DESC:METHOD FOR INSULATION DETECTION IN ELECTRIC VEHICLE(S)
CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims priority from Indian Provisional Patent Application No. 202421021045 filed on 19/03/2024, the entirety of which is incorporated herein by a reference.
TECHNICAL FIELD
The present disclosure generally relates to a motor drive of an electric vehicle. Particularly, the present disclosure relates to a method of isolation detection for a motor drive of an electric vehicle.
BACKGROUND
The electric vehicle (EV) market is rapidly expanding, driven by advancements in battery technology, government incentives, and increasing environmental concerns. The Auto-manufacturers re investing heavily in EV infrastructure, including fast-charging networks and improved energy efficiency. Additionally, the solid-state batteries and high-efficiency powertrains are emerging as key innovations for future EVs.
Recently, the motor drive system in electric vehicles has evolved with advancements in power electronics, control algorithms, and efficiency optimization. The modern electric and hybrid vehicles utilize high-efficiency inverters and advanced motor designs like PMSM and induction motors. Also, the emerging trends include SiC and GaN-based inverters for reduced losses and higher power density. However, with increasing usage of motor drive in vehicles, the insulation problems in the motor drive arises. The insulation problems in the motor drive occur due to factors such as electrical stress, thermal degradation, mechanical vibrations, and environmental conditions like moisture or contaminants. Over time, high-voltage stress may cause insulation breakdown, leading to leakage currents and reduced system efficiency. Also, excessive heat from prolonged operation accelerates material aging, weakening insulation properties. Furthermore, the mechanical shocks and continuous vibrations may create microcracks in insulating layers, increasing the risk of failure. Additionally, dust, humidity, and chemical exposure can degrade insulation surfaces, leading to unintended short circuits or safety hazards.
Traditionally, the isolation in the motor drives of electric vehicles traditionally monitored using resistance-based measurement techniques, voltage monitoring methods, and insulation resistance testers. These methods primarily relied on measuring the insulation resistance between the high-voltage (HV) system and the vehicle chassis to detect any potential faults or degradation in isolation. One of the common technique is resistance measurement method, where a high-value resistor is connected between the HV bus and the chassis ground. By applying a known voltage and measuring the leakage current, the insulation resistance is calculated. If the resistance dropped below a predefined threshold, an isolation fault is detected. However, the method has significant drawbacks. Firstly, these method required additional passive components that added to the system complexity and cost. Secondly, the method may not detect dynamic isolation failures, such as insulation breakdown occurring due to transient voltage spikes or mechanical stress over time. Moreover, during operation, insulation degradation is often gradual and not easily captured by periodic resistance measurements, leading to potential undetected faults. Another conventional approach involved voltage-based monitoring, where the voltage difference between the HV system and the chassis ground is continuously observed. Any unexpected fluctuations in the voltage difference may be indicate a loss of isolation. While the method is relatively straightforward, but the method suffered from low sensitivity to minor faults, making the method ineffective in detecting early-stage insulation degradation. Additionally, the method prone to false positives due to external noise, temperature variations, or minor fluctuations in the high-voltage system, leading to unnecessary warnings or system shutdowns. Moreover, a more manual method is often used which is the insulation resistance test using a megohmmeter, where a high DC voltage (e.g., 500V to 1000V) is applied to the motor drive circuit while the vehicle is off, and the resulting leakage current is measured to determine insulation integrity. This method is highly effective in detecting severe insulation breakdowns but not impractical for real-time monitoring, as the method required the vehicle to be taken offline for testing. Moreover, the method may be only detecting the insulation failures that had already occurred and is not effective in predicting insulation degradation over time.
Therefore, there is a need to provide an improved technique for isolation detection in a motor drive of an electric vehicle to overcome one or more problems associated as set forth above.
SUMMARY
An object of the present disclosure is to provide a method of isolation detection for a motor drive of an electric vehicle.
In accordance with an aspect of the present disclosure, there is provided a method of isolation detection for a motor drive of an electric vehicle. The method comprises detecting, by a current sensor, a plurality of current values of the motor drive in idle powered-up condition, generating, by a control unit, a control signal corresponding to current settings of the motor drive and determining, by the control unit, an isolation status of the motor drive based on the detected plurality of current values and the current settings of the motor drive.
The present disclosure provides a method of isolation detection for a motor drive of an electric vehicle. The method as disclosed by present disclosure is advantageous in terms of enhanced both safety and reliability. Beneficially, the method enables early identification of insulation degradation or isolation faults, thereby reduces the risk of electrical failures. Furthermore, the method significantly improves the diagnostic accuracy by distinguishing transient variations from genuine faults. Additionally, the method ensures a comprehensive evaluation of isolation status under diverse operating conditions for accurate isolation detection. Beneficially, the method enhances the responsiveness of the vehicle’s safety system, thereby allows the timely corrective actions such as generating an alert signals. Furthermore, the method ensures minimal interference with normal vehicle operation which helps with effective maintenance and predictive fault analysis.
Additional aspects, advantages, features and objects of the present disclosure would be made apparent from the drawings and the detailed description of the illustrative embodiments constructed in conjunction with the appended claims that follow.
It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the appended claims.
BRIEF DESCRIPTION OF DRAWINGS
The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers.
Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein:
FIG. 1 illustrates a flow chart of a method of isolation detection for a motor drive of an electric vehicle, in accordance with another aspect of the present disclosure.
In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.
DETAILED DESCRIPTION
The following detailed description illustrates embodiments of the present disclosure and ways in which they can be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognise that other embodiments for carrying out or practising the present disclosure are also possible.
The description set forth below in connection with the appended drawings is intended as a description of certain embodiments of a method of isolation detection for a motor drive of an electric vehicle and is not intended to represent the only forms that may be developed or utilised. The description sets forth the various structures and/or functions in connection with the illustrated embodiments; however, it is to be understood that the disclosed embodiments are merely exemplary of the disclosure that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimised to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.
The terms “comprise”, “comprises”, “comprising”, “include(s)”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, system that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or system. In other words, one or more elements in a system or apparatus preceded by “comprises... a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.
In the following detailed description of the embodiments of the disclosure, reference is made to the accompanying drawings and which are shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.
The present disclosure will be described herein below with reference to the accompanying drawings. In the following description, well known functions or constructions are not described in detail since they would obscure the description with unnecessary detail.
As used herein, the terms “electric vehicle”, “EV”, and “EVs” are used interchangeably and refer to any vehicle having stored electrical energy, including the vehicle capable of being charged from an external electrical power source. This may include vehicles having batteries which are exclusively charged from an external power source, as well as hybrid-vehicles which may include batteries capable of being at least partially recharged via an external power source. Additionally, it is to be understood that the ‘electric vehicle’ as used herein includes electric two-wheeler, electric three-wheeler, electric four-wheeler, electric pickup trucks, electric trucks and so forth.
As used herein, the term “isolation detection” refers to a method or system for identifying electrical insulation faults or leakage paths in an electric vehicle's motor drive system. The method for isolation detection involves monitoring electrical parameters, such as current, voltage, or impedance, to determine the integrity of insulation between high-voltage components and the vehicle chassis or ground. The process may include detecting abnormal leakage currents, comparing measured values with predefined thresholds, and generating alerts when an isolation fault is identified.
As used herein, the terms “motor drive” refers to a system configured to control the operation of an electric motor by regulating electrical power supplied to the motor, wherein the system comprises power electronics, control circuitry, and associated components to facilitate torque generation, speed regulation, and operational safety in an electric vehicle or similar application
As used herein, the term “current sensor” refers to a device configured to detect, measure, and monitor an electric current flowing through a conductor or circuit. The current sensor generates an output signal corresponding to the detected current, which may be used for control, protection, or diagnostic purposes in an electrical system. The current sensor may operate based on one or more sensing principles, including but not limited to Hall-effect sensing, shunt-based measurement, fluxgate sensing, Rogowski coil measurement, or magneto-resistive sensing.
As used herein, the term “plurality of current values” and “current values” are used interchangeably and refer to two or more discrete or continuous electrical current measurements obtained over a period of time or under varying operating conditions of the motor drive.
As used herein, the term “powered-up condition” refers to a state in which the motor drive or electrical system of the vehicle is supplied with electrical power and is operational but may not necessarily be actively driving the motor or performing propulsion functions. The powered-up condition implies that the system is energized, capable of executing control functions, and able to monitor parameters such as current, voltage, or insulation resistance. The powered-up condition may occur during vehicle startup, standby mode, or diagnostic operations when power is applied to the motor drive, but the vehicle remains idle or not in motion.
As used herein, the term “control unit” refers to an electronic module configured to execute instructions for monitoring, controlling, or regulating one or more operational parameters of a device, system, or component. Optionally, the control unit includes, but is not limited to, a microprocessor, a micro-controller, a complex instruction set computing (CISC) microprocessor, a reduced instruction set (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, or any other type of processing circuit. Furthermore, the term “processor” may refer to one or more individual processors, processing devices and various elements associated with a processing device that may be shared by other processing devices. Furthermore, the control unit may comprise ARM Cortex-M series processors, such as the Cortex-M4 or Cortex-M7, or any similar processor designed to handle real-time tasks with high performance and low power consumption. Furthermore, the control unit may comprise custom and/or proprietary processors. As used herein, the term “control signal” refers to
As used herein, the term “current settings” refers to the operational parameters of the motor drive that influence or are associated with the current flow characteristics within the system. The current settings may include, but are not limited to, operating voltage, temperature, torque demand, motor speed, or other control parameters that determine the electrical behaviour of the motor drive under various conditions. The current settings may be dynamically adjusted based on real-time system requirements, predefined thresholds, or historical performance data to optimize motor drive operation and ensure proper fault detection.
As used herein, the term “isolation status” refers to a condition indicative of the electrical insulation integrity between high-voltage components of a motor drive and the vehicle chassis or other conductive parts. The isolation status represents whether the insulation is intact, degraded, or faulty based on measured electrical parameters such as leakage current, resistance values, or deviations from expected thresholds. The isolation status may be classified into different conditions, such as normal (no fault), degraded, or faulty.
As used herein, the term “threshold values” refers to predefined numerical or qualitative limits used as a reference to determine a specific condition or event. The threshold values serve as a benchmark for assessing whether a parameter, such as current, voltage, temperature, pressure, or speed, has exceeded or fallen below a critical level, triggering a corresponding action or response.
As used herein, the term “isolation fault” refers to a condition where the electrical insulation between the high-voltage system such as the motor drive and the vehicle chassis or low-voltage components is compromised. This fault can result in unintended current leakage, posing safety hazards such as electric shocks, malfunctioning vehicle systems, or increased risk of short circuits. An isolation fault may be caused by insulation degradation, physical damage, moisture ingress, or manufacturing defects. Detection of such a fault typically involves monitoring leakage currents, insulation resistance, or deviations from expected electrical parameters to ensure compliance with safety standards and prevent hazardous conditions.
As used herein, the term “operating voltage” refers to the voltage level at which an electrical system, such as the motor drive of an electric vehicle, is designed to operate under normal, intended conditions. The operating voltage is the range of voltage within which the system may function efficiently and safely, ensuring optimal performance and preventing damage to components. The operating voltage is typically specified based on the system’s design, including factors such as motor characteristics, power requirements, and the electrical components voltage tolerances.
As used herein, the term “historical current values” refers to previously recorded or stored current measurements of a motor drive system under various operating conditions of an electric vehicle. The historical current values represents the current characteristics observed over time, including during different load conditions, temperatures, voltages, torque demands, and motor speeds. The historical current values serve as a reference dataset, enabling comparison with newly detected current values to assess deviations indicative of insulation degradation or isolation faults.
As used herein, the term “detected current value” refers to the measured electrical current flowing through the motor drive of an electric vehicle, as sensed by a current sensor under specified conditions. The detected current value represents the real-time current magnitude captured during the operation, idle powered-up state, or a diagnostic sequence of the motor drive. The detected current value may be influenced by various parameters, including but not limited to operating voltage, temperature, torque demand, and motor speed.
As used herein, the term “alert signal” refers to an electrical, visual, audible, or communication-based signal generated in response to a detected condition, such as an isolation fault, to notify a control system, operator, or external monitoring unit for initiating corrective action or further diagnosis.
As used herein, the term “vehicle control unit” and “VCU” are used interchangeably and refer to an electronic control unit configured to manage, coordinate, and regulate various functions of a vehicle's powertrain, propulsion, and auxiliary systems. The VCU processes input signals from sensors, actuators, and communication networks, executes control algorithms, and generates corresponding output signals to optimize vehicle performance, safety, and efficiency. In electric vehicles, the VCU interacts with subsystems such as the motor drive, battery management system, braking system, and thermal management system to ensure seamless operation. The VCU may also facilitate diagnostics, fault detection, and communication with external devices through wired or wireless interfaces.
As used herein, the term “leakage current” refers to an unintended electric current that flows through an insulation medium or unintended conductive path in an electrical system. The leakage current typically arises due to insulation degradation, contamination, or defects in electrical components, leading to unintended current flow between high-voltage conductors and the chassis or ground.
As used herein, the term “diagnostic sequence” refers to a predefined series of steps or operations executed by a control unit or diagnostic system to assess, verify, and determine the status of a system component, such as the isolation condition of a motor drive. The diagnostic sequence may involve measuring electrical parameters, comparing detected values with threshold criteria, executing test signals, analysing historical data, and generating reports or alerts based on the evaluation.
As used herein, the term “diagnostic data” refers to information collected, processed, and stored during the operation of a system or component for the purpose of detecting, analysing, and identifying faults, performance deviations, or potential failures. The diagnostic data may include sensor readings, historical performance records, error codes, system parameters, operational conditions, and any other relevant information that aids in assessing the health, efficiency, or functionality of the system.
As used herein, the term “vehicle diagnostic log” refers to a data storage system or record that logs diagnostic information related to the operational status, faults, and performance parameters of a vehicle's components. The vehicle diagnostic log stores the historical and real-time diagnostic data generated by vehicle control units, sensors, or monitoring systems to facilitate fault detection, predictive maintenance, and system analysis. The diagnostic log may include entries such as error codes, isolation fault data, current and voltage readings, temperature variations and system alerts associated with detected anomalies. The stored data can be accessed for troubleshooting, performance optimization, regulatory compliance, and service maintenance purposes.
Figure 1, describes a method 100 of isolation detection for a motor drive of an electric vehicle. The method 100 starts at step 102 and completes at step 106. At step 102, the method 100 comprises detecting, by a current sensor, a plurality of current values of the motor drive in idle powered-up condition. At step 104, the method 100 comprises generating, by a control unit, a control signal corresponding to current settings of the motor drive. At step 106, the method 100 comprises determining, by the control unit, an isolation status of the motor drive based on the detected plurality of current values and the current settings of the motor drive.
The present disclosure provides a method 100 of isolation detection for a motor drive of an electric vehicle. The method 100 as disclosed by present disclosure is advantageous in terms of enhanced both safety and reliability. By detecting current values in an idle powered-up state, the method 100 beneficially ensures that insulation degradation or isolation faults to be identified without interfering with active driving conditions. Beneficially, the method 100 minimizes the risk of unexpected electrical failures during vehicle operation, thereby improving overall vehicle safety. Furthermore, the method 100 leverages the real-time current sensing and the control signal generation which allows the dynamic assessment of insulation health based on operating voltage, temperature, torque demand, and motor speed. Moreover, the real-time current sensing and the control signal generation significantly ensures the accurate fault detection across varying environmental and operational conditions. Furthermore, the integration of historical current data comparison enables trend analysis and predictive maintenance, thereby reduces the likelihood of sudden breakdowns. Furthermore, by detecting leakage currents indicative of insulation degradation, the method 100 enhances the longevity of the motor drive components, ultimately reducing maintenance costs. Additionally, the method 100 includes an alert system able to trigger visual, audible, or communication-based warnings, thereby ensures the faults are promptly addressed by the vehicle control unit. Furthermore, the ability to store diagnostic data in the vehicle log is advantageous for the root cause analysis and regulatory compliance. Furthermore, the inclusion of a diagnostic sequence further improves accuracy by verifying isolation status before final fault determination. Overall, the method 100 provides the enhanced system reliability, improves vehicle uptime, and ensures compliance with safety standards, making the method 100 a robust solution for insulation fault detection in modern electric powertrains.
In an embodiment, the method 100 comprises comparing the detected plurality of current values with predetermined threshold values and determining an isolation fault when the detected plurality of current values exceeds the predetermined threshold values. The current sensor continuously detects the plurality of current values, which are then analysed by the control unit to assess insulation integrity. The control unit compares the detected current values against predefined threshold values that represent acceptable insulation performance under normal operating conditions. If any of the detected current values exceed the predetermined thresholds, the control unit determines that an isolation fault is present. Beneficially, the method 100 ensures that insulation faults are detected in a timely manner, preventing potential safety risks and enhancing the reliability of the motor drive system in electric vehicles.
In an embodiment, the current settings of the motor drive comprise at least one of operating voltage, temperature, torque demand and motor speed parameters. Furthermore, the method 100 comprises storing historical current values of the motor drive during different operating conditions of the electric vehicle. Furthermore, the method 100 comprises comparing the detected current value with the historical current values to determine the isolation status. The at least one of operating voltage, temperature, torque demand and motor speed parameters influence the electrical characteristics of the motor drive, and the method 100 ensures a more comprehensive evaluation of the insulation status. Furthermore, the historical data serves as the reference for identifying deviations in current behavior that may indicate insulation degradation or an isolation fault. By comparing the detected current values with the stored historical current values, the control unit may determine the isolation status with greater precision. The comparison of the detected current values with the stored historical current values enables a more adaptive and predictive approach to insulation fault detection, as the comparison accounts for the variations in current due to normal operating conditions rather than treating all fluctuations as potential faults. Beneficially, the method 100 ensures a more reliable and data-driven approach to isolation detection, improving the accuracy of fault identification while minimizing false positives. Also, the method 100 enhances the safety, durability, and maintainability of the motor drive system in electric vehicles.
In an embodiment, the method 100 comprises generating an alert signal when the isolation fault is detected. Furthermore, the alert signal comprises at least one of a visual alert, an audible alert, a communication signal to a vehicle control unit 106 or a combination thereof. When the control unit determines the isolation fault based on the detected current values exceeding the predetermined threshold, the alert signal may be generated to notify the vehicle operator or relevant control systems. The alert signal may include a visual indicator, such as a dashboard warning light, an audible alarm, or a communication signal sent to the vehicle control unit for further diagnostic actions. Beneficially, the alert mechanism ensures that insulation faults are promptly identified, allowing for immediate corrective measures to prevent potential electrical hazards, performance degradation, or system failures.
In an embodiment, the method 100 comprises detecting a leakage current indicative of insulation degradation in the motor drive. The current sensor may be configured to measure the leakage current while the motor drive may be in the idle powered-up state. The control unit processes the detected current values and compares the values against predefined threshold values that characterize normal insulation performance. If the leakage current exceeds the threshold, the control unit determines that insulation degradation may be present. The system may also store historical leakage current data, allowing for trend analysis and predictive maintenance. Beneficially, the method 100 ensures the early detection of the insulation degradation, thereby enhancing the reliability and safety of the motor drive system.
In an embodiment, determining isolation status is performed during a predetermined time window, when the motor drive is idle and powered-up. The control unit initiates the isolation diagnostic routine by instructing the current sensor to measure the plurality of current values within the motor drive system. The predetermined time window may be strategically selected to avoid interference with active driving conditions, ensuring that the isolation assessment does not impact vehicle performance or user experience. The control unit then processes the detected current values in correlation with the motor drive’s current settings, such as operating voltage, temperature, torque demand, and motor speed, to determine the insulation status of the system. Beneficially, the method 100 ensures that isolation monitoring is conducted in a controlled environment, thereby optimizing the reliability of the diagnostic process.
In an embodiment, the method 100 comprises initiating a diagnostic sequence to verify the isolation status and storing isolation diagnostic data in a vehicle diagnostic log. The diagnostic sequence may be executed when the vehicle is in an idle powered-up state, allowing for precise assessment of insulation integrity without interfering with vehicle operation. The control unit processes real-time current data, compares the data with predefined thresholds and historical values, and determines whether the isolation fault exists. If an abnormality is detected, the system records the isolation diagnostic data in the vehicle diagnostic log. Beneficially, the log serves as the historical reference for maintenance, troubleshooting, and predictive analytics, enabling early detection of insulation degradation and reducing the risk of sudden electrical failures.
In an embodiment, the method 100 of isolation detection for the motor drive of the electric vehicle. The method 100 starts at step 102 and completes at step 106. At step 102, the method 100 comprises detecting, by the current sensor, the plurality of current values of the motor drive in idle powered-up condition. At step 104, the method 100 comprises generating, by the control unit, the control signal corresponding to current settings of the motor drive. At step 106, the method 100 comprises determining, by the control unit, the isolation status of the motor drive based on the detected plurality of current values and the current settings of the motor drive. Furthermore, the method 100 comprises comparing the detected plurality of current values with predetermined threshold values and determining an isolation fault when the detected plurality of current values exceeds the predetermined threshold values. Furthermore, the current settings of the motor drive comprise the at least one of operating voltage, temperature, torque demand and motor speed parameters. Furthermore, the method 100 comprises storing historical current values of the motor drive during different operating conditions of the electric vehicle. Furthermore, the method 100 comprises comparing the detected current value with the historical current values to determine the isolation status. Furthermore, the method 100 comprises generating the alert signal when the isolation fault is detected. Furthermore, the alert signal comprises the at least one of the visual alert, the audible alert, the communication signal to the vehicle control unit or the combination thereof. Furthermore, the method 100 comprises detecting the leakage current indicative of insulation degradation in the motor drive. Furthermore, determining isolation status is performed during the predetermined time window, when the motor drive is idle and powered-up.
In an exemplary embodiment, the insulation detection method 100 for the motor drive in the electric vehicle operates by continuously monitoring leakage currents and analyzing deviations in electrical characteristics to detect insulation faults. When the motor drive is in the idle powered-up condition, the current sensor positioned within the system detects leakage or stray currents flowing through the motor casing or unintended conductive paths. The current sensor captures high-resolution current waveforms over a predefined sampling period and transmits the signals to the control unit for further analysis. Upon receiving the waveform signals, the control unit processes the signals using signal conditioning techniques such as noise filtering and amplification to extract relevant current characteristics. The processed signals are then converted from analog to digital format using an ADC (Analog-to-Digital Converter) to facilitate computational analysis. The control unit segments the digitized waveform data into discrete time intervals and applies Fourier Transform or Wavelet Transform techniques to analyze frequency components that may indicate insulation degradation. The method 100 then calculates root mean square (RMS) values and peak-to-peak variations of the current waveform to identify abnormal leakage currents. The computed values are compared with predetermined threshold values stored in the system’s memory, which are derived from empirical data corresponding to healthy insulation conditions. If the detected current values exceed the predefined thresholds, the control unit identifies the insulation fault and classifies the fault based on severity.
In the description of the present invention, it is also to be noted that, unless otherwise explicitly specified or limited, the terms “disposed,” “mounted,” and “connected” are to be construed broadly, and may for example be fixedly connected, detachably connected, or integrally connected, either mechanically or electrically. They may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Modifications to embodiments and combination of different embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as “including”, “comprising”, “incorporating”, “have”, “is” used to describe and claim the present disclosure are intended to be construed in a non- exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural where appropriate.
Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the present disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.
,CLAIMS:WE CLAIM:
1. A method (100) of isolation detection for a motor drive of an electric vehicle, wherein the method (100) comprises:
- detecting, by a current sensor, a plurality of current values of the motor drive in idle powered-up condition;
- generating, by a control unit, a control signal corresponding to current settings of the motor drive; and
- determining, by the control unit, an isolation status of the motor drive based on the detected plurality of current values and the current settings of the motor drive.
2. The method (100) as claimed in claim 1, wherein the method (100) comprises:
- comparing the detected plurality of current values with predetermined threshold values; and
- determining an isolation fault when the detected plurality of current values exceeds the predetermined threshold values.
3. The method (100) as claimed in claim 1, wherein the current settings of the motor drive comprise at least one of: operating voltage, temperature, torque demand and motor speed parameters.
4. The method (100) as claimed in claim 1, wherein the method (100) comprises storing historical current values of the motor drive during different operating conditions of the electric vehicle.
5. The method (100) as claimed in claim 4, wherein the method (100) comprises comparing the detected current value with the historical current values to determine the isolation status.
6. The method (100) as claimed in claim 1, wherein the method (100) comprises generating an alert signal when the isolation fault is detected.
7. The method (100) as claimed in claim 6, wherein the alert signal comprises at least one of: a visual alert, an audible alert, a communication signal to a vehicle control unit or a combination thereof.
8. The method (100) as claimed in claim 1, wherein the method (100) comprises detecting a leakage current indicative of insulation degradation in the motor drive.
9. The method (100) as claimed in claim 1, wherein determining isolation status is performed during a predetermined time window, when the motor drive is idle and powered-up.
10. The method (100) as claimed in claim 1, wherein the method (100) comprises:
- initiating a diagnostic sequence to verify the isolation status; and
- storing isolation diagnostic data in a vehicle diagnostic log.