"brushless low DC current high torque motor and regenerator with controller

Abstract

Disclosed is a brushless low DC current motor and regenerator with controller for high torque generation. The brushless direct current motor (124) includes a first control unit (104) to receive inputs from a first input unit (108), a second input unit (112), a third input unit (116), and power from a battery (120) to control the speed of the motor (124), to generate the required torque. The motor (124) includes an inner stator (304), an outer stator (308) and a rotor (312) coaxially rotatable around the motor axis. The inner stator (304) and the outer stator (308) is coaxially attached with the motor and have equal number of teethes. The plurality of magnets (324) is positioned on the rotor (312).

Description

[0001] “BRUSHLESS LOW DC CURRENT HIGH TORQUE MOTOR AND REGENERATOR WITH CONTROLLER”

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a Brush Less Direct Current (BLDC) motor and more particularly to control a BLDC motor for generation of high torque with low DC current.

[0004] BACKGROUND OF THE INVENTION

[0005] Brushless DC motors (BLDC) are used in a wide variety of application requirements such as varying loads, constant loads and positioning applications in the fields of industrial control, automotive electric vehicle (EV), aviation, automation systems, health care equipment, etc.

[0006] The BLDC motor includes a stator, and a rotor. A BLDC Motor is a type of synchronous motor in the sense that the magnetic field generated by the stator and the rotor revolve at the same frequency. The speed of BLDC Motor is controlled by varying supply voltage. Normally, BLDC motor produces low torque at low speed. For high torque, load is applied at low speed of motor that draws high current that is harmful to the motor as well as to the total system. While regeneration, BLDC produces low voltage at low speed and high voltage at high speed. Although the two-phase or three-phase brushless motors are driven through or by a wave bipolar magnetization, that is a conventional optimum driving method. However, limitations exist in utilizing the magnetic energy to the maximum in view of the principal structure, and structural problems arise in improving efficiencies. Also, when the BLDC motors work at high pulse width modulation (PWM) frequency, it causes the change in magnetic flux with high frequency. As magnetic flux changes frequently more heat is generated. This reduces efficiency of the motor.

[0007] The United States Patent No. US8183733B2 to Young-Chun Jeung teaches a brushless motor that includes a two-phase winding stator having 4xn winding poles and auxiliary poles provided between the winding poles. The two-phase brushless motor is driven by a control device that transforms electric power and rectifies electronically. However, normally in two phase motor that has 50% winding coils remain unutilised at any given time that causes 50% capacity of torque generation to remain unutilised leading to less generation of torque. Also, at the time of voltage regeneration, only 50% coils are utilised.

[0008] Normally, three phase BLDC motors are used in many applications. In three phase motor, 33% winding coils remain off at the time when motor is working. Accordingly, 33% capacity of torque generation remains unutilised and hence 33% less torque is generated by three phase BLDC motors. It is likely that 33% extra coils are required in the three phase BLDC motors that increases motor cost by around 25% and also while regeneration 33% coils are unutilised. Accordingly, there is a need of a brushless DC current motor and regenerator with controller for high torque generation on low current. There is also a need of a system for controlling brushless direct current motor regenerator to regenerate high voltage at lower speed to improve regeneration efficiency with wide range.

[0009] SUMMARY

[0010] The present invention discloses a brushless low DC current high torque motor and regenerator with controller for controlling power from battery. The brushless low DC current high torque motor and regenerator includes a first control unit, that is configured on a motor to transmit, and receive the signals for controlling power from battery to the motor.

[0011] The first control unit includes a controller, a second control unit, a third control unit, and a signal generator. The controller is configured on the first control unit for receiving a current input from a first input, a user predefined speed signal, a user predefined speed direction and a user predefined current limit value from a second input in a first mode of torque generation. The first control unit also receives a rotor position signal with respect to a stators’ signal from the motor and a power from a battery in a first mode of torque generation to monitor current consumption by the motor, that generates controlled high torque. The first control unit transfers and analysescontrolled analog and digital output signal to a signal generator and a third control unit. The signal generator is configured to change duty cycle ratio of amount of current flow in coils synchronizing the PWM signal and transfers to a second control unit. The second control unit is configured for controlling the speed of the motor according to the signal from the signal generator and transfers to the third control unit. The third control unit is configured for receiving the power from a battery and control signal from the first control unit and the second control unit.

[0012] The third control unit transfers the controlled battery power to the coil windings of the stator of the motor to avoid heat generation while generating high torque in a first mode and for regenerating high voltage and power at lower speed in a second mode.

[0013] The brushless low DC current high torque motor and regenerator includes the motor. The motor includes an inner stator, an outer stator and a rotor. The inner stator is coaxially attached with the motor. The outer stator is coaxially attached with the motor and the rotor. The outer stator is coaxially positioned such that the rotor is rotatable around the motor axis and positioned between inner and outer stators.

[0014] The inner stator includes a first plurality of teethes and the outer stator includes a second plurality of teethes, both respectively having same even number of teethes and coil windings. The first plurality of teethes and the second plurality of teethes are positioned such that teethes have offset by half (1 / 2) of angular pitch of the outer stator and the inner stator windings. The first plurality of teethes and the second plurality of teethes are positioned in the manner where consecutive teethes are wind in opposite direction to create opposite polarity in consecutive teethes when power is applied to change the current flow direction respective to rotor position change.

[0015] The winding connections of the inner stator and the outer stator receives controlled power from the third control unit. The winding connections of the inner stator and the outer stator are selectively arranged in series or parallel. The series or parallel arrangement of winding being selected according to the requirement of size and power of the motor.

[0016] The sensor is positioned on motor to detect the holes on the rotor, that generates a respective pulse signal when the hole is passed in front of the sensor. The said pulse signal as the position signal is transferred to the first control unit. The plurality of magnets is positioned on the rotor and arranged such that the direction of opposite poles of the consecutive magnets is toward the center of the rotor.

[0017] The third control unit controls the current by selecting the number of coils of the stators to be connected in series connection or selects the number of coils to be connected in parallel connection to control current within the limit set by user and provides the controlled power to the motor. The third control unit controls the speed of the motor and generates the torque.

[0018] The windings of both stators generate power while braking and transfers the generated power to third control unit in the second mode of the regeneration. The first control unit finds speed and generates voltage in the second mode of the regeneration. The first control unit is for analysis and to determine the current flow direction through the inner stator and the outer stator of the motor.

[0019] The controller is configured to find electrical angle of rotation of the rotor with respective stators from the signal received from the third input. The controller switches current flow direction in coils to generate synchronous rotating magnetic field with respect to rotor magnet field and respective user inputs, that rotates the motor in clock wise or counter clock wise direction for rotating the magnetic field. The third control unit includes a plurality of switches for connecting the coils of stators of the motor in series and in parallel.

[0020] In the second mode of regeneration, the third control unit receives power from stator coils and transfers controlled voltage power to the battery by changing coils connection in different series and parallel combinations. The signal generator and the first controller unit receive the first input and the second input to analyze and generate pulse width modulation (PWM) proportional to the user requirement and within current limits set by user. The first input is current, that is consumed and the second input is user requirement of speed.

[0021] Advantageously, the brushless low DC current high torque motor and regenerator with controller provides increased efficiency of torque generation with minimum current consumption. Also, the motor and regenerator advantageously provide high efficiency as the average current is low. The motor and regenerator reduce heat generation and decreases heat losses. The motor and regenerator are economical as it reduces cost and weight of the equipment and also reduces heat generation. In regeneration mode, the motor and regenerator produce sufficient high voltage and power to charge battery even at low speed of vehicle (equipment), accordingly increases regeneration efficiency.

[0022] BRIEF DESCRIPTION OF DRAWINGS

[0023] The objectives and advantages of the present invention will become apparent from the following description read in accordance with the accompanying drawings wherein

[0024] FIG. 1 shows a high-level schematic of a brushless low DC current high torque motor and regenerator with controller 100 in accordance with a preferred embodiment of the present invention;

[0025] FIG. 2 shows a schematic of the brushless low DC current high torque motor and regenerator with controller of the present invention of FIG. 1 ;

[0026] FIG. 3A shows an exploded view of the brushless direct current motor in the preferred embodiment of FIG. 1 along a Y-axis;

[0027] FIG. 3B shows a sectional view of the brushless direct current motor of the preferred embodiment of the present invention of FIG. 1 ;

[0028] FIG. 4 shows a schematic diagram of a third control unit of the preferred embodiment of the present invention of FIG. 1 ; FIG. 4A shows a flow chart showing various steps involved in the controlling motor speed and the current consumption of brushless low DC current high torque motor in the preferred embodiment of FIG. 1 ;

[0029] FIG. 5 shows a comparative graphical representation of comparative analysis for torque generation with respect to motor rotation angle of the brushless low DC current high torque motor and regenerator with controller in the preferred embodiment of FIG. 1 ;

[0030] FIG. 6A shows a first combination of coils of the motor of the present invention of FIG. 1;

[0031] FIG. 6B shows a second combination of coils of the motor of the present invention of FIG. 1;

[0032] FIG. 6C shows a third combination of coils of the motor of the present invention of FIG. 1;

[0033] FIG. 6D shows a fourth combination of coils of the motor of the brushless low de current high torque motor and regenerator with controller of FIG. 1 ;

[0034] FIG. 7 shows a comparison of current drawn from battery and speed of vehicle with respective time of the brushless low DC current high torque motor and regenerator with controller of FIG. 1 ;

[0035] FIG. 8A shows graphical analysis of regenerative voltage with respect to speed of vehicle of the brushless low DC current high torque motor and regenerator with controller of FIG. 1 ; and FIG. 8B shows graphical analysis of power regenerated with respect to speed of vehicle of the brushless low DC current high torque motor and regenerator with controller of FIG. 1.

[0036] DETAILED DESCRIPTION OF THE INVENTION

[0037] The invention described herein is explained using specific exemplary details for better understanding. However, the invention disclosed can be worked on by a person skilled in the art without the use of these specific details.

[0038] References in the specification to "one embodiment" or "an embodiment" means that particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.

[0039] References in the specification to “preferred embodiment” means that a particular feature, structure, characteristic, or function described in detail thereby omitting known constructions and functions for clear description of the present invention.

[0040] The foregoing description of specific embodiments of the present invention has been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. In general aspect, the present invention teaches a brushless low DC current motor and regenerator with a controller (100) having dual functionality, generating high torque for a vehicle in a first operational mode and regenerating high voltage during braking in a second mode to charge the battery. In the first mode, the brushless low DC current high torque motor and regenerator with the controller (100) regulates the power from the battery (the first input) to the motor’s stator coils, ensuring the motor’s speed, direction, and current consumption aligned with predefined user requirements. In the second mode, the same system regenerates power at a high voltage to recharge the battery during braking. The brushless DC motor and regenerator with controller (100) operates on low current to minimize heat generation.

[0041] Referring to FIG. 1, the brushless low DC current high torque motor and regenerator with controller (100), hereinafter, referred to as the motor and regenerator 100 includes a first control unit (104), a first input (108), a second input (112) and a third input (116). The first input (108) is a current sensor (106) (Not shown in Fig. 1) to monitor the output current of a battery (120) and current through motor winding coils. The first input (108) also includes a current limiting sensor (110) (Not shown in Fig. 1). The second input (112) includes a sensor to provide speed requirement of the user (114) (Not shown in Fig. 1). The second input senses the requirement of speed and direction of the rotation of motor. The third input (116) provides a rotor position signal with respect to a stator received from a motor (124). The system (100) also includes the motor (124) that provides output to an equipment (128). The first control unit (104), for example a microcontroller, is configured to receive power from the battery (120) and to transfer controlled power of the motor (124) to the equipment (128). Also, the system (100) transfers controlled regenerated power to battery while braking.

[0042] The motor and regenerator (100) in accordance with the present invention advantageously controls the power from battery and generates high torque. The motor and regenerator (100) advantageously provide a high torque and avoids heat generation. The first control unit (104) receives analog input from the first input (108) and continuously monitors the current consumption by the motor (124). The first input (108) includes the current sensor (106) (not shown in FIG. 1) that monitors the output current of the battery (120) and current through motor winding coils. The current sensor for example, a magnetic sensor, cored sensor, coreless sensor, amplifier, shunt resistor, etc. that is assembled on the battery output (120) and coil of motor (124). The first input (108) also includes the current limiting sensor (not shown in FIG. 1). The current limiting sensor (110) for example, a potentiometer that is positioned at dashboard of equipment (e.g., vehicle) for setting the current limit.

[0043] Also, the first control unit (104) receives the second input (112) as a predefined speed signal, a direction signal and a predefined current limit set by a user (114) (not shown in FIG. 1). The second input (112) includes the sensor to provide speed requirement of the user (114) (not shown in Fig. 1), for example, a potentiometer to sense the requirement of speed and direction of the rotation of motor. Additionally, the first control unit (104) receives the third input (116) from the motor (124). The third input (116) provides the rotor position signal with respect to the stator received from the motor (124). The first control unit (104) receives power from the battery (120) and transfers-controlled power to the motor (124).

[0044] In a first mode, the system controls power from battery while generating high torque. The brushless low DC current high torque motor and regenerator with the controller (100) regulates the power from the battery to the motor’s stator coils, ensuring the motor’s speed, direction, and current consumption aligned with predefined user requirements. In the first mode of torque generation, the current consumption by the motor (124) is monitored, analyzed and controlled by the first control unit (104).

[0045] In a second mode, the same system regenerates power at a high voltage to recharge the battery during braking. In the second mode of regeneration, the system generates high voltage at low speed. In the second mode of regeneration, windings of motors generate power and transfers the generated power to the first control unit (104). The first control unit (104) receives power from stator coils and transfers- controlled voltage power to battery by changing coils connection in different series and parallel combinations to recharge the battery during braking at low speed.

[0046] Referring to FIG. 2, a schematic of the brushless direct current motor and regenerator with controller (100) is described. In accordance with the present invention, the first control unit (104) includes a first controller (200), a second control unit (204), and a third control unit (212). The first control unit (104) is configured to monitor the current consumed by the motor (124) and to generate high torque with low current. The system (100) also avoids heat generation and also avoids losses due to heat generation.

[0047] Accordingly, the first controller (200) is configured to receive input signals from the first input (108), the second input (112), and the third input (116), and transfers-controlled signal to a signal generator (208) and the third control unit (212). The first controller (200) receives digitized rotor position signal from a position sensor, for example a photosensor, hall sensor, from the motor (124). Each pulse from position sensor is transferred to the first controller (200).

[0048] Further, the speed of motor is changed by changing PWM duty cycle ratio as per the signals received from the user. The first controller (200) provides analysed and controlled analog output signal to the signal generator (208) for changing duty cycles ratio. Also, first controller (200) provides same analysed and controlled digitized output signal to the signal generator (208) to synchronize the PWM signal with the rotor position of the motor unit (124). In the second mode of regeneration, the first controller (200) calculates the speed.

[0049] In accordance with the preferred embodiment of the present invention, the second control unit (204) receives synchronized PWM signal from the signal generator (208) and transfers the controlled signal to the third control unit (212). The second control unit (204) is configured to control the speed of the motor (124) according to signal from the signal generator (208). Further, the third control unit (212) includes a plurality of switches for example, transistors and a plurality of switches (not shown in FIG. 2), for example mosfets, to connect the coils of stators of the motor (124) in series and in parallel connection as per instructions by the third control unit (212). The third control unit (212) is configured for receiving the power from battery and control signal from first control unit (104) and the second control unit (204). And accordingly transfers the controlled battery power to the winding coils of the stator of the motor (124) to maintain motor speed, direction and current consumption as per selected user input. While regeneration, the third control unit (212) receives power from stator coils and transfers-controlled voltage power to battery by changing coils connection in different series and parallel combinations.

[0050] Referring to FIG. 3 A and FIG. 3B, exploded view of the motor (124) of preferred embodiment of the present invention is described. The motor (124) receives power from the third control unit (212). The motor (124) includes an inner stator (304), an outer stator (308) and a rotor (312). The inner stator (304) is attached with the motor (124) and the outer stator (308) that is coaxially connected with the motor (124). The rotor (312) is coaxially positioned between an inner stator (304) and an outer stator (308). The rotor (312) is coaxially rotatable around the motor axis.

[0051] In the preferred embodiment of the present invention, the inner stator (304) includes a first plurality of teethes (316). The outer stator (308) also includes a second plurality of teethes (320). The first plurality of teethes (316) and the second plurality of teethes (320) has same number of teethes and has coil windings (not shown in FIG. 3A and 3B). The winding connections of the inner stator (304) and the outer stator (308) are selectively arranged in series or parallel.

[0052] In accordance with the present invention, the series or parallel arrangement of winding is selected according to the requirement of size and power of the motor. The windings of both the stators receive controlled power from the third control unit (212). In the second mode of regeneration, windings of both stators (304) and (308) generate power and transfers the generated power to third control unit (212).

[0053] Advantageously, the rotor (312) includes a plurality of magnets (324) positioned on the rotor. The number of magnets (324) and the number of teethes of the stator (304) are equal. The plurality of magnets (324) is positioned and arranged such that the direction of the magnets is towards the centre of the rotor axis. Additionally, the magnets are arranged and positioned in such a manner that if the north pole of first magnet faces towards rotor axis, the south pole of consecutive next magnet faces towards rotor axis.

[0054] In the preferred embodiment of the present invention, the first plurality of teethes (316) and the second plurality of teethes (320) are positioned such that, the teethes has offset by half (1 / 2) of angular pitch of the rotor (312). The inner stator (304) and outer stator (308) have windings in the manner where consecutive teethes are wind in opposite direction to create opposite polarity in consecutive teethes when power is applied. Advantageously, this arrangement in the second mode of regeneration produces current in same direction in consecutive teethes winding, that helps to generate high voltage at low speed. Further, the rotor (312) has a plurality of holes (328) (not shown in FIG. 3 A and 3B). The plurality of holes has the number of holes that are two times the number of the teethes of the stator (304). Additionally, the holes (328) are positioned at equal angular pitch equal to * the pitch of the rotor (312) and also aligned with the respective magnet (324) centres.

[0055] In the present invention, a sensor (332) (not shown in a FIG. 3A and 3B), for example photosensor, is positioned on the motor body (124) to detect the holes (328) on the rotor (312). Accordingly, the sensor (332) detects the hole (328) and generates a respective pulse signal when the hole passes in front of the sensor (332). The pulse signal provides input as the position signal to the first control unit (104). The first control unit (104) finds speed by calculating rotor rotation with respect to time.

[0056] In another embodiment of the present invention, the first position sensor is positioned on outer stator (308) slot and the second position sensor is positioned on inner stator (304) slot. The rotor (312) is positioned with respect to stators (304) and (308), that position signal is sensed by position sensors, that is digital pulse signals is input to the first control unit (104).

[0057] Now referring to FIG. 4, the schematic diagram of the third control unit 212 of the preferred embodiment of the present invention is described herein. The third control unit 212 includes a second controller 404 (not shown in FIG. 4), a first plurality of switches 408, a second plurality of switches 412 and a third plurality of switches 416 to control current direction. The third control unit 212 also includes a fourth switch 420, the fourth switch 420 (CCS) is, for example a power electronic switch. The second controller 404 is, for example, a microcontroller or a digital control circuit.

[0058] In accordance with the present invention, the second controller 404 receives the signal from the third input 116 at each *4 th of electrical cycle rotation of rotor, that equals to i angular pitch of stator teeth. The motor coils are divided in ‘n’ equal parts, ‘n’ is a 2 raised to power ‘n’ series number. The coils 424 are LI, L2, L3, L4, L5, L6, L7, L8...Ln. Respectively, the first plurality of switches 408 are, OCfl to OCfn, OCrl to OCrn, ICfl to ICfn, ICrl to ICrn connected to the coil 424 of the motor 124. The first plurality of switches 408 are, for example, power switches like a mosfet.

[0059] The first plurality of switches 408 is operated by the signal from the second controller 404. The respective base of each switch receives signal from the second controller 404. The first plurality of switches 408 operates according to rotor position with respect to electrical cycle.

[0060] Also, the second plurality of switches 412 are, S I to Sn-1, for example, power switches like mosfet. The third plurality of switches 416 are, Pl to P 2n+l, for example, power switches like mosfet. The second plurality of switches 412, SI to Sn-1, and the third plurality of switches 416 Pl to P 2n+l is operated according to respective signals to base of each switch from the second controller 404. The second plurality of switches 412 and the third plurality of switches 416 changes and selects the coil 424 connections in series or parallel as per required combination. The switches operate according to speed based on the predefined logic.

[0061] The fourth switch 420 is controlled by the second controller 404. The fourth switch 420 controls the current. The first input 108 includes current sensors CCS1 and CCS2. The current sensor 424 is positioned on the battery output and coil respectively, that senses the battery output current flow. Further, the second input 112 transfers the signal of switching off the fourth switch 420 CCS to the second controller 404 when the current flow is above the battery limits, that avoids the battery damage.

[0062] Normally, in BLDC motor, as the speed increases back emf in motor increases, as back emf is directly proportional to speed. As the back emf becomes equal to the applied voltage, further the motor speed does not increase further i.e. motor reaches to it maximum speed. In present invention, the second plurality of switches 412, SI to Sn-1, and the third plurality of switches 416 Pl to P 2n+l, selects series and parallel combinations of coils.

[0063] The motor achieves speed according to the different combinations of the coil 424 of the motor. In a first combination, all ‘n’ number of the coils 424 are arranged in series to achieve the speed ‘SP 1’. The SP is, SP 1= (V x KF) / K (‘K’ is motor constant, K=Torque / Amp current, KF = Friction constant depends on motor condition.)

[0064] Further, to increase the speed of the motor, the third unit 212 switches to a second combination of the coils 424. In the second combination, all the ‘n’ coils are arranged in two groups, like n / 2 coils are in series. Further the two groups of n / 2 coils are arranged in parallel. Accordingly, the “K’ value gets divided by 2 and the maximum speed is, SP2

[0065] SP2 = (V x KF) / (K / 2) = 2xSP - (1)

[0066] Next, for further increase of speed above 2xSP, the third unit switches to a third combination. In the third combination, all the ‘n’ coils are arranged in four groups, like n / 4 groups. The n / 4 th no. of the coils 424 are arranged in series and n / 2 groups of coils 424 are arranged in parallel. Accordingly, ‘K” value gets divided by 4 and the maximum speed is, SP3.

[0067] SP3 = (V x KF) / (K / 4) = 4xSP - (2)

[0068] Accordingly, n / 2 combinations are arranged for n number of coils.

[0069] Now referring to Fig. 4A, a flow chart showing various steps involved in controlling the motor speed and the current consumption of the present invention is described. Initially in a step 504, the first control unit (104) receives three inputs from the first input unit (108), the second input (112) and the third input (116). In a next step 508, the first control unit (104) analyses the received input and accordingly finds the current flow direction through the inner stator (304) and the outer stator (308) of the motor (124). The first controller (200) finds electrical angle of rotation of rotor with respective stators from the signal received from the second input 112.

[0070] In a next step 512, the second control unit (204) receives PWM signal from the signal generator (208), accordingly finds duty cycle ratio of PWM signal to change the speed as per the user requirement. The second control unit (204), that controls the speed of the motor (124) includes a circuit of a current control switch CCS. The switch CCS is controlled by applying signal to its base connection by microcontroller or any digital circuit.

[0071] In a next step 516, the third control unit (212) receives the input power from the battery (120), the first controller (200) and second control unit (204). Accordingly, the third control unit (212) controls the current by selecting the number of coils of stators to be connected in series connection or selecting the number of coils to be connected in parallel connection to control current within the limit set by user. In the final step 520, the third control unit (212) provides the controlled power to the motor (124) that controls the speed of the motor (124) and generates the required torque. While in the second mode of regeneration, the third control unit (212) receives power from stator coils and transfers-controlled voltage power to battery by changing coils connection in different series and parallel combinations.

[0072] Accordingly, the brushless DC current motor and regenerator with controller generates high torque on low current in the first mode. The first control unit controls power to the motor (124) that controls the speed of the motor (124) and generates the required torque respective to motor’s speed, direction, and current consumption aligned with predefined user requirements. In the second mode, the first control unit (104) receives power from stator coils and transfers- controlled voltage power to battery by changing coils connection in different series and parallel combinations to regenerate high voltage at lower speed to improve regeneration efficiency with wide range.

[0073] Referring to FIG. 1 to 4A, an operation process of the preferred embodiment of the present invention in accordance with the present invention is described. Initially, the first control unit (104) receives three inputs from the first input (108), the second input (112) and the third input (116). The first control unit (104) receives current from the first input (108), speed signal and direction of rotation from the second input (112) and a rotor magnets pole (north / south) position signal from the sensor (332).

[0074] Further, the first controller (200) analyses the inputs and decides the current flow direction through the inner stator (304) and the outer stator (308) of the motor (124). The current flow energises the inner stator coils (304) as north poles are created in front of north poles of rotor magnets and south poles in front of south poles of rotor magnets.

[0075] Further, for clock wise rotation of the motor, the outer stator (308) is energised such that north poles are created to left side of north poles of rotor magnets and south poles are created at right side of north poles of rotor magnets. The south poles are created at left side of south poles of rotor magnets and north poles at right side of south poles of rotor magnets. Accordingly, this rotor rotates i pitch of the teethes of the outer stators (308) in clock wise direction.

[0076] For anti-clock wise rotation of the motor, the outer stator (308) is energized such that the north poles are created to left side of south poles of the rotor magnets and the south poles at right side of south poles of the rotor magnets. The south poles are created at left side of the north poles of the rotor magnets and the north poles are at right side of the north poles of the rotor magnets. Accordingly, this rotor rotates i pitch of the teethes of the outer stators (308) in anti-clock wise direction.

[0077] The signal generator (208) generates the pulse signal. The second control unit (204) finds duty cycle ratio of PWM signal. The PWM signal is transferred to the third control unit (212) to change the speed of the motor (124).

[0078] Now, the third control unit (212) receives the input power from the battery (120), first controller (200) and the second control unit (204) controls the current by selecting the number of coils of stators to be connected in series connection or selecting the number of coils to be connected in parallel connection to control current within the limit set by user.

[0079] Further, if current consumption is lower than the current limit set by user, the number of coils connected in parallel is increased, that increases the power supply to the motor (124) to increase speed. If the current consumption is more than the current limit set by user, the number of coils connected in series is increased to reduce the current consumption and generates high torque. The third control unit (212) transfers the battery power to motor stator winding coils in a controlled manner and maintains motor speed, direction and current consumption.

[0080] In second mode of regeneration of the present invention, if the speed is high the voltage generated in each coil is high hence, number of coils are connected in parallel connection is increased. If the speed is low, the voltage generated in each coil is less hence, number of coils are connected in series to add up the voltage to get sufficient high voltage output to charge battery.

[0081] In the second mode of regeneration of the present invention, number of coils are connected in parallel connection is increased. For the high speed of equipment, the voltage generated in each coil is high, hence increased no. of coils are connected in parallel connection.

[0082] EXAMPLES:

[0083] Example 1: Comparative performance test of the motor and regenerator (100)

[0084] The motor and regenerator 100 is described using specific exemplary details. Now, the 3 phase BLDC motor is selected for comparative performance test of the present invention. The specifications of the 3 phase BLDC motor and present invention are prescribed in the table 1 as follows.

[0085] Table 1A: Specifications

[0086] Table IB: Result Observation

[0087] It is noted that, Table 1 A represents the specifications of 3 Phase Brushless Direct Current Motor (BLDC Motor) and the motor and regenerator (100) of the present invention tested for comparative performance of torque generation.

[0088] Table 2. Torque generation with respective motor rotation angle Table 2 presents the statistical data of torque generation by 3 phase BLDC motor and present invention at 7 Amp current from battery in the first mode of the present invention.

[0089] Now referring to FIG. 5 and Table 2, the comparative analysis for torque generation by 3 phase BLDC motor and present invention is described herein. The graphical representation of torque generated by present invention was 70 Nm. (Refer 5A in the FIG. 5). The graphical representation of torque generated by 3 phase BLDC motor was near about 40 Nm (Refer 5B in FIG. 5). It is to be noted that the torque generated by present invention was much higher, that indicates improved efficiency of the present invention.

[0090] Example 2: Comparative performance of the motor and regenerator (100) with different combinations of motor coil is described herein.

[0091] Now, referring to specifications of present invention mentioned in Table 1, the motor coil of the regenerator motor 100 was divided in 8 equal parts. The coils 424 of the motor 124 were Li, L2, L3, L4, L5, Le, L7, and Ls. Respectively, the first plurality of switches 408 were, OCfi to OCfs, OCri to OCrs, ICfs to ICfs, and ICri to ICrs, that were connected to the coil 424 of the motor 124. The second plurality of switches 412, that is Si to S7, and the third plurality of switches 416, that is Pi to P 17, were operated according to respective signals to base of each switch from the second controller 404.

[0092] The second plurality of switches 412 and the third plurality of switches 416 changes and selects the coil 424 connections in series or parallel as per required combination based on the logic shown in the truth table 3. The first plurality of switches 408, were operated according to rotor rotation with respect to electrical cycle based on the logic shown in the truth table 4. Table 3: Switching Logic Table for Different Combinations of Coils

[0093] Table 4: Switching Logic table of the first plurality of switches 408

[0094] Table 4 shows the switching logic table for operating the first plurality of switches 408 with respect to each *4111of electrical cycle rotation of rotor. The electric cycle of rotation of the motor was generated respective to the digital signal from the third input 116. The digital signal from the third input 116 was regarding the rotor rotation. Next, the first controller 200 detects the rotor position with respect to stators and the first controller 200, and operates the first plurality of switches 408 (refer table 4), to decide current flow direction in coils. The first controller 200 finds the speed according to rotations per time. Next, the controller decides the series, parallel combination of coils with respect to the calculated speed.

[0095] The second plurality of switches 412 and the third plurality of switches 416 changes and selects the coil 424 connections in series or parallel as per required combination based on the logic shown in the truth table 3.

[0096] Table 5: Switching logic table for the first input 108

[0097] Now, table 5 shows switching logic table for the first input 108 current sensors CCS1 and CCS2 to avoid the battery damage. The second input 112 transferred the signal of switching off the fourth switch 420 CCS to the second controller 404 when the current flow was above the battery limits to avoid the battery damage. Current sensor CCS2 positioned on one coil connection senses current flow in coil, this information is sent to controller in analog form. Also, the second input (112) from user received by controller is in analog form, that indicates user requirement of speed acceleration.

[0098] According to user inputs controller decides current limit proportional to acceleration but below the amplectic value of coil winding. Further, the controller compares the current limit and actual current information received form sensor CCS2. If the current value is greater than set current limit, that switches off the CCS switch. If the current value is less than set current limit, that operates the CCS switch on (Refer switching logic table 5). In this way, by operating switches CCS, the PWM signal proportional to the current are generated in signal generator unit (208).

[0099] Table 6 Current drawn by motor against vehicle running time in sec

[0100] It is to be noted that the Table 6 and FIG. 7 shows a comparative performance of 3 Phase BLDC motor and present invention for load of two wheels in running condition by monitoring current drawn by respective motor. Now referring FIG. 6A, FIG. 7 and switch combination mentioned in Table

[0101] 3, and Table 6, the performance of the motor 100 with the first combination as all 8 coils 424 in series arrangement is described herein. FIG. 6A represents the series arrangement of coils of the motor (Li to Ls). The arrangement of second plurality of switches 412 and the third plurality of switches 416 as mentioned in Sr. No. 1 of table 3, arranged the coils in the first combination.

[0102] In the first combination, all 8 number of the coils 424 were arranged in series to achieve the speed ‘ SP 1’ . It is to be noted that the speed SP 1 was generated by the motor 124 in the first combination of the coil. The speed SP1 is represented by ‘7A’ in FIG. 7. For the speed SP1, from 0 to 12 KMPH the peak current drawn by the present invention is 14 amp. However, 3Phase BLDC motor requires current peak 104 amp, is represented by ‘7D’ in FIG. 7. The graphical representation ‘7A’ represents that low current was drawn by the present invention for the same speed for the present invention than the 3PH BLDC motor.

[0103] Further, to increase the speed of the motor 124, the third unit 212 switched to a second combination of the coils 424. Now, referring to FIG. 6B, FIG. 7 and switch combination mentioned in Table 3, the performance of the motor and regenerator 100 with second combination of coil LI and L8 is described herein. The arrangement of second plurality of switches 412 and the third plurality of switches 416 as mentioned in Sr. No. 2 of table 3, arranged the coils in the second combination.

[0104] In the second combination of coils, first group was formed, where coils LI to L4 were connected in series, and second group was formed, where coils L5 to L8 were connected in series arrangement. Further, two respective groups were connected in parallel arrangement. Accordingly, the ‘K’ value was divided by 2 and the maximum speed was SP2. It is to be noted that the speed SP2 was generated by the motor 124 in the second combination of the coil. The SP2 is represented by 7B in FIG. 7. For the speed SP2, from 12 to 25 KMPH the peak current drawn by the present invention was28 amp. However, 3Phase BLDC motor requires current peak 94 amp for the speed from 12 to 25 KMPH, is represented by ‘7D’ in FIG. 7. The graphical representation ‘7B’ represents that low current was drawn by the present invention for the same speed for the present invention than the 3PH BLDC motor.

[0105] Next, for further increase of speed above two times SP1 (that is 2 X SPi), the third control unit 212 was switched to a third combination of the coils 424. Now, referring to FIG. 6C, FIG. 7 and switch combination mentioned in Table 3, the performance of the motor and regenerator 100 with third combination of coils Li and Ls is described herein. The arrangement of second plurality of switches 412 and the third plurality of switches 416 as mentioned in Sr. No. 3 of table 3, arranged the coils in the third combination.

[0106] In the third combination of coils, third group was formed, where coils Li and L2 were connected in series and fourth group was formed, where coils L3 to L4 were connected in series arrangement. Next group was formed, where coils L5 to L<> were connected in series arrangement and fourth group was formed, where coils L7 to Ls were connected in series arrangement. Further, all respective four groups of coils were connected in parallel arrangement. Accordingly, ‘K’ value was divided by 4 and the maximum speed was SP3. It is to be noted that the speed SP3 was generated by the motor 124 in the third combination of the coil. The SP3 is represented by 7C in FIG. 7. For the speed SP3, from 25 to 45 KMPH the peak current drawn by the present invention was 38 amp. However, 3Phase BLDC motor requires current peak 94 amp, is observed and represented by ‘7D’ in FIG. 7. The graphical representation ‘7C’ represents that low current was drawn by the motor and regenerator 100 of the present invention for the same speed than the 3PH BLDC motor.

[0107] Example 3: Performance of the present invention motor and regenerator 100 for load of 2 wheels.

[0108] Table 7: Specifications of Load

[0109] Table 8: Heat generated by High Torque BLDC motor and 3PH BLDC Motor It is to be noted that the Table 8 shows a comparative performance of 3 Phase BLDC motor and present invention for load of two wheel in running condition by monitoring a generated heat.

[0110] Now referring to FIG. 7, Table 6, Table 7 and Table 8, the average current during 0 to 45 KMPH speed (Time 0 to 120 sec) was 18.476 amp. For average current of all four combinations, 18.476 Amp, time 120 sec and resistance of coil, the heat generated during this time was 10292 Joules. The comparative performance of the heat generated represents that low heat was generated by the present invention for the same duration and speed than the 3PH BLDC motor. Example 4. Performance of the present invention motor and regenerator 100 in regenerator mode

[0111]

[0112] Table 9: comparative performance for Regeneration Voltage and Power

[0113] Referring to Table 9, FIG. 8 A, and 8B comparative performance of regenerative voltage and power for 3 phase BLDC motor and present invention is described. The voltage generated with respect to vehicle speed is described. Referring to FIG. 8A, 8-al indicates graphical representation of voltage regenerated according to speed by 3PH BLDC motor, and 8-a2 indicates graphical representation of voltage regenerated according to speed by present invention in regenerator mode. 8-a2 graphical representation represents higher efficiency of voltage regeneration, of the present invention than the 3PH BLDC motor.

[0114] Referring to FIG. 8B, 8-bl indicates graphical representation of power regenerated according to speed by 3PH BLDC motor. And 8-b2 indicates graphical representation of power regenerated according to speed by present invention in regenerator mode. 8-b2 graphical representation represents higher efficiency of power regeneration of the present invention than the 3PH BLDC motor.

[0115] Advantageously, the brushless low DC current high torque motor and regenerator with controller (100) provides increased efficiency of torque generation with minimum current consumption. Also, the motor and regenerator (100) advantageously provide high efficiency as the average current is low. The motor and regenerator (100) reduce heat generation and decreases heat losses. The motor and regenerator (100) are economical as it reduces cost and weight of the equipment. Additionally, the motor and regenerator (100) consume 40% low current for same torque as compared to the 3-phase motor commonly used in most equipment.

[0116] The brushless low DC current high torque motor and regenerator reduces heat generation. In regeneration mode, the motor and regenerator (100) produce sufficient high voltage and power to charge battery even at low speed of vehicle (equipment), accordingly increases regeneration efficiency.

[0117] The embodiment is chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others, skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the scope of the present invention.

Claims

CLAIMS1. A brushless low DC current high torque motor and regenerator (100) with controller for controlling power from battery comprising: a first control unit (104), the first control unit (104) being configured on a motor (124) for transmitting, and receiving the signals, for controlling power from battery (120) to the motor (124), the first control unit (104) including: a first controller (200), the first controller 200 being configured on the first control unit (104) for receiving, a current input from a first input (108), a user predefined speed signal, a user predefined speed direction and a user predefined current limit value from a second input (112), a rotor position signal with respect to a stators signal from the motor (124), and a power from the battery (120), in a first mode of torque generation, for monitoring current consumption by the motor (124), for generating controlled high torque and transferring analyzed controlled analog and digital output signal to a signal generator (208) and a third control unit (212), and the signal generator (208) being configured for changing duty cycle ratio of amount of current flow in coils synchronizing the PWM signal and transferring to a second control unit (204); the second control unit (204) being configured for controlling the speed of the motor (124) according to the signal fromthe signal generator (208) and transferring to the third control unit (212); and the third control unit (212) being configured for receiving the power from the battery and control signal from the first control unit (104) and the second control unit (204) and transferring the controlled battery power to the coil windings of the stator of the motor (124) for avoiding heat generation while generating high torque in a first mode and for regenerating high voltage and power at lower speed in a second mode.

2. The brushless low DC current high torque motor and regenerator (100) with controller as claimed in claim 1, wherein the motor 124 including an inner stator (304), the inner stator (304) being coaxially attached with the motor (124), an outer stator (308), the outer stator (308) being coaxially attached with the motor (124) and a rotor (312) being coaxially positioned such that rotor (308) being rotatable around the motor axis and positioned between inner and outer stators.

3. The brushless low DC current high torque motor and regenerator (100) with controller as claimed in claim 2, wherein, the inner stator (304) including a first plurality of teethes (316) and the outer stator (308) including a second plurality of teethes (320), both respectively having same even number of teethes and coil windings, being positioned such that, teethes having offsetby half (1 / 2) of angular pitch of the outer stator (308) and the inner stator (304) windings being in the manner where consecutive teethes are wind in opposite direction to create opposite polarity in consecutive teethes when power is applied for changing the current flow direction respective to rotor (312) position change.

4. The brushless low DC current high torque motor and regenerator (100) with controller as claimed in claim 2, wherein, the winding connections of the inner stator (304) and the outer stator (308) receiving controlled power from the third control unit (212), being selectively arranged in series or parallel, the series or parallel arrangement of winding being selected according to the requirement of size and power of the motor (124).The brushless low DC current high torque motor and regenerator (100) with controller as claimed in claim 1, wherein a sensor (332) being positioned on motor (124) for detecting the holes (328) on the rotor (312), for generating a respective pulse signal when the hole (328) being passed in front of the sensor (332), that pulse signal as the position signal being transferred to the first control unit (104).

5. The brushless low DC current high torque motor and regenerator (100) with controller as claimed in claim 2, wherein the plurality of magnets (324) is positioned on the rotor (312) and being arranged such that the direction ofopposite poles of the consecutive magnets being toward the center of the rotor (312).

6. The brushless low DC current high torque motor and regenerator (100) with controller as claimed in claim 1, wherein, the third control unit (212) for controlling the current by selecting the number of coils of the stators to be connected in series connection or selecting the number of coils to be connected in parallel connection to control current within the limit set by user and providing the controlled power to the motor (124) for controlling the speed of the motor (124) and for generating the torque.

7. The brushless low DC current high torque motor and regenerator (100) with controller as claimed in claim 2, wherein windings of both stators (304) and (308) being generated power while braking and transferring the generated power to third control unit (212) in the second mode of the regeneration.

8. The brushless low DC current high torque motor and regenerator (100) with controller as claimed in claim 1, wherein the first control unit (104) for finding speed and generating voltage in the second mode of the regeneration.

9. The brushless low DC current high torque motor and regenerator (100) with controller as claimed in claim 1, wherein the first control unit (104) beingfor analysis and for determining the current flow direction through the inner stator (304) and the outer stator (308) of the motor (124).

10. The brushless low DC current high torque motor and regenerator (100) with controller as claimed in claim 1, the first controller (200) being for finding electrical angle of rotation of the rotor (312) with respective stators (304) and (308) from the signal received from the third input 116.

11. The brushless low DC current high torque motor and regenerator (100) with controller as claimed in claim 1, the first controller (200) for switching current flow direction in coils, for generating synchronous rotating magnetic field with respect to rotor magnet field and respective user inputs for rotating the motor in clock wise or counter clock wise direction for rotating the magnetic field.

12. The brushless low DC current high torque motor and regenerator (100) with controller as claimed in claim 1, wherein the third control unit (212) including a plurality of switches for connecting the coils of stators of the motor (124) in series and in parallel.

13. The brushless low DC current high torque motor and regenerator (100) with controller as claimed in claim 1, wherein in the second mode of regeneration the third control unit (212) being for receiving power from stator coils and for transferring controlled voltage power to the battery bychanging coils connection in different series and parallel combinations in the second mode of regeneration.

14. The brushless low DC current high torque motor and regenerator (100) with controller as claimed in claim 1, the signal generator (208) and first controller unit (200) receiving the first input (108) current being consumed and the second input (112) from user requirement of speed for analyzing and generating pulse width modulation (PWM) proportional to the user requirement and within current limits set by user.

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