Method for judging insulation failure degree of spaceflight permanent magnet motor in strong irradiation environment

Abstract

The invention discloses a method for judging the insulation failure degree of a spaceflight permanent magnet motor in a strong irradiation environment, and the method comprises the steps: collecting the current of a stator winding through an original three-phase current sensor, and calculating a zero-sequence current component; carrying out difference on the real-time zero-sequence current component and a zero-sequence current reference value to obtain a zero-sequence offset; the ratio of the zero-sequence offset absolute value to the zero-sequence current reference value is calculated, and the insulation degradation percentage is obtained; and performing grading judgment on the insulation state of the spaceflight permanent magnet motor according to the insulation degradation percentage. According to the method, on-orbit online real-time judgment is achieved, and the limitation that a traditional method cannot adapt to complex environments such as on-orbit irradiation disturbance and temperature cycle is broken through; a third-level judgment standard is constructed based on the insulation degradation percentage, and accurate quantitative evaluation of the insulation failure degree is achieved; an original three-phase current sensor is reused, extra hardware cost is avoided, the algorithm is simple, the calculation amount is low, and the method is adaptive to aerospace application scenes; failure risks are early warned in advance, and technical support is provided for long-term on-orbit reliability of the spacecraft key executing mechanism.

Description

Technical Field

[0001] This invention relates to a method for determining the degree of insulation failure of aerospace permanent magnet motors under strong radiation conditions, and belongs to the technical field of fault diagnosis of aerospace permanent magnet motors. Background Technology

[0002] Aerospace permanent magnet motors are widely used in key units such as spacecraft attitude control mechanisms, solar array deployment mechanisms, antenna pointing mechanisms, and payload execution mechanisms. The insulation performance of their windings is a core indicator for ensuring the long-term reliability of the motors during on-orbit operation. Because these motors typically operate in a highly irradiated space environment, the insulating materials are continuously exposed to high-energy electrons, protons, and ultraviolet radiation, leading to a decrease in dielectric strength, accelerated surface charge accumulation, and the gradual emergence of degradation characteristics such as reduced breakdown field strength and creepage path formation. Simultaneously, the coupling of irradiation and thermal cycling accelerates the cracking, hardening, and resistance decay of the insulation layer, causing the risk of insulation failure to accumulate continuously during long-term on-orbit service. Therefore, effective assessment and timely determination of the insulation condition of aerospace permanent magnet motors are critical technical requirements for ensuring the reliability of aerospace actuators.

[0003] Current research on insulation degradation in aerospace permanent magnet motors mainly focuses on prediction methods based on material properties and irradiation degradation mechanisms. A common approach is to establish models of dielectric constant changes, volume resistivity decreases, and partial discharge initiation voltage reductions in insulating materials under high-energy particle irradiation, and then combine these models with ground-based accelerated irradiation test data to estimate on-orbit insulation lifetime. Afaf M. Abd El-Hameed, in his paper "Radiation effects on composite materials used in space systems: a review," summarized various prediction methods for assessing the irradiation degradation of aerospace composite and insulating materials, including models based on dielectric constant changes, breakdown field strength decreases, volume resistivity decay, molecular chain breakage rates, and irradiation dose-performance degradation curves. These methods essentially rely on ground-based experimental data and the physical properties of the insulating materials for parameter prediction, and cannot provide online judgment results for irradiation disturbances, temperature cycling, and electromagnetic load changes in actual service environments. Therefore, existing methods have the limitation of not being able to measure or identify the degree of insulation failure on-orbit. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of the prior art and to propose a method for determining the degree of insulation failure of aerospace permanent magnet motors under strong radiation conditions, which is proposed to address the problem that traditional methods for assessing radiation degradation of aerospace composite materials and insulating materials cannot achieve on-orbit measurement and identification of the degree of insulation failure.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for determining the degree of insulation failure of aerospace permanent magnet motors under strong radiation conditions includes the following steps: S1 Three-phase current acquisition and zero-sequence component calculation: The stator winding current is acquired using the three-phase current sensor of the aerospace motor, and the zero-sequence current component is calculated. S2 calculates the zero-sequence current differential offset by subtracting the real-time zero-sequence current component from the zero-sequence current reference value to obtain the zero-sequence offset. S3 calculates the percentage of insulation degradation by calculating the ratio of the absolute value of the zero-sequence offset to the zero-sequence current reference value. The S4 insulation failure level assessment classifies the insulation status of aerospace permanent magnet motors based on the percentage of insulation degradation.

[0006] Preferably, in step S1, the stator winding current i is collected. a i b and i c Construct the formula for calculating the zero-sequence current component i0: .

[0007] Preferably, in step S2, the zero-sequence offset is Δi0. , where i 0,ref This is the zero-sequence current reference value.

[0008] Preferably, in step S3, the percentage of insulation degradation is η. .

[0009] Preferably, in step S4, when η < 20%, the insulation is in a healthy state; when 20% ≤ η < 100%, the insulation is slightly degraded; and when η ≥ 100%, the insulation fails significantly.

[0010] The beneficial effects of this invention are mainly reflected in: 1. Achieve real-time online judgment in orbit, overcoming the limitations of traditional methods that cannot adapt to complex environments such as in-orbit irradiation disturbances and temperature cycling; 2. A three-level judgment standard is constructed based on the percentage of insulation degradation to achieve accurate quantitative assessment of the degree of insulation failure; 3. Reuses existing three-phase current sensors, with no additional hardware cost, simple algorithm, low computational load, and suitable for aerospace application scenarios; 4. Provide early warning of failure risks, and offer technical support for the long-term on-orbit reliability of key spacecraft actuators. Attached Figure Description

[0011] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1This is a flowchart illustrating the method for determining the degree of insulation failure of aerospace permanent magnet motors under strong radiation conditions, as per the present invention. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0013] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in the present application can be combined with each other.

[0014] This invention provides a method for determining the degree of insulation failure of aerospace permanent magnet motors under strong radiation conditions, such as... Figure 1 As shown, it includes the following steps: Three-phase current acquisition and zero-sequence component calculation: The stator winding current i is acquired using a three-phase current sensor from an aerospace motor. a i b and i c The zero-sequence current component i0 is calculated using the following formula: .

[0015] When the insulation of the aerospace permanent magnet motor is healthy, the three-phase currents are symmetrical and i0 is close to zero. When insulation degradation leads to interphase leakage current, the three-phase currents are no longer balanced and i0 becomes a non-zero offset.

[0016] Calculate the zero-sequence current differential offset by subtracting the real-time zero-sequence current i0 from the reference value to obtain the zero-sequence offset Δi0. .

[0017] Among them, i 0,ref The zero-sequence current reference value is derived from the zero-sequence current data recorded under the corresponding operating conditions when the motor is in a healthy insulation state during ground calibration test.

[0018] To calculate the percentage of insulation degradation, substitute the zero-sequence current reference value and the zero-sequence offset Δi0 into the following formula to calculate the percentage of insulation degradation η. .

[0019] η is used to quantify the degree of insulation degradation; the larger the value of η, the more severe the insulation failure.

[0020] Insulation failure severity assessment: The insulation status of the aerospace permanent magnet motor is graded based on the percentage of insulation degradation η. When η < 20%, the zero-sequence current deviation is considered to be within the normal fluctuation range, and the insulation is in a healthy state; when 20% ≤ η < 100%, the insulation is considered to have undergone slight degradation, but it does not affect the normal operation of the motor, and its changes can be continuously tracked through on-orbit monitoring; when η ≥ 100%, the insulation failure is considered to be obvious, and it is in a state of severe degradation or has a risk of failure.

[0021] In one specific embodiment, the parameters of the aerospace permanent magnet motor are as follows: zero-sequence current reference value i 0,ref =0.1 A, the collected stator winding current i a =2.3 A, i b =1.1 A and i c =-3.8 A. The implementation process of the method for determining the degree of insulation failure of aerospace permanent magnet motors under strong radiation environment is as follows: .

[0022] The real-time zero-sequence current i0 = -0.133 is compared with the zero-sequence current reference value i 0,ref =0.1 is used to perform a difference to obtain the zero-sequence offset Δi0.

[0023] .

[0024] The zero-sequence current reference value i 0,ref Substituting 0.1 and zero-sequence offset Δi0 = 0.033 into the following formula, the insulation degradation percentage η is calculated: .

[0025] At this point, if 20% ≤ η < 100%, it is considered that the insulation has undergone slight degradation, but it does not affect the normal operation of the motor. Its changes can be continuously tracked through on-orbit monitoring.

[0026] As described above, this method achieves real-time online judgment in orbit, overcoming the limitations of traditional methods that cannot adapt to complex environments such as in-orbit irradiation disturbances and temperature cycling; it constructs a three-level judgment standard based on the percentage of insulation degradation, enabling accurate quantitative assessment of the degree of insulation failure; it reuses existing three-phase current sensors, incurring no additional hardware costs, and its algorithm is simple, computationally efficient, and suitable for aerospace application scenarios; it provides early warning of failure risks, offering technical support for the long-term on-orbit reliability of key spacecraft actuators.

[0027] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent in such process, method, article, or apparatus / device.

[0028] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A method for determining the degree of insulation failure of aerospace permanent magnet motors under strong radiation conditions, characterized in that... Includes the following steps: S1 Three-phase current acquisition and zero-sequence component calculation: The stator winding current is acquired using the three-phase current sensor of the aerospace motor, and the zero-sequence current component is calculated. S2 calculates the zero-sequence current differential offset by subtracting the real-time zero-sequence current component from the zero-sequence current reference value to obtain the zero-sequence offset. S3 calculates the percentage of insulation degradation by calculating the ratio of the absolute value of the zero-sequence offset to the zero-sequence current reference value. The S4 insulation failure level assessment classifies the insulation status of aerospace permanent magnet motors based on the percentage of insulation degradation.

2. The method for determining the degree of insulation failure of aerospace permanent magnet motors under strong radiation environment according to claim 1, characterized in that: In step S1, the stator winding current i is collected. a i b and i c Construct the formula for calculating the zero-sequence current component i0: .

3. The method for determining the degree of insulation failure of aerospace permanent magnet motors under strong radiation environment according to claim 2, characterized in that: In step S2, the zero-order offset is Δi0. , where i 0,ref This is the zero-sequence current reference value.

4. The method for determining the degree of insulation failure of aerospace permanent magnet motors under strong radiation environment according to claim 3, characterized in that: In step S3, the percentage of insulation degradation is η. .

5. The method for determining the degree of insulation failure of aerospace permanent magnet motors under strong radiation environment according to claim 4, characterized in that: In step S4, when η < 20%, the insulation is in a healthy state; when 20% ≤ η < 100%, the insulation is slightly degraded; and when η ≥ 100%, the insulation fails significantly.

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