in Figure 27 powers a second motor coil adjacent the motor coil 602
  • the two motor coils act in concert to keep the motor shaft and rotor rotating in the first rotational direction While the first motor coil 602 is being energized in the first direction in response to the first control signal (A), the second motor coil is deenergized
  • the motor coil 602 is energized in the second direction in response to ye the second control signal (B) closing the third and fourth switches 620, 622, the second motor coil is deenergized
  • Energizing the first motor coil 602 in response to the first control signal and energizing the second motor coil moves the rotor sufficiently to move permanent magnets of opposite polarity adjacent the first motor coil
  • energizing the first motor coil 602 in the second direction continues to propel the rotor and motor shaft in the first rotational direction
  • the third motor coil energized Energizing the first motor coil 602 in response to the first control signal and energizing the second motor coil moves the
  • Shown in Figure 28 is a timing diagram of an electric motor driven by two drive circuits identical to the drive circuit 600 shown in Figure 27
  • the second circuit is controlled by control signals (C) and (D) corresponding to the control signals (A) and (B) shown in Figure 27
  • the voltage waveform driving coil 2 is identical to the voltage waveform driving coil 1 except for a 90 degree phase shift
  • the delay between the removal of the first control signal (A) and the application of the second control signal (B) is present to ensure that all of the switches 606, 608, 620, 622 are not simultaneously closed, which likely would damage the switches
  • the drive circuit 700 includes a motor coil 702 that preferably is one of several motor coils on a stator ofthe electric motor as discussed above Preferably, each motor coil on the stator is driven by an identical drive circuit 700
  • the drive circuit 700 includes first and second power sources 704, 706 that alternately supply electrical energy to the motor coil 702 which causes the motor coil to create a magnetic field
  • the motor controller (not shown) provides a first control signal (A) to a first switch 708
  • the first switch 708 closes to form a first closed circuit between the motor coil 702 and the first power source 704
  • Electrical current flows from the first power source 704 through the first switch 708, a spike protection diode 710, and the motor coil 702 and back to the first power source
  • the motor controller switches off the first switch 708 Switching off the first switch 708 causes the first closed circuit to open, which causes the magnetic field in the motor coil 702 to collapse The magnetic energy in the magnetic field ofthe motor coil 702 is thereby converted into electrical energy which is transmitted via a first recapture diode 712 to a first storage capacitor 714
  • the first storage capacitor 714 stores the energy received from the motor coil 702 for subsequent use in powering the motor coil Alternatively, the stored energy can be used to recharge the second power supply 706 if a rechargeable battery is employed While the motor coil 702 is de-energized, another motor coil is energized to keep the motor shaft turning in the first rotational direction as described above with respect to Figures 6-9
  • the motor controller provides a second control signal (B) to a second switch 716
  • the second control signal causes the second switch 716 to close and thereby form a second closed circuit between the second power source 706 and the motor coil 702
  • the second power supply 706 drives electrical energy through the motor coil 702 in a second direction (right to left in Figure 29), which reverses the polarity of the motor coil
  • the electrical energy flows from the second power source 706 through the second switch 716, a second spike protection diode 718, and the motor coil 702 and back to the second power source 706
  • the second closed circuit formed by the motor coil 702, second power source 706, second switch 716, and second spike protection diode 718 causes the motor coil to form a magnetic field of a second polarity, which continues to drive the motor shaft in the first rotational direction
  • the motor controller opens the second switch 716.
  • Opening the second switch 716 causes the second closed circuit to open, which causes the magnetic field in the motor coil 702 to collapse.
  • the magnetic energy from the collapsing magnetic field of the motor coil 702 is converted to electrical energy and transmitted via a second recapture diode 720 to a second storage capacitor 722
  • the second storage capacitor 722 stores the electrical energy for subsequent use in energizing the motor coil 702 or recharging the first power source 704 It will be appreciated that the recapture diodes 712 and 720 form a half-wave rectifier rather than the full-wave rectifier shown in Figure 27
  • the drive circuit 700 shown in Figure 29 is cheaper and more efficient than the drive circuit 600 shown in Figure 27
  • the drive circuit 700 is cheaper because it employs two transistors and four diodes rather than the four transistors and 12 diodes employed in the drive circuit 600. Moreover, limiting the number of transistors and diodes reduces the heating losses created by the drive system 700
  • FIG. 30 Shown in Figure 30 is another alternative drive circuit 800 for bi-directional control of an electric motor
  • the drive circuit 800 includes a motor coil 802 powered by a power source 804 To energize the motor coil 802 with electrical energy, the motor coil provides a first control signal (A) to a switch 806 In response to the first control signal, the switch 806 closes to form a closed circuit between the motor coil 802 and the power source 804
  • the motor controller switches off the switch 806 which disconnects the power source 804 from the motor coil
  • the driver circuit 800 includes a freewheel diode 808 in parallel with the motor coil 802 such that current continues to flow through the motor coil 802 temporarily after the switch 806 is opened As a result, the freewheel diode 808 returns the energy from the motor coil 802 back to the motor coil As such, the freewheel diode 808 enables the switch 806 to be opened sooner than would be possible with prior art drive circuits
  • Shown in Figure 31 is a timing diagram of an electric motor powered by four adjacent motor coils Each motor coil is driven by an identical drive circuit 800 as shown in Figure 30 Effectively, the voltage waveforms of coils 1 and 2 shown in Figure 31 together are equivalent to the voltage waveform shown for coil 1 in Figure 21 Similarly, the voltage waveforms of coils 3 and 4 of Figure 31 together are equivalent to the voltage waveform of coil 2 shown in Figure 21 As a result, the operation of the electric motor is substantially similar to that discussed above
  • the present invention provides a more efficient electric motor drive circuit than prior art designs
  • the invention recaptures in a storage element electrical energy produced by the collapsing electric fields of the motor coils
  • the recaptured energy can subsequently be used to re-energize the motor coils or recharge the power source rather than simply being wasted like prior art designs.
  • a freewheel diode can be employed to return electrical energy immediately back to the motor coil without storing the electrical energy in a separate storage element.
  • the drive circuit can efficiently drive the motor coils without damage to the circuit elements.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Control Of Ac Motors In General (AREA)

Abstract

L'invention porte sur un moteur permettant d'améliorer un rendement donné, ce moteur comprenant plusieurs bobines produisant chacune de l'énergie magnétique emmagasinée dans un champ magnétique. On utilise une partie de cette énergie magnétique emmagasinée pour faire fonctionner le moteur. Chaque bobine comporte au moins une boucle de fil conducteur. Le moteur comprend un circuit de reprise d'énergie recevant de l'énergie électrique produite par les champs magnétiques effondrés des bobines lorsqu'une coupure de courant survient dans les bobines. Le circuit de reprise d'énergie comporte un condensateur à accumulation d'énergie emmagasinant l'énergie provenant des bobines pour une utilisation ultérieure, à savoir la recharge de la source d'énergie qui excite les bobines ou les excite à nouveau indirectement. Le moteur comporte également des commutateurs d'attaqueur commandant chaque bobine de moteur dans les deux sens de rotation. Le moteur comporte, de surcroît, des circuits de protection d'attaqueur protégeant lesdits commutateurs contre les pointes de tension ou les tensions inverses.
PCT/US1996/018446 1995-11-15 1996-11-15 Procede et appareil permettant d'accroitre le rendement d'un moteur a aimant permanent WO1997018617A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US55850095A 1995-11-15 1995-11-15
US08/558,500 1995-11-15
US65083596A 1996-05-20 1996-05-20
US08/650,835 1996-05-20

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003005537A1 (fr) * 2001-07-05 2003-01-16 Willian Martin Crookes Moteur électrique amélioré
WO2006012690A1 (fr) * 2004-08-03 2006-02-09 Precursor Engineering Pty Ltd Alternateur de stator chargé
WO2008014112A2 (fr) 2006-07-26 2008-01-31 Palmer Robert A Moteur électrique
WO2008122437A2 (fr) * 2007-04-10 2008-10-16 Klaus Thissen Convertisseur destiné à convertir de l'énergie magnétique en énergie cinétique et/ou en énergie électrique et procédé destiné à convertir de l'énergie magnétique en énergie cinétique et/ou en énergie électrique au
WO2010019812A1 (fr) * 2008-08-13 2010-02-18 Millenial Resarch Corporation Appareil, système et procédé pour une transmission à rapport variable
WO2016100030A1 (fr) * 2014-12-17 2016-06-23 Apparent Energy, Inc. Moteur électrique
EP2279552A4 (fr) * 2008-05-23 2017-04-19 Associação Keppe & Pacheco Moteur électromagnétique et équipement destiné à générer un couple de travail
US9800111B2 (en) 2008-08-15 2017-10-24 Millennial Research Corporation Regenerative motor and coil

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Publication number Priority date Publication date Assignee Title
US4358693A (en) * 1981-06-15 1982-11-09 Charles L. Palmer Permanent magnet motor
EP0422226A1 (fr) * 1988-10-07 1991-04-17 Kabushikigaisha Sekogiken Moteur a reluctance
EP0444198A1 (fr) * 1989-09-08 1991-09-04 Kabushikigaisha Sekogiken Moteur a reluctance
FR2717013A1 (fr) * 1994-03-01 1995-09-08 Cachan Ecole Normale Superieur Dispositif de commutation hybride, onduleurs d'alimentation de moteurs électriques incluant ce dispositif et moteurs ainsi alimentés.

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4358693A (en) * 1981-06-15 1982-11-09 Charles L. Palmer Permanent magnet motor
EP0422226A1 (fr) * 1988-10-07 1991-04-17 Kabushikigaisha Sekogiken Moteur a reluctance
EP0444198A1 (fr) * 1989-09-08 1991-09-04 Kabushikigaisha Sekogiken Moteur a reluctance
FR2717013A1 (fr) * 1994-03-01 1995-09-08 Cachan Ecole Normale Superieur Dispositif de commutation hybride, onduleurs d'alimentation de moteurs électriques incluant ce dispositif et moteurs ainsi alimentés.

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2381966B (en) * 2001-07-05 2005-02-16 William Martin Crookes Improved electric motor
WO2003005537A1 (fr) * 2001-07-05 2003-01-16 Willian Martin Crookes Moteur électrique amélioré
WO2006012690A1 (fr) * 2004-08-03 2006-02-09 Precursor Engineering Pty Ltd Alternateur de stator chargé
EP2070182A4 (fr) * 2006-07-26 2013-01-09 Robert A Palmer Moteur electrique
WO2008014112A2 (fr) 2006-07-26 2008-01-31 Palmer Robert A Moteur électrique
EP2070182A2 (fr) * 2006-07-26 2009-06-17 Robert A. Palmer Moteur electrique
US8853907B2 (en) 2006-07-26 2014-10-07 Millennial Research Corporation Electric motor
WO2008122437A2 (fr) * 2007-04-10 2008-10-16 Klaus Thissen Convertisseur destiné à convertir de l'énergie magnétique en énergie cinétique et/ou en énergie électrique et procédé destiné à convertir de l'énergie magnétique en énergie cinétique et/ou en énergie électrique au
WO2008122437A3 (fr) * 2007-04-10 2009-03-19 Klaus Thissen Convertisseur destiné à convertir de l'énergie magnétique en énergie cinétique et/ou en énergie électrique et procédé destiné à convertir de l'énergie magnétique en énergie cinétique et/ou en énergie électrique au
EP2279552A4 (fr) * 2008-05-23 2017-04-19 Associação Keppe & Pacheco Moteur électromagnétique et équipement destiné à générer un couple de travail
CN102187124A (zh) * 2008-08-13 2011-09-14 米伦尼尔研究公司 用于可变比变速器的设备、系统和方法
US8142318B2 (en) 2008-08-13 2012-03-27 Palmer Denis L Apparatus, system, and method for a variable ratio transmission
WO2010019812A1 (fr) * 2008-08-13 2010-02-18 Millenial Resarch Corporation Appareil, système et procédé pour une transmission à rapport variable
US9800111B2 (en) 2008-08-15 2017-10-24 Millennial Research Corporation Regenerative motor and coil
WO2016100030A1 (fr) * 2014-12-17 2016-06-23 Apparent Energy, Inc. Moteur électrique
US9559574B2 (en) 2014-12-17 2017-01-31 Apparent Energy, Inc. Electric motor

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