A calibration device and method for a polarization index of an insulation resistance of a rotating electric machine

Abstract

The application belongs to the technical field of power equipment state detection, and specifically discloses a calibration device and method for polarization index of insulation resistance of a rotating electric machine, which comprises a direct-current voltage source, a first standard resistor, an absorption characteristic simulation module, a voltmeter, an ammeter and a controller. The first end of the ammeter and the negative pole of the direct-current voltage source constitute two ends of the calibration device. The positive pole of the direct-current voltage source is electrically connected with the first end of the first standard resistor and the first end of the absorption characteristic simulation module. The negative pole of the direct-current voltage source is electrically connected with the first end of the voltmeter. The second end of the voltmeter is electrically connected with the second end of the ammeter, the second end of the first standard resistor and the second end of the absorption characteristic simulation module. The controller is used to acquire a standard PI value based on a voltage measurement value and a current measurement value, judge a PI value error of an insulation resistance tester and generate a calibration result. Through the application, the polarization index measurement function of the insulation resistance tester can be calibrated.

Description

Technical Field

[0001] This application belongs to the field of power equipment condition monitoring technology, and more specifically, relates to a calibration device and method for the polarization index of insulation resistance of a rotating electric machine. Background Technology

[0002] In the insulation condition assessment of rotating electrical machines (such as generators and motors), the polarization index (PI) is a key indicator, defined as the insulation resistance value of the motor when a DC voltage is continuously applied for 10 minutes (t2). Insulation resistance value after 1 minute of pressurization (t1) The ratio ( Currently, insulation resistance testers with polarization index measurement function are commonly used on-site for direct measurement. and The polarization index is calculated accordingly. This method assumes that the resistance measurement value output by the tester is accurate and reliable. However, in practical applications, the high-voltage source and sampling circuit inside the insulation resistance tester will change with the duration of use, ambient temperature and humidity, etc., leading to... and Errors in the measured values ​​can lead to deviations in the calculation of the polarization index, affecting the accurate assessment of the motor's insulation condition. Therefore, how to implement the polarization index measurement function in the calibration of insulation resistance testers is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the purpose of this application is to realize the polarization index measurement function of the calibration insulation resistance tester.

[0004] To achieve the above objectives, in a first aspect, this application provides a calibration device for the polarization index of the insulation resistance of a rotating electric machine, comprising:

[0005] DC voltage source, first standard resistor, absorption characteristic simulation module, voltmeter, ammeter and controller;

[0006] The first terminal of the ammeter and the negative terminal of the DC voltage source constitute the two ends of the calibration device. During the calibration process, the two ends of the calibration device are electrically connected to the corresponding ports of the insulation resistance tester.

[0007] The positive terminal of the DC voltage source is electrically connected to the first terminal of the first standard resistor and the first terminal of the absorption characteristic simulation module; the negative terminal of the DC voltage source is electrically connected to the first terminal of the voltmeter; the second terminal of the voltmeter is electrically connected to the second terminal of the ammeter, the second terminal of the first standard resistor, and the second terminal of the absorption characteristic simulation module.

[0008] Absorption characteristic simulation module, used to simulate the absorption characteristics of the insulating medium of rotating electrical machines;

[0009] The controller is used to obtain a standard PI value based on the voltage measurement value provided by the voltmeter and the current measurement value provided by the ammeter during the calibration process; based on the standard PI value and the measured PI value provided by the insulation resistance tester, it determines whether the PI value error of the insulation resistance tester exceeds the error threshold, and if so, generates a calibration result.

[0010] In one possible implementation, the absorption characteristic simulation module is constructed by connecting a second standard resistor and a standard capacitor in series.

[0011] In one possible implementation, a standard PI value is obtained during the calibration process based on the voltage measurement provided by the voltmeter and the current measurement provided by the ammeter, including determining the standard PI value using the following formula:

[0012] ;

[0013] ;

[0014] ;

[0015] in, This indicates the time 1 minute after the start time during the calibration process. This indicates the time 10 minutes after the start time during the calibration process. The start time is the moment when the insulation resistance tester begins to apply a DC test voltage to the two ends of the calibration device. In order to be in The voltage measurement value provided by the voltmeter at that moment. In order to be in The voltage measurement value provided by the voltmeter at that moment. In order to be in The current measurement value provided by the ammeter at that moment. In order to be in The current measurement value provided by the ammeter at that moment. This indicates the internal resistance of the ammeter. Indicates in The insulation resistance value simulated by the calibration device at that time. Indicates in The insulation resistance value simulated by the calibration device at that time. This indicates the standard PI value simulated by the calibration device.

[0016] In one possible implementation, the controller is also used for:

[0017] Obtain the target PI value and its corresponding At what time is the target value of insulation resistance and The target value of insulation resistance at that time. , Indicates the target PI value. express corresponding The target value of insulation resistance at that time. express corresponding Target value of insulation resistance at a given time;

[0018] By adjusting the output voltage of the DC voltage source, control At this moment and The difference between them is less than the first resistance difference threshold, and control At this moment and The difference between them is less than the second resistance difference threshold, so that and The difference between them is less than the PI difference threshold;

[0019] in, This indicates the time 1 minute after the start time during the calibration process. This indicates the time 10 minutes after the start time during the calibration process. The start time is the moment when the insulation resistance tester begins to apply a DC test voltage to the two ends of the calibration device. Indicates in The insulation resistance value simulated by the calibration device at that time. Indicates in The insulation resistance value simulated by the calibration device at that time. This indicates the standard PI value simulated by the calibration device.

[0020] In one possible implementation, the calibration results include: the DC test voltage provided by the insulation resistance tester, the measured PI value, and the PI value error.

[0021] In one possible implementation, the calibration results also include a PI error curve, which is obtained through the following steps:

[0022] For a given DC test voltage, based on the set of measured PI values ​​and the PI value error corresponding to each measured PI value in the set of measured PI values, a PI error curve is obtained through curve fitting.

[0023] Among them, the PI error curve is used to characterize the mapping relationship between the measured PI value and the PI value error when the insulation resistance tester provides a specified DC test voltage;

[0024] The set of measured PI values ​​and the corresponding PI error of each measured PI value in the set of measured PI values ​​are obtained by simulating multiple different standard PI values ​​through the calibration device during the calibration process and recording the measured PI values ​​and the corresponding PI error.

[0025] In one possible implementation, the calibration results also include Insulation resistance measurement error curve at any time and Error curve of insulation resistance measurement at any time. Insulation resistance measurement error curve at any time and The error curve of insulation resistance measurement at any given time is obtained through the following steps:

[0026] For a specified DC test voltage, based on Set of measured insulation resistance values ​​at any given time The insulation resistance measurement error corresponding to each measured insulation resistance value in the set of measured insulation resistance values ​​at any given time is obtained through curve fitting. Error curve of insulation resistance measurement at any time;

[0027] For a specified DC test voltage, based on Set of measured insulation resistance values ​​at any given time The insulation resistance measurement error corresponding to each measured insulation resistance value in the set of measured insulation resistance values ​​at any given time is obtained through curve fitting. Error curve of insulation resistance measurement at any time;

[0028] in, The time-varying insulation resistance measurement error curve is used to characterize the insulation resistance tester when a specified DC test voltage is provided. The mapping relationship between the measurement error and the insulation resistance;

[0029] The time-varying insulation resistance measurement error curve is used to characterize the insulation resistance tester when a specified DC test voltage is provided. The mapping relationship between the measurement error and the insulation resistance;

[0030] Set of measured insulation resistance values ​​at any given time The insulation resistance measurement error corresponding to each measured insulation resistance value in the set of measured insulation resistance values ​​at any given time is simulated by a calibration device to obtain multiple different values. and record This is obtained from the corresponding insulation resistance measurement error;

[0031] Set of measured insulation resistance values ​​at any given time The insulation resistance measurement error corresponding to each measured insulation resistance value in the set of measured insulation resistance values ​​at any given time is simulated by a calibration device to obtain multiple different values. and record This is obtained from the corresponding insulation resistance measurement error;

[0032] This indicates the time 1 minute after the start time during the calibration process. This indicates the time 10 minutes after the start time during the calibration process. The start time is the moment when the insulation resistance tester begins to apply a DC test voltage to the two ends of the calibration device. Indicates in The insulation resistance value simulated by the calibration device at that time. Indicates in The insulation resistance value simulated by the calibration device at that time. Indicates in The measured insulation resistance value provided by the insulation resistance tester at that time. Indicates in The measured value of insulation resistance provided by the insulation resistance tester at that time.

[0033] Secondly, this application provides a calibration method for the polarization index of the insulation resistance of a rotating electrical machine, applied to the calibration apparatus for the polarization index of the insulation resistance of a rotating electrical machine described in the first aspect or any possible implementation thereof, comprising:

[0034] During the calibration process, a standard PI value is obtained based on the voltage measurement value provided by the voltmeter and the current measurement value provided by the ammeter.

[0035] Based on the standard PI value and the measured PI value provided by the insulation resistance tester, determine whether the PI value error of the insulation resistance tester exceeds the error threshold. If so, generate a calibration result.

[0036] In one possible implementation, a standard PI value is obtained during the calibration process based on the voltage measurement provided by the voltmeter and the current measurement provided by the ammeter, including determining the standard PI value using the following formula:

[0037] ;

[0038] ;

[0039] ;

[0040] in, This indicates the time 1 minute after the start time during the calibration process. This indicates the time 10 minutes after the start time during the calibration process. The start time is the moment when the insulation resistance tester begins to apply a DC test voltage to the two ends of the calibration device. In order to be in The voltage measurement value provided by the voltmeter at that moment. In order to be in The voltage measurement value provided by the voltmeter at that moment. In order to be in The current measurement value provided by the ammeter at that moment. In order to be in The current measurement value provided by the ammeter at that moment. This indicates the internal resistance of the ammeter. Indicates in The insulation resistance value simulated by the calibration device at that time. Indicates in The insulation resistance value simulated by the calibration device at that time. This indicates the standard PI value simulated by the calibration device.

[0041] One possible implementation also includes:

[0042] Obtain the target PI value and its corresponding At what time is the target value of insulation resistance and The target value of insulation resistance at that time. , Indicates the target PI value. express corresponding The target value of insulation resistance at that time. express corresponding Target value of insulation resistance at a given time;

[0043] By adjusting the output voltage of the DC voltage source, control At this moment and The difference between them is less than the first resistance difference threshold, and control At this moment and The difference between them is less than the second resistance difference threshold, so that and The difference between them is less than the PI difference threshold;

[0044] in, This indicates the time 1 minute after the start time during the calibration process. This indicates the time 10 minutes after the start time during the calibration process. The start time is the moment when the insulation resistance tester begins to apply a DC test voltage to the two ends of the calibration device. Indicates in The insulation resistance value simulated by the calibration device at that time. Indicates in The insulation resistance value simulated by the calibration device at that time. This indicates the standard PI value simulated by the calibration device.

[0045] Overall, the technical solutions conceived in this application have the following beneficial effects compared with the prior art:

[0046] The calibration device provided in this application constructs an equivalent circuit capable of simulating the absorption characteristics of the insulating medium of a rotating electrical machine through a combination of a DC voltage source, a first standard resistor, and an absorption characteristic simulation module. During calibration, the two ends of the calibration device are electrically connected to the corresponding ports of the insulation resistance tester. A voltmeter and an ammeter measure the voltage and current in the circuit in real time and provide the measured values ​​to the controller. Based on these measurement data, the controller calculates a standard PI value reflecting the polarization characteristics of the insulating medium. Simultaneously, the controller acquires the measured PI value provided by the insulation resistance tester under the same test conditions. By comparing the standard PI value with the measured PI value, it determines whether the PI value error exceeds a preset error threshold. If it does, the controller further generates a calibration result containing deviation analysis and correction information based on the measurement data collected by the calibration device and the measurement data provided by the insulation resistance tester, thereby achieving the calibration of the polarization index measurement function of the insulation resistance tester. Attached Figure Description

[0047] Figure 1 This is a schematic diagram illustrating the calibration of an insulation resistance tester using a calibration device, as provided in an embodiment of this application.

[0048] Figure 2 This is a schematic flowchart of the calibration method for the polarization index of the insulation resistance of a rotating electric motor provided in the embodiments of this application. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0050] In this application, the terms "first" and "second," etc., are used to distinguish different objects, not to describe a specific order of objects. For example, "first standard resistor" and "second standard resistor," etc., are used to distinguish different standard resistors, not to describe a specific order of standard resistors.

[0051] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0052] In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more, for example, multiple processing units means two or more processing units, multiple elements means two or more elements, etc.

[0053] The embodiments of this application are described below with reference to the accompanying drawings.

[0054] Figure 1 This is a schematic diagram illustrating the calibration of an insulation resistance tester using a calibration device, as provided in an embodiment of this application. Figure 1 As shown, the calibration device includes:

[0055] DC voltage source, first standard resistor, absorption characteristic simulation module, voltmeter, ammeter and controller.

[0056] like Figure 1 As shown, This indicates a DC voltage source, for example, a DC voltage source can output a voltage range of 0 to 1000V; and These represent the first and second terminals of the ammeter, respectively. and These represent the first and second terminals of the voltmeter, respectively. and These represent the first and second ends of the absorption characteristic simulation module, respectively. Indicates the first standard resistance, for example , and These represent the first and second terminals of the first standard resistor, respectively.

[0057] like Figure 1 As shown, the first terminal of the ammeter and the negative terminal of the DC voltage source constitute the two ends of the calibration device. During the calibration process, the two ends of the calibration device are electrically connected to the corresponding ports of the insulation resistance tester. This indicates the built-in voltage source of the insulation resistance tester, used to provide DC test voltage, such as 2500V DC or 5000V DC. This indicates the built-in resistance of the insulation resistance tester.

[0058] like Figure 1As shown, the positive terminal of the DC voltage source is electrically connected to the first terminal of the first standard resistor and the first terminal of the absorption characteristic simulation module; the negative terminal of the DC voltage source is electrically connected to the first terminal of the voltmeter; and the second terminal of the voltmeter is electrically connected to the second terminal of the ammeter, the second terminal of the first standard resistor, and the second terminal of the absorption characteristic simulation module.

[0059] The absorption characteristic simulation module is used to simulate the absorption characteristics of the insulating medium of rotating electrical machines.

[0060] The absorption characteristics of the insulating medium of a rotating electrical machine refer to the dynamic process by which the internal charge of the insulating material redistributes and establishes a stable electric field under the action of a DC voltage. This characteristic is typically manifested as follows: after applying a DC voltage, the current in the insulating medium gradually decreases over time, eventually reaching a stable leakage current value. This process mainly stems from the delayed response of the polarization effects within the insulating medium, including electronic polarization, ionic polarization, dipole reversal polarization, and interfacial polarization. The absorption characteristics can be quantitatively evaluated using a polarization index (such as the ratio of insulation resistance over 10 minutes to that over 1 minute).

[0061] The controller is used to obtain a standard PI (polarization index) value based on the voltage measurement value provided by the voltmeter and the current measurement value provided by the ammeter during the calibration process; based on the standard PI value and the measured PI value provided by the insulation resistance tester, it determines whether the PI value error of the insulation resistance tester exceeds the error threshold, and if so, generates a calibration result.

[0062] It is understood that the calibration device provided in this application constructs an equivalent circuit capable of simulating the absorption characteristics of the insulating medium of a rotating electrical machine (such as a generator or motor) through a combination of a DC voltage source, a first standard resistor, and an absorption characteristic simulation module. During calibration, the two ends of the calibration device are electrically connected to the corresponding ports of the insulation resistance tester. A voltmeter and an ammeter measure the voltage and current in the circuit in real time and provide the measured values ​​to the controller. Based on these measurement data, the controller calculates a standard PI value reflecting the polarization characteristics of the insulating medium. Simultaneously, the controller acquires the measured PI value provided by the insulation resistance tester under the same test conditions. By comparing the standard PI value with the measured PI value, it determines whether the PI value error exceeds a preset error threshold. If it does, the controller further generates a calibration result containing deviation analysis and correction information based on the measurement data collected by the calibration device and the measurement data provided by the insulation resistance tester, thereby achieving the calibration of the polarization index measurement function of the insulation resistance tester.

[0063] Furthermore, adjusting the output voltage of the DC voltage source changes the voltage across the absorption characteristic simulation module, which in turn alters the current flowing through the module, thus changing the current through the insulation resistance tester. This, in turn, changes the insulation resistance value simulated by the calibration device, and consequently, the standard PI value simulated by the calibration device. Based on the mapping relationship between the output voltage of the DC voltage source and the simulated standard PI value, controlling the output voltage of the DC voltage source allows the standard PI value to be controlled to a specified value, thereby achieving continuous adjustment of the standard PI value.

[0064] For example, the DC voltage source can specifically be a DC voltage source with adjustable output voltage (hereinafter referred to as an adjustable DC voltage source). The DC voltage source is controlled by a controller, which can adjust the output voltage of the DC voltage source to a specified voltage.

[0065] For example, the PI value error can be determined based on the difference between the standard PI value and the measured PI value. For instance, the difference can be calculated by calculating the standard PI value (denoted as PI). ) and measured PI value (denoted as The absolute value of the difference between the two is then divided by the absolute value. , recorded as .

[0066] For example, the above-mentioned determination of whether the PI value error of the insulation resistance tester exceeds the error threshold can be a comparison The value between the PI value and the error threshold is determined. If the PI value is greater than the error threshold, then it can be determined that the PI value of the insulation resistance tester exceeds the error threshold.

[0067] The calibration device provided in this application is applicable to various insulation resistance testers with polarization index measurement functions. For example, an insulation resistance tester with polarization index measurement function can specifically be a water-cooled generator insulation resistance tester, which is an instrument specifically designed for measuring the insulation resistance of water-cooled generators.

[0068] In one possible implementation, the above-mentioned absorption characteristic simulation module is constructed by connecting a second standard resistor and a standard capacitor in series.

[0069] like Figure 1 As shown, Indicates the second standard resistor. This represents a standard capacitor, connected in series. and This can form a module for simulating absorption characteristics. For example, .For example, .

[0070] In one possible implementation, the standard PI value is obtained during the calibration process based on the voltage measurement value provided by the voltmeter and the current measurement value provided by the ammeter, including determining the standard PI value using the following formula:

[0071] ;

[0072] ;

[0073] ;

[0074] in, This indicates the time 1 minute after the start time during the calibration process. This indicates the time 10 minutes after the start time during the calibration process. The start time is when the insulation resistance tester begins to apply a DC test voltage (e.g., ...) to the two ends of the calibration device. Figure 1 As shown, the insulation resistance tester uses its built-in voltage source. When providing DC test voltage, In order to be in The voltage measurement value provided by the voltmeter at that moment. In order to be in The voltage measurement value provided by the voltmeter at that moment. In order to be in The current measurement value provided by the ammeter at that moment. In order to be in The current measurement value provided by the ammeter at that moment. This indicates the internal resistance of the ammeter. Indicates in The insulation resistance value simulated by the calibration device at that time. Indicates in The insulation resistance value simulated by the calibration device at that time. This indicates the standard PI value simulated by the calibration device.

[0075] For example, regarding the internal resistance of the ammeter You can determine the relationship between the current measurement range and the internal resistance by referring to a table (which reflects the relationship between the current measurement range and the internal resistance). (Table showing the correspondence between them), obtain the internal resistance of the ammeter. .

[0076] Understandably, the internal resistance of the ammeter This will affect the insulation resistance value simulated by the calibration device. The formula for determining the standard PI value mentioned above covers the internal resistance of the ammeter. This ensures that the standard PI value can be calculated accurately.

[0077] In one possible implementation, the controller described above is also used for:

[0078] Obtain the target PI value and its corresponding At what time is the target value of insulation resistance and The target value of insulation resistance at that time. , Indicates the target PI value. express corresponding The target value of insulation resistance at that time. express corresponding Target value of insulation resistance at a given time;

[0079] By adjusting the output voltage of the DC voltage source, control At this moment and The difference between them is less than the first resistance difference threshold, and control At this moment and The difference between them is less than the second resistance difference threshold, so that and The difference between them is less than the PI difference threshold (achieving that the control standard PI value approaches the target PI value).

[0080] in, This indicates the time 1 minute after the start time during the calibration process. This indicates the time 10 minutes after the start time during the calibration process. The start time is the moment when the insulation resistance tester begins to apply a DC test voltage to the two ends of the calibration device. Indicates in The insulation resistance value simulated by the calibration device at that time. Indicates in The insulation resistance value simulated by the calibration device at that time. This indicates the standard PI value simulated by the calibration device.

[0081] Specifically, define For the start time and The time between moments (e.g.) (The time interval is 30 seconds from the start time), which can be obtained from Starting at a certain moment, the output voltage of the DC voltage source is adjusted according to a variable step size, so as to achieve... Before the time, compare the insulation resistance value simulated by the calibration device with... Once the difference between the two resistances is reduced to less than the first resistance difference threshold, the output voltage of the DC voltage source is stopped from being adjusted after confirming that the difference is less than the first resistance difference threshold, ensuring... At this moment and The difference between them is less than the first resistance difference threshold.

[0082] definition for Time and The time between (e.g.) (The time interval of 9 minutes and 30 seconds from the start time) can be obtained from Starting at a certain moment, the output voltage of the DC voltage source is adjusted according to a variable step size, so as to achieve... Before the time, compare the insulation resistance value simulated by the calibration device with... Once the difference between the two resistances is reduced to less than the second resistance difference threshold, the output voltage of the DC voltage source is stopped from being adjusted after confirming that the difference is less than the second resistance difference threshold, ensuring... At this moment and The difference between them is less than the second resistance difference threshold.

[0083] Therefore, during the calibration process, the output voltage of the DC voltage source is adjusted to make... and The difference between them is less than the PI difference threshold, ensuring that the standard PI value tends to ( Close to the target PI value ( This enables precise control of the standard PI value simulated by the calibration device, and allows for continuous adjustment of the standard PI value.

[0084] In one possible implementation, the calibration results include: the DC test voltage provided by the insulation resistance tester, the measured PI value, and the PI value error.

[0085] Specifically, the DC test voltage and the measured PI value are measurement data provided by the insulation resistance tester. The PI value error (determined based on the difference between the standard PI value and the measured PI value) is measurement data collected by the calibration device.

[0086] When measuring with an insulation resistance tester, the appropriate compensation amount can be determined based on the PI value error corresponding to the measured PI value. The measured PI value and the compensation amount are then superimposed to form the compensated PI value, thereby realizing the polarization index measurement function of the insulation resistance tester.

[0087] Understandably, insulation resistance testers provide a DC test voltage during the testing process. For two different DC test voltages (e.g.) and Due to factors such as the nonlinearity of the insulating material, the DC test voltage is... The measured PI value under the condition and the DC test voltage are The measured PI values ​​differ under various conditions. Therefore, by recording the DC test voltage provided by the insulation resistance tester in the calibration results, the DC test voltage to which the measured PI value and PI value error correspond in the calibration results can be clearly identified, thus improving the accuracy of the calibration results.

[0088] In one possible implementation, the calibration results also include a PI error curve, which is obtained through the following steps:

[0089] For a given DC test voltage, based on the set of measured PI values ​​and the PI value error corresponding to each measured PI value in the set of measured PI values, a PI error curve is obtained through curve fitting.

[0090] Among them, the PI error curve is used to characterize the mapping relationship between the measured PI value and the PI value error when the insulation resistance tester provides a specified DC test voltage;

[0091] The set of measured PI values ​​and the corresponding PI value errors for each measured PI value in the set of measured PI values ​​are obtained by simulating multiple different standard PI values ​​through the calibration device during the calibration process, and recording the measured PI values ​​(adding the recorded measured PI values ​​to the set of measured PI values) and the corresponding PI value errors.

[0092] Understandably, when measuring with an insulation resistance tester, the PI value error can be efficiently determined based on the measured PI value and the PI error curve, thereby determining the appropriate compensation amount. The measured PI value and the compensation amount are then superimposed to form the compensated PI value, thus achieving efficient calibration of the polarization index measurement function of the insulation resistance tester.

[0093] In one possible implementation, the calibration results also include Insulation resistance measurement error curve at any time and Error curve of insulation resistance measurement at any time. Insulation resistance measurement error curve at any time and The error curve of insulation resistance measurement at any given time is obtained through the following steps:

[0094] For a specified DC test voltage, based on Set of measured insulation resistance values ​​at any given time The insulation resistance measurement error corresponding to each measured insulation resistance value in the set of measured insulation resistance values ​​at any given time is obtained through curve fitting. Error curve of insulation resistance measurement at any time;

[0095] For a specified DC test voltage, based on Set of measured insulation resistance values ​​at any given time The insulation resistance measurement error corresponding to each measured insulation resistance value in the set of measured insulation resistance values ​​at any given time is obtained through curve fitting. Error curve of insulation resistance measurement at any time;

[0096] in, The time-varying insulation resistance measurement error curve is used to characterize the insulation resistance tester when a specified DC test voltage is provided. The mapping relationship between the measurement error and the insulation resistance;

[0097] The time-varying insulation resistance measurement error curve is used to characterize the insulation resistance tester when a specified DC test voltage is provided. The mapping relationship between the measurement error and the insulation resistance;

[0098] Set of measured insulation resistance values ​​at any given time The insulation resistance measurement error corresponding to each measured insulation resistance value (provided by the insulation resistance tester) in the set of measured insulation resistance values ​​at any given time is simulated by a calibration device to obtain multiple different values. and record and the corresponding insulation resistance measurement error (based on) and The difference between them (which determines the error) was obtained;

[0099] Set of measured insulation resistance values ​​at any given time The insulation resistance measurement error corresponding to each measured insulation resistance value in the set of measured insulation resistance values ​​at any given time is simulated by a calibration device to obtain multiple different values. and record and the corresponding insulation resistance measurement error (based on) and The difference between them (which determines the error) was obtained;

[0100] This indicates the time 1 minute after the start time during the calibration process. This indicates the time 10 minutes after the start time during the calibration process. The start time is the moment when the insulation resistance tester begins to apply a DC test voltage to the two ends of the calibration device. Indicates in The insulation resistance value simulated by the calibration device at that time. Indicates in The insulation resistance value simulated by the calibration device at that time. Indicates in The measured insulation resistance value provided by the insulation resistance tester at that time. Indicates in The measured value of insulation resistance provided by the insulation resistance tester at that time.

[0101] Understandably, when performing measurements with an insulation resistance tester, it is possible to base the measurement on... and The error curve of insulation resistance measurement at any time can be efficiently determined. The measurement error of insulation resistance at any given time can then be used to determine the appropriate... real-time compensation amount, Combined with the compensation amount, it forms The insulation resistance value after compensation at this time ;based on and The error curve of insulation resistance measurement at any time can be efficiently determined. The measurement error of insulation resistance at any given time can then be used to determine the appropriate... real-time compensation amount, Combined with the compensation amount, it forms The insulation resistance value after compensation at this time Through calculation This allows for the efficient calibration of the polarization index measurement function of the insulation resistance tester, resulting in a compensated PI value.

[0102] It is worth noting that for those with a specified standard PI value ( A rotating motor, assuming the rotating motor is in The actual insulation resistance value at that time is ,exist The actual insulation resistance value at that time is Even if the calibration device can simulate the same However, the calibration device is in moment or The simulated insulation resistance value at time ( , ) and the rotating motor at the corresponding time ( time, The actual insulation resistance value at time ( ) , There may be differences between them.

[0103] For example, in ,and In this case, This represents the proportional coefficient, although the actual PI value of the rotating motor ( ) and the standard PI value simulated by the calibration device ( (Keep the same, but the calibration device is in) moment or The simulated insulation resistance value at time ( , The actual insulation resistance value of the rotating electric motor at the corresponding moment () , There may be differences between them.

[0104] If the measured insulation resistance value and the insulation resistance measurement error are non-linear, then there will be a certain deviation between the PI error curve obtained by the calibration device and the actual PI error curve of the insulation resistance tester during the measurement of the rotating motor. This may result in poor calibration accuracy when using the above-mentioned PI error curve to compensate for the measured PI value.

[0105] In comparison, adopting Insulation resistance measurement error curve at any time and The insulation resistance measurement error curve at different times was determined. Time-based compensation and The amount of compensation at any time is then obtained. and , can ensure Equal to (or approaching) ,and Equal to (or approaching) This ensures that the compensated PI value is equal to (or close to) the actual PI value of the rotating motor, thus guaranteeing calibration accuracy.

[0106] This application also provides a calibration method for the polarization index of the insulation resistance of a rotating electric machine, applicable to any of the aforementioned calibration devices for the polarization index of the insulation resistance of a rotating electric machine. Figure 2 This is a schematic flowchart of the calibration method for the polarization index of the insulation resistance of a rotating electric motor provided in this application embodiment, as shown below. Figure 2 As shown, the method includes steps S101 and S102. The entity executing the method may be a controller in the calibration device.

[0107] Step S101: During the calibration process, a standard PI value is obtained based on the voltage measurement value provided by the voltmeter and the current measurement value provided by the ammeter.

[0108] Step S102: Based on the standard PI value and the measured PI value provided by the insulation resistance tester, determine whether the PI value error of the insulation resistance tester exceeds the error threshold. If so, generate a calibration result.

[0109] The calibration method provided in this application can be used to calibrate the polarization index measurement function of an insulation resistance tester.

[0110] It is understood that the various numerical designations used in the embodiments of this application are merely for the convenience of description and are not intended to limit the scope of the embodiments of this application.

[0111] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A calibration device for the polarization index of insulation resistance of a rotating electric motor, characterized in that, include: DC voltage source, first standard resistor, absorption characteristic simulation module, voltmeter, ammeter and controller; The first terminal of the ammeter and the negative terminal of the DC voltage source constitute the two ends of the calibration device. During the calibration process, the two ends of the calibration device are electrically connected to the corresponding ports of the insulation resistance tester. The positive terminal of the DC voltage source is electrically connected to the first terminal of the first standard resistor and the first terminal of the absorption characteristic simulation module; the negative terminal of the DC voltage source is electrically connected to the first terminal of the voltmeter; the second terminal of the voltmeter is electrically connected to the second terminal of the ammeter, the second terminal of the first standard resistor, and the second terminal of the absorption characteristic simulation module. Absorption characteristic simulation module, used to simulate the absorption characteristics of the insulating medium of rotating electrical machines; The controller is used to obtain a standard PI value based on the voltage measurement value provided by the voltmeter and the current measurement value provided by the ammeter during the calibration process; based on the standard PI value and the measured PI value provided by the insulation resistance tester, it determines whether the PI value error of the insulation resistance tester exceeds the error threshold, and if so, generates a calibration result. The controller is also used for: Obtain the target PI value and its corresponding At what time is the target value of insulation resistance and The target value of insulation resistance at that time. , Indicates the target PI value. express corresponding The target value of insulation resistance at that time. express corresponding Target value of insulation resistance at a given time; By adjusting the output voltage of the DC voltage source, control At this moment and The difference between them is less than the first resistance difference threshold, and control At this moment and The difference between them is less than the second resistance difference threshold, so that and The difference between them is less than the PI difference threshold; in, This indicates the time 1 minute after the start time during the calibration process. This indicates the time 10 minutes after the start time during the calibration process. The start time is the moment when the insulation resistance tester begins to apply a DC test voltage to the two ends of the calibration device. Indicates in The insulation resistance value simulated by the calibration device at that time. Indicates in The insulation resistance value simulated by the calibration device at that time. This indicates the standard PI value simulated by the calibration device.

2. The calibration device for the polarization index of the insulation resistance of a rotating electric motor according to claim 1, characterized in that, The absorption characteristic simulation module is constructed by connecting a second standard resistor and a standard capacitor in series.

3. The calibration device for the polarization index of the insulation resistance of a rotating electric motor according to claim 1, characterized in that, During the calibration process, a standard PI value is obtained based on the voltage measurement value provided by the voltmeter and the current measurement value provided by the ammeter, including determining the standard PI value using the following formula: ； ； ； in, This indicates the time 1 minute after the start time during the calibration process. This indicates the time 10 minutes after the start time during the calibration process. The start time is the moment when the insulation resistance tester begins to apply a DC test voltage to the two ends of the calibration device. In order to be in The voltage measurement value provided by the voltmeter at that moment. In order to be in The voltage measurement value provided by the voltmeter at that moment. In order to be in The current measurement value provided by the ammeter at that moment. In order to be in The current measurement value provided by the ammeter at that moment. This indicates the internal resistance of the ammeter. Indicates in The insulation resistance value simulated by the calibration device at that time. Indicates in The insulation resistance value simulated by the calibration device at that time. This indicates the standard PI value simulated by the calibration device.

4. The calibration device for the polarization index of the insulation resistance of a rotating electric motor according to claim 1, characterized in that, The calibration results include: the DC test voltage provided by the insulation resistance tester, the measured PI value, and the PI value error.

5. The calibration device for the polarization index of the insulation resistance of a rotating electric motor according to claim 4, characterized in that, The calibration results also include a PI error curve, which is obtained through the following steps: For a given DC test voltage, based on the set of measured PI values ​​and the PI value error corresponding to each measured PI value in the set of measured PI values, a PI error curve is obtained through curve fitting. Among them, the PI error curve is used to characterize the mapping relationship between the measured PI value and the PI value error when the insulation resistance tester provides a specified DC test voltage; The set of measured PI values ​​and the corresponding PI error of each measured PI value in the set of measured PI values ​​are obtained by simulating multiple different standard PI values ​​through the calibration device during the calibration process and recording the measured PI values ​​and the corresponding PI error.

6. The calibration device for the polarization index of the insulation resistance of a rotating electric motor according to claim 4, characterized in that, The calibration results also include Insulation resistance measurement error curve at any time and Error curve of insulation resistance measurement at any time. Insulation resistance measurement error curve at any time and The error curve of insulation resistance measurement at any given time is obtained through the following steps: For a specified DC test voltage, based on Set of measured insulation resistance values ​​at any given time The insulation resistance measurement error corresponding to each measured insulation resistance value in the set of measured insulation resistance values ​​at any given time is obtained through curve fitting. Error curve of insulation resistance measurement at any time; For a specified DC test voltage, based on Set of measured insulation resistance values ​​at any given time The insulation resistance measurement error corresponding to each measured insulation resistance value in the set of measured insulation resistance values ​​at any given time is obtained through curve fitting. Error curve of insulation resistance measurement at any time; in, The time-varying insulation resistance measurement error curve is used to characterize the insulation resistance tester when a specified DC test voltage is provided. The mapping relationship between the measurement error and the insulation resistance; The time-varying insulation resistance measurement error curve is used to characterize the insulation resistance tester when a specified DC test voltage is provided. The mapping relationship between the measurement error and the insulation resistance; Set of measured insulation resistance values ​​at any given time The insulation resistance measurement error corresponding to each measured insulation resistance value in the set of measured insulation resistance values ​​at any given time is simulated by a calibration device to obtain multiple different values. and record This is obtained from the corresponding insulation resistance measurement error; Set of measured insulation resistance values ​​at any given time The insulation resistance measurement error corresponding to each measured insulation resistance value in the set of measured insulation resistance values ​​at any given time is simulated by a calibration device to obtain multiple different values. and record This is obtained from the corresponding insulation resistance measurement error; This indicates the time 1 minute after the start time during the calibration process. This indicates the time 10 minutes after the start time during the calibration process. The start time is the moment when the insulation resistance tester begins to apply a DC test voltage to the two ends of the calibration device. Indicates in The insulation resistance value simulated by the calibration device at that time. Indicates in The insulation resistance value simulated by the calibration device at that time. Indicates in The measured insulation resistance value provided by the insulation resistance tester at that time. Indicates in The measured value of insulation resistance provided by the insulation resistance tester at that time.

7. A method for calibrating the polarization index of the insulation resistance of a rotating electric motor, characterized in that, A calibration apparatus for the polarization index of insulation resistance of a rotating electric machine as described in any one of claims 1-6, comprising: During the calibration process, a standard PI value is obtained based on the voltage measurement value provided by the voltmeter and the current measurement value provided by the ammeter. Based on the standard PI value and the measured PI value provided by the insulation resistance tester, determine whether the PI value error of the insulation resistance tester exceeds the error threshold; if so, generate a calibration result. Also includes: Obtain the target PI value and its corresponding At what time is the target value of insulation resistance and The target value of insulation resistance at that time. , Indicates the target PI value. express corresponding The target value of insulation resistance at that time. express corresponding Target value of insulation resistance at a given time; By adjusting the output voltage of the DC voltage source, control At this moment and The difference between them is less than the first resistance difference threshold, and control At this moment and The difference between them is less than the second resistance difference threshold, so that and The difference between them is less than the PI difference threshold; in, This indicates the time 1 minute after the start time during the calibration process. This indicates the time 10 minutes after the start time during the calibration process. The start time is the moment when the insulation resistance tester begins to apply a DC test voltage to the two ends of the calibration device. Indicates in The insulation resistance value simulated by the calibration device at that time. Indicates in The insulation resistance value simulated by the calibration device at that time. This indicates the standard PI value simulated by the calibration device.

8. The calibration method for the polarization index of the insulation resistance of a rotating electric motor according to claim 7, characterized in that, During the calibration process, a standard PI value is obtained based on the voltage measurement value provided by the voltmeter and the current measurement value provided by the ammeter, including determining the standard PI value using the following formula: ； ； ； in, This indicates the time 1 minute after the start time during the calibration process. This indicates the time 10 minutes after the start time during the calibration process. The start time is the moment when the insulation resistance tester begins to apply a DC test voltage to the two ends of the calibration device. In order to be in The voltage measurement value provided by the voltmeter at that moment. In order to be in The voltage measurement value provided by the voltmeter at that moment. In order to be in The current measurement value provided by the ammeter at that moment. In order to be in The current measurement value provided by the ammeter at that moment. This indicates the internal resistance of the ammeter. Indicates in The insulation resistance value simulated by the calibration device at that time. Indicates in The insulation resistance value simulated by the calibration device at that time. This indicates the standard PI value simulated by the calibration device.

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