Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K1/00—Details of the magnetic circuit
  • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
  • H02K1/22—Rotating parts of the magnetic circuit
  • H02K1/27—Rotor cores with permanent magnets
  • H02K1/2706—Inner rotors
  • H02K1/272—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis
  • H02K1/274—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of two or more circumferentially positioned magnets
  • H02K1/2753—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of two or more circumferentially positioned magnets the rotor consisting of magnets or groups of magnets arranged with alternating polarity
  • H02K1/278—Surface mounted magnets; Inset magnets
• • 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
  • H02P9/00—Arrangements for controlling electric generators for the purpose of obtaining a desired output
  • H02P9/48—Arrangements for obtaining a constant output value at varying speed of the generator, e.g. on vehicle
• • 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
  • H02P25/00—Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details
  • H02P25/16—Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details characterised by the circuit arrangement or by the kind of wiring
  • H02P25/18—Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details characterised by the circuit arrangement or by the kind of wiring with arrangements for switching the windings, e.g. with mechanical switches or relays
• • 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
• • 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
  • H02P6/14—Electronic commutators

Definitions

• the present invention relates to an auxiliary coil for an electric machine and more particularly to the auxiliary coil for the electric machine that is capable of being accommodated in a two- wheeler or a three-wheeler.
• a motor has a fixed Voltage constant (K e ) and torque constant (K t ) depending on the number of turns in each phase.
• K e Voltage constant
• K t torque constant
• the range of the motor can be extended by many methods such as the flux weakening, the double stator, reconfiguring the stator coils and even moving the rotor to provide less flux path, thereby operating the motor efficiently in each possible speed band.
• a way of reconfiguring the coils is done with the help of switches (or relays) to extend the operating speed band.
• the switches are energized with the help of voltage supplied from the controller. If the switches are to be energized by the controller, then it needs additional input or output ports on the controller, additional current from the controller or even sensors to calculate the speed to alter the switching configurations.
• variable speed motor that comprises a main winding that includes the first and second main windings and also an auxiliary winding that includes the first and second auxiliary windings. Both the main winding and the auxiliary winding are wound on the stator to form more than one pole and relay that execute a switching operation between the connections of the first and the second main windings or first and second auxiliary windings that can be parallel or serial.
• the variable speed motor comprises a stator having wounded a four and a twelve pole winding, there are more than one tap winding that are connected to the four poles main winding in series and form four poles, extends the variable range of motorDs rotation speed during the four pole operation mode, and a phase control circuit that varies the motorDs rotational speed by controlling during a twelve-pole operation mode a phase of an input power-supply signal.
• the variable speed motor extends the range of the variable speed of the motor greatly, and an additional drive unit is not required for varying the motor speed, such that there is a great reduction in the production costs and electromagnetic vibration noise generated by the low-speed control mode of the motor.
• the rotation speed of the motor is controlled by the winding switching operation and the phase control operation so that the power consumption is reduced and the motor speed is controlled by the variable motor.
• the variable speed motor described above needs additional electronic control system for the switches are to be energized by the controller, which in turn needs additional input or output ports on the controller
• a two speed induction motor with tapped auxiliary winding is also known that describes a two-speed motor that increases the low-speed efficiency.
• the invention comprises a six lead, two speed, and single -phase induction motor, consequently wound with a tapped auxiliary winding that has two modes: a two- pole high-speed mode and a four pole low-speed mode.
• a portion of the auxiliary winding, in series, is connected with the four pole winding.
• the four pole low- speed mode has an efficiency of over 80%.
• accommodation of such multi-speed configuration complicates the construction of the motor and also requiring additional components especially to accommodate in a compact two- wheeler or a three-wheeler.
• a multi-speed induction motor that comprises two stator windings, that is, a low pole and a high pole count winding that is wound around a common stator core.
• the stators teeth radially extend itself inward from a stator yoke and have slots open in the inner diameter.
• the high poled count winding is wound first on the stator core in a way that the high pole count winding is next to the stator yoke.
• the low pole count winding is wound later and is interior radially to the high pole count winding.
• a permanent magnet type rotating electric machine is known with the deterring of the increased magnetization current during demagnetization and magnetization and achievement of variable-speed high- output operation over a wide range from low speed to high speed.
• a rotor consists of a rotor core, permanent magnets for which the product in the magnetic direction of the magnetic coercive force and the thickness is small and a permanent magnet for which this same product is large.
• a magnetic field is caused to act in the opposite direction of the direction of the magnetization of the permanent magnets with the help of the armature coil current, to reduce the interlinking of the magnetic fluxes of the permanent magnets.
• the magnetic field is caused to act in the same direction of the direction of the magnetization of the permanent magnets with the help of the armature coil current.
• An inductive current is induced in the short-circuit coils, which are provided at the flux path portions of the permanent magnets excluding the permanent magnets, by the magnetic fields produced by the magnetization current and by the inductive current magnetic fields are generated around the short-circuit coils.
• the permanent magnets are magnetized by the latter magnetic fields and by the magnetic fields generated by the magnetization current.
• the present invention includes an auxiliary coil wound around the stator tooth and the voltage induced in the auxiliary coil is used to control the switches that are used for winding reconfiguration.
• the voltage induced in the coils depending on the speed of rotation for a given number of turns.
• the voltage has to be above a threshold, which is achieved above a rotational speed.
• the switches for reconfiguration are arranged such that they are normally in one configuration, and when energized, they give rise to another winding configuration, resulting in changed motor characteristics. Since the motor characteristics need to change above a predetermined rotational speed which is served by the auxiliary coils energizing the switches above a predetermined speed.
• this invention uses the voltage induced in the auxiliary coil to operate the switches. This process saves the energy and the controller modifications.
• the voltage from the controller is used to operate the reconfiguration switches, with feedback from a rotational speed sensor.
• the present subject matter provides an electric machine that saves energy and controller modifications.
• the electric machine includes a rotor and a stator separated by an air-gap.
• a main coil wound around plurality of teeth ⁇ tooth of the stator.
• One or more switches connected to the main coil for winding reconfiguration.
• the electric machine includes an auxiliary coil wound around the teeth of said stator.
• One or more switches functionally connected to the auxiliary coil and the auxiliary coil depending on pre-determined parameter of the electric machine enables switching of the one or more switches for winding reconfiguration.
• the pre-determined parameters may include speed of the rotor.
• Figure 1 illustrates a schematic diagram of an electronic circuit with an odd number of sections of coils in the stator, in accordance with an embodiment of the present subject matter.
• Figure 2 illustrates the vehicle with an electric machine which has an auxiliary coil, in accordance with one embodiment of the present subject matter.
• Figure 3 illustrates the electronic circuit with a three-phase diode bridge.
• Figure 4 illustrates the electronic circuit with single -phase diode bridge.
• An electric machine 16 consists of a rotor 18 and a stator 15 separated by an air-gap.
• the rotor 18 is rotatable about the rotor 18 axis relative to the fixed stator 15, and it has multiple pairs of magnets (not shown) pasted on the inner surface of the rotor 18.
• the stator 15 consists of slots through which the wires/main coil(s) 19 are wound according to the winding configuration. The winding configuration depends upon the number of poles and slots in the electric machine 16.
• the electric machine 16 can be an n-phase machine with a minimum configuration of at least two phases. When current is applied to the coils 19 wound around the stator-teeth, the stator-teeth become an electromagnet.
• the electric machine 16 is provided with the stator 15 composed of multiple coils for each phase, while some switches slOl, si 02 are connected at the coil-ends.
• the terms DmotorD and Delectric machineD are interchangeably used herein.
• the switches slOl, sl02 are useful in changing the winding pattern of the motor 16, for example, the number of parallel paths.
• An example of main coil along with the switches in the motor 16 configuration is shown as in Figure 1.
• the present invention includes an auxiliary coil 20 in the machine 16 for toggling the switches.
• the auxiliary coil 20 [as shown in Figure 2] does not aid in torque production, and it is wound over or adjacent to the main coil 19 in the stator- winding.
• Figure 2 depicts an exemplary vehicle 11 having one or more wheels 12, 13 and the vehicle 11 is colloquially referred to as a two-wheeler or a three-wheeler.
• the vehicle 11 is provided with the electric machine 16 mounted onto a power unit 14 of said vehicle 11.
• the stator 15 is having a the main coil 19 wound around the stator 15 teeth and also the auxiliary coil 20 wound around the stator 15 teeth separate from the main coil 19.
• the purpose of the auxiliary coils is to turn-on the switches that are used for purposes other than creating a rotating magnetic field, such as reconfiguring the coils in the stator 15 winding.
• auxiliary coils 20 are connected in a series configuration and wound on all tooth of each phase of the stator 15.
• the switches slOl, si 02 can be relays which can be operated by the voltage induced by the auxiliary coil 20 of the electric machine 20.
• the switches slOl, sl02 are required to operate only after a pre-set value of a pre-determined parameter like the set speed.
• the voltage induced in the auxiliary coil 20 should be able to meet the voltage required by the switches slOl, sl02 for toggling after the set speed.
• the turns of the auxiliary coil 20 are chosen such that the required voltage is generated only after the set speed.
• the set speed is the speed at which the switches slOl, si 02 are turned on to extend the speed range of the motor 16 to the next possible speed range.
• the next possible speed range is the minimum change in the value of the Ke that is affected by the winding reconfiguration once the switches slOl, si 02 are energized.
• the reconfiguration is elaborated in the later part of this document. For example, if the voltage required to turn on the switches slOl, sl02 is 5volts, the sufficient number of turns on auxiliary winding are wound on each phase, so that it reaches the voltage at the set rpm and the switches slOl, si 02 are closed thereby enabling the coils to be reconfigured. This saves energy as the auxiliary coil 20 automatically and effectively controls the switches slOl, sl02 without the need for the control unit energy or control unit current.
• the number of turns to be wound in the auxiliary coils 20 also depends on the geometry of the electric machine 16 and the set rpm at which the coils have to be reconfigured. A number of turns will generate the voltage even before the set rpm thereby closing the switches slOl, si 02 and extending the speed range before it is required. Less number of turns will not be able to produce the required voltage at the set rpm thereby not allowing the electric machine 16 to extend its speed range to its next permissible band.
• the back-emf of the auxiliary coil 20 of the electric machine 16 depends on many parameters like number of poles, winding factor, and the rotor 18 is having outer radius, average air-gap flux density, number of slots per pole per phase and the number of turns.
• the back-emf of the auxiliary coil 20 of the electric machine 16 can be calculated by dividing the voltage to be induced with the motor set speed in rad/s.
• the back-emf of the auxiliary coil 20 of the electric machine 16 is fixed for the geometry of the electric machine 16, and the only changing part can be the turns in this case.
• K ea is the back-emf constant for the auxiliary coil 20.
• An ideal motor needs high starting torque at the starting, with a wide speed band.
• the electric machine 16 is initially designed with higher K t .
• K t more number of turns is needed.
• each section of coils are connected such a way that the end of the first section of coils and the start of the next section of coils are connected, the start of the first section of coil is connected to the phase of the controller and the end wire of the last section of coil is connected to the ground. Then, each phase has more number of turns that are connected in a series configuration with respect to each other.
• the switch configurations are energized such that there are some sections of coils which are connected in parallel and some sections of coils are in series, based on the sections and the turns in the entire section of coils.
• the electric machine 16 is allowed to operate at that operating range so that the resistance is reduced and it can be conveniently operated in the highest efficiency of that band.
• the speed bands are increased by switching arrangements to reduce the turns and to increase the sections of the coils in parallel, to make sure that the electric machine 16 is always operated near the maximum efficiency range by all possible switch combinations.
• the three coils sections (1, 2), (3, 4), (5, 6) are now connected in parallel, reducing the turns, thereby increasing the no-load speed and the operating range of the motor.
• the parallel combination also offers less resistance.
• the efficiency of the motor is also shifted to the right side of the curve, improving the system efficiency.
• the auxiliary coils 20 can also be connected in series and wound on at least one tooth in each phase, to produce the necessary voltage to toggle the switches slOl, sl02.
• all the turns that are required to produce the voltage at the set speed are wound on one single tooth in each phase. This maintains the K ea of the machine to the same value as in the previous case.
• the switches slOl, si 02 can be relays which can be operated by the voltage induced from the auxiliary coil 20 of the machine 16.
• the switches sl01, sl02 are required to operate only after the set speed.
• the voltage induced in the auxiliary coil 20 should be able to meet the voltage required by the switch slOl, si 02 for toggling after the set speed.
• the turns in the auxiliary coil 20 are chosen such that the required voltage is generated only after the set speed.
• the set speed is the speed at which the switches slOl, si 02 are turned on to extend the speed range of the motor 16 to the next possible speed range.
• the next possible speed range is the minimum change in the value of the K e that is affected by the winding reconfiguration once the switches are energized. The reconfiguration is elaborated in the later part of this document.
• the sufficient number of turns (auxiliary winding) are wound on the tooth of each phase, so that it reaches the voltage at the set rpm and the switches slOl, si 02 are closed thereby enabling the coils to be reconfigured.
• the number of turns to be wound in the auxiliary coils 20 also depends at least in part on the geometry of the electric machine 16 and the set rpm at which the coils have to be reconfigured. More the number of turns will generate the voltage even before the set rpm thereby closing the switches si 01, si 02, and extending the speed range before it is actually required. Less number of turns will not be able to produce the required voltage at the set rpm thereby not allowing the electric 16 machine to extend its speed range to its next permissible band.
• the back-emf of the electric machine 16 depends on many parameters like number of poles, winding factor, rotor-outer radius, average air-gap flux density, number of slots per pole per phase and the number of turns.
• the back-emf of the electric 16 machine can be calculated by dividing the voltage to be induced with the motor set speed in rad/s.
• the back-emf of the electric machine 16 is fixed for the geometry of the electric machine 16 and the only changing part can be the turns in this case.
• the turns are calculated for each phase, thereby generating the required voltage at the set rpm.
• the auxiliary coils 20 can also be connected in series and wound on at least one tooth in any one of the phases, to produce the necessary voltage to toggle the switches. In this case all the turns that are required to produce the voltage at the set speed are wound on one single tooth in any one of the phases. This maintains the K ea of the electric machine 16 to the same value as in the previous case.
• the switches slOl, si 02 can be relays which can be operated by the voltage induced from the auxiliary coil of the electric machine 16.
• the switches slOl, si 02 are required to operate only after the set speed.
• the voltage induced in the auxiliary coil 20 should be able to meet the voltage required by the switch for toggling after the set speed.
• the turns in the auxiliary coil are chosen such that the required voltage is generated only after the set speed.
• the set speed is the speed at which the switches slOl, sl02 are turned on to extend the speed range of the motor 16 to the next possible speed range.
• the next possible speed range is the minimum change in the value of the K e that is affected by the winding reconfiguration once the switches slOl, si 02 are energized.
• the reconfiguration is elaborated in the later part of this document.
• the voltage required to turn on the switches slOl, sl02 is 5 volts, the sufficient number of turns (auxiliary winding) are wound on that one tooth in any one of the phases, so that it reaches the voltage at the set rpm and the switches slOl, si 02 are closed thereby enabling the coils to be reconfigured.
• the two switches slOl, si 02 represent an exemplary embodiment and are not limiting as the electric machine may include one or more switches depending on the auxiliary coil configuration and the electric machine configuration.
• the number of turns to be wound in the auxiliary coils 20 also depends on the geometry of the machine 16 and the set rpm at which the coils have to be reconfigured. More the number of turns will generate the voltage even before the set rpm thereby closing the switches and extending the speed range before it is required. Less number of turns will not be able to produce the required voltage at the set rpm thereby not allowing the machine 16 to extend its speed range to its next permissible band.
• the back-emf of the machine depends on many parameters like number of poles, winding factor, rotor 18 outer radius, average air-gap flux density, number of slots per pole per phase and the number of turns.
• the back-emf of the machine can be calculated by dividing the voltage to be induced with the motor set speed in rad/s.
• the back-emf of the electric machine 16 is fixed for the geometry of the electric machine 16 and the only changing part can be the turns in this case.
• the turns are calculated and it is wound around the tooth for any one of the phases, thereby generating the required voltage at the set rpm.
• the electronic circuit consisting of three-phase diode bridge, as shown in Figure 3, is connected in case of the first embodiment and the second embodiment, as the voltage generated will be a three-phase alternating current (AC), which has to rectify and regulated to the voltage required by the switch for toggling its condition.
• the rectifier for these three-phase circuits must use a three- phase bridge, which has six diodes Dl, D2, D3, D4, D5, D6 to provide full-wave rectification with two diodes for each line of the three phases, Dl and D2, D3 and D4, D5 and D6.
• Figure 3 shows the electrical diagram for a three-phase bridge rectifier.
• the output of the auxiliary coil of the electric machine is shown connected to the diode rectifier.
• Coil A of the three-phase voltage from the auxiliary coil of the electric machine is connected to the point where the cathode of diode D2 is connected to the anode of diode Dl.
• Coil B is connected to the point where the cathode of diode D4 is connected to the anode of diode D3
• Coil C is connected to the point where the cathode of diode D6 is connected to the anode of diode D5.
• the anodes of diodes D2, D4 and D6 are connected together to provide a common point for the DC negative terminal of the output power.
• diodes Dl, D3 and D5 are connected to provide a common point for the DC positive terminal of the output power.
• a circuit consisting of single-phase diode bridge is shown in Figure 4, is used in case of the third embodiment as the coils are wound only on one phase and can be rectified and regulated to the voltage required by the switch for toggling its condition.
• the four diodes labelled D7, D8, D9, and D10 are arranged in D series pairsD such that during each half cycle only two diodes conducting current.
• diodes D7 and D10 conduct in series while diodes D8 and D9 are reverse biased and the current flows through the load as shown below.
• diodes D8 and D9 conduct in series, but diodes D10 and D7 switch D OFFD as they are now reverse biased. The current flows through the load in the same direction as before.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Windings For Motors And Generators (AREA)
• Control Of Electric Motors In General (AREA)
• Control Of Ac Motors In General (AREA)

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• 2018
  • 2018-02-08 WO PCT/IB2018/050768 patent/WO2018146604A1/en active Application Filing
  • 2018-02-09 TW TW107104610A patent/TWI770116B/zh not_active IP Right Cessation

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