US-12618905-B2 - Superconducting motor quench detection method and apparatus based on rotational symmetry of motor

Abstract

The present invention discloses a superconducting motor quench detection method and apparatus based on rotational symmetry of a motor, belonging to the technical field of superconducting motor quench detection. The method includes: acquiring terminal voltages of each group of superconducting magnets in a superconducting motor, where the superconducting motor is pre-divided into at least two unit motors by using the rotational symmetry of the motor, and superconducting magnets located at corresponding positions are selected from the at least two unit motors as a group of superconducting magnets; calculating an absolute value of a terminal voltage difference of each group of superconducting magnets; and judging whether the absolute value exceeds a preset threshold, and if the absolute value exceeds the preset threshold, determining that the superconducting magnets are in a quench state. According to the present invention, induced voltages coupled by the terminal voltages of superconducting magnets are eliminated.

Inventors

• Xianglin LI
• Shaorui Wang
• Mingzhe SANG
• Wei Hua
• Dongyu LI
• Yubin Wang

Assignees

• QINGDAO UNIVERSITY

Dates

Publication Date

20260505

Application Date

20250715

Priority Date

20240326

Claims (8)

1. 1 . A superconducting motor quench detection method based on rotational symmetry of a motor, comprising: step 101 : acquiring terminal voltages of each group of superconducting magnets in a superconducting motor, wherein the superconducting motor is pre-divided into at least two unit motors that are arranged symmetrically with respect to a rotational axis and have identical electromagnetic structures by using the rotational symmetry of the motor, and the superconducting magnets at corresponding symmetric positions in the at least two unit motors have same geometric structure; the superconducting magnets located at corresponding positions are selected from the at least two unit motors as a group of superconducting magnets; the terminal voltages are acquired in real time and the terminal voltage of each superconducting magnet is coupled with an induced voltage and induced voltage components in the two superconducting magnets have same variation process; step 102 : for each group of superconducting magnets, calculating the terminal voltage difference between adjacent unit motors in the same group, where magnetic fields passing through the superconducting magnets at the same position n in adjacent unit motors have same waveform and variation process, so that the induced voltage components in the terminal voltages of the two superconducting magnets have the same variation process and the induced voltage components are eliminated in the terminal voltage difference, then calculating an absolute value of a terminal voltage difference of each group of superconducting magnets; and step 103 : judging whether the absolute value exceeds a preset threshold, and if the absolute value exceeds the preset threshold, determining that the superconducting magnets are in a quench state; wherein comparing the obtained absolute values of the terminal voltage differences with the preset threshold, if both |U n(t−1)t and |U nt(+1) | are greater than the preset threshold, considering that the superconducting magnet located at the position n in the unit motor t is in the quench state, wherein U nt(t+n) is a difference between a terminal voltage of the superconducting magnet located at the position n in the unit motor t and a terminal voltage of a superconducting magnet located at a position n in a unit motor t+1.
2. 2 . The method according to claim 1 , wherein the superconducting motor consists of T unit motors arranged at intervals of 360°/T and having a same structure, T is greater than or equal to 2, each unit motor has N superconducting magnets distributed from a position 1 to a position N, and the superconducting magnets located at the corresponding positions in each unit motor have a same geometric structure and are arranged at intervals of 360°/T in the superconducting motor.
3. 3 . The method according to claim 2 , wherein the step 101 comprises: dividing the superconducting magnets located at the corresponding positions in the T unit motors into a group, each unit motor having N superconducting magnets, dividing all superconducting magnets into N groups, each group of superconducting magnets consisting of T superconducting magnets, and subsequently acquiring the terminal voltages of each group of superconducting magnets in real time: a ⁢ group ⁢ 1 : u 11 u 1 ⁢ 2 … u 1 ⁢ t … u 1 ⁢ T a ⁢ group ⁢ 2 : u 2 ⁢ 1 u 2 ⁢ 2 … u 2 ⁢ t … u 2 ⁢ T ⋮ ⋮ ⋮ ⋮ ⋮ a ⁢ group ⁢ n : u n ⁢ 1 u n ⁢ 2 … u n ⁢ t … u nT ⋮ ⋮ ⋮ ⋮ ⋮ a ⁢ group ⁢ N : u N ⁢ 1 u N ⁢ 2 … u N ⁢ t … u NT wherein n represents the positions of the superconducting magnets located in the unit motors, t represents the unit motors where the superconducting magnets are located, and u nt is a terminal voltage of a superconducting magnet located at a position n in a unit motor t.
4. 4 . The method according to claim 3 , wherein the step 102 comprises: calculating N groups of terminal voltages of the superconducting magnets according to the following expression to obtain N groups of terminal voltage differences: a ⁢ group ⁢ 1 : U 1 ⁢ 1 ⁢ 2 = u 1 ⁢ 1 - u 1 ⁢ 2 U 1 ⁢ 2 ⁢ 3 = u 1 ⁢ 2 - u 1 ⁢ 3 … U 1 ⁢ t ⁡ ( t + 1 ) = u 1 ⁢ t - u 1 ⁢ ( t + 1 ) … U 1 ⁢ T ⁢ 1 = u 1 ⁢ T - u 1 ⁢ 1 a ⁢ group ⁢ 2 : U 2 ⁢ 1 ⁢ 2 = u 2 ⁢ 1 - u 2 ⁢ 2 U 2 ⁢ 2 ⁢ 3 = u 2 ⁢ 2 - u 2 ⁢ 3 … U 2 ⁢ t ⁡ ( t + 1 ) = u 2 ⁢ t - u 2 ⁢ ( t + 1 ) … U 2 ⁢ T ⁢ 1 = u 2 ⁢ T - u 2 ⁢ 1 ⋮ ⋮ ⋮ ⋮ ⋮ a ⁢ group ⁢ n : U n ⁢ 1 ⁢ 2 = u n ⁢ 1 - u n ⁢ 2 U n ⁢ 2 ⁢ 3 = u n ⁢ 2 - u n ⁢ 3 … U n ⁢ t ⁡ ( t + 1 ) = u n ⁢ t - u n ⁡ ( t + 1 ) … U n ⁢ T ⁢ 1 = u nT - u n ⁢ 1 ⋮ ⋮ ⋮ ⋮ ⋮ a ⁢ group ⁢ N : U N ⁢ 1 ⁢ 2 = u N ⁢ 1 - u N ⁢ 2 U N ⁢ 2 ⁢ 3 = u N ⁢ 2 - u N ⁢ 3 … U N ⁢ t ⁡ ( t + 1 ) = u N ⁢ t - u N ⁡ ( t + 1 ) … U N ⁢ T ⁢ 1 = u NT - u N ⁢ 1 wherein U nt(t+1) is a difference between a terminal voltage of the superconducting magnet located at the position n in the unit motor t and a terminal voltage of a superconducting magnet located at a position n in a unit motor t+1; subsequently calculating the absolute values of the terminal voltage differences to obtain: a ⁢ group ⁢ 1 : ❘ "\[LeftBracketingBar]" U 1 ⁢ 1 ⁢ 2 ❘ "\[RightBracketingBar]" ❘ "\[LeftBracketingBar]" U 1 ⁢ 2 ⁢ 3 ❘ "\[RightBracketingBar]" … ❘ "\[LeftBracketingBar]" U 1 ⁢ t ⁡ ( t + 1 ) ❘ "\[RightBracketingBar]" … ❘ "\[LeftBracketingBar]" U 1 ⁢ T ⁢ 1 ❘ "\[RightBracketingBar]" a ⁢ group ⁢ 2 : ❘ "\[LeftBracketingBar]" U 2 ⁢ 1 ⁢ 2 ❘ "\[RightBracketingBar]" ❘ "\[LeftBracketingBar]" U 2 ⁢ 2 ⁢ 3 ❘ "\[RightBracketingBar]" … ❘ "\[LeftBracketingBar]" U 2 ⁢ t ⁡ ( t + 1 ) ❘ "\[RightBracketingBar]" … ❘ "\[LeftBracketingBar]" U 2 ⁢ T ⁢ 1 ❘ "\[RightBracketingBar]" ⋮ ⋮ ⋮ ⋮ ⋮ a ⁢ group ⁢ n : ❘ "\[LeftBracketingBar]" U n ⁢ 1 ⁢ 2 ❘ "\[RightBracketingBar]" ❘ "\[LeftBracketingBar]" U n ⁢ 2 ⁢ 3 ❘ "\[RightBracketingBar]" … ❘ "\[LeftBracketingBar]" U n ⁢ t ⁡ ( t + 1 ) ❘ "\[RightBracketingBar]" … ❘ "\[LeftBracketingBar]" U n ⁢ T ⁢ 1 ❘ "\[RightBracketingBar]" ⋮ ⋮ ⋮ ⋮ ⋮ a ⁢ group ⁢ N : ❘ "\[LeftBracketingBar]" U N ⁢ 1 ⁢ 2 ❘ "\[RightBracketingBar]" ❘ "\[LeftBracketingBar]" U N ⁢ 2 ⁢ 3 ❘ "\[RightBracketingBar]" … ❘ "\[LeftBracketingBar]" U N ⁢ t ⁡ ( t + 1 ) ❘ "\[RightBracketingBar]" … ❘ "\[LeftBracketingBar]" U N ⁢ T ⁢ 1 ❘ "\[RightBracketingBar]" so as to obtain the absolute values of the terminal voltage differences.
5. 5 . A superconducting motor quench detection apparatus based on rotational symmetry of a motor, used for a superconducting motor, wherein the superconducting motor quench detection apparatus comprises: an acquisition module, configured to acquire terminal voltages of each group of superconducting magnets in the superconducting motor, wherein the superconducting motor is pre-divided into at least two unit motors that are arranged symmetrically with respect to a rotational axis and have identical electromagnetic structures by using the rotational symmetry of the motor, and the superconducting magnets at corresponding symmetric positions in the at least two unit motors have the same geometric structure; superconducting magnets located at corresponding positions are selected from the at least two unit motors as a group of superconducting magnets; the terminal voltages are acquired in real time and the terminal voltage of each superconducting magnet is coupled with an induced voltage and induced voltage components in the two superconducting magnets have same variation process; a calculation module, configured to calculate the terminal voltage difference between adjacent unit motors in the same group, where magnetic fields passing through the superconducting magnets at the same position n in adjacent unit motors have same waveform and variation process, so that the induced voltage components in the terminal voltages of the two superconducting magnets have the same variation process and the induced voltage components are eliminated in the terminal voltage difference, then calculate an absolute value of a terminal voltage difference of each group of superconducting magnets; and a judgment module, configured to judge whether the absolute value exceeds a preset threshold, and if the absolute value exceeds the preset threshold, to determine that the superconducting magnets are in a quench state; wherein comparing the obtained absolute values of the terminal voltage differences with the preset threshold, if both |U n(t−1)t and |U nt(+1) | are greater than the preset threshold, considering that the superconducting magnet located at the position n in the unit motor t is in the quench state, wherein U nt(t+1) is a difference between a terminal voltage of the superconducting magnet located at the position n in the unit motor t and a terminal voltage of a superconducting magnet located at a position n in a unit motor t+1.
6. 6 . The apparatus according to claim 5 , wherein the superconducting motor consists of T unit motors arranged at intervals of 360°/T and having a same structure, T is greater than or equal to 2, each unit motor has N superconducting magnets distributed from a position 1 to a position N, and the superconducting magnets located at the corresponding positions in each unit motor have a same geometric structure and are arranged at intervals of 360°/T in the superconducting motor.
7. 7 . The apparatus according to claim 6 , wherein the acquisition module comprises: an acquisition sub-module, configured to divide the superconducting magnets located at the corresponding positions in the T unit motors into a group, each unit motor having N superconducting magnets, to divide all superconducting magnets into N groups, each group of superconducting magnets consisting of T superconducting magnets, and to subsequently acquire the terminal voltages of each group of superconducting magnets in real time: a ⁢ group ⁢ 1 : u 11 u 1 ⁢ 2 … u 1 ⁢ t … u 1 ⁢ T a ⁢ group ⁢ 2 : u 2 ⁢ 1 u 2 ⁢ 2 … u 2 ⁢ t … u 2 ⁢ T ⋮ ⋮ ⋮ ⋮ ⋮ a ⁢ group ⁢ n : u n ⁢ 1 u n ⁢ 2 … u n ⁢ t … u nT ⋮ ⋮ ⋮ ⋮ ⋮ a ⁢ group ⁢ N : u N ⁢ 1 u N ⁢ 2 … u N ⁢ t … u NT wherein n represents the positions of the superconducting magnets located in the unit motors, t represents the unit motors where the superconducting magnets are located, and u nt is a terminal voltage of a superconducting magnet located at a position n in a unit motor t.
8. 8 . The apparatus according to claim 7 , wherein the calculation module comprises: a calculation sub-module, configured to calculate N groups of terminal voltages of the superconducting magnets according to the following expression to obtain N groups of terminal voltage differences: a ⁢ group ⁢ 1 : U 1 ⁢ 1 ⁢ 2 = u 1 ⁢ 1 - u 1 ⁢ 2 U 1 ⁢ 2 ⁢ 3 = u 1 ⁢ 2 - u 1 ⁢ 3 … U 1 ⁢ t ⁡ ( t + 1 ) = u 1 ⁢ t - u 1 ⁢ ( t + 1 ) … U 1 ⁢ T ⁢ 1 = u 1 ⁢ T - u 1 ⁢ 1 a ⁢ group ⁢ 2 : U 2 ⁢ 1 ⁢ 2 = u 2 ⁢ 1 - u 2 ⁢ 2 U 2 ⁢ 2 ⁢ 3 = u 2 ⁢ 2 - u 2 ⁢ 3 … U 2 ⁢ t ⁡ ( t + 1 ) = u 2 ⁢ t - u 2 ⁢ ( t + 1 ) … U 2 ⁢ T ⁢ 1 = u 2 ⁢ T - u 2 ⁢ 1 ⋮ ⋮ ⋮ ⋮ ⋮ a ⁢ group ⁢ n : U n ⁢ 1 ⁢ 2 = u n ⁢ 1 - u n ⁢ 2 U n ⁢ 2 ⁢ 3 = u n ⁢ 2 - u n ⁢ 3 … U n ⁢ t ⁡ ( t + 1 ) = u n ⁢ t - u n ⁡ ( t + 1 ) … U n ⁢ T ⁢ 1 = u nT - u n ⁢ 1 ⋮ ⋮ ⋮ ⋮ ⋮ a ⁢ group ⁢ N : U N ⁢ 1 ⁢ 2 = u N ⁢ 1 - u N ⁢ 2 U N ⁢ 2 ⁢ 3 = u N ⁢ 2 - u N ⁢ 3 … U N ⁢ t ⁡ ( t + 1 ) = u N ⁢ t - u N ⁡ ( t + 1 ) … U N ⁢ T ⁢ 1 = u N ⁢ T - u N ⁢ 1 wherein U nt(t+1) is a difference between a terminal voltage of the superconducting magnet located at the position n in the unit motor t and a terminal voltage of a superconducting magnet located at a position n in a unit motor t+1; to subsequently calculate the absolute values of the terminal voltage differences to obtain: a ⁢ group ⁢ 1 : ❘ "\[LeftBracketingBar]" U 1 ⁢ 1 ⁢ 2 ❘ "\[RightBracketingBar]" ❘ "\[LeftBracketingBar]" U 1 ⁢ 2 ⁢ 3 ❘ "\[RightBracketingBar]" … ❘ "\[LeftBracketingBar]" U 1 ⁢ t ⁡ ( t + 1 ) ❘ "\[RightBracketingBar]" … ❘ "\[LeftBracketingBar]" U 1 ⁢ T ⁢ 1 ❘ "\[RightBracketingBar]" a ⁢ group ⁢ 2 : ❘ "\[LeftBracketingBar]" U 2 ⁢ 1 ⁢ 2 ❘ "\[RightBracketingBar]" ❘ "\[LeftBracketingBar]" U 2 ⁢ 2 ⁢ 3 ❘ "\[RightBracketingBar]" … ❘ "\[LeftBracketingBar]" U 2 ⁢ t ⁡ ( t + 1 ) ❘ "\[RightBracketingBar]" … ❘ "\[LeftBracketingBar]" U 2 ⁢ T ⁢ 1 ❘ "\[RightBracketingBar]" ⋮ ⋮ ⋮ ⋮ ⋮ a ⁢ group ⁢ n : ❘ "\[LeftBracketingBar]" U n ⁢ 1 ⁢ 2 ❘ "\[RightBracketingBar]" ❘ "\[LeftBracketingBar]" U n ⁢ 2 ⁢ 3 ❘ "\[RightBracketingBar]" … ❘ "\[LeftBracketingBar]" U n ⁢ t ⁡ ( t + 1 ) ❘ "\[RightBracketingBar]" … ❘ "\[LeftBracketingBar]" U n ⁢ T ⁢ 1 ❘ "\[RightBracketingBar]" ⋮ ⋮ ⋮ ⋮ ⋮ a ⁢ group ⁢ N : ❘ "\[LeftBracketingBar]" U n ⁢ 1 ⁢ 2 ❘ "\[RightBracketingBar]" ❘ "\[LeftBracketingBar]" U N ⁢ 2 ⁢ 3 ❘ "\[RightBracketingBar]" … ❘ "\[LeftBracketingBar]" U N ⁢ t ⁡ ( t + 1 ) ❘ "\[RightBracketingBar]" … ❘ "\[LeftBracketingBar]" U N ⁢ T ⁢ 1 ❘ "\[RightBracketingBar]" so as to obtain the absolute values of the terminal voltage differences.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The application claims priority to Chinese patent application No. 2024103465108, filed on Mar. 26, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD The present invention relates to the technical field of superconducting motor quench detection, and specifically, to a superconducting motor quench detection method and apparatus based on rotational symmetry of a motor. BACKGROUND Superconducting motors exhibit potential application prospects in high-capacity propulsion systems, high-power direct-driven wind turbines, and other fields due to their advantages of high power density and high efficiency. However, due to external disturbances and other reasons, superconducting magnets used for the superconducting motors may undergo quench faults. When quench occurs in the superconducting magnets, it not only leads to degradation of current-carrying capacity but may also cause irreversible damage to the superconducting motors. Therefore, it is necessary to detect quench faults of the superconducting motors in an early stage, thus avoiding serious consequences caused by the progression of quench degrees of the superconducting magnets. At present, superconducting magnet quench detection methods include temperature detection, pressure detection, flow rate detection, ultrasonic wave detection, optical fiber temperature measurement, and voltage detection, etc. For example, the invention patent application Ser. No. 200710175335.7 discloses a superconducting coil quench detection method, No. 202210224963.4 discloses a superconducting coil quench detection apparatus based on an active power method, No. 202311555618.X discloses a superconducting magnet quench detection system and method based on distributed optical fiber acoustic wave sensing, and No. 202311535540.5 discloses a high-temperature superconductor quench detection method and system based on ultrasonic waveguides, and the like. Temperature-based detection involves implementing temperature detection of the superconducting magnets by arranging thermocouples or other temperature sensors on the superconducting magnets. This method can only detect temperature variations at a certain point, requiring increased installation density of the sensors to achieve detection of the overall magnets, which poses certain difficulties. In addition, temperature detection has a lag and can only be used as a backup quench detection method. Pressure detection and flow rate detection involve performing quench detection on the superconducting magnets by detecting quench of variations in pressure and flow rates of coolants in cooling pipelines, which has a large lag and poor reliability. Signals detected by ultrasonic wave detection methods are weak and susceptible to external interference, resulting in poor reliability. Optical fiber temperature measurement involves implementing temperature variation detection on the superconducting magnets by detecting reflected wave parameters of optical fibers installed on the superconducting magnets, requiring higher equipment costs. Conventional quench detection methods based on voltage signals offer operational convenience. However, due to the presence of excitation magnetic fields and armature magnetic fields in the superconducting motors, terminal voltages of the superconducting magnets are coupled with induced voltage components, which leads to decrease in accuracy and reliability of the quench detection methods based on the voltage signals. Therefore, how to solve the problem of induced voltage interference is a current research focus in the quench detection methods based on the voltage signals. SUMMARY The technical problem to be solved by the present invention is to provide a superconducting motor quench detection method and apparatus based on rotational symmetry of a motor, aiming to solve the problem of induced voltage interference encountered when existing quench detection methods based on voltage signals are applied to a superconducting motor. To solve the above technical problem, the present invention provides the following technical solutions: In one aspect, a superconducting motor quench detection method based on rotational symmetry of a motor is provided, including: step 101: acquiring terminal voltages of each group of superconducting magnets in a superconducting motor, where the superconducting motor is pre-divided into at least two unit motors by using the rotational symmetry of the motor, and superconducting magnets located at corresponding positions are selected from the at least two unit motors as a group of superconducting magnets;step 102: calculating an absolute value of a terminal voltage difference of each group of superconducting magnets; andstep 103: judging whether the absolute value exceeds a preset threshold, and if the absolute value exceeds the preset threshold, determining that the superconducting magnets are in a quench state. In another a