A method for measuring dielectric loss of an electrical device based on a damped oscillation voltage

Abstract

The application relates to a kind of electrical equipment dielectric loss measurement methods based on damping oscillation voltage, including the construction damping oscillation voltage generation module, direct current high voltage power supply is connected with the measured equipment through the damping oscillation voltage generation module;Dielectric loss measurement module is constructed, the dielectric loss measurement module is connected in parallel at the two ends of the measured equipment;The direct current high voltage power supply is charged to the measured equipment through the damping oscillation voltage generation module, reaches preset condition, obtains the sampling voltage of the dielectric loss measurement module;According to the sampling voltage, the dielectric loss angle corresponding to the measured equipment is calculated. The damping oscillation circuit is used for boosting large capacitance or super large capacitance electrical equipment, since the damping oscillation circuit is connected to short-circuit discharge process in charging process, there is no capacitive current in the charging process, there is no short-time overload problem, so long-time continuous work without cooling can be carried out.

Description

Technical Field

[0001] This application relates to the field of dielectric loss measurement, and in particular to a method for measuring dielectric loss of electrical equipment based on damped oscillating voltage. Background Technology

[0002] Dielectric loss is a crucial characteristic of the electrical properties of dielectrics and a primary test measurement item for electrical equipment. During testing, a high AC voltage needs to be applied to the tested electrical equipment. For equipment with large equivalent capacitance, a very high capacitive current is generated during testing, requiring the dielectric loss measuring device to have a very high capacity. This not only results in a large device size but also poses a significant challenge to the on-site power supply. Traditionally, this problem is addressed primarily through short-time overload testing, where the dielectric loss measuring device is subjected to a high-amplitude capacitive current for a short period (typically 1 minute), and then immediately stopped to allow the equipment to cool down. This prevents continuous dielectric loss measurement of large-capacitance electrical equipment, severely impacting the efficiency of on-site testing, prolonging power outage testing time, and even making direct measurement of the dielectric loss of some ultra-large-capacitance electrical equipment impossible, requiring an external high-capacity power supply.

[0003] The current method for measuring the dielectric loss of large-capacity electrical equipment cannot be performed continuously, which seriously affects the efficiency of field testing. The dielectric loss of some ultra-large-capacity electrical equipment cannot even be measured directly, requiring an external high-capacity power supply. There is an urgent need to solve the problems of continuous measurement of dielectric loss in large-capacity electrical equipment and direct measurement of dielectric loss in ultra-large-capacity electrical equipment. Summary of the Invention

[0004] Therefore, it is necessary to provide a method for measuring the dielectric loss of electrical equipment based on damped oscillation voltage, which can solve the above-mentioned technical problems.

[0005] Specifically, the method for measuring dielectric loss of electrical equipment based on damped oscillating voltage proposed in this embodiment measures the dielectric loss of electrical equipment using the damped oscillating voltage of a transient process, including:

[0006] A damped oscillation voltage generating module is constructed, and the DC high-voltage power supply S is connected to the device under test C via the damped oscillation voltage generating module. X connect;

[0007] Add a connection to the device under test C X Parallel dielectric loss measurement module C Y ;

[0008] The DC high-voltage power supply S is controlled to charge the device under test via the damped oscillation voltage generating module. When the preset conditions are met, the dielectric loss measurement module C acquires the voltage. Y The sampling voltage;

[0009] The dielectric loss angle of the device under test is calculated based on the sampling voltage.

[0010] In one embodiment, the damped oscillation voltage generating module includes:

[0011] A reactor L is provided, one end of which is connected to the DC high voltage source S via a protective resistor R, and the other end of which is grounded via a voltage divider. A grounding switch K is provided between the reactor L and the protective resistor R.

[0012] The other end of the reactor L is connected to the device under test C. X The device under test C X The other end is grounded, and the dielectric loss measurement module C Y One end of the dielectric loss measurement module C is electrically connected to the other end of the reactor L. Y The other end is grounded.

[0013] In one embodiment, the voltage divider includes:

[0014] A capacitor branch, and a resistor branch connected in parallel with the capacitor branch;

[0015] Voltage sampling points are provided on both the capacitor branch and the resistor branch.

[0016] In one embodiment, the capacitor branch includes:

[0017] Capacitor C1, one end of which is electrically connected to reactor L, and the other end of which is grounded via capacitor C2.

[0018] In one embodiment, the resistor branch includes:

[0019] Resistor R1, one end of which is electrically connected to reactor L, and the other end of resistor R1 is grounded via resistor R2.

[0020] In one embodiment, the dielectric loss measurement module C Y include:

[0021] A first branch, and a second branch connected in parallel with the first branch, wherein the first branch includes a capacitor C. A and the capacitor C A Series capacitor C B ;

[0022] The capacitor C A The capacitor C is far away from the middle B One end is equipped with a device for acquiring the sampling voltage U A The first voltage sampling point, the capacitor CB The capacitor C is far away from the middle A One end is grounded.

[0023] In one embodiment, the first branch includes:

[0024] In the capacitor C A With the capacitor C B There is a space between them for obtaining the sampling voltage U B The second voltage sampling point.

[0025] In one embodiment, the second branch includes:

[0026] Capacitor C M The capacitor C M One end of the capacitor C is electrically connected to the first voltage sampling point. M The other end is connected to a capacitor C N The capacitor C N The capacitor C is far away from the middle M One end of the capacitor C is grounded. M With the capacitor C N There is a sampling voltage U between them. N The third voltage sampling point.

[0027] In one embodiment, the preset conditions include:

[0028] The boost voltage of the DC high-voltage power supply reaches the test voltage.

[0029] In one embodiment, calculating the dielectric loss angle corresponding to the device under test based on the sampled voltage includes:

[0030] The difference in phase angle between the sampled voltages is obtained, and the difference is the dielectric loss angle.

[0031] By using a damped oscillation circuit to boost the voltage of large or ultra-large capacitance electrical equipment, since the damped oscillation circuit is a DC charging connection that short-circuits the discharging process, no capacitive current is generated during the charging process, and there is no short-term overload problem. Therefore, it can operate continuously for a long time without cooling. Attached Figure Description

[0032] Figure 1 This is an application environment diagram of an electrical equipment dielectric loss measurement method based on damped oscillation voltage in one embodiment;

[0033] Figure 2 This is a flowchart illustrating the process environment of a method for measuring dielectric loss of electrical equipment based on damped oscillation voltage in one embodiment.

[0034] Figure 3This is a schematic diagram of the circuit structure of a damped oscillation voltage generating module in one embodiment;

[0035] Figure 4 This is a schematic diagram of the circuit structure of the dielectric loss measurement module in one embodiment. Detailed Implementation

[0036] 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.

[0037] The method for measuring dielectric loss of electrical equipment based on damped oscillation voltage provided in this application embodiment can be applied to, for example... Figure 1 In the application environment shown, terminal 102 communicates with server 104 via a network. A data storage system can store the data that server 104 needs to process. The data storage system can be integrated onto server 104 or located in the cloud or on other network servers. Specific quality assessment methods for the electronic endoscopy inspection process are implemented in the terminal or server. Terminal 102 can be, but is not limited to, various personal computers, laptops, smartphones, tablets, etc. Server 104 can be implemented using a standalone server or a server cluster consisting of multiple servers.

[0038] In one embodiment, the electrical equipment dielectric loss measurement method based on damped oscillation voltage proposed in this embodiment, such as... Figure 2 As shown, it includes:

[0039] Step S20: Construct a damped oscillation voltage generating module. The DC high-voltage power supply S is connected to the device under test C via the damped oscillation voltage generating module. X connect.

[0040] The damped oscillation voltage generation module here is used to boost the voltage of the device under test, so as to measure the dielectric loss based on the boosted voltage value.

[0041] Step S22, add a connection to the device under test C X Parallel dielectric loss measurement module C Y .

[0042] Medium measurement module C here Y Used to obtain the voltage value after boosting the voltage across the device under test, and then calculate the dielectric loss of the device under test based on the obtained voltage value.

[0043] Step S24: Control the DC high-voltage power supply to charge the device under test through the damped oscillation voltage generation module. When the preset conditions are met, acquire the dielectric loss measurement module C.Y The sampling voltage.

[0044] The key to this application lies in measuring the dielectric loss of electrical equipment using the damped oscillation voltage of a transient process. Specifically, to obtain a voltage value that facilitates the calculation of dielectric loss, a DC high-voltage power supply needs to be controlled to charge the device under test. When the voltage across the device under test reaches a predetermined test voltage, the dielectric loss measurement module C at this point is used to obtain the voltage value. Y The voltage is used as the sampling voltage for calculating the dielectric loss angle.

[0045] Step S26: Calculate the dielectric loss angle corresponding to the device under test based on the sampling voltage.

[0046] The specific method for calculating the dielectric loss angle is to obtain the phase angle of the sampled voltage.

[0047] This embodiment provides a method for measuring the dielectric loss of large-capacity electrical equipment based on damped oscillation voltage. Its working principle is as follows: a damped oscillation circuit is used to boost the voltage of large-capacity or ultra-large-capacity electrical equipment, and a digital bridge is used to measure the dielectric loss. The damped oscillation circuit operates through a DC charging and short-circuit discharging process; therefore, no capacitive current is generated during the charging process, eliminating short-term overload problems, thus eliminating the need for cooling, and allowing for continuous operation for extended periods.

[0048] In one embodiment, a damped oscillation voltage generator module is needed to generate the required voltage, such as... Figure 3 As shown, the damped oscillation voltage generating module includes:

[0049] A reactor L is provided, one end of which is connected to the DC high voltage source S via a protective resistor R, and the other end of which is grounded via a voltage divider. A grounding switch K is provided between the reactor L and the protective resistor R.

[0050] The other end of the reactor L is connected to the device under test C. X The device under test C X The other end is grounded, and the dielectric loss measurement module C Y One end of the dielectric loss measurement module C is electrically connected to the other end of the reactor L. Y The other end is grounded.

[0051] The boost process here is achieved using the LC oscillation circuit in the damped oscillation voltage generation module. The core component of the LC oscillation circuit is an oscillation circuit consisting of an inductor and a capacitor, which is used to generate a high-frequency sine wave signal.

[0052] Common LC resonant circuits include transformer-feedback, inductive three-point, and capacitive three-point types. Their frequency selection networks typically employ parallel LC resonant circuits. The radiated power of this type of resonant circuit is proportional to the fourth power of the oscillation frequency. To radiate a sufficiently large amount of electromagnetic waves, simply increase the oscillation frequency. The oscillation of an LC resonant circuit occurs because it utilizes the energy storage characteristics of capacitors and inductors, causing the alternating conversion of electromagnetic and electrical energy. Since both electrical and magnetic energy have maximum and minimum values, oscillation occurs.

[0053] In this embodiment, the DC high-voltage power supply S is connected to the device under test C through a resistor R and a reactor L. X Dielectric loss measurement module C Y Electrical connection enables the DC high-voltage power supply S to supply power to the device under test C during measurement. X Dielectric loss measurement module C Y The purpose of charging. After reaching the test voltage, grounding K closes, and C... X and C Y The charge discharges to ground through reactor L, creating oscillations. The frequency of the oscillations is determined by C. X、 C Y The parameters of C and L are jointly determined. To avoid the tested device C X The effect of capacitance change on oscillation frequency, taking C Y Much larger than C X .

[0054] A damped oscillation voltage generator module provides high voltage throughout the circuit, facilitating dielectric loss measurement in subsequent circuits. This damped oscillation circuit enables both DC charging and short-circuit discharging. The charging process does not generate capacitive current, eliminates short-term overload issues, requires no cooling, and allows for continuous operation over extended periods.

[0055] In one embodiment, the voltage divider includes:

[0056] A capacitor branch, and a resistor branch connected in parallel with the capacitor branch;

[0057] Voltage sampling points are provided on both the capacitor branch and the resistor branch.

[0058] In practice, to facilitate dielectric loss measurement, a voltage divider is needed to divide the high voltage obtained from the damped oscillation voltage generator module, thereby ensuring that the voltage obtained for dielectric loss measurement is within the usable range. The voltage divider connected to the damped oscillation voltage generator module consists of a capacitor branch and a resistor branch, both with voltage sampling points.

[0059] The capacitor branch includes: capacitor C1, one end of which is electrically connected to the reactor L, and the other end of which is grounded via capacitor C2.

[0060] The resistor branch includes: resistor R1, one end of which is electrically connected to the reactor L, and the other end of which is grounded via resistor R2.

[0061] In implementation, the capacitor branch of the voltage divider consists of capacitors C1 and C2 connected in series and grounded, while the resistor branch consists of resistors R1 and R2, which are similarly structured and connected in series and grounded. Both branches obtain different voltage values ​​at their respective voltage sampling points through voltage division. The voltage value obtained at each voltage sampling point is the voltage value of the device under test (C). X The measured voltage value.

[0062] In one embodiment, such as Figure 4 As shown, the dielectric loss measurement module includes:

[0063] A first branch, and a second branch connected in parallel with the first branch, wherein the first branch includes a capacitor C. A and the capacitor C A Series capacitor C B The capacitor C A The capacitor C is far away from the middle B One end is equipped with a device for acquiring the sampling voltage U A The first voltage sampling point, the capacitor C B The capacitor C is far away from the middle A One end of the capacitor C is grounded. A With the capacitor C B There is a space between them for obtaining the sampling voltage U B The second voltage sampling point.

[0064] The second branch includes: capacitor C M The capacitor C M One end of the capacitor C is electrically connected to the first voltage sampling point. M One end is connected to a capacitor C N The capacitor C N The capacitor C is far away from the middle M One end of the capacitor C is grounded. M With the capacitor C N There is a sampling voltage U between them. N The third voltage sampling point.

[0065] In implementation, Figure 3 The damped oscillation voltage generator module shown is for transmitting voltage to the device under test (C). X Provides the high voltage required for measurement; the dielectric loss measurement module C here...Y The C of the device under test is calculated by the specific sampling voltage. X The corresponding dielectric loss angle. Additionally, to improve the accuracy of the final dielectric loss angle calculation, preset conditions must be met. These conditions include: after the DC high-voltage power supply reaches the test voltage, to avoid the tested device C... X The effect of capacitance change on oscillation frequency, where C Y The value of is much greater than C. X The value of .

[0066] In one embodiment, calculating the dielectric loss angle corresponding to the device under test based on the sampled voltage includes:

[0067] The difference in phase angle between the sampled voltages is obtained, and the difference is the dielectric loss angle.

[0068] In practice, under the influence of an alternating electric field, the dielectric behavior of a dielectric may exhibit two different behaviors depending on the electric field frequency and the type of dielectric. For an ideal dielectric, there is no phase difference between the electric displacement and the electric field strength in time. In this case, the polarization intensity is in phase with the alternating electric field, and the alternating current just leads the voltage by π / 2. For a real dielectric, there is a phase difference between the electric displacement and the electric field strength. In this case, the phase angle by which the alternating current of the dielectric capacitor leads the voltage is less than π / 2. Therefore, the dielectric loss angle is equal to the complementary angle of the phase angle difference between the alternating current and voltage of the dielectric capacitor. The dielectric loss angle is the complementary angle δ of the angle between the current vector and the voltage vector flowing through the dielectric under an alternating electric field (i.e., the power vector angle ф). It is an important indicator reflecting the insulation performance of high-voltage electrical equipment. Changes in the dielectric loss angle can reflect insulation defects such as moisture absorption, deterioration, or gas discharge in the insulation. Therefore, measuring the dielectric loss angle is an important aspect of studying insulation aging characteristics and online monitoring of insulation conditions.

[0069] Based on Figure 3 as well as Figure 4 The circuit structure is described in this embodiment, and the device under test C is calculated. X The method for calculating the dielectric loss angle is to obtain... Figure 4 Medium sampling voltage U B With sampling voltage U N The phase angle difference.

[0070] Based on the above circuit structure, the specific process for obtaining the dielectric loss angle is as follows:

[0071] Step S1, construct as follows Figure 3 The circuit shown establishes a damped oscillation voltage generation module, constructing as follows: Figure 4 The circuit shown establishes a dielectric loss measurement module.

[0072] Step S2, the DC high voltage power supply passes through resistor R, reactor L, and capacitor C. Y Connection, Device C under test X With capacitor C Y In parallel connection, at the start of measurement, the DC high-voltage power supply S boosts the voltage, which then flows through resistor R and reactor L to form capacitor C. Y and the device under test C X Charge.

[0073] Step S3: After the charging voltage reaches the test voltage, the grounding switch K closes, and capacitor C... Y and the device under test C X The charge discharges to ground through L, creating oscillations. The oscillation frequency is determined by the capacitance C. Y、 Test device C X The value is determined jointly by the inductor L and the reactor C. To avoid the tested device C... X The effect of capacitance change on oscillation frequency, where C Y The value of is much greater than C. X The value of .

[0074] In step S4, the voltage of the sample to be tested is measured by a voltage divider composed of resistors R1 and R2 and capacitors C1 and C2.

[0075] Step S5, the device under test C X Synchronous access Figure 4 The dielectric loss measurement module shown acquires the sampling voltage U. B and sampling voltage U N The voltage value is obtained and the phase is calculated to obtain the dielectric loss angle.

[0076] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0077] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0078] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for measuring dielectric loss of electrical equipment based on damped oscillating voltage, characterized in that... The dielectric loss of electrical equipment is measured using the damped oscillating voltage of a transient process. The method for measuring the dielectric loss of electrical equipment includes: A damped oscillation voltage generating module is constructed, and the DC high-voltage power supply S is connected to the device under test C via the damped oscillation voltage generating module. X connect; Add a connection to the device under test C X Parallel dielectric loss measurement module C Y ; The DC high-voltage power supply S is controlled to supply power to the device under test C via the damped oscillation voltage generating module. X When charging reaches the preset conditions, the dielectric loss measurement module C acquires the data. Y The sampling voltage; Calculate the dielectric loss angle corresponding to the device under test based on the sampling voltage; The dielectric loss measurement module C Y include: A first branch, and a second branch connected in parallel with the first branch, wherein the first branch includes a capacitor C. A and the capacitor C A Series capacitor C B ; The capacitor C A The capacitor C is far from the center. B One end is equipped with a device for acquiring the sampling voltage U A The first voltage sampling point, the capacitor C B The capacitor C is far from the center. A One end is grounded; The first branch includes: In the capacitor C A With the capacitor C B There is a space between them for obtaining the sampling voltage U B The second voltage sampling point; The second branch includes: Capacitor C M The capacitor C M One end of the capacitor C is electrically connected to the first voltage sampling point. M The other end is connected to a capacitor C N The capacitor C N The capacitor C is far from the center. M One end of the capacitor C is grounded. M With the capacitor C N There is a sampling voltage U between them. N The third voltage sampling point; The device under test C X The dielectric loss angle is calculated by obtaining the sampling voltage U. B With the sampling voltage U N The phase angle difference; The preset conditions include: The boost voltage of the DC high-voltage power supply reaches the test voltage; C Y Much larger than C X .

2. The method for measuring dielectric loss of electrical equipment based on damped oscillating voltage according to claim 1, characterized in that, The damped oscillation voltage generating module includes: A reactor L is provided, one end of which is connected to the DC high voltage source S via a protective resistor R, and the other end of which is grounded via a voltage divider. A grounding switch K is provided between the reactor L and the protective resistor R. The other end of the reactor L is connected to the device under test C. X The device under test C X The other end is grounded, and the dielectric loss measurement module C Y One end of the dielectric loss measurement module C is electrically connected to the other end of the reactor L. Y The other end is grounded.

3. The method for measuring dielectric loss of electrical equipment based on damped oscillating voltage according to claim 2, characterized in that, The voltage divider includes: A capacitor branch, and a resistor branch connected in parallel with the capacitor branch; Voltage sampling points are provided on both the capacitor branch and the resistor branch.

4. The method for measuring dielectric loss of electrical equipment based on damped oscillating voltage according to claim 3, characterized in that, The capacitor branch includes: Capacitor C1, one end of which is electrically connected to reactor L, and the other end of which is grounded via capacitor C2.

5. The method for measuring dielectric loss of electrical equipment based on damped oscillating voltage according to claim 3, characterized in that, The resistor branch includes: Resistor R1, one end of which is electrically connected to reactor L, and the other end of resistor R1 is grounded via resistor R2.

6. The method for measuring dielectric loss of electrical equipment based on damped oscillating voltage according to claim 1, characterized in that, The step of calculating the dielectric loss angle corresponding to the device under test based on the sampled voltage includes: The difference in phase angle between the sampled voltages is obtained, and the difference is the dielectric loss angle.

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