CN111146902A - Electromechanical drive device, brake system and battery management system - Google Patents

Abstract

A dual motor powered compact drive includes two motors powering a planetary gear mechanism. Dual drives can provide variable speed and torque. A single motor brake system with screw driven wedge brake pads is described using a compact test apparatus. The system comprises: at least one motor and a screw spindle connected to transmit power to the sliding plunger, and brake pads on the brake disc, and a force sensor for measuring the braking force, and means for measuring parameters of the brake motor, which parameters are used as input for establishing the control strategy. Systems and methods for monitoring a battery pack including a plurality of cells are provided. The battery management system also includes a control strategy for implementing a balancing algorithm. The balancing strategy includes determining the cells to balance and calculating a balancing current.

Description

Electromechanical drive device, brake system and battery management system

Technical Field

The present invention relates generally to the field of propulsion, braking, and battery management systems employed in the use of electromechanical systems.

Background

Electromechanical systems using a single motor suffer from poor performance and poor efficiency. Examples of these types of systems may include light travel vehicles such as electric scooters, electric bicycles, minicars, industrial robots, and the like. Electromechanical systems employing dual motors can overcome many of these problems.

One object of the dual motor drive apparatus is to provide continuously variable transmission with enhanced performance and efficiency in a compact package. Some embodiments involve the use of two motors. In some embodiments, the primary motor is used for fixed power output and has dimensions designed for high efficiency. The secondary motor is used to vary the speed of the desired output. The two motors are coupled together by a planetary gear mechanism. The primary motor drives the sun gear and the secondary motor drives the planet carrier. The output from the ring gear fixed to the housing may drive the wheels. These components are assembled on a fixed shaft within a compact housing that can be mounted directly on a wheel or shaft for driving an electromechanical system.

The concept can also be extended to any type of motor/engine combination where the primary motor/engine is selected based on torque demand and the secondary motor is selected according to desired speed variation. Planetary gear mechanisms can be designed with a desired combination of input and output gears to meet speed and torque requirements. The use of compound planetary gear mechanisms can provide robustness and flexibility in controlling speed and torque.

The development of drive-by-wire technology has increased the demand for electromechanical brake systems. Although many vehicle systems are equipped with electromechanical braking systems, existing systems are still not sufficiently efficient and reliable. Therefore, there is a need to innovate and develop an effective braking mechanism including an electric motor. Wedge-based braking is an innovative approach to help improve braking efficiency with self-energizing capability, but is known to suffer from jamming problems.

Many electromechanical braking systems are limited to medium and heavy commercial vehicles. The electromechanical braking system described herein is suitable for use in light personal travel vehicles and commercial vehicles. These systems have the additional advantage of being compact.

In some embodiments, a test fixture is described to evaluate the braking performance of a wedge/flat brake using a brushless Direct Current (DC) motor. The braking/clamping force generated as a function of time may be obtained from the operation of the test fixture. The magnitude of the load and induced current may be correlated to brake activation at a given time.

Batteries are essential in electronic devices, especially in simple vehicle systems such as electric bicycles, electric scooters and electric motorcycles. The battery can provide power to the system and reduce travel time. In fact, different devices may operate at different voltages, and battery problems may affect their use and may lead to serious accidents. Therefore, innovative battery management systems should be used to manage the battery during device operation. Different types of batteries may have different management systems that cannot be applied to the different types of batteries. This results in increased cost and extended development cycle. In addition, since each battery cell has different charge and discharge characteristics, the batteries should be balanced. Battery imbalance can lead to reduced battery life and can constitute a potential hazard.

Accordingly, there is a need in the art for an electromechanical drive apparatus that provides improved performance and efficiency while providing desired torque and speed requirements. There is a need in the art for an electromechanical braking system that is applicable to light-duty personal travel vehicles and commercial vehicles. There is a need in the art for a battery management system that optimizes battery power usage in an electromechanical system.

Disclosure of Invention

Thus, and advantageously, some embodiments provide for the use of dual motors in an electromechanical system that meets required torque and speed requirements while providing improved performance and efficiency.

Electromechanical systems employing dual motors provide an alternative to systems employing a single motor. The dual motor drive apparatus can provide improved performance and improved efficiency through continuously variable speed and torque.

A wedge mechanism operated motor driven brake system is proposed as an innovative method for implementing a compact brake system in light personal travel vehicles and commercial vehicles. Compact electromechanical test fixtures were developed for performance evaluation of flat/wedge brake systems.

For light-duty personal travel vehicles and commercial vehicles, a fixed caliper brake system incorporating a flexible rotor is described. In some embodiments, a motor drives a wedge brake pad to force the rotor against a fixed flat brake pad. When the brake is applied, the rotor is elastically deformed, thereby achieving a firm grip of the brake and reducing the slip of the brake. In addition, the wedge-induced self-powered brake system reduces the application of force to the brake motor.

A battery management system is described that includes a control unit and a balancing algorithm that efficiently uses the battery when applied to an electromechanical system.

The dual motor driving apparatus according to the present invention includes: a main motor; an auxiliary motor; a fixed shaft; and a planetary gear mechanism comprising a sun gear, one or more planet gears and a ring gear; wherein the primary motor and the secondary motor are operable to provide power for the electromechanical system.

According to the dual motor driving apparatus of the present invention, the stator of the main motor is rigidly attached to the fixed shaft; and the stator of the main motor drives the rotor of the main motor due to the induced magnetic field. The rotor of the main motor is attached to the sun gear. The sun gear drives the ring gear. The ring gear is connected to the motor housing and provides the output power of the apparatus. The rotor of the main motor is attached to the stationary shaft by a ball bearing.

According to the dual motor driving apparatus of the present invention, the stator of the sub motor is rigidly attached to the fixed shaft; and the stator of the auxiliary motor drives the rotor of the auxiliary motor due to the induced magnetic field. The rotor of the secondary motor is attached to one or more planetary gears. The rotor of the secondary motor is attached to the stationary shaft by a ball bearing.

According to the dual motor driving apparatus of the present invention, the power output of the main motor is kept constant, and the power output of the sub motor is kept at zero to provide a constant speed. The power output of the primary motor is held constant and the power output of the secondary motor is varied to provide variable speed.

An electric wedge brake system according to the present invention includes: a motor-driven screw shaft, the free end of which is fitted with a magnet, driving a wedge-shaped plunger which reciprocates in a recess of the inner caliper block/floating caliper; a wedge-shaped brake pad in magnetic contact with the screw shaft; an external caliper block housing a flat brake pad, magnetic spacers (to hold the flat brake pad in place), a force sensor and an adjustment screw; a brake rotor passing through a groove between caliper blocks with brake pads on either side of the caliper blocks; a brake motor coupled to the screw shaft; and non-contact type accessories such as NFC, optical, solenoid, acoustic, etc. to measure the rotational speed of the brake shaft by their respective control signals.

The electric wedge brake system according to the invention brakes by pressing a wedge brake pad against a fixed flat brake pad on a brake rotor by a cylindrical plunger with a wedge counterpart. The invention particularly uses the configuration of a cylindrical wedge-shaped plunger having a threaded bore through which the brake screw passes and a guide rail projecting on its periphery extending along an axis aligned with a slot on the caliper block to prevent rotation of the plunger with reciprocating movement when the brake is operated.

The brake testing device comprises a driving motor, a driving motor and a brake testing device, wherein the driving motor is provided with a supporting plate; a motor drive shaft having an attached brake rotor and a flywheel with bearing support; a braking system, which may be the electric wedge braking system described above; and an electric brake control unit including a motor controller, a driver, and a user-defined program.

A control strategy may be employed in the test device involving a user-defined program in which the user may input parameters such as desired braking force, tuning parameters, braking duration, acceleration, etc. to evaluate braking performance.

Two different braking technologies (i.e., flexible rotor-fixed caliper, rigid rotor-floating caliper) are combined with the wedge mechanism.

The battery management system according to the present invention includes: a battery pack including a plurality of battery cells; a power management circuit for measuring voltages, currents and temperatures of the battery and the battery cell, for filtering the voltages and currents, for switching connections between the battery pack and the balancing circuit, for diagnosing and identifying circuit faults and for preventing circuit faults; the control unit can be programmed repeatedly and is used for uploading and updating the control strategies of the warning module, the display module, the data storage module, the communication module and the power switch and processing information obtained from the internal module and the external equipment; a warning module for generating a sound signal, a light signal and a vibration signal; the display module is used for displaying information of a battery unit and a battery management system in the battery pack; the display module is used for displaying information of the battery pack, the battery unit and the battery management system; the data storage module is used for storing; and the communication module is used for establishing connection between the battery management system and external equipment.

The balancing strategy according to the invention comprises: determining the battery cells to be balanced, and parameters of the battery pack and the battery cells; the balance current is calculated according to the acquired parameters and the preset parameters, so that high balance efficiency can be provided, and the high temperature problem is prevented; the power of the battery cells to be balanced is balanced according to the calculated balancing current.

These and other advantages are achieved in accordance with the present invention as described in detail below.

Drawings

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. The figures are not drawn to scale and the relative dimensions of the various elements in the figures are schematically depicted and not drawn to scale.

The techniques of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings, in which:

fig. 1 is a schematic diagram showing an example of a dual motor driving apparatus.

Fig. 2 is a flow chart of possible operating modes of the dual motor drive apparatus.

Fig. 3 is a sectional view showing the assembly of the components.

FIG. 4 is a schematic illustration of an electromechanical wedge brake test fixture assembly.

FIG. 5 is a schematic view of a test fixture of the brake mechanism showing a single motor flexible rotor-fixed caliper design.

FIG. 6 is an exploded view of a single motor flexible rotor-fixed caliper design electromechanical wedge brake.

FIG. 7 is a cross-section of a brake mechanism employed in a single motor flexible rotor-fixed caliper design.

FIG. 8 is a schematic view of a brake mechanism of the single motor floating caliper brake system.

FIG. 9 is an exploded view of a single motor floating caliper brake system.

FIG. 10 is a cross section of a brake mechanism employed in a single motor floating caliper brake system.

FIG. 11 is a flow chart depicting possible operating modes of the braking system.

Fig. 12 is a block diagram of a battery management system.

FIG. 13 is a block diagram of a power management module.

FIG. 14 is a flow chart of a battery balancing strategy.

Detailed Description

A detailed description of one or more embodiments is provided below along with accompanying figures. A detailed description is provided in connection with such embodiments, but is not limited to any particular example. The scope is limited only by the claims and encompasses numerous alternatives, modifications and equivalents. In the following description, numerous specific details are set forth in order to provide a thorough understanding. These details are provided for the purpose of example and the described techniques may be practiced according to the claims without some or all of these specific details. For the purpose of clarity, technical material that is known in the technical fields related to the embodiments has not been described in detail so that the description is not unnecessarily obscured.

It must be noted that, as used herein and in the claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component" includes two or more components and the like.

Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit, between the upper and lower limits of that range, is encompassed within the invention. If the modifier "about" or "approximately" is used, the stated amount may vary by up to 10%.

The term "horizontal" as used herein will be understood as a plane defined as being parallel to the plane or surface of the earth. The term "vertical" will refer to a direction perpendicular to the previously defined horizontal. Terms such as "above …", "below …", "bottom", "top", "side", "upper", "lower", "upper", "above … and below … are defined relative to the horizontal plane. The term "on" refers to direct contact between elements. "above …" (above) will allow for the presence of intermediate elements.

As used herein, the terms "above" … and "above" … are to be understood to mean directly contacting or separated by an intermediate element.

As used herein, the term "in.. above (on)" will be understood to mean direct contact.

As used herein, the term "between" (when used with a range of values) is to be understood to mean that any value between the boundary values and the boundary may be within the range of values.

As used herein, the terms "first," second, "and other ordinals" are to be understood to provide a distinction only, and not to impose any particular spatial or temporal order.

As used herein, the term "substantially" generally refers to ± 5% of a stated value.

Electromechanical systems using single motor drive devices suffer from poor performance and poor efficiency. Examples of these types of systems may include light travel vehicles such as electric scooters, electric bicycles, minicars, industrial robots, miniature motor vehicles, and the like. Electromechanical systems employing dual motor drive devices can overcome many of these problems. In some embodiments, the dual motor drive apparatus includes a planetary drive unit mounted directly on a wheel or shaft. The dual motor drive apparatus includes two electric motor inputs that power a planetary gear mechanism. The rotational output of the gearbox directly drives the wheel or shaft. The dual motor drive device can provide continuously variable speed and torque.

Fig. 1 is a schematic diagram showing an example of a dual motor driving apparatus. In some embodiments, the dual motor drive apparatus includes a primary motor 101 and a secondary motor 102. The main motor 101 includes a main stator 103 and a main rotor 104. The auxiliary motor 102 includes an auxiliary stator 105 and an auxiliary rotor 106. The dual motor drive apparatus further includes a sun gear 107, a planetary gear 108, and a ring gear 109. The main stator 103 and the auxiliary stator 105 are rigidly fixed to the shaft 110.

Fig. 2 is a flow chart of possible operating modes of the dual motor drive apparatus. For consistency, the same element numbers as previously used and described have been used. As previously described, the dual drive motor system includes a primary motor 101 and a secondary motor 102. The two motors are coupled with the planetary gear mechanism 200 to provide dual motor power transmission. Those skilled in the art will appreciate that the planetary gear mechanism 200 includes elements such as the sun gear 107, the planet gears 108 and the ring gear 109 previously described.

In some embodiments, the dual motor drive apparatus provides a desired speed of the electromechanical system. In some embodiments, a slow down mode (i.e., slow down) 202 is desired. In embodiments requiring a dual motor drive apparatus to provide deceleration, both the primary motor 101 and the secondary motor 102 are disabled and a braking system is employed.

In some embodiments, a constant speed mode (i.e., cruise) 203 is desired. In embodiments requiring a dual motor drive device to provide constant speed, the primary motor 101 is engaged while the secondary motor 102 is disabled.

In some embodiments, an acceleration mode (i.e., increasing power) 204 is desired. In embodiments requiring a dual motor drive apparatus to provide acceleration, the primary motor 101 is engaged and the secondary motor 102 is also engaged.

Fig. 3 is a sectional view showing the assembly of the components. For consistency, the same element numbers as used and described in FIG. 1 have been used. The main stator 103 of the main motor 101 is rigidly connected to the fixed shaft 110 using a key 300. The main stator 103 includes copper windings around the stacked laminations and drives the main rotor 104 due to the induced magnetic field. The main rotor 104 is configured as a cylinder including permanent magnets 301 on its inner circumference. The main rotor 104 is connected to the sun gear 107 using fasteners and is operable to rotate the sun gear. The main rotor 104 is also connected to the fixed shaft 110 using two ball bearings 302, while a circlip 303 is used to constrain its axial movement. The sun gear 107 drives a ring gear 109 connected to a motor housing 304. The motor housing 304 is connected to the wheel as a dual motor drive output.

The secondary stator 105 of the secondary motor 102 is rigidly connected to the fixed shaft 110 using a key 305. The secondary stator 105 includes copper windings around the stacked laminates and drives the secondary rotor 106 due to the induced magnetic field. The secondary rotor 106 is configured as a cylinder including permanent magnets 306 on its inner circumference. The auxiliary rotor 106 is connected to the fixed shaft 110 using two bearings 307, a circlip 308 and an overrunning clutch 309. The three sets of planet gears 108 may be mounted to the secondary rotor 106 using at least one of bolts 310, using screws and snap springs 311, and using ball bearings 312.

In some embodiments, the rotational speed of the main motor 101 is kept constant at a predetermined value to provide a constant power output from the dual motor drive apparatus. For various applications, a constant power output may be used to drive a wheel at a constant speed or to drive a shaft at a constant rotation. As discussed with respect to fig. 2, engaging only the primary motor may be considered a constant speed mode 203. During the constant speed mode 203, the auxiliary motor is not engaged and the auxiliary rotor 106 is restricted for reverse rotation by the main drive using the overrunning clutch 309.

In some embodiments, a requirement for a dual motor drive apparatus is to provide acceleration. As discussed with respect to fig. 2, engaging both the primary and secondary motors may be considered an acceleration mode 204. In some embodiments, engaging the secondary rotor 106 and associated planet gears 108 increases the speed of the ring gear 109 during the acceleration mode. This is in addition to the power output of the main motor and increases the total power output of the dual motor drive apparatus. The limit speed of the constant speed mode (main motor only) may be selected based on calculations of maximum main motor performance and efficiency. By engaging the secondary motor without sacrificing performance or efficiency of the primary motor, the requirements for additional speed or acceleration of the dual motor drive device may be met.

In some embodiments, the dual motor drive apparatus is incorporated into a light travel vehicle, such as an electric scooter, electric bicycle, electric motorcycle, minibus, industrial robot, micro-motor vehicle, or the like.

FIG. 4 is a schematic illustration of an electromechanical wedge brake test fixture assembly. In some embodiments, the test fixture includes a drive unit and a brake unit. In some embodiments, the drive unit is an Alternating Current (AC) servo motor 400 and the driven flywheel 401 is used to apply an inertial load to the brake rotor 402. In some embodiments, the brake unit includes a brushless dc motor 403 and a driven wedge mechanism for transmitting the motor force to a flexible brake rotor 402 connected to a driven shaft 404.

In some embodiments, the drive motor 400 and the brake motor 403 are mounted on clamp plates 405 and 406, respectively. The shaft of the drive motor 400 is connected to the flexible rotor 402 by a flange 407 and a coupling 414. Flywheel 401 is supported between clamping plates 406 and 409, coupled to brake rotor 402, on bearings 408. A brake caliper 410 holding all brake components is mounted on a clamping plate 411 by a coupling 413. The entire test fixture may be mounted on the substrate 412.

In some embodiments, electronic control systems and control methods employed in test fixtures are included. In some embodiments, the drive motor 400 and the brake motor 403 are controlled using a controller and user defined program, wherein the user may input desired parameters, such as braking force, adjustment parameters, and the like. The test fixture is designed to measure brake performance and validate the brake system. The force is measured using a force sensor. In some embodiments, any common non-contact type of auxiliary unit (to avoid any impact on braking performance) such as Near Field Communication (NFC), optical, solenoid, acoustic, etc. may be used to measure the parameters of the brake motor. In some embodiments, a set of permanent magnets may be attached to the brake motor shaft based on a particular polarity arrangement, and a coil wound around it may be used to measure the induced current/voltage during braking, and the induced current or voltage is used as an input to a brake controller to establish a control strategy for the brake motor.

FIG. 5 is a schematic view of a test fixture of the brake mechanism showing a single motor flexible rotor-fixed caliper design. For consistency, the same element numbers as previously used and described have been used. In some embodiments, brake motor 403 is mounted on one side of clamp plate 406, while caliper block assemblies 500 and 501 are mounted on the other side. The limit switch 503 limits the caliper.

FIG. 6 is an exploded view of a single motor flexible rotor-fixed caliper design electromechanical wedge brake. For consistency, the same element numbers as previously used and described have been used. The brake motor 403 is connected to a screw shaft 502, which screw shaft 502 in turn drives the plunger 600 back and forth. Plunger 600 is a cylindrical portion having a threaded bore, a pair of protruding rails along its axis at its periphery so that it can slide in the elongated hole of caliper block 500. The front surface of plunger 600 is wedged into engagement with inner brake pad 601 at an oblique angle. Once the brake is fully applied at the tail end by limit switch 503, the movement of plunger 600 within caliper block 500 on screw shaft 502 is controlled by the limit force registered by load cell 603. The forward end of plunger 600 mates with a wedge counterpart on inner brake pad 601. When the brake is off, inner brake pad 601 is attached to the magnetic end of screw shaft 502 to avoid contact with rotor 402. After applying the brake, plunger 600 pushes inner brake pad 601 towards rotor 402. The flexible rotor 402 elastically deforms to come into contact with the fixed flat brake pad 604 placed on the other end of the rotor 402. The distance between rotor 402 and outer brake pad 601 may be changed using adjustment screw 605.

FIG. 7 is a cross-section of a braking mechanism employed in the single motor flexible rotor-fixed caliper design described with respect to FIG. 6. To maintain consistency, the same element numbers as previously used and described are used.

FIG. 8 is a schematic view of a brake mechanism of the single motor floating caliper brake system. FIG. 9 is an exploded view of a single motor floating caliper brake system. For consistency, the same element numbers as previously used and described have been used. In some embodiments, the braking system, which may be a wedge brake, includes a rigid rotor 800 having a floating caliper 801. Floating caliper 801 is mounted on brake adapter 802 using two spring loaded guide rods 803. The body of the floating caliper 801 has a hollow piston 801a on one side that reciprocates around a brake adapter 802 and a brake motor 804 on the other side. The brake motor 804 drives the plunger 900 through the screw shaft 901. Once the brake is applied, plunger 900 pushes tilt brake pad 805 towards rotor 800 until contact is made. Once further advancement is not possible, plunger 900 will push floating caliper 801 rearward and in so doing pull opposing brake pads 806 closer to rotor 800. The opposite side brake pad 806 is mounted on a flat plate 807 which is in turn spring loaded to the brake adapter 802 by the same guide rod 803 of the floating caliper 801.

FIG. 10 is a cross section of a brake mechanism employed in a single motor floating caliper brake system. For consistency, the same element numbers as previously used and described have been used.

FIG. 11 is a flow chart depicting possible operating modes of the braking system. In operation 1100, operation of the brake system begins. In operation 1101, a system is initialized. In operation 1102, the system is diagnosed to confirm that there is no fault. Operation 1103 is a decision operation. If a fault is detected in operation 1103, the system proceeds to operation 1104 where a warning and error code is generated and communicated or displayed in operation 1104. The system then proceeds to end step 1105 and waits for repair or correction of the fault. In decision operation 1103, if there is no fault, the system proceeds to operation 1106, where in operation 1106, the parameters of the brake system are determined. In operation 1107, a control strategy for the brake system is employed. In operation 1108, the brake motor is activated using the control strategy. Operation 1109 is a decision operation. If the desired braking force has not been applied, the system loops back to operation 1106 and repeats operations 1106-1108. If the desired braking force has been applied, the system proceeds to end step 1105.

Fig. 12 is a block diagram of a Battery Management System (BMS). In some embodiments, a configuration 1200 of a BMS is described. In some embodiments, BMS 1200 includes battery pack 1201 (including a plurality of battery cells), power management 1202, control unit 1203, warning module 1204, display module 1205, data storage module 1206, communication module 1207. BMS 1200 may be connected to external device 1208.

FIG. 13 is a block diagram of a power management module. For consistency, the same element numbers as previously used and described have been used. In some embodiments, battery pack 1201 is connected to power management module 1202 via a wiring harness. In some embodiments, the power management module 1202 includes a switch module 1301 and a balancing module 1302.

In some embodiments, the power management module 1202 includes a switching module 1301, a balancing module 1302, and other modules (not shown) for measuring and filtering voltages and currents and protecting system circuitry. In some embodiments, the power management module 1202 has the functionality to diagnose, identify and protect against overcharge, overdischarge, overvoltage, undervoltage, overheating, short circuit and open circuit problems.

In some embodiments, a switch module 1301 and a balancing module 1302 are connected. The switch module 1301 has a channel switching function, is determined by the number of battery cells in the battery pack 1201, and is controlled by the control unit 1203.

In some embodiments, the control unit 1203 has a function of repeatedly uploading and updating control policies for the power management module 1202, the warning module 1204, the display module 1205, the data storage module 1206, the communication module 1207, and processing information on parameters obtained from the internal module and the external device through the communication module 1207.

In some embodiments, BMS 1200 includes a communication module 1207. Communication module 1207 has a function for information exchange between BMS 1200 and an external device. In some embodiments, the communication module 1207 has functions of uploading and updating a control policy and communicating with an external device through a wired or wireless communication method, such as inter-integrated circuit (IIC), Serial Peripheral Interface (SPI), Controller Area Network (CAN), 2.4G or 5G wireless fidelity (Wi-Fi), and bluetooth.

In some embodiments, BMS 1200 includes a warning module 1204. The warning module 1204 has a function of generating an acoustic signal, an optical signal and/or a vibration signal in response to the detected system failure.

In some embodiments, BMS 1200 includes a display module 1205. The display module 1205 has a function of information display. The voltage, current, state of charge (SOC), state of health (SOH) and temperature of the battery pack 1201, the temperature of the battery cells, and the operating state and location of the battery management system 1201 may be determined and presented on the display module 1205. The detailed information is programmed by the control unit 1203 and the communication module 1207.

In some embodiments, BMS 1200 includes a data storage module 1206. The data storage module 1206 has a function of saving specific information to a readable and writable storage medium. The data storage module 1206 may use a secure digital memory card (SD card), a universal serial bus flash drive (USB flash drive), a floppy disk, a DVD, or other common storage media.

FIG. 14 is a flow chart of a cell balancing algorithm. In some embodiments, the previously described control unit is used to control each module. Specifically, the control unit includes software designed to implement an algorithm to balance the battery pack, as shown in fig. 14.

In operation 1401, the algorithm performs a system check to determine if there are any faults. Operation 1402 is a decision operation. If a fault is detected in operation 1401, the system proceeds to operation 1409 where an alert and error code is generated and communicated or displayed in operation 1409 and the system waits for repair or correction of the fault. If no fault is detected in operation 1401, then in operation 1403, the system determines the cells and parameters to balance. These data are communicated to the data acquisition and balance current calculation operation 1411. Operation 1404 is a decision operation. If the difference between the maximum SOC and the minimum SOC is greater than a predetermined threshold (SOC _ th), the system proceeds to operation 1405. If the difference between the maximum SOC and the minimum SOC is less than a predetermined threshold (SOC _ th), the system is in a balanced state and returns to the start operation 1401. Operation 1405 is a decision operation. If the battery pack is currently being charged, the balancing current is transmitted from the battery cell having the maximum SOC to the battery cell having the minimum SOC in operation 1410 according to the balancing current calculation in operation 1411. If the battery pack is not currently being charged, the system proceeds to operation 1406. Operation 1406 is a decision operation. If the idle time between charges is greater than the predetermined time threshold (T _ th), the system returns to the balance current calculation in operation 1411 to request new balance parameters and proceeds to operation 1407. If the idle time between charges is greater than the predetermined time threshold (T _ th), the balancing current is transmitted from the cell having the maximum SOC to the cell having the minimum SOC according to the balancing current calculation in operation 1411 in operation 1407, and the system proceeds to operation 1408 to achieve battery balancing. If the idle time between charges is less than the predetermined time threshold (T _ th), the system is in a balanced state and returns to the start operation 1401.

The balancing current calculated from operation 1411 is a function of the acquired data or parameters, for example, I ═ f (N, V, Temp _ th, SOCs, Δ SOC, SOC _ th, Ws, T _ th), where N is the number of battery cells to be balanced, V is the voltage of the battery and the battery cells, Temp is the temperature of the battery and the battery cells, SOC is the state of charge of the battery and the battery cells, Δ SOC represents the difference between the maximum SOC and the minimum SOC of the battery cells, Temp _ th, SOC _ th and T _ th are predetermined values, and Ws represents the operating state of the battery pack.

Although various embodiments which incorporate the teachings of the present invention have been shown and described in detail herein, those skilled in the art can readily devise many other varied embodiments that still incorporate these teachings.

Claims (10)

1. An apparatus, the apparatus comprising:

a main motor;

an auxiliary motor;

a fixed shaft; and

a planetary gear mechanism comprising a sun gear, one or more planet gears and a ring gear;

wherein the primary motor and the secondary motor are operable to provide power for the electromechanical system.

2. The apparatus of claim 1, wherein:

the stator of the main motor is rigidly attached to the stationary shaft; and

the stator of the main motor drives the rotor of the main motor due to the induced magnetic field.

3. The apparatus of claim 2, wherein:

the rotor of the main motor is attached to the sun gear.

4. The apparatus of claim 3, wherein:

the sun gear drives the ring gear.

5. The apparatus of claim 4, wherein:

the ring gear is connected to the motor housing and provides the output power of the apparatus.

6. The apparatus of claim 2, wherein:

the rotor of the main motor is attached to the stationary shaft by a ball bearing.

7. The apparatus of claim 1, wherein:

the stator of the secondary motor is rigidly attached to the stationary shaft; and

the stator of the secondary motor drives the rotor of the secondary motor due to the induced magnetic field.

8. The apparatus of claim 7, wherein:

the rotor of the secondary motor is attached to one or more planetary gears.

9. The apparatus of claim 7, wherein:

the rotor of the secondary motor is attached to the stationary shaft by a ball bearing.

10. The apparatus of claim 1, wherein:

the power output of the primary motor is held constant and the power output of the secondary motor is held at zero to provide a constant speed.

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