A low-speed generator with management system

Abstract

A generator system for El-assist vehicles motors that require activation via human energy comprises: a generator having, a shaft positioned on a rotation axis, at least two stator and rotor positioned between stators and all are coaxially mounted on the shaft, plurality of magnets positioned angularly in respect to radial direction of the rotation axis, plurality of magnets having pie-shaped cross-section in respect to plane which is right-angled to the rotation axis, a generator output means to deliver generated energy to an El-assist vehicles, a hybrid battery, a management system configured to distribute an energy generated between the engine output and the hybrid battery.

Description

[0001] A LOW-SPEED GENERATOR WITH MANAGEMENT SYSTEM

[0002] Technical Field

[0003] The invention is related to a generator system for El-assisted motors and vehicles are driven by said motors that require activation via human energy such as pedaling.

[0004] Prior Art

[0005] For transportation, different kinds of vehicles, e.g cars, small boats, that are driven by internal combustion engines are used. However, this kind of system are not sustainable because of air pollution created, so demand for electric vehicles is increasing.

[0006] In spite of advantages, the performance of electric motor driven vehicles don’t match of exceed internal combustion motor driven vehicles yet because of range limitations before recharging is required and time taken to re-charge. Limitations on range in turn generates “range fear” which inhibits the take up of electric vehicles by some consumers.

[0007] All electric vehicles have a requirement to re-charge battery packs at frequent intervals, and

[0008] / or to increase the size of a battery pack to extend the range of the vehicles. The demand for charging stations (for re-charging EVs) across many cities is greater than city-infrastructure is able to provide now or in the immediate future.

[0009] El-assisted motors are a sub-group of electric motors which require activation via human energy such as pedaling. This kind of motors are used to drive mostly e-bike or similar LWVs

[0010] (lightweight vehicles). A typical e-bike has a range between 30-90 KMs which is very low for a consumer utilizing e-bikes for every day to transport places between like home and workplace.

[0011] Furthermore, weight of battery packs is generally between 4-6kg of a battery pack. More weight means higher battery energy consumption and lower maximum speed for electric vehicles.

[0012] For solving range problem, W02021107902A1 discloses multiple generators which are able to recharge battery. This generator system recharge battery during pedaling. In this system the charging efficiency of the batteries is increased by simultaneous utilization of a small axial flux generator positioned on the wheel of e-bike and a vertical axial flux generator attached to the frame of e-bike. Also, a power management system is utilized for management of batteries by regulating inconsistent power generated by pedaling. The two main drawback for this system are requirement of multiple generators and the output energy. Despite of using multiple generators, this system only can be used for 2- or 3 -wheel vehicles and is insufficient for 4-wheel LWVs.

[0013] As a result, all of the problem mentioned above has made it necessary to provide a novelty in the related field.

[0014] Objects and Brief Description of the Invention

[0015] Main objective of the invention is to increase output of El-assisted motors with generators at relatively low speeds.

[0016] Another objective of the invention is to increase range of El-assisted motors without increasing capacity of the battery. This invention also allows for self-charging of El-assisted vehicles and that substantially reduces or eliminates a requirement for access to charging stations. Thereby the range, or distance travelled, of Electric vehicles are substantially increased.

[0017] Another objective of the invention is to provide El-assisted motors with generators for 4- wheel LWVs and LWVs has similar output requirement, e.g watercraft like small boats.

[0018] Another objective of the invention is to eliminate multiple generator requirement and lowering weight of the system.

[0019] Another objective of the invention is to provide continuous self-charging.

[0020] To achieve mentioned objective, a generator system for El-assisted motors comprises a rotatable shaft positioned on a rotation axis, typically at least two stator and at least one rotor positioned between the stators and all are coaxially mounted on the shaft, plurality of angularly positioned magnets in respect to radial direction of the rotation axis, plurality of coils of which cross section have three edges that connect to each other to form closed loop, in respect to plane which is right-angled to the rotation axis, a battery system configured to store energy generated by the generator and transmit the energy to the El-assisted motor.

[0021] Performance of the generator is achievable by ‘cramming’ a maximum number of angled / skewed magnets into the available surface area of a rotor and two-way effectiveness of the magnets. The front and back (largest surface area) of each magnet or stator are each exposed to respectively stators or magnets. This virtually doubles the efficiency of the magnetic interaction. “Two-way” system, with both faces of the magnets each facing separate stators, or vice-versa, virtually doubling the number area of magnetic flux. Thereby developing a dense EMF (electro-magnetic field), which results in a greater electric charge. This improvement also reduces the air gap between the magnets, an area that is a key factor to the total air gap flux density calculation.

[0022] In the preferred embodiment of the invention, circumferential portion of the rotor is serrated; thereby improving air flow performance. The serrated rotor adds efficiency of waterproofing by pushing pushing water droplets to out of the system.

[0023] In the preferred embodiment of the invention, the inlet and / or the outlet are formed in the shape of a curved channel extending circumferentially from the portion of the cover that covers the generator. Said channels improves air flow performance by letting air flows in circular way inside the cover.

[0024] In the preferred embodiment of the invention, there is a control unit used to control energy transmission among the generator, the battery system and the El-assisted motor. The control unit configured to perform energy regulation. The generator of the invention is configured to generate energy from mechanic movement, especially from human energy such as pedaling. However, the mechanic input from human is generally inconsistent and this inconsistency prevent continuous charging of the batteries. The control unit prevents such an inconsistency by using transformers. The control unit regulates transformers according to data from drive mean, such as pedal or gears. The control unit keeps a steady voltage or current output regardless of the inputs which is how energy is kept constant under a range of operating speeds.

[0025] In the preferred embodiment of the invention, the battery system comprises at least two batteries which one of them is the first and other one is second battery. The second battery transmit energy to the El-assisted motor, the first battery stores energy and transmit it to the second battery. The energy distribution between battery prevents waste of energy and the control unit is configured to perform such a task. This distribution is performed according to demand of the El-assisted motor. If demand is high, the energy is directly transmitted to the second battery and if demand is low, energy is transmitted to the first battery for storing.

[0026] Description of the Figures of the Invention

[0027] The figures and related descriptions necessary for the subject matter of the invention to be understood better are given below.

[0028] Figure 1. Side view of the a low-speed generator with management system on a LWV. Figure 2. Cross-section of the a low-speed generator.

[0029] Figure 3a. Front view of the one rotor and one stator together.

[0030] Figure 3b. Front view of the stator.

[0031] Figure 3c. Front view of the rotor and the stator.

[0032] Figure 4. Magnetically induced voltage graph of the invention.

[0033] Figure 5. Schematic view of the management system.

[0034] Reference Numbers

[0035] The parts and components are given in the figures are referenced for the subject matter of the invention to be understood better.

[0036] 10. Generator

[0037] 11. Rotor

[0038] 110. Serrated section

[0039] 111. Circumferential edge

[0040] 112. Serrated edge

[0041] 12. Stator

[0042] 13. Inlet

[0043] 14. Outlet

[0044] V. Vehicle

[0045] F. Frame

[0046] CM. Connection means

[0047] CV. Cover

[0048] CU. Control unit

[0049] D. Driving mean

[0050] E. El-assisted motor

[0051] TE. Transmission element

[0052] B. Battery Bl. First battery

[0053] B2. Second battery

[0054] M. Magnet

[0055] C. Coil

[0056] S. Shaft

[0057] RC. Rectifier

[0058] T. Transformer

[0059] R. Rotation axis

[0060] P. Plane

[0061] Detailed Description of the Invention

[0062] The invention is related to a generator system for El-assisted motors and vehicles are driven by said motors that require activation via human energy such as pedaling.

[0063] Referring to the Fig. 1 ; the generator system is configured to used for lightweight vehicles that uses El-assisted motors. Such a lightweight vehicle is maybe e-bike. In this detailed description, embodiments are disclosed according to e-bike implementation however this generator system can be used for other lightweight vehicles 3- or 4-wheel vehicles or small boats which uses El-assisted motors.

[0064] An axial flux permanent magnet generator (10) is fixed on a frame (F) of a vehicle (V) by using connection means (CM). If the vehicle (V) is an e-bike, the plate shaped connection means (CM) may be fixed between pipe of the frame in such a way that the AFPM generator (10) is positioned over a drive mean (D), such as a pedal. The connection means (CM) can be used as place-holder for the generator

[0065] The AFPM generator (10) also connected to the drive mean (D) in a such way that mechanical energy generated by the drive mean (D) is transmitted to the AFPM generator (10), more specifically shaft (S) of it. Preferably, the AFPM generator (10) is configured as a Supra-low- speed generator. The term “Supra-low-speed generator” indicates the generator that works speed under 1000 rpm (Revolutions per minute). The connection between the drive means (D) and the shaft (S) may be provided by transmission element (TE), such as chain, preferably with sprocket. The gear of pedal and gear connected to the shaft (S) may be connected to each other by chain. Besides that, the shaft (S) may be coaxially connected to the pedal rod or pedal rod and the shaft (S) are integrated.

[0066] The drive mean (D) also connected to the El-assisted motor (M) in a such way that mechanical energy generated by the El-assisted motor (M) is transmitted to the drive mean (D). To connection between the drive mean (D) and the shaft (S) may be provided by transmission element (TE), such as chain. The gear of pedal and gear connected to the El- assisted motor (M) may be connected to each other by chain. Besides that, El-assisted motor (M) may be coaxially connected to the pedal rod or pedal rod and the motor El-assisted (M) shaft are integrated.

[0067] Furthermore, a system comprises a battery system (B) that is connected to the vehicle (V), especially connected to frame (F) of vehicle (V) or to the generator system itself. The battery system also comprises connection cable for connecting to the El-assisted motor (M) and the generator (10).

[0068] Referring to the Fig. 2; the AFPM generator (10) comprises a two stator (12) and a rotor (11) which is positioned between the stators (12). Also, maybe more than one rotor (11) can be positioned between the stators (12) to increase out of the AFPM generator (10). The rotor (11) and the stators (12) coaxially coupled by shaft (S). The position of the shaft (S) defines the rotation axis (R).

[0069] The AFPM generator (10) comprises magnets (S) and coils (C). The magnets (M) and the coils (S) generates electrical power by relative rotational movement the rotor (11) and the stator (12). The magnets (M) and the coils (C) are fixed to the rotor (11) and the stator (12), respectively or to the stator (12) and the rotor (11) respectively.

[0070] Preferably the magnets (M) are positioned on the rotor (11).

[0071] In above disclosure, the magnets (S) and the coils (C) can be mounted on both the rotor (11) and the stator (12). After this point, embodiments are explained, according to the embodiment where magnets (M) are positioned on the rotor (11) however it should be understood that below explanations are valid for embodiment where magnets (M) are positioned on the stator (12), unless otherwise stated.

[0072] Referring to the 3 a; the rotor (11) is positioned on the rotation axis (R) which goes through center of the rotor (11). The rotor (12) preferably comprises circular body. The magnets (M) are positioned around the rotation axis (R).

[0073] The magnets (M) are positioned angularly in respect to radial direction of the rotation axis

[0074] (R). In the other word, the magnets are skewed in respect to radial direction of the rotation axis (R). Preferably, angle between the radial axis and the axis of the magnet is between 12- 15 degrees.

[0075] The magnets (M) are preferably linearly extended magnets (M). Also, preferably magnets (M) are evenly distributed around the rotation axis (R).

[0076] Referring to the 3a; the stator (12) is positioned on the rotation axis (R) which goes through center of the stator (12). The stator (12) preferably comprises circular body. The magnets (M) are positioned around the rotation axis (R).

[0077] The coils (12) cross-section have three sides that connect to each other to form closed loop, in respect to plane (P) which is right-angled to the rotation axis (R). The mentioned sides are walls of the coils (C). Said walls are connected to each other via its ends. The connection ends maybe pointy and / or curved. The conductive windings are wound on the walls.

[0078] The coils (C) may be in form of pie-shape or triangular. The pie-shaped coil (C) has two straight edge and a curved edge that connects the straight edges. The triangular coil (C) has three straight edges. Preferably, at least two straight edges are identical.

[0079] Referring to the Fig 3a and 3b; positioning of the magnets (M) and forms of the coils (C) providing denser electro-magnetic field, which results in a greater electric charge by two-way effectiveness of magnetic interaction between the magnets (M) and the coils (C). This interaction carried out by transmitting mechanical rotation of the drive mean (D) to the shaft

[0080] (S) which rotates the rotor (11) relative to the stator (12).

[0081] Referring to the Fig 3c; rotor (11) may comprise serrated edges in its circumferential portion. The serrated parts are formed by circumferential edges (111) and serrated edge (112). Circumferential edges (111) are curved circumferential parts of the rotor (11) and serrated edge (112) are edge that extends from circumferential edges (111) to the rotor (11). Preferably, extension axis of serrated edge (112) is skewed in respect to radial axis of the rotation axis (R). The circumferential edges (111) and serrated edges (112) pushes liquids away from the rotor (11). Also, this serrated structure improves air flow.

[0082] The rotor (11) and the stator (12) are protected by a cover (CV) against environmental effects, such as dust, water or impacts. Generation of electrical energy causes heating of the generator so it is important that providing healthy air flow inside the cover (CV). To improve air flow, the cover (CV) comprises an air inlet (13) and an air outlet (14).

[0083] The air inlet (13) and the air outlet (14) are both curved channels extend from cover (CV) body. The curved structure of channels helps circular flow which is best option the structure has already comprises rotational parts, such as rotor (11).

[0084] Furthermore, the generator may comprise a damper or a flywheel (not shown in figures) on the rotor (11) shaft (S) to dampen the reduction of speed when the vehicle (V) is temporarily stopped

[0085] Referring to the Fig. 5; before transmitting energy generated by the generator, said energy may be needed a regulate. For this regulation, a control unit (CU) and the at least one, preferably two transformers (TE) are used. The control unit (CU) is configured to receive data from the driver mean (D) or the generator. When there is inconsistency in generation of energy, which is caused by inconsistent human energy input, such as inconsistent pedaling, this inconsistency is determined by a sensor (not shown in figures), e.g. torque sensor, and the sensor sends the data obtained to the control unit (CU) and the control unit (CU) regulates transformer (TE) or transformers accordingly.

[0086] Optionally, a rectifier (RC) is connected to the system to AC current generated by the generator (10) to DC current.

[0087] In a preferred embodiment of the invention, the control unit (CU) is especially configured to distribute the energy generated by the generator (10) between multiple batteries. For this battery system (B) comprises at least two batteries which are a first battery (Bl) and a second battery (B2). The first battery (Bl) is configured to store energy generated by the generator (10) and to transmit stored energy to a second battery (B2) and the second battery (B2) is configured to receive energy from the first battery (Bl) or the generator (10) and to transmit the energy to the El-assisted motor (M).

[0088] The control unit (CU) monitors the demand of the El-assisted motor (M) and energy generation of the generator (10) continuously. When demand is increased, route of the energy generated by the generator (10) is changed by the control unit in such way that to the second battery (B2) and then El-assisted motor (M) or to directly to the El-assisted motor (M). In controversy to that, when demand is decreased, route of the energy generated by the generator (10) is changed by the control unit (CU) in such way that to the first battery (Bl) and transmitted energy is stored in first battery (Bl) until demand is increased. The stored energy can be directed to the second battery (B2) or the El-assisted motor (M), when energy generation is lower than demand of the El-assisted motor (M).

[0089] The battery system (B) mentioned may be provided as hybrid-capacitor system.

[0090] Furthermore, the first battery (Bl) may be pre-charged and having charging unit to enable charging by other sources than the generator (10).

[0091] All generators feature copper coils and magnets (in various configurations) to produce a current output (electricity) but typically require thousands of revolutions-per-minute (rpm) at a constant speed. Conventional bicycles (fitted with a conventional dynamo) under conventional usage produces only 6V. In the case of el-assist e-bikes fitted with a conventional 250W El-motor it requires 58V.

[0092] Coupled to the generator is a management system, (see above / previous) plus two small battery packs whereby one is pre-charged, providing energy to a typical 250-500W motor, while the other battery pack stores energy. The Smart Management system handles input / output variations via a hybrid battery-capacitor system.

[0093] In the context of this application, a complex generator (10) is designed. This generator (10) at approximately 15cm in diameter and 5cm in width, with an overall weight of approximately 2kgs.

[0094] Coil Design:

[0095] A size that according to our calculations of the weight, based on the cable length, weight of the stator / s (12) and support material for the coils (C) would fit the demand of the lightweight vehicle due its voltage production, weight, and the material required for its manufacturing process.

[0096] For the different AFPM topologies shapes of coils (C) effect the output (as well as diameter and length of the wire) of each coil (C). For the stator (11) design, pie-shaped coils (C) are adopted to reduce Torque Ripple Factor (TRF) for better stator utilization.

[0097] Following analysis of the ferrite effect it was decided to minimize ferrite components for weight-saving purposes, reducing power losses through eddy current, and providing high voltage, low current, and high electrical load at low RPM. This also allows for a better slot packing factor (Spf) which increases the effective area on the surface of the coil (C) facing the magnets, therefore, allowing for a smaller axial length and ensuring a uniform magnetic field throughout the cross-sectional area of the coil (C).

[0098] The inter-magnet distance is reduced, which combined with skewed rectangular magnets on the rotor, results of voltage and power output are higher due to a reduction of the air gap between magnets.

[0099] Rotor Design:

[0100] Distribution of the magnets (M) is important because it is directly related to the voltage induced on the stator (12) coils (C). Typically, magnets (M) in this topology are distributed vertical to the axle; such magnets (M) are machined to a fan-shape to increase surface area of the magnets.

[0101] After experimentation / simulation it was found that distributing magnets (M) at a skewed angle to the axle had the benefit of increasing the number of - and frequency of - poles rotating over each coil (C). The efficiency of this design overcomes the need for two rotors (11) and risks associated with misalignment of rotors (11) and a variable air-gap.

[0102] The configuration of the magnets (11) on the rotor (12) represents a particularly dense EMF (electro-magnetic field), operating with only a 0,4mm air gap ensures operating efficiency of the machine.

[0103] For experimental purpose, the stators (12) having 16cm diameter and 2mm width is provided. 12 pie-shaped coils (C) having 9mm width is positioned on surface of stator (12). The rotor (11) having 15 cm diameter and 4 mm width is positioned between said stator (12) and 28 magnet is positioned angularly on the rotor (11) with evenly distribution. 4 mm air gaps between the rotor (11) and stator (12) is positioned.

[0104] According to the specifications of the 18650 batteries the fast-charging requirements of the battery are 58V and 1.6C = 4Amps. Capacity that according to the calculations are predicted to be achieved at a speed between 250 and 300 rpm with the AFPM generator (10) design for this project. Based on this specification the generator must produce a minimum 232Wh to maintain the charging rate.

[0105] Between the battery and the generator (10), a full wave bridge rectifier (RC) and plus one or two DC-DC converters to maintain the battery input power as stable as possible during the working cycles.

[0106] The generator itself is designed to operate efficiently at typical pedaling speeds of a non- sportsperson-user. The output of this generator design can be multiplied by 50% with each additional Rotor added, thereby encouraging the development of Sustainable Urban Mobility vehicles. The battery packs referred to here are each 630g (considerably smaller than typical battery packs, 2-4kgs, associated with 250-500W motors).

[0107] Referring to Fig. 4; the calculation shows the RMS voltage production per stator (12coils in each stator), and the 28-magnet rotor, the voltage production would be doubled when the two stators are combined in series, with a star-alignment for the Three phases (provides a better quality of high voltage. Each phase has a resistance of 3.12Q [ohms], and inductance of 1200 microhenry [pH]per phase.

Claims

CLAIMS1. A generator system for El-assisted motors that require activation via human energy comprises• An axial flux permanent magnet generator having,A rotatable shaft positioned on a rotation axis,At least two stator and at least one rotor positioned between the stators and all are coaxially mounted on the shaft,Plurality of angularly positioned magnets in respect to radial direction of the rotation axis,Plurality of coils of which cross-section have three edges that connect to each other to form closed loop, in respect to plane which is right-angled to the rotation axis,• A battery system configured to store energy generated by the generator and transmit the energy to the El-assisted motor,2. A system according to the Claim 1, characterized by angles of the angularly positioned magnets are same, in respect to radial direction of the rotation axis.

3. A system according to the Claim 1 or 2, characterized by the magnets are evenly distributed in respect to the rotation axis.

4. A system according to the any of Claim 1-3, characterized by the magnets are linearly extended.

5. A system any of the preceding Claims, characterized by the cross-section of the coils are in form of pie-shaped.

6. A system according to the Claim 1 or 5, characterized by the coils are evenly distributed around the rotation axis.

7. A system any of the preceding Claims, characterized by comprising more than one rotor.

8. A system according to the Claim 1, characterized by circumferential portion of the rotor is serrated.

9. A system according to the Claim 1 or 8, characterized by further comprising a cover for the generator.

10. A system according to the Claim 9, characterized by the cover comprising an inlet and an outlet for air flow.

11. A system according to the Claim 10, characterized by the inlet and / or the outlet in shape of curved channel extend from circumferentially portion of the cover.

12. A system according to the Claim 1, characterized by further comprises a control unit configured to control energy transmission among the generator, the battery system and the El-assisted motor.

13. A system according to the Claim 12, characterized by a control unit configured to control energy transmission among the generator, the battery system and the El- assisted motor.

14. A system according to the Claim 13, characterized by further comprises at least one transformer configured to be controlled by the control unit for regulating the energy generated by the generator.

15. A system according to the Claim 12 or 13, characterized by further comprises at least one rectifier configured to be controlled by the control unit for regulating the energy generated by the generator.

16. A system according to any of Claim 12-15, characterized by the battery system comprises, a first battery configured to store energy generated by the generator and to transmit stored energy to a second battery and a second battery configured to receive energy from the first battery or the generator and to transmit the energy to the El-assisted motor.

17. A system according to the Claim 16, characterized by the control unit is configured to control energy transmission among the generator, the battery system and the El- assisted motor by distributing the energy generated by the generator between the first battery and the second battery, according to the energy demand of the El-assisted motor.

18. A method for system of Claim 17, characterized by; comprising steps of, Determining data of the generated energy by the generator,Calculating conversion rate for the energy before transmitting it to the battery system, Determining energy demand of the El-motor, Distributing the energy generated by the generator between the first battery and the second battery of the battery system.

19. A method according to the Claim 18, characterized by transmitting the generated energy by the generator to the first battery, if energy demand of the El-motor is lower than the generated energy.

20. A method according to the Claim 18 or 19, characterized by transmitting the generated energy by the generator to the second battery, if energy demand of the El-motor is equal or higher than the generated energy.

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