System and method for performing controlled power stage off of a motor

Abstract

The present disclosure relates to a system (500) for performing controlled power stage off of a motor (16). The system (500) includes a controller (504) that is configured to detect a power stage off request received from an internal system or an external system, and based on the detection of the power stage off request, ramp down a torque of the motor (16) to zero. Further, in response to ramping down the torque, the controller (504) is to create a closed loop path to facilitate circulation of current within windings of the motor (16). Further, the controller (504) is to convert the current into signals and transmit the signals to switching devices to perform controlled power stage off of the motor (16). Therefore, the system (500) overcomes the damage to the motor (16) by performing the controlled shutdown process, enhancing an overall system performance and component longevity.

Description

SYSTEM AND METHOD FOR PERFORMING CONTROLLED POWER STAGE OFF OF A MOTORTECHNICAL FIELD

[0001] The present disclosure relates to automotive technology. In particular, the present disclosure relates to a system and a method for performing controlled power stage off of a motor, thereby preventing damage to the motor and motor controller and ensuring a more reliable and durable motor operation.BACKGROUND

[0002] In an electric vehicle, at times a sudden power cut-off of a motor is necessary, either due to a fault or a user request. If the power cut-off is not performed properly and in an uncontrolled manner, this can lead to several issues that may result in the failure of a controller, the motor, or a battery. These issues include high voltage or back Electromotive Force (EMF) spikes and inductive kickback, as well as high current surges. To address these problems, typical systems mainly use hardware-based solutions, such as additional brake circuits and snubber, and sometimes software-based solutions, such as controlled deceleration and a Pulse Width Modulation (PWM) dithering. However, these systems may have inherent drawbacks or be complex.

[0003] When the motor is running, there are multiple reasons that necessitate an instantaneous switch-off. These reasons include major system faults, such as overvoltage, overcurrent, temperature, or throttle faults, external factors like vehicle falls or accidents, user requests, and power loss due to battery failure or key power loss. An uncontrolled shutdown can lead to overvoltage at a Direct Current (DC) bus, causing stress and failure of Field Effect Transistors (FETs) and bulk capacitors, overcurrent into the battery affecting cell life and leading to failure, and in rare cases, major accidents like fires or unintended motor operation. During the fault, an immediate but controlled shutdown is imperative, depending on the severity of the fault. However, critical faults may require an immediate cut-off.

[0004] Additionally, the motor is a complex inductive load with back Electromotive Force (EMF). If all the FETs are suddenly turned off when the back EMF is higher than the battery voltage, the higher back EMF can cause current to flow back to the battery through a body diode of the FETs until the back EMF drops to the battery voltage. Depending on the fault type and how the control system cuts off the FETs, this can lead to failure of the inverter FETs and damage to the battery due to high reverse current. Typically, a combination ofhardware and / or software methods are implemented to manage this. However, hardware solutions like additional braking circuits and snubber circuits tend to be lossy, further add complexity and cost to the system, while software solutions like Pulse Width Modulation (PWM) dithering and controlling the braking circuit increase system complexity and require better processing units, which are typically not available in cost-sensitive applications. Therefore, to overcome these limitations, there is a need for a simpler solution within the innate system itself that can manage these problems effectively without requiring additional hardware or adding higher complexity in the software.

[0005] Therefore, there is a need to address the above-mentioned drawbacks, along with any other shortcomings, or at the very least, to provide a viable alternative system and method.OBJECTS OF THE PRESENT DISCLOSURE

[0006] A general object of the present disclosure relates to an efficient and a reliable system and method that obviates the above-mentioned limitations of existing systems and methods.

[0007] An object of the present disclosure relates to a system and a method for performing controlled power stage off of a motor, thereby preventing damage to the motor and ensuring a more reliable and durable motor operation.

[0008] Another object of the present disclosure relates to a system and a method for ramping down a torque of a motor to zero based on detection of a power stage off request, thereby ensuring a smooth and controlled shutdown process that prevents damage to system components and enhances overall system reliability.SUMMARY

[0009] Aspects of the disclosure relate to automotive technology. In particular, the present disclosure relates to a system and a method for performing controlled power stage off of a motor, thereby preventing damage to the motor, motor controller, and battery and ensuring a more reliable and durable motor operation.

[0010] In an aspect, the present disclosure relates to a system for performing controlled power stage off of a motor. The system includes a controller and a memory. The controller is associated with a processor and the memory is operatively coupled with the processor, where the memory includes one or more instructions which, when executed, cause the controller to detect a power stage off request received from at least one of an internal system or anexternal system, and based on the detection of the power stage off request, ramp down a torque of the motor to zero. Further, in response to ramping down the torque, the controller is to create a closed loop path to facilitate circulation of current within one or more windings of the motor. Further, the controller may be configured to convert the current into one or more signals, and transmit the one or more signals to one or more switching devices to perform controlled power stage off of the motor.

[0011] In an embodiment, the controller may be operatively connected to a switch mechanism and a delay circuit.

[0012] In an embodiment, based on the detection of the power stage off request, the switch mechanism may be configured to send an input to the delay circuit.

[0013] In an embodiment, based on the input, the delay circuit may be configured to add a delay factor to one or more switching devices, such that the one or more switching devices delay to perform a switching operation of the motor for a predetermined time.

[0014] In an embodiment, when the one or more switching devices delay to perform the switching operation of the motor for the predetermined time, the controller may be configured to perform the controlled power stage off of the motor.

[0015] In an embodiment, when the controller fails to perform the controlled power stage off of the motor within the predetermined time, the one or more switching devices may be configured to disable the switching of the switching devices and turn off an operation of the motor.

[0016] In an embodiment, the one or more signals may be transmitted to the one or more switching devices through a gate drive circuit.

[0017] In an embodiment, the controller may be configured to convert the current into one or more Pulse Width Modulation (PWM) signals.

[0018] In an embodiment, the gate drive circuit may convert the one or more PWM signals into one or more gate signals, and transmit the one or more gate signals to the one or more switching devices.

[0019] In an embodiment, the controller may be configured to detect turning off of one or more switching elements associated with the motor due to an abrupt shutdown of the system from an operational state.

[0020] In an embodiment, the controller may be configured to detect turning off of the one or more switching elements associated with the motor based on a detection of at least one of a fault condition in the system, and the power stage off request received from a user through a switch mechanism.

[0021] In an embodiment, based on the detection of turning off of the one or more switching elements, the controller may be configured to control a back flow of the current from the one or more windings of the motor to a battery based on a State of Charge (SOC) of the battery, and perform controlled braking of the motor by circulating the current in the windings of the motor.

[0022] In another aspect, the present disclosure relates to a method for performing controlled power stage off of a motor. The method includes detecting, by a controller associated with a system, a power stage off request received from at least one of an internal system or an external system, and based on the detection of the power stage off request, ramping down, by the controller, a torque of the motor to zero. Further, in response to ramping down the torque, the method includes creating, by the controller, a closed loop path to facilitate circulation of current within one or more windings of the motor, and converting, by the controller, the current into one or more signals. Further, the method includes transmitting, by the controller, the one or more signals to one or more switching devices to perform controlled power stage off of the motor.

[0023] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent components.BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0025] FIG. 1 illustrates a schematic view of an Electric Vehicle (EV), in accordance with embodiments of the present disclosure.

[0026] FIG. 2 illustrates a schematic representation of a system including a 3-phase inverter connected to a 3-phase motor, in accordance with embodiments of the present disclosure.

[0027] FIGs. 3 and 4 illustrate block diagrams for implementing torque ramp-down management using a Microcontroller Unit (MCU), in accordance with embodiments of the present disclosure.

[0028] FIG. 5 illustrates a flow diagram depicting a process implemented in the system in which a kill switch provides an emergency switch-off mechanism to a motor, in accordance with embodiments of the present disclosure.

[0029] FIG. 6 illustrates an example flow chart for implementing a method for performing a controlled power stage off of the motor, in accordance with embodiments of the present disclosure.DETAILED DESCRIPTION

[0030] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosures as defined by the appended claims.

[0031] For the purpose of understanding of the principles of the present disclosure, reference will now be made to the various embodiments and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the present disclosure is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the present disclosure as illustrated therein being contemplated as would normally occur to one skilled in the art to which the present disclosure relates.

[0032] It will be understood by those skilled in the art that the foregoing general description and the following detailed description are explanatory of the present disclosure and are not intended to be restrictive thereof.

[0033] Whether or not a certain feature or element was limited to being used only once, it may still be referred to as “one or more features” or “one or more elements” or “at least one feature” or “at least one element.” Furthermore, the use of the terms “one or more” or “at least one” feature or element do not preclude there being none of that feature or element, unless otherwise specified by limiting language including, but not limited to, “there needs to be one or more” or “one or more elements is required.”

[0034] Reference is made herein to some “embodiments.” It should be understood that an embodiment is an example of a possible implementation of any features and / or elements of the present disclosure. Some embodiments have been described for the purpose ofexplaining one or more of the potential ways in which the specific features and / or elements of the proposed disclosure fulfil the requirements of uniqueness, utility, and non-obviousness.

[0035] Use of the phrases and / or terms including, but not limited to, “a first embodiment,” “a further embodiment,” “an alternate embodiment,” “one embodiment,” “an embodiment,” “multiple embodiments,” “some embodiments,” “other embodiments,” “further embodiment”, “furthermore embodiment,” “additional embodiment” or other variants thereof do not necessarily refer to the same embodiments. Unless otherwise specified, one or more particular features and / or elements described in connection with one or more embodiments may be found in one embodiment, or may be found in more than one embodiment, or may be found in all embodiments, or may be found in no embodiments. Although one or more features and / or elements may be described herein in the context of only a single embodiment, or in the context of more than one embodiment, or in the context of all embodiments, the features and / or elements may instead be provided separately or in any appropriate combination or not at all. Conversely, any features and / or elements described in the context of separate embodiments may alternatively be realized as existing together in the context of a single embodiment.

[0036] Any particular and all details set forth herein are used in the context of some embodiments and therefore should not necessarily be taken as limiting factors to the proposed disclosure.

[0037] The terms “comprise,” “comprising,” or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or sub-systems or elements or structures or components proceeded by “comprises... a” does not, without more constraints, preclude the existence of other devices or other sub-systems or other elements or other structures or other components or additional devices or additional sub-systems or additional elements or additional structures or additional components.

[0038] Embodiments of the present disclosure will be described below in detail with reference to the accompanying drawings.

[0039] For the sake of clarity, the first digit of a reference numeral of each component of the present disclosure is indicative of the Figure number, in which the corresponding component is shown. For example, reference numerals starting with digit “1” are shown at least in Figure 1. Similarly, reference numerals starting with digit “2” are shown at least in Figure 2.

[0040] An Electric Vehicle (EV) or a battery powered vehicle including, and not limited to two-wheelers such as scooters, mopeds, motorbikes / motorcycles; three-wheelers such as auto-rickshaws, four-wheelers such as cars and other Light Commercial Vehicles (LCVs) and Heavy Commercial Vehicles (HCVs) primarily work on the principle of driving an electric motor using the power from the batteries provided in the EV. Furthermore, the electric vehicle may have at least one wheel which is electrically powered to traverse such a vehicle. The term ‘wheel’ may be referred to any ground-engaging member which allows traversal of the electric vehicle over a path. The types of EVs include Battery Electric Vehicle (BEV), Hybrid Electric Vehicle (HEV) and Range Extended Electric Vehicle. However, the subsequent paragraphs pertain to the different elements of a Battery Electric Vehicle (BEV).

[0041] FIG. 1 illustrates a schematic view of an Electric Vehicle (EV), in accordance with embodiments of the present disclosure.

[0042] In construction, an EV (10) typically comprises a battery or battery pack (12) enclosed within a battery casing and includes a Battery Management System (BMS), an onboard charger (14), a Motor Controller Unit (MCU), an electric motor (16) and an electric transmission system (18). The primary function of the above-mentioned elements is detailed in the subsequent paragraphs: The battery of an EV (10) (also known as Electric Vehicle Battery (EVB) or traction battery) is re-chargeable in nature and is the primary source of energy required for the operation of the EV, wherein the battery (12) is typically charged using the electric current taken from the grid through a charging infrastructure (20). The battery may be charged using Alternating Current (AC) or Direct Current (DC), wherein in case of AC input, the on-board charger (14) converts the AC signal to DC signal after which the DC signal is transmitted to the battery via the BMS. However, in case of DC charging, the on-board charger (14) is bypassed, and the current is transmitted directly to the battery via the BMS.

[0043] The battery (12) is made up of a plurality of cells which are grouped into a plurality of modules in a manner in which the temperature difference between the cells does not exceed 5 degrees Celsius. The terms “battery”, “cell”, and “battery cell” may be used interchangeably and may refer to any of a variety of different rechargeable cell compositions and configurations including, but not limited to, lithium-ion (e.g., lithium iron phosphate, lithium cobalt oxide, other lithium metal oxides, etc.), lithium-ion polymer, nickel metal hydride, nickel cadmium, nickel hydrogen, nickel-zinc, silver zinc, or other battery type / configuration. The term “battery pack” as used herein may be referred to multiple individual batteries enclosed within a single structure or multi -piece structure. The individualbateries may be electrically interconnected to achieve a desired voltage and capacity for a desired application. The Batery Management System (BMS) is an electronic system whose primary function is to ensure that the batery (12) is operating safely and efficiently. The BMS continuously monitors different parameters of the batery such as temperature, voltage, current and so on, and communicates these parameters to the Electronic Control Unit (ECU) and the Motor Controller Unit (MCU) in the EV using a plurality of protocols including and not limited to Controller Area Network (CAN) bus protocol which facilitates the communication between the ECU / MCU and other peripheral elements of the EV (10) without the requirement of a host computer.

[0044] The MCU primarily controls / regulates the operation of the electric motor based on the signal transmited from the vehicle batery, wherein the primary functions of the MCU include starting of the electric motor (16), stopping the electric motor (16), controlling the speed of the electric motor (16), enabling the vehicle to move in the reverse direction and protect the electric motor (16) from premature wear and tear. The primary function of the electric motor (16) is to convert electrical energy into mechanical energy, wherein the converted mechanical energy is subsequently transferred to the transmission system of the EV (10) to facilitate movement of the EV (10). Additionally, the electric motor (16) also acts as a generator during regenerative braking (i.e., kinetic energy generated during vehicle braking / deceleration is converted into potential energy and stored in the batery of the EV (10)). The types of motors generally employed in EVs include, but are not limited to DC series motor, Brushless DC motor (also known as BLDC motors), Permanent Magnet Synchronous Motor (PMSM), Three Phase AC Induction Motors and Switched Reluctance Motors (SRM).

[0045] The transmission system (18) of the EV (10) facilitates the transfer of the generated mechanical energy by the electric motor (16) to the wheels (22a, 22b) of the EV (10). Generally, the transmission systems (18) used in EVs include single speed transmission system and multi-speed (i.e., two-speed) transmission system, wherein the single speed transmission system comprises a single gear pair whereby the EV (10) is maintained at a constant speed. However, the multi-speed / two-speed transmission system comprises a compound planetary gear system with a double pinion planetary gear set and a single pinion planetary gear set thereby resulting in two different gear ratios which facilitates higher torque and vehicle speed.

[0046] In one embodiment, all data pertaining to the EV (10) and / or charging infrastructure (20) are collected and processed using a remote server (known as cloud) (24),wherein the processed data is indicated to the rider / driver of the EV (10) through a display unit present in the dashboard (26) of the EV (10). In an embodiment, the display unit may be an interactive display unit. In another embodiment, the display unit may be a non-interactive display unit.

[0047] Embodiments of the present disclosure will be described below in detail with reference to the accompanying drawings.

[0048] For the sake of clarity, the first digit of a reference numeral of each component of the present disclosure is indicative of the Figure number, in which the corresponding component is shown. For example, reference numerals starting with digit “1” are shown at least in Figure 1. Similarly, reference numerals starting with digit “2” are shown at least in Figure 2.

[0049] Basically, when a system turns off suddenly from running conditions, Field Effect Transistors (FETs) open suddenly. Current can only pass through a body diode if a back Electromotive Force (EMF) is greater than a voltage of a battery, otherwise, the circuit may be open. The sudden opening of the circuit may lead to inductive kickback, and depending on the trace, wire length from the battery to a controller, and from the controller to a motor, decides a parasitic inductance, a voltage spike occurs across the FETs and bulk capacitors. At high speeds, where the motor back EMF is higher than the voltage of the battery voltage, the body diode acts as a rectifier, resulting in further voltage build-up at an instant of turn-off This results in current flow to the battery until the speed drops below a level where the motor back EMF is lower than the battery voltage. At high State of Charge (SOC) of the battery, the current flow to the battery can affect cell life or lead to failure if the current is high.

[0050] In existing technologies, the sudden cut-offs cannot be prevented in the event of a software failure, necessitating the implementation of hardware-based solutions if the application demands such measures. The present disclosure may incorporate a method to add redundancy to the power stage off operation through the use of a kill switch circuit. Further, the kill switch, typically an emergency switch, is designed to power off the motor through user intervention and may guarantee motor shutdown even if software fails. This redundancy is achieved by a hardware circuit that cuts Pulse Width Modulation (PWM) signals to a gate of an inverter, thus interrupting power to the motor independently of the software. Both software and hardware control the PWM signals through an AND gate, ensuring a more robust solution. The proposed system switches off the motor through a ramp-down mechanism where the torque is reduced in a controlled manner, achieving motor braking.

[0051] Embodiments of the present disclosure relate to automotive technology. In particular, the present disclosure relates to a system and a method for performing controlled power stage off of a motor, thereby preventing damage to the motor, motor controller, and battery and ensuring a more reliable and durable motor operation.

[0052] Various embodiments of the present disclosure will be explained in detail with respect to FIGs. 2 to 6.

[0053] FIG. 2 illustrates a schematic representation of a system (200) including a 3- phase inverter connected to a 3-phase motor (16) (e.g., a motor), in accordance with embodiments of the present disclosure.

[0054] Referring to FIG. 2, a system (200) may include a battery (202), a capacitor bank (204), an inverter (e.g., a switching device), and the 3-phase motor (16) as presented in FIG. 1. In an embodiment, the system (200) may utilize power from the battery (204) for operation. In an embodiment, the capacitor bank (204) may stabilize voltage and reduce ripples. In an embodiment, the inverter may consist of multiple Field Effect Transistors (FETs) (e.g., switching elements (206)) that may switch to convert Direct Current (DC) to 3- phase Alternate Current (AC) for the motor (16) for operation. In an embodiment, the battery (202) may supply the DC power to the capacitor bank (204), which may stabilize the voltage. The inverter may switch the FETs (e.g., 206) to convert the DC power to 3-phase AC power, which the 3-phase motor (16) receives and operates accordingly. During dynamic braking, the inverter may manage current flow within windings of the motor (16) to decelerate the motor (16) smoothly.

[0055] In an embodiment, the system (200) may utilize multiple subcomponents to achieve a controlled and safe cut-off of power of the 3-phase motor power within a short period. The system (200) may include a module (e.g., a controller) for detecting sudden motor cut-off requests (e.g., a power stage off request) from internal sources (e.g., the controller) or external sources (e.g., a kill switch), and the controller may perform zero torque operation on the motor (16). Additionally, the module may maintain time and trigger requests to switch off the system and safely switch off the FETs.

[0056] In an embodiment, upon receiving the request (e.g., the power stage off request) for a controlled power stage off, the system (200) may ramp down a torque of the motor (16) to zero, effectively performing controlled braking. The ramp down of the torque may create a closed-loop path for facilitating current circulation within windings of the motor (16). By managing a process of the ramp down of the torque in a controlled manner, the system (200) may ensure that braking occurs while either limiting the current flow back to the battery(202) or preventing the current flow back to the battery altogether, depending on a State of Charge (SOC) of the battery (202).

[0057] FIGs. 3 and 4 illustrate block diagrams (300 and 400) depicting torque rampdown management using a Microcontroller Unit (MCU), in accordance with embodiments of the present disclosure.

[0058] Referring to FIG. 3, the controller or the kill switch may transmit a torque request (e.g., the power stage off request) to a Field Oriented Control (FOC) block (302), which may handle the torque ramp-down request (e.g., the power stage off request). The FOC block (302) may process the power stage off request and transmit feedback to the motor (16), which may receive the controlled torque adjustments, and to the vehicle (10).

[0059] Referring to FIG. 4, a Maximum Torque Per Ampere (MTPA) block (402) may determine an optimal current for maximum torque, and a Battery Current controller (404) may manage current limits of the battery (e.g., 202). A Direct Axis Current Reference (IDREF) selection module (406) may select an appropriate direct current reference, and a Quadrature Axis Current Reference (IQREF) calculation module (408) may calculate a quadrature axis current reference. Finally, a Space Vector Pulse Width Modulation (SVPWM) block (410) may convert these current references into PWM pulses to control the inverter.

[0060] In an embodiment, the torque ramp down may be managed by a Microcontroller Unit (MCU) (e.g., the controller), where the FOC block (302) may process the ramp down request (e.g., the power stage off request) using the IQREF for torque and the IDREF for flux. Based on these references, the current control loops for IQ and ID may be converted into the required PWM pulses in the SVPWM block (410) for inverter switching.

[0061] FIG. 5 illustrates a flow diagram depicting a process implemented in a system (500) in which the kill switch provides an emergency switch-off mechanism to the motor (16), in accordance with embodiments of the present disclosure.

[0062] Referring to FIG. 5, in an embodiment, the system (500) (e.g., system (200) as illustrated in FIG. 2) may include the MCU (504) (e.g., the controller), the kill switch, a hardware delay circuit (506) (e.g., a delay circuit), an AND gate (508), and a gate drive circuit (510). In an embodiment, the kill switch input (502) may be provided as a signal to both the MCU (504) and the hardware delay circuit (506). The MCU (504) may manage control signals for the drive, and attempt the controlled power-off of the motor (16) upon receiving the control signal. If the MCU (504) fails to act within a predefined time (e.g., 200ms), the hardware delay circuit (506) may be triggered. In an embodiment, the AND gate(508) may combine the control signals from the MCU (504) and the hardware delay circuit (506) before transmitting the final control signal. In an embodiment, a gate drive circuit (510) may then receive this final control signal and transmit gate signals to the switching elements (e.g., 206) as represented in FIG. 2 in the inverter, thereby safely switching off and ensuring that the inverter is powered down without causing damage.

[0063] In an embodiment, the kill switch in the vehicle (10) may provide an emergency switch-off mechanism for the motor (16). Typically, the kill switch may operate as an independent system, bypassing the software and performing the power stage off directly. In an embodiment, the system may add a delay factor in the hardware performing the motor cutoff, instead of performing a direct kill-off During this delay, the software may perform a controlled power stage off. If the software is unable to perform a controlled cut-off within the predefined off delay time, the hardware, for example, the kill switch may perform the cut-off, adding redundancy.

[0064] In an embodiment, the system (500) may include the controller (e.g., MCU (504)) associated with a processor and a memory operatively coupled with the processor. In an embodiment, the controller (504) may be operatively connected to the switch mechanism (e.g., the kill switch) and the delay circuit (e.g., 506). In an embodiment, the memory may include one or more instructions which, when executed, cause the controller (504) to detect the power stage off request received from at least one of the internal system (e.g., the controller) or the external system (e.g., the kill switch), and ramp down the torque of the motor (16) to zero. In an embodiment, the switch mechanism may be configured to send an input to the delay circuit (506) based on the detection of the power stage off request. In an embodiment, based on the input, the delay circuit (506) may be configured to add a delay factor to the switching devices, such that the switching devices may delay to enable or disable a switching operation of the motor (16) for a predetermined time. In an embodiment, when the switching devices delay to enable or disable the switching operation of the motor (16) for the predetermined time, the controller (504) may be configured to perform the controlled power stage off of the motor (16). In an embodiment, when the controller (504) fails to perform the controlled power stage off of the motor (16) within the predetermined time, the switching devices may be configured to disable the switching of the switching devices and turn off an operation of the motor (16).

[0065] In an embodiment, in response to ramping down the torque, the controller (504) may create the closed loop path to facilitate circulation of the current within the windings of the motor (16). In an embodiment, the controller (504) may be configured to convert thecurrent into signals. In an embodiment, the signals may be transmitted to the switching devices through a gate drive circuit (510) to perform controlled power stage off of the motor (16). In an embodiment, the controller (504) may be configured to convert the current into the PWM signals. In an embodiment, the gate drive circuit (510) may convert the PWM signals into the gate signals, and transmit the gate signals to the switching devices.

[0066] In an embodiment, the controller (504) may be configured to detect turning off of switching elements (e.g., FETs (206) as represented in FIG. 2) associated with the motor (16) due to an abrupt shutdown of the system from an operational state. In an embodiment, the controller (504) may be configured to detect turning off of the switching elements (206) associated with the motor (16) based on a detection of at least one of a fault condition in the system, and the power stage off request received from the user through the switch mechanism (e.g., the kill switch). In an embodiment, based on the detection of turning off of the switching elements (206), the controller (504) may be configured to control a back flow of the current from the windings of the motor (16) to the battery (e.g., 202) as represented in FIG. 2 based on the SOC of the battery (202), and / or perform controlled braking of the motor (16) by circulating the current in the windings of the motor (16).

[0067] FIG. 6 illustrates a flow chart for implementing a method (600) for performing a controlled power stage off of the motor (16), in accordance with embodiments of the present disclosure.

[0068] Referring to FIG. 6, at (602), the method (600) may include detecting the power stage off request received from at least one of the internal system or the external system. At (604), based on the detection of the power stage off request, the method (600) may include ramping down the torque of the motor (16) to zero. At (606), in response to ramping down the torque, the method (600) may include creating the closed loop path to facilitate circulation of the current within the windings of the motor (16). At (608), the method (600) may include converting the current into the signals. At (610), the method (600) may include transmitting the signals to switching devices to perform controlled power stage off of the motor (16).

[0069] In this application, unless specifically stated otherwise, the use of the singular includes the plural and the use of “or” means “and / or.” Furthermore, use of the terms “including” or “having” is not limiting. Any range described herein will be understood to include the endpoints and all values between the endpoints. Features of the disclosed embodiments may be combined, rearranged, omitted, etc., within the scope of the disclosureto produce additional embodiments. Furthermore, certain features may sometimes be used to advantage without a corresponding use of other features.

[0070] While the foregoing describes various embodiments of the disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof. The scope of the disclosure is determined by the claims that follow. The disclosure is not limited to the described embodiments, versions, or examples, which are included to enable a person having ordinary skill in the art to make and use the disclosure when combined with information and knowledge available to the person having ordinary skill in the art.ADVANTAGES OF THE PRESENT DISCLOSURE

[0071] The present disclosure performs controlled power stage off of a motor, thereby preventing damage to the motor, motor controller, and battery and ensuring a more reliable and durable motor operation.

[0072] The present disclosure prevents damage to components internal and external to a system by providing a controlled and graceful shutdown through proper interaction between the hardware circuit and software, which avoids damage to a motor controller and other components due to sudden inductive kickback and voltage spikes.

[0073] The present disclosure improves system longevity by minimizing abrupt changes, and protection against excessive currents, which may extend the lifespan of both the motor and the battery.

[0074] The present disclosure provides redundancy to an operation of a kill switch by adding an AND gate to facilitate both software and hardware motor cut-off.

Claims

We Claim:

1. A system (500) for performing controlled power stage off of a motor (16), the system (500) comprising: a controller (504) associated with a processor; and a memory operatively coupled with the processor, wherein the memory comprises one or more instructions which, when executed, cause the controller (504) to: detect a power stage off request received from at least one of an internal system or an external system; based on the detection of the power stage off request, ramp down a torque of the motor (16) to zero; in response to ramping down the torque, create a closed loop path to facilitate circulation of current within one or more windings of the motor (16); convert the current into one or more signals; and transmit the one or more signals to one or more switching devices to perform controlled power stage off of the motor (16).

2. The system (500) as claimed in claim 1, wherein the controller (504) is operatively connected to a switch mechanism and a delay circuit (506).

3. The system (500) as claimed in claim 2, wherein based on the detection of the power stage off request, the switch mechanism is configured to send an input to the delay circuit (506).

4. The system (500) as claimed in claim 3, wherein based on the input, the delay circuit (506) is configured to add a delay factor to one or more switching devices, such that the one or more switching devices delay to perform a switching operation of the motor (16) for a predetermined time.

5. The system (500) as claimed in claim 4, wherein when the one or more switching devices delay to perform the switching operation of the motor (16) for the predetermined time, the controller (504) is configured to perform the controlled power stage off of the motor (16).

6. The system (500) as claimed in claim 5, wherein when the controller (504) fails to perform the controlled power stage off of the motor (16) within the predetermined time, the one or more switching devices are configured to disable switching of the switching devices and turn off an operation of the motor (16).

7. The system (500) as claimed in claim 1, wherein the one or more signals are transmitted to the one or more switching devices through a gate drive circuit ( 10).

8. The system (500) as claimed in claim 1, wherein the controller (504) is configured to convert the current into one or more Pulse Width Modulation (PWM) signals.

9. The system (500) as claimed in claim 7, wherein the gate drive circuit (510) converts one or more PWM signals into one or more gate signals, and transmits the one or more gate signals to the one or more switching devices.

10. The system (500) as claimed in claim 1, wherein the controller (504) is configured to detect turning off of one or more switching elements (206) associated with the motor (16) due to an abrupt shutdown of the system (500) from an operational state.

11. The system (500) as claimed in claim 10, wherein the controller (504) is configured to detect turning off of the one or more switching elements (206) associated with the motor (16) based on detection of at least one of: a fault condition in the system and the power stage off request received from a user through a switch mechanism.

12. The system (500) as claimed in claim 11, wherein based on the detection of turning off of the one or more switching elements (206), the controller (504) is configured to control a back flow of the current from the one or more windings of the motor (16) to a battery (202) based on a State of Charge (SOC) of the battery (202), and perform controlled braking of the motor (16) by circulating the current in the windings of the motor (16).

13. A method (600) for performing controlled power stage off of a motor (16), the method (600) comprising: detecting (602), by a controller (504) associated with a system, a power stage off request received from at least one of an internal system or an external system; based on the detection of the power stage off request, ramping down (604), by the controller (504), a torque of the motor (16) to zero; in response to ramping down the torque, creating (606), by the controller (504), a closed loop path to facilitate circulation of current within one or more windings of the motor (16); converting (608), by the controller (504), the current into one or more signals; and transmitting (610), by the controller (504), the one or more signals to one or more switching devices to perform controlled power stage off of the motor (16).

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