DESC:CURRENT INSULATION DETECTION METHOD AND SYSTEM
CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims priority from Indian Provisional Patent Application No. 202421021148 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. Particularly, the present disclosure relates to an insulation detection system for a motor drive. Furthermore, the present disclosure relates to a method for detecting insulation abnormalities in a motor drive.
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 an insulation detection system for a motor drive.
Another object of the present disclosure is to provide a method for detecting insulation abnormalities in a motor drive.
In accordance with first aspect of the present disclosure, there is provided an insulation detection system for a motor drive. The system comprises an impedance network coupled to a three-phase motor drive, a voltage sampling circuit configured to sample voltage signals from the impedance network and a processing unit coupled to the voltage sampling circuit. The processing unit is configured to compare characteristics of an AC voltage signal sampled by the voltage sampling circuit with predetermined thresholds of characteristics to determine insulation resistance status of one or more phases of the three-phase motor drive.
The present disclosure provides the insulation detection system for the motor drive. The system as disclosed by present disclosure is advantageous in terms of providing an enhanced safety and operational reliability. Beneficially, the system enables continuous monitoring of insulation resistance in a three-phase motor drive significantly helps to detect potential insulation failures before leads to critical faults. Furthermore, the system ensures the real-time assessment, thereby allows the prompt identification of abnormalities. Additionally, the ability to generate alarm signals and shut down the motor drive in case of insulation failure helps prevent equipment damage and electrical hazards. Furthermore, the system significantly improves the fault detection accuracy. Moreover, the system beneficially enhances the adaptability, thereby ensures the precise fault detection under varying load and environmental conditions. Beneficially, the system is able to reduce the unexpected downtime and extending the lifespan of the motor drive. Overall, the insulation detection system enhances the motor drive safety, reliability, and maintenance efficiency.
In accordance with second aspect of the present disclosure, there is provided a method for detecting insulation abnormalities in a motor drive. The method comprises coupling an impedance network to a three-phase motor drive, sampling, by a voltage sampling circuit, voltage signals from the impedance network, processing, by a processing unit, the sampled voltage signals to determine characteristics of an AC voltage signal and comparing, by the processing unit, characteristics of an AC voltage signal sampled by the voltage sampling circuit with predetermined thresholds of characteristics to determine insulation resistance status of one or more phases of the three-phase motor drive.
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 block diagram of an insulation detection system for a motor drive, in accordance with an aspect of the present disclosure.
FIG. 2 illustrates a flow chart of a method for detecting insulation abnormalities in a motor drive, 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 an insulation detection system for a motor drive 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 “insulation detection system” refers to a system configured to monitor and evaluate the insulation resistance of an electrical system, such as a motor drive, by detecting abnormalities in insulation integrity. The system typically comprises an impedance network coupled to the electrical system, a voltage sampling circuit for acquiring electrical signals, and a processing unit configured to analyze the sampled signals to determine insulation resistance status. Based on the analysis, the system can generate alerts, store historical data, or initiate protective actions, such as shutting down the system, to prevent electrical faults, leakage currents, or insulation failures that may lead to equipment damage or safety hazards.
As used herein, the terms “motor drive” and “three phase motor drive” are used interchangeably and refer to an electronic control system configured to regulate the operation of an electric motor by controlling parameters such as speed, torque, and direction. The motor drive may include a power conversion unit, a control unit, and a feedback mechanism to optimize motor performance based on operational requirements. The motor drive can be used with AC or DC motors and may incorporate various control techniques such as pulse-width modulation (PWM) or field-oriented control (FOC) to achieve efficient and precise motor control. The three-phase motor drive is a type of motor drive specifically designed to control the three-phase electric motor by regulating the frequency, voltage, and phase sequence of the supplied three-phase AC power.
As used herein, the term “coupled” refers to a bi-directional connection between the various components of the system. The bi-directional connection between the various components of the system enables exchange of data between two or more components of the system. Similarly, bi-directional connection between the system and other elements/modules enables exchange of data between system and the other elements/modules.
As used herein, the term “impedance network” refers to an electrical circuit comprising one or more passive components, such as resistors, capacitors, and inductors, arranged in a specific configuration to establish a predefined impedance characteristic. The impedance network is configured to interact with an electrical system, such as a three-phase motor drive, to influence voltage, current, or signal behavior in accordance with desired operational parameters.
As used herein, the term “voltage sampling circuit” refers to an electronic circuit configured to measure and extract voltage signals from a target system and convert the signals into a format suitable for further processing. The circuit typically comprises components such as resistors, capacitors, operational amplifiers, and an analog-to-digital converter (ADC) to capture voltage levels with precision. The voltage sampling circuit is coupled to the impedance network and is designed to sample AC or DC voltage signals from a motor drive. The sampled voltage signals are then processed to assess insulation resistance status, detect abnormalities, or enable control actions based on predefined thresholds.
As used herein, the term “processing unit” refers to a computational element that is operable to respond to and processes instructions that drive the system. Optionally, the data processing arrangement 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 data processing arrangement 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 data processing arrangement may comprise custom and/or proprietary processors.
As used herein, the term “predetermined thresholds” refers to the predefined values or limits set for specific parameters in the system, against which measured or calculated data is compared to determine a condition, status, or operational state. The predetermined thresholds are established based on design criteria, empirical data, or regulatory requirements and serve as reference points for decision-making processes within the system.
As used herein, the term “insulation resistance status” refers to the condition of the insulation resistance in an electrical system, determined based on the measured electrical characteristics, such as voltage, current, or impedance, to assess the integrity of insulation between conductive components and ground or between different phases. The insulation resistance status indicates whether the insulation is in a normal, degraded, or faulty state, thereby enabling fault detection, predictive maintenance, and operational safety in electrical and electronic systems.
As used herein, the term “resistors” refers to an electrical component configured to oppose or limit the flow of electric current within a circuit, thereby regulating voltage levels, controlling current flow, or enabling signal conditioning. The resistor may be implemented as a discrete component or as an integrated element within a circuit and may be composed of various resistive materials, including but not limited to carbon, metal film, or wire-wound structures. The resistance value of the resistor may be fixed or variable, depending on the application, and may be defined in terms of its electrical resistance, tolerance, power rating, and temperature coefficient.
As used herein, the term “capacitors” refers to an electrical component configured to store and release electrical energy in the form of an electrostatic field between a pair of conductive plates separated by a dielectric material. The capacitor is designed to accumulate electric charge when subjected to a potential difference and discharge the stored energy as required by the circuit. The capacitance value, determined by the surface area of the plates, the separation distance, and the dielectric constant of the insulating material, governs the energy storage capability and reactive properties of the capacitor.
As used herein, the term “detection circuit” refers to an electrical circuit configured to monitor, identify, and analyze specific electrical parameters, such as voltage, current, impedance, or frequency, to detect anomalies, faults, or predefined conditions within a system. The detection circuit may include components such as resistors, capacitors, inductors, sensors, analog-to-digital converters, and processing units to facilitate signal measurement, processing, and response generation.
As used herein, the term “analog-to-digital converter” and “ADC” are used interchangeably and refer to an electronic circuit or device configured to convert an analog input signal into a corresponding digital output signal by sampling the analog signal at discrete time intervals and representing its amplitude as a digital value. The ADC typically comprises a sampling circuit, a quantizer, and an encoding unit, wherein the sampling circuit captures the analog signal, the quantizer assigns a discrete numerical value to the sampled signal, and the encoding unit generates a digital representation of the quantized signal.
As used herein, the term “alarm signal” refers to an electrical, visual, or audible notification generated by a system to indicate an abnormal condition, fault, or operational anomaly. The alarm signal may be triggered based on predefined thresholds, detected faults, or system diagnostics and can be used to alert users, activate protective measures, or initiate corrective actions within the system.
As used herein, the term “insulation abnormalities” refers to any deviation, degradation, or fault in the electrical insulation system of a component, circuit, or equipment that compromises its ability to effectively isolate conductive elements. Such abnormalities may include reduced insulation resistance, leakage currents, dielectric breakdown, moisture ingress, thermal degradation, mechanical damage, or contamination, which can lead to performance deterioration, electrical faults, or safety hazards. The insulation abnormalities specifically pertain to faults in the insulation of stator windings, cables, or associated components that may result in unintended current paths, phase-to-phase or phase-to-ground faults, and reduced operational reliability.
As used herein, the term “frequency domain analysis” refers to a method of signal processing in which a time-domain signal is transformed and analyzed in the frequency domain to identify its spectral components. The frequency domain analysis involves decomposing a signal into its constituent frequencies using mathematical transformations, such as the Fourier Transform (FT) or Fast Fourier Transform (FFT), to extract frequency-related characteristics.
As used herein, the term “motor drive operating conditions” and “operating conditions” are used interchangeably and refer to the set of electrical, mechanical, and environmental parameters that influence the performance, efficiency, and functionality of the motor drive during operation. The motor drive operating conditions include, but are not limited to, input voltage and current levels, output frequency and voltage, load torque, rotational speed, temperature, humidity, vibration, cooling efficiency, and duty cycle. Additionally, motor drive operating conditions may encompass dynamic factors such as transient loads, regenerative braking events, and variations in supply voltage or control inputs that affect the drive’s operation.
As used herein, the term “historical data” refers to previously recorded or stored data related to the operational parameters, performance characteristics, or status conditions of a system or component over a defined period. The historical data may be utilized for analysis, trend identification, predictive maintenance, fault diagnosis, or system optimization. The historical data may include past insulation resistance values, voltage characteristics, fault occurrences, or other relevant parameters that enable comparative assessment and proactive decision-making to enhance system reliability and performance.
As used herein, the term “trend analysis” refers to a method or process of systematically collecting, storing, and evaluating historical data over time to identify patterns, variations, or anomalies that indicate changes in a system's performance, condition, or behavior. In the case of an insulation detection system for a motor drive, trend analysis involves monitoring and analyzing insulation resistance values over time to detect gradual degradation, predict potential failures, and optimize maintenance schedules, thereby enhancing system reliability and preventing unexpected downtime.
Figure 1, in accordance with an embodiment describes an insulation detection system 100 for a motor drive. The system 100 comprises an impedance network 102 coupled to a three-phase motor drive 104, a voltage sampling circuit 106 configured to sample voltage signals from the impedance network 102 and a processing unit 108 coupled to the voltage sampling circuit 106. The processing unit 108 is configured to compare characteristics of an AC voltage signal sampled by the voltage sampling circuit 106 with predetermined thresholds of characteristics to determine insulation resistance status of one or more phases of the three-phase motor drive 104.
The present disclosure provides the insulation detection system 100 for the motor drive. The system 100 as disclosed by present disclosure is advantageous in terms of providing an enhanced safety, reliability, and the predictive maintenance in three-phase motor applications. Beneficially, by integrating the impedance network 102, the system 100 ensures the accurate detection of insulation degradation by continuously monitoring the voltage characteristics. Furthermore, the voltage sampling circuit 106 as disclosed by present disclosure is advantageously enables the precise acquisition of electrical signals, and the use of an analog-to-digital converter (ADC) ensures the high-resolution data conversion for effective digital processing. Beneficially, the processing unit 108 significantly allows for immediate detection of insulation faults based on predetermined voltage thresholds that adapt dynamically to motor drive operating conditions. Furthermore, the ability of the system 100 to generate alarm signals when insulation resistance values fall below safe limits, allows preventive action before a failure occurs. Additionally, the system 100 may be able to initiate an automatic motor drive shutdown when insulation failure is detected, thereby preventing the damage to critical components and reducing the risk of electrical hazards such as short circuits or leakage currents. Additionally, the incorporation of frequency domain analysis further enhances the detection capability by identifying subtle insulation degradation trends. Furthermore, by continuously recording the insulation resistance values over time, the system 100 allows for predictive maintenance strategies, helping operators to efficiently identify the gradual deterioration and schedule timely interventions, thereby minimizing unexpected downtime and extending the motor lifespan. Furthermore, the flexibility of adjusting voltage thresholds based on real-time motor drive conditions ensures adaptability across different load and environmental conditions, thereby improving the overall robustness of the insulation detection system 100.
In an embodiment, the impedance network 102 comprises a resistors and a capacitors configured to create a detection circuit connected to the three-phase motor drive 104. The detection circuit may be strategically integrated within the system 100 to allow the measurement of leakage currents or voltage variations resulting from insulation degradation. The presence of resistors in the impedance network 102 helps to establish a known reference path for voltage measurement, while capacitors provide a filtering mechanism, enhancing the accuracy of the sampled signals. Beneficially, the impedance network 102 enables the voltage sampling circuit 106 to capture the relevant electrical parameters, which are subsequently processed by the processing unit 108 for insulation fault analysis.
In an embodiment, the voltage sampling circuit 106 comprises an analog-to-digital converter 110 configured to convert the sampled voltage signals to digital signals for processing by the processing unit 108. The voltage sampling circuit 106 may be electrically coupled to the impedance network 102, which may be connected to the three-phase motor drive 104. During operation, the impedance network 102 interacts with the voltage characteristics of the motor drive phases, allows the voltage sampling circuit 106 to measure the corresponding AC voltage signals. The ADC 110 ensures the precise and accurate voltage signal conversion. The sampled analog voltage signals, which represent insulation resistance characteristics, are converted into digital format by the ADC 110 to facilitate further processing by the processing unit 108. The processing unit 108 then analyzes the digital signals by comparing characteristics with predetermined thresholds to determine the insulation resistance status of one or more phases of the three-phase motor drive 104. Beneficially, the system 100 ensures the high-resolution signal processing, enabling accurate detection of insulation abnormalities. Additionally, the inclusion of the ADC 110 allows for the real-time monitoring, reducing errors associated with analog noise and improving the reliability of insulation resistance measurement.
In an embodiment, the processing unit 108 is configured to generate an alarm signal when the one or more phases of the three-phase AC insulation resistance status is determined to be abnormal. The processing unit 108 may be programmed to analyze the sampled signals and compare the characteristics against predefined thresholds of insulation resistance. If the insulation resistance of one or more phases deviates beyond the acceptable threshold, indicating a potential insulation fault or degradation, the processing unit 108 triggers the alarm signal. The alarm signal serves as an early warning mechanism which allows an operators or an automated control system to take corrective actions before insulation failure leads to critical motor damage or electrical hazards. Beneficially, the triggering of the alarm signals enhances the reliability of the system 100 by providing the real-time fault alerts.
In an embodiment, the processing unit 108 is configured to calculate insulation resistance values for each phase of the three-phase motor drive 104 based on the sampled voltage signals. The processing unit 108 receives the digitized voltage data and applies computational algorithms to determine insulation resistance values for each phase. The calculation process involves analyzing the relationship between the measured voltage, leakage current, and the impedance characteristics of the detection circuit. Beneficially, the processing unit 108 ensures precise monitoring of phase-wise insulation health which enables the early fault detection, predictive maintenance, and improved motor drive reliability, particularly in applications where insulation integrity is critical for operational safety.
In an embodiment, the processing unit 108 is further configured to shut down the motor drive when the one or more phases of the three-phase AC insulation resistance are determined to be abnormal. The processing unit 108 compares the sampled voltage signals with predetermined insulation resistance thresholds stored in memory. If the insulation resistance of any phase falls below the defined threshold, indicating the potential insulation failure, the processing unit 108 triggers the shutdown operation to disconnect power from the motor drive. Beneficially, the preventive action of shutdown the motor drive significantly minimizes the risk of electrical faults, leakage currents, and potential damage to motor drive components.
In an embodiment, the processing unit 108 is configured to perform a frequency domain analysis on the sampled voltage signals to determine the insulation resistance status abnormalities. The voltage sampling circuit 106 captures the electrical signals influenced by insulation resistance variations and converts the electrical signals into the digital signals using the analog-to-digital converter 110. The processing unit 108 then processes the digital signals to extract frequency components through techniques such as Fast Fourier Transform (FFT) or Wavelet Transform. By analyzing the signal in the frequency domain, the system 100 may be able to identify the abnormal spectral signatures, which may indicate insulation degradation, leakage currents, or potential failure conditions. Beneficially, the approach to the frequency domain analysis allows for early detection of insulation deterioration, even when abnormalities are not easily identifiable in the time domain.
In an embodiment, the predetermined voltage threshold is adjusted based on motor drive operating conditions. For instance, during high-load operation, increased current flow and thermal effects may cause minor fluctuations in insulation resistance, which may be misinterpreted as the fault. To prevent false alarms, the system 100 adjusts the predetermined voltage threshold, allowing for tolerance variations within safe operating limits. Conversely, during low-load or idle conditions, the system 100 may apply stricter detection thresholds to identify early-stage insulation degradation that might be masked under normal operating conditions. Beneficially, the system 100 provides the more intelligent and context-aware approach to insulation detection, making the system 100 well-suited for applications where motor drives experience frequent load changes, environmental variations, or prolonged operational cycles.
In an embodiment, the processing unit 108 is configured to store historical data of the insulation resistance status values for trend analysis. The processing unit 108 may be designed to record insulation resistance values over time, creating a historical data log. The stored data enables the system 100 to analyze trends in insulation degradation by comparing present resistance values with past records. The trend analysis feature helps in detecting gradual insulation deterioration, identifying patterns that indicate early signs of insulation breakdown, and predicting potential failures before they become critical. Beneficially, the trend analysis functionality facilitates predictive maintenance, allowing operators to take proactive measures rather than relying solely on real-time fault detection.
In an embodiment, the insulation detection system 100 for the motor drive. The system 100 comprises the impedance network 102 coupled to the three-phase motor drive 104, the voltage sampling circuit 106 configured to sample voltage signals from the impedance network 102 and the processing unit 108 coupled to the voltage sampling circuit 106. The processing unit 108 is configured to compare characteristics of the AC voltage signal sampled by the voltage sampling circuit 106 with predetermined thresholds of characteristics to determine insulation resistance status of one or more phases of the three-phase motor drive 104. Furthermore, the impedance network 102 comprises the resistors and the capacitors configured to create the detection circuit connected to the three-phase motor drive 104. Furthermore, , the voltage sampling circuit 106 comprises the analog-to-digital converter 110 configured to convert the sampled voltage signals to digital signals for processing by the processing unit 108. Furthermore, the processing unit 108 is configured to generate the alarm signal when the one or more phases of the three-phase AC insulation resistance status is determined to be abnormal. Furthermore, the processing unit 108 is configured to calculate insulation resistance values for each phase of the three-phase motor drive 104 based on the sampled voltage signals. Furthermore, the processing unit 108 is further configured to shut down the motor drive when the one or more phases of the three-phase AC insulation resistance are determined to be abnormal. Furthermore, the processing unit 108 is configured to perform the frequency domain analysis on the sampled voltage signals to determine the insulation resistance status abnormalities. Furthermore, the predetermined voltage threshold is adjusted based on motor drive operating conditions. Furthermore, the processing unit 108 is configured to store historical data of the insulation resistance status values for trend analysis.
Figure 2, describes a method 200 for detecting insulation abnormalities in a motor drive. The method 200 starts at step 202 and completes at step 208. At step 202, the method 200 comprises coupling an impedance network 102 to a three-phase motor drive 104. At step 204, the method 200 comprises sampling, by a voltage sampling circuit 106, voltage signals from the impedance network 102. At step 206, the method 200 comprises processing, by a processing unit 108, the sampled voltage signals to determine characteristics of an AC voltage signal. At step 208, the method 200 comprises comparing, by the processing unit 108, characteristics of an AC voltage signal sampled by the voltage sampling circuit 106 with predetermined thresholds of characteristics to determine insulation resistance status of one or more phases of the three-phase motor drive 104.
It would be appreciated that all the explanations and embodiments of the insulation detection system 100 also applies mutatis-mutandis to the method 200.
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. An insulation detection system (100) for a motor drive, wherein the system (100) comprises:
- an impedance network (102) coupled to a three-phase motor drive (104);
- a voltage sampling circuit (106) configured to sample voltage signals from the impedance network (102); and
- a processing unit (108) coupled to the voltage sampling circuit (106),
wherein the processing unit (108) is configured to compare characteristics of an AC voltage signal sampled by the voltage sampling circuit (106) with predetermined thresholds of characteristics to determine insulation resistance status of one or more phases of the three-phase motor drive (104).
2. The insulation detection system (100) as claimed in claim 1, wherein the impedance network (102) comprises a resistors and a capacitors configured to create a detection circuit connected to the three-phase motor drive (104).
3. The insulation detection system (100) as claimed in claim 1, wherein the voltage sampling circuit (106) comprises an analog-to-digital converter (110) configured to convert the sampled voltage signals to digital signals for processing by the processing unit (108).
4. The insulation detection system (100) as claimed in claim 1, wherein the processing unit (108) is configured to generate an alarm signal when the one or more phases of the three-phase AC insulation resistance status is determined to be abnormal.
5. The insulation detection system (100) as claimed in claim 1, wherein the processing unit (108) is configured to calculate insulation resistance values for each phase of the three-phase motor drive (104) based on the sampled voltage signals.
6. The insulation detection system (100) as claimed in claim 1, wherein the processing unit (108) is further configured to shut down the motor drive when the one or more phases of the three-phase AC insulation resistance are determined to be abnormal.
7. The insulation detection system (100) as claimed in claim 1, wherein the processing unit (108) is configured to perform a frequency domain analysis on the sampled voltage signals to determine the insulation resistance status abnormalities.
8. The insulation detection system (100) as claimed in claim 1, wherein the predetermined voltage threshold is adjusted based on motor drive operating conditions.
9. The insulation detection system (100) as claimed in claim 1, wherein the processing unit (108) is configured to store historical data of the insulation resistance status values for trend analysis.
10. A method (200) for detecting insulation abnormalities in a motor drive, wherein the method (200) comprises:
- coupling an impedance network (102) to a three-phase motor drive (104);
- sampling, by a voltage sampling circuit (106), voltage signals from the impedance network (102);
- processing, by a processing unit (108), the sampled voltage signals to determine characteristics of an AC voltage signal; and
- comparing, by the processing unit (108), characteristics of an AC voltage signal sampled by the voltage sampling circuit (106) with predetermined thresholds of characteristics to determine insulation resistance status of one or more phases of the three-phase motor drive (104).