Magnetic gap length estimation device, magnetic gap length estimation method, and drive device for rotating electric motor

Abstract

A magnetic gap length estimation device is provided that does not require a current sensor or current load and does not require measurement of the voltage at the neutral point of the wiring. The magnetic gap length estimation device (1) for estimating the magnetic gap length in an M-group N-phase rotating motor driven by an inverter includes: a voltage acquisition unit (2) for acquiring the line-to-line no-load induced voltage when there is no load; and a magnetic gap estimation unit (3). The magnetic gap estimation unit includes: a spectrum analysis unit (37) for converting the line-to-line no-load induced voltage acquired by the voltage acquisition unit into the amplitude and phase of each frequency; a frequency analysis unit (38) for extracting the amplitude and phase of the fundamental component and the Nth harmonic component of the line-to-line no-load induced voltage; and an estimation calculation unit (35) for estimating the magnetic gap length.

Description

Technical Field

[0001] This application relates to a magnetic gap length estimation device, a magnetic gap length estimation method, and a drive device for a rotating electric motor. Background Technology

[0002] In rotating electrical machines such as electric motors, there exists static eccentricity, where the rotor's central axis is misaligned with the stator's central axis, and dynamic eccentricity, where the rotor's shape center is misaligned with its rotation center. This eccentricity causes magnetic imbalance in the magnetic gap between the rotor and stator. This magnetic imbalance contributes to low-frequency vibrations and noise. During the manufacturing process of rotating electrical machines, eccentricity, which causes magnetic imbalance in the magnetic gap, arises in processes such as rotor assembly, rotor insertion into the stator, and sealing the rotating shaft with a bracket after insertion. Furthermore, this eccentricity can also occur due to malfunctions in the rotor's bearings during the operation of the rotating electrical machine. Therefore, it is difficult to completely eliminate eccentricity in rotating electrical machines. Consequently, techniques for detecting and correcting eccentricity during the manufacturing process and techniques for analyzing the current and voltage of the rotating electrical machine during operation to detect eccentricity are needed.

[0003] As a method for detecting eccentricity in rotating electric machines, the following techniques have been proposed: In electric motors employing magnetic bearing systems, the eccentricity is estimated by detecting the circulating current flowing through parallel connecting lines (see, for example, Patent Document 1). Additionally, as another method, a technique has been proposed for estimating the eccentricity in bearingless motors by detecting the three-phase induced voltage using position control windings (see, for example, Patent Document 2). Furthermore, as yet another method, a technique has been proposed for estimating the eccentricity by detecting the phase voltage and phase current of the inverter supplying power to the induction motor during the drive process (see, for example, Patent Document 3).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 6193377

[0007] Patent Document 2: Japanese Patent No. 3044539

[0008] Patent Document 3: Japanese Patent No. 3561882 Summary of the Invention

[0009] The technical problem that the invention aims to solve

[0010] In conventional methods that estimate eccentricity by detecting the circulating current flowing through parallel connections, a current sensor for detecting the circulating current is essential. Therefore, applying this method to eccentricity checks in manufacturing processes leads to a problem of increasing the size of the inspection equipment. Furthermore, this method contradicts the recent trend towards miniaturized, sensorless drive systems for rotating electric machines. Additionally, methods that estimate eccentricity by detecting three-phase induced voltage require a current load to detect the voltage. Therefore, applying this method to eccentricity checks in manufacturing processes also leads to a problem of increasing the size of the inspection equipment. Moreover, methods that estimate eccentricity by detecting the phase voltage and phase current of the inverter require measuring the voltage at the neutral point of the wiring to determine the phase voltage. Therefore, it is difficult to use this method for eccentricity checks in manufacturing processes. Furthermore, applying this method to drive systems for rotating electric machines leads to a problem of increasing system size.

[0011] This application is made to solve the aforementioned technical problems, and aims to provide a magnetic gap length estimation device that does not require a current sensor and current load and does not require measuring the voltage of the neutral point of the wiring.

[0012] Technical solutions for solving technical problems

[0013] The magnetic gap length estimation device of this application is for estimating the magnetic gap length in an M-group N-phase rotating motor, where M is a natural number and N is a natural number greater than 2. The M-group N-phase rotating motor is configured with a phase difference of 360 / N degrees between each phase and is driven by an inverter. The magnetic gap length estimation device includes: a voltage acquisition unit for acquiring the no-load induced voltage between the lines when there is no load; and a magnetic gap estimation unit for estimating the magnetic gap length of the rotating motor. The magnetic gap estimation unit includes: a spectrum analysis unit for converting the no-load induced voltage between the lines acquired by the voltage acquisition unit into the amplitude and phase of each frequency; a frequency analysis unit for extracting the amplitude and phase of the fundamental component and the Nth harmonic component of the no-load induced voltage between the lines from the amplitude and phase of each frequency obtained by the spectrum analysis unit; and an estimation calculation unit for estimating the magnetic gap length of the rotating motor based on the amplitude and phase of the fundamental component and the Nth harmonic component of the no-load induced voltage between the lines extracted by the frequency analysis unit.

[0014] Invention Effects

[0015] In the magnetic gap length estimation device of this application, the magnetic gap estimation unit includes: a spectrum analysis unit that converts the line-to-line no-load induced voltage acquired by the voltage acquisition unit into the amplitude and phase of each frequency; a frequency analysis unit that extracts the amplitude and phase of the fundamental component and the Nth harmonic component of the line-to-line no-load induced voltage; and an estimation calculation unit that estimates the magnetic gap length of the rotating motor. Therefore, there is no need for a current sensor and a current load, and there is no need to measure the voltage of the neutral point of the wiring. Attached Figure Description

[0016] Figure 1 This is a structural diagram of the magnetic gap length estimation device according to Embodiment 1.

[0017] Figure 2 This is a structural diagram of the magnetic gap estimation section in Embodiment 1.

[0018] Figure 3 This is a structural diagram of the rotary electric motor according to Embodiment 1.

[0019] Figure 4 This is a wiring diagram for the rotary motor in Embodiment 1.

[0020] Figure 5 This is a schematic diagram of the rotary motor according to Embodiment 1.

[0021] Figure 6 This is a flowchart of the method for estimating the magnetic gap length in Implementation Method 1.

[0022] Figure 7 An explanatory diagram showing the fundamental component of the phase voltage in the rotating electric machine of Embodiment 1.

[0023] Figure 8 An explanatory diagram showing the third harmonic component of the phase voltage in the rotating electric machine of Embodiment 1.

[0024] Figure 9 This is an explanatory diagram of the method for estimating the magnetic gap length in Implementation Method 1.

[0025] Figure 10 This is an explanatory diagram of the method for estimating the magnetic gap length in Implementation Method 1.

[0026] Figure 11 This is an explanatory diagram of the method for estimating the magnetic gap length in Implementation Method 1.

[0027] Figure 12 This is an explanatory diagram of the method for estimating the magnetic gap length in Implementation Method 1.

[0028] Figure 13 A diagram showing the estimation results of the magnetic gap length estimation device of Embodiment 1.

[0029] Figure 14This is a structural diagram of the rotary electric motor according to Embodiment 1.

[0030] Figure 15 This is a structural diagram of the drive device for the rotary electric motor in Embodiment 2.

[0031] Figure 16 This is a structural diagram of the magnetic gap length estimation device in Embodiment 3.

[0032] Figure 17 This is a structural diagram of the rotary motor in Embodiment 3.

[0033] Figure 18 This is a structural diagram of the rotary motor in Embodiment 3.

[0034] Figure 19 This is a structural diagram of the rotary motor in Embodiment 3.

[0035] Figure 20 This is a structural diagram of the magnetic gap length estimation device in Embodiment 4.

[0036] Figure 21 This is a structural diagram of the rotary motor in embodiment 4.

[0037] Figure 22 An explanatory diagram showing the fundamental component of the phase voltage in the rotating electric machine of Embodiment 4.

[0038] Figure 23 This is a structural diagram of the magnetic gap length estimation device in Embodiment 5.

[0039] Figure 24 This is a structural diagram of the rotary motor in Embodiment 5.

[0040] Figure 25 This is a structural diagram of the rotary motor in Embodiment 5.

[0041] Figure 26 An explanatory diagram showing the fundamental component of the phase voltage in the rotating electric machine of Embodiment 5.

[0042] Figure 27 This is a structural diagram of the drive device for the rotary electric motor according to Embodiment 6.

[0043] Figure 28 This is a schematic diagram illustrating an example of the hardware of the magnetic gap length estimation device and the drive device of the rotary electric motor according to embodiments 1 to 6.

[0044] Figure Labels

[0045] 1: Magnetic gap length estimation device; 2: Voltage acquisition unit; 3: Magnetic gap estimation unit; 4a, 4b, 4c, 4d: Inverter; 5: Rotating motor; 6, 8: External output terminals; 7: Control parameter calculation unit; 10: Drive unit; 31: Memory unit; 32: Basic characteristic storage unit; 33: Estimation reference storage unit; 34: Analysis unit; 35: Estimation calculation unit; 36: Calculation result storage unit; 37: Spectrum analysis unit; 38: Frequency analysis unit; 51: Stator; 52: Rotor; 100: Processor; 101: Storage device. Detailed Implementation

[0046] The magnetic gap length estimation device and the drive device for the rotary electric motor used in implementing the embodiments of this application will be described in detail below with reference to the accompanying drawings. Furthermore, the same reference numerals in the figures denote the same or equivalent parts.

[0047] Implementation method 1.

[0048] Figure 1 This is a structural diagram of the magnetic gap length estimation device according to Embodiment 1. The magnetic gap length estimation device in this embodiment is a device for estimating the magnetic gap length of three sets of three-phase rotating motors driven by inverters. The magnetic gap length estimation device 1 of this embodiment includes a voltage acquisition unit 2 and a magnetic gap estimation unit 3. The voltage acquisition unit 2 acquires the voltage of the nine wires connecting the three inverters 4a, 4b, and 4c to the rotating motor 5. The magnetic gap estimation unit 3 estimates the magnetic gap. This magnetic gap estimation unit has an external output terminal 6. For example, by connecting an external monitor to this external output terminal 6, the state of the magnetic gap can be visualized.

[0049] Figure 2 This is a structural diagram of the magnetic gap estimation unit 3 according to this embodiment. The magnetic gap estimation unit 3 includes: a memory unit 31 that stores data sent from the voltage acquisition unit 2; a basic characteristic storage unit 32 that stores the basic characteristics of the rotary motor; an estimation reference storage unit 33 that stores data as a reference for estimating the magnetic gap length; an analysis unit 34 that extracts the amplitude and phase of the fundamental component and the Nth harmonic component of the line-to-line unloaded induced voltage based on the data sent from the memory unit 31; an estimation calculation unit 35 that performs estimation calculations on the magnetic gap length based on the data extracted by the analysis unit 34; and a calculation result storage unit 36 ​​that stores the calculation results estimated by the estimation calculation unit 35.

[0050] The basic characteristic storage unit 32 stores various parameters such as the dimensions and standard speed of the rotating motor 5 to be measured. The estimation reference storage unit 33 stores estimation reference data required to estimate the magnetic gap length. Estimation reference data may include, for example, the relationship between the no-load induced voltage between the coils of the rotating motor 5 and the magnetic gap length. This estimation reference data is obtained in advance through measurement or calculated in advance through theoretical calculation. Here, the no-load induced voltage between the coils refers to the voltage induced between the coils when the rotating motor is rotated at its rated speed under no-load conditions without applying current to the armature. Furthermore, the no-load induced voltage between the coils will hereafter be simply referred to as the coil voltage.

[0051] The analysis unit 34 includes: a spectrum analysis unit 37, which transforms the data obtained from the memory unit 31 into amplitude and phase information for each frequency; and a frequency analysis unit 38, which extracts the amplitude and phase of the fundamental component and the Nth harmonic component of the phase voltage from the amplitude and phase of each frequency. Although the spectrum analysis unit 37 uses an algorithm such as the Fast Fourier Transform to transform the data into amplitude and phase information, other algorithms can be used as long as the same spectrum analysis algorithm can be implemented.

[0052] Figure 3 This is a structural diagram of the rotary motor 5, which is the object of measurement in this embodiment. Figure 3 The rotary motor 5 shown is envisioned as a 3-group, 3-phase, 6-pole, 36-slot rotary motor with an inverter-driven structure. Furthermore, Figure 3 The rotor is omitted. The stator 51 is a structure formed by independently wound coils in three groups: group 1, group 2, and group 3. Each group is arranged circumferentially along the stator with a mechanical angular phase difference of 360 / 3 = 120°. Furthermore, in Figure 3 In this embodiment, the direction of current flowing through each coil is represented by two symbols. A comma with a cross indicates current flowing from the outside to the inside of the paper, while a comma with a black dot indicates current flowing from the inside to the outside. The stator 51 of the rotary motor 5 in this embodiment has a distributed winding structure with coils arranged across multiple slots. The three groups each include phases U, V, and W, and each phase includes two coils. For example, U1, representing the U-phase coil of group 1, has two coils, U11 and U12. Figure 3 In the diagram, arrows indicate the winding direction of each coil in group 1. The winding direction of each coil in groups 2 and 3 is the same as that in group 1. Each coil in each group is wound continuously circumferentially in the order of U, W, V phases. For example, in group 1, the coils are arranged counterclockwise in the order of U11, U12, W11, W12, V11, V12. The same arrangement is used in groups 2 and 3.

[0053] That is, when M and K are natural numbers and N is a natural number greater than 2, when the m-th group, n-th phase, k-th coil of a rotary motor with M groups and N phases, each phase including K coils, is recorded as C(m, n, k), in the rotary motor 5 of this embodiment, 1≤m≤M, 1≤n≤N, 1≤k≤K, and M=3, N=3, K=2. Furthermore, the coils of the rotary motor 5 are arranged counterclockwise from group 1 in the following sequence: C(1,1,1), C(1,1,2), C(1,2,1), C(1,2,2), C(1,3,1), C(1,3,2), C(2,1,1), C(2,1,2), C(2,2,1), C(2,2,2), C(2,3,1), C(2,3,2), C(3,1,1), C(3,1,2), C(3,2,1), C(3,2,2), C(3,3,1), C(3,3,2). By continuously arranging the coils of each group and each phase in this circumferential manner, the amplitude difference of the voltage waveform of each phase caused by the imbalance of the magnetic gap length due to static and dynamic eccentricity increases. Details will be explained later. As the amplitude difference of each phase voltage waveform increases, the difference of the Nth harmonic component of the inter-line voltage used to estimate the magnetic gap length also increases, thus further improving the estimation accuracy of the magnetic gap length.

[0054] Figure 4 This is the wiring diagram of the rotating electric motor in this embodiment. Each group of coils is configured with its own independent Y-connection, and the coils of each phase are connected in series. By adopting this circuit structure, the amplitude difference of the voltage waveforms of each phase becomes larger, and therefore, for the same reasons as above, the estimation accuracy of the magnetic gap length can be further improved. Furthermore, because the coils of each group are Y-connected and the coils of each phase are connected in series, no circulating current is generated. Therefore, there is no influence from the induced voltage caused by circulating current, thus improving the detection accuracy of the line-to-line voltage.

[0055] The method for estimating the magnetic gap length of the magnetic gap length estimation device 1 in this embodiment will be described next. Figure 5 This is a schematic diagram illustrating a state of static eccentricity in a rotating electric motor of the test object. In this rotating electric motor 5, it is assumed that the central axis of the rotor 52 is eccentric relative to the direction of the central axis group 3 of the stator 51. In this case, the magnetic gap between the stator 51 and the rotor 52 becomes uneven along the circumferential direction. The explanation for this will be provided later. Figure 5 The method for estimating the magnetic gap length of the rotating electric machine is shown.

[0056] Figure 6This is a flowchart of the method for estimating the magnetic gap length according to this embodiment. In step S1, using phase U1 as a reference, the line-to-line unloaded induced voltage (hereinafter referred to as line-to-line voltage) is obtained between phase U1 and other phases. Specifically, the voltage acquisition unit 2 of the magnetic gap length estimation device 1 acquires the line-to-line voltages between U1-V1, U1-W1, U1-U2, U1-V2, U1-W2, U1-U3, U1-V3, and U1-W3. Next, in step S2, the voltage acquisition unit 2 sends the acquired line-to-line voltage data to the magnetic gap estimation unit 3. The magnetic gap estimation unit 3 stores the received line-to-line voltage data in the memory unit 31.

[0057] Next, in step S3, the spectrum analysis unit 37 of the analysis unit 34 performs spectrum analysis on the line-to-line voltage data stored in the memory unit 31. Specifically, the spectrum analysis unit 37 applies a fast Fourier transform algorithm to the line-to-line voltage data to transform it into amplitude and phase information for each frequency. Next, in step S4, the frequency analysis unit 38 extracts the amplitude and phase of the fundamental component and the Nth harmonic component of each line-to-line voltage from the amplitude and phase information for each frequency.

[0058] Here, the relationship between the fundamental and Nth harmonic components of the phase voltage and the line-to-line voltage and the magnetic gap length is explained. Furthermore, in this embodiment, N = 3.

[0059] Figure 7 and Figure 8 This is an explanatory diagram showing the phase voltage and line voltage of groups 1 and 3 of the rotating electric motor 5. Figure 7 This is the vector representation of the fundamental component. Figure 8 This is the vector representation of the third harmonic component. Figure 7 and Figure 8 In the diagram, solid arrows represent vectors of group 1, and dashed arrows represent vectors of group 3. It is assumed that, in the absence of static eccentricity (i.e., when the magnetic gap length is uniform), the fundamental phase difference of the phase voltage components in each group is 120°, and the third harmonic components of each group are in phase. However, in cases such as... Figure 5 When the gap length in group 3 becomes shorter, the magnetic flux through the coil increases due to the decrease in the magnetic reluctance of the gap. Therefore, the phase voltage of group 3 increases compared to the case where the gap length is uniform. On the other hand, because the gap length in group 1 becomes wider, the magnetic flux through the coil decreases due to the increase in the magnetic reluctance of the gap in group 1. Therefore, the phase voltage of group 1 decreases compared to the case where the gap length is uniform. This corresponds to... Figure 7 and Figure 8 The cases where the vector lengths of phases U3, V3, and W3 in group 3 are greater than the vector lengths of phases U1, V1, and W1 in group 1, respectively.

[0060] Furthermore, due to static eccentricity, the magnetic flux through each coil becomes uneven, causing the phase of the phase voltage to deviate from the phase of the phase voltage when the magnetic gap length is uniform. Therefore, the direction of the vector in group 1 differs from the direction of the vector in group 3. This is of concern. Figure 8 The third harmonic component is shown. Assuming a uniform magnetic gap length, since the lengths and directions of the phase voltage vectors in all groups are consistent, no line-to-line voltage, represented as the difference between phase voltage vectors, will be generated. However, when the magnetic gap length is non-uniform, the lengths and directions of the phase voltage vectors in each group will differ. Therefore, as... Figure 8 As shown, line-to-line voltages are generated between U1-U3, U1-V3, and U1-W3. In other words, it can be seen that the third harmonic component of the line-to-line voltage is a characteristic quantity exhibited when the magnetic gap length is uneven.

[0061] Next, return to Figure 6 The flowchart illustrates the method for estimating the magnetic gap length.

[0062] In step S5, the frequency analysis unit 38 uses the fundamental component of each inter-line voltage to estimate the fundamental component and third harmonic component of the phase voltage. In this estimation, it is assumed that the phase deviation of the phase voltage when the magnetic gap length is uneven is small compared with the phase voltage when the magnetic gap length is uniform, and this deviation is ignored. The theoretical relative relationship between the inter-line voltage vector and the phase voltage vector is used. Figure 9 This diagram illustrates the method for estimating the phase voltage of phase U1 and the phase of the third harmonic component based on the line-to-line voltage of U1-V1 in step S5. Figure 9 The estimation method shown assumes a sine wave as the phase voltage waveform of phase U1. The phase fundamental component of the phase voltage of phase U1 lags behind the phase fundamental component of the line-to-line voltage of U1-V1 by 30°, and the phase of the third harmonic component of the phase voltage of phase U1 is three times the phase of the phase fundamental component of the phase voltage of phase U1. This is based on the theory of AC circuits and... Figure 7 and Figure 8 The relationship between the vectors is obvious. Using this relationship, the phase of the third harmonic component of the phase voltage of phase U1 can be estimated. Furthermore, assuming a cosine wave as the phase voltage waveform of phase U1, it is clear that the phase of the third harmonic component of the phase voltage of phase U1 is 180° different from three times the phase of the fundamental component of the phase voltage of phase U1.

[0063] Next, the estimation calculation unit 35 uses the third harmonic component of the line voltage and the third harmonic component of the phase voltage to estimate the magnetic gap length. Therefore, in step S6, the estimation calculation unit 35 estimates the absolute value of the displacement of the magnetic gap length at the center position of the group with each phase coil wound relative to the magnetic gap length at the center position of the group with the reference phase coil wound. Next, in step S7, the estimation calculation unit 35 estimates whether the displacement of the magnetic gap length at the center position of the group with each phase coil wound relative to the magnetic gap length at the center position of the group with the reference phase coil wound is positive or negative based on the relationship between the phase of the third harmonic component of the line voltage and the phase of the third harmonic component of the phase voltage estimated in step S5.

[0064] Figure 10 This is an explanatory diagram illustrating an example of the relationship between the displacement of the magnetic gap length of the reference phase and other phases and the amplitude of the third harmonic component of the inter-line voltage. As explained in step S5, assuming that the phase voltage phase deviation is small when the magnetic gap length is uneven and when the magnetic gap length is uniform, the displacement of the magnetic gap length is related to, and approximately proportional to, the amplitude of the third harmonic component of the inter-line voltage. A database of the relationship between the displacement of the magnetic gap length of the reference phase and each phase and the amplitude of the third harmonic component of the inter-line voltage is created in advance through theoretical calculations, simulations, experiments, etc., and stored in the estimation reference storage unit 33. In step S6, the estimation calculation unit 35 uses the relationship between the displacement of the magnetic gap length of the reference phase and other phases and the amplitude of the third harmonic component of the inter-line voltage stored in the estimation reference storage unit 33 to estimate the absolute value of the displacement of the magnetic gap length of the group with each phase coil wound on it.

[0065] Figure 11 and Figure 12 An explanatory diagram illustrating an example of a method for determining the direction of narrowing or widening of the magnetic gap length. Figure 11 and Figure 12 The relationship between the phases of the third harmonic component of the phase voltage estimated in step S5 is shown. Figure 11 This shows the case where the third component of the phase voltage of phase V3 is greater than the third component of the phase voltage of phase U1. Figure 12 This illustrates the case where the third component of the phase voltage of phase V3 is less than the third component of the phase voltage of phase U1. For example... Figure 11 As shown, the case where the third component of the phase voltage of phase V3 is greater than the third component of the phase voltage of phase U1 corresponds to the case where the magnetic gap length of group 3, with the V3 phase coil wound, is smaller than the magnetic gap length of group 1, with the U1 phase coil wound. In this case, the direction of the vector of the third component of the U1-V3 line voltage is within a range of 90° or more and less than 270° relative to the direction of the vector of the third component of the phase voltage of phase U1, which serves as the reference. On the other hand, as... Figure 12As shown, the case where the third component of the phase voltage of phase V3 is less than the third component of the phase voltage of phase U1 corresponds to the case where the magnetic gap length of group 3, which has the V3 phase coil wound, is larger than the magnetic gap length of group 1, which has the U1 phase coil wound. In this case, the direction of the vector of the third component of the U1-V3 line voltage relative to the direction of the vector of the third component of the phase voltage of the reference U1 phase is in the range of 0° or more and less than 90°, or 270° or more and less than 360°. In step S7, the estimation calculation unit 35 uses this relationship to estimate whether the displacement of the magnetic gap length of the group with each phase coil wound is positive or negative relative to the magnetic gap length of the group with the reference phase coil wound. As shown in this embodiment, the case where static eccentricity occurs in the direction of decreasing magnetic gap length of group 3 is... Figure 8 The relationship shown is related to... Figure 11 The relationship shown is the same. Therefore, it can be determined that the magnetic gap length of group 3, which has the V3 phase coil wound on it, is smaller than the magnetic gap length of group 1, which has the U1 phase coil wound on it.

[0066] The magnetic gap length estimation device 1 of this embodiment can estimate the magnetic gap length of the rotating motor to be measured. Figure 13 To illustrate the magnetic gap length estimation device 1 of this embodiment... Figure 5 The diagram shows the result obtained by estimating the magnetic gap length of the rotating electric motor. Figure 13 In the diagram, the dashed circular line represents the magnetic gap length without eccentricity, the solid circular line represents the theoretically calculated magnetic gap value with eccentricity based on prior analytical data, and the black dots represent the estimated magnetic gap length in this embodiment. In this embodiment, the magnetic gap length is estimated using three sets of three-phase rotating motors, thus allowing the estimation of the magnetic gap length at 3×3=9 points. Furthermore, in Figure 13 In order to make it easy to visually grasp the spatial distribution of the magnetic gap length, the angle between the line segment connecting the origin and each estimated point is set to be consistent with the angle between the line segment connecting the center of the actual structure of the rotating electric machine and the center of the assembly, so that the spatial arrangement of the nine estimated points of the magnetic gap length corresponds to the actual structure of the rotating electric machine. Then, the distance from the origin to each estimated point is set as a relative value obtained by adding or subtracting the displacement of each estimated point when the magnetic gap length of the winding position of the reference phase is set to 1.

[0067] like Figure 13As shown, the magnetic gap length estimation device 1 of this embodiment can estimate the relative value of the magnetic gap length of each phase in other groups at the center position to the magnetic gap length of group 1 with the reference phase U1 wound around it at the center position. Furthermore, it can be seen that the theoretically calculated value, represented by the solid circular line, is generally consistent with the estimated value of the magnetic gap length obtained by the magnetic gap length estimation device 1 of this embodiment. However, an error may also occur between the theoretically calculated value and the estimated value. It is generally believed that this error is caused by the small deviation between the phase of the phase voltage when the magnetic gap length is assumed to be uneven in step S6 and the phase of the phase voltage when the magnetic gap length is uniform. Even with some errors, the magnetic gap length estimation device of this embodiment can clearly estimate the location and direction of the eccentricity.

[0068] As described above, the magnetic gap length estimation device of this embodiment includes: a voltage acquisition unit for acquiring the line-to-line voltage induced under no-load conditions; and a magnetic gap estimation unit for estimating the magnetic gap length of the rotating motor. Furthermore, the magnetic gap estimation unit includes: a spectrum analysis unit for converting the line-to-line voltage into amplitude and phase at each frequency; a frequency analysis unit for extracting the amplitude and phase of the fundamental component and the Nth harmonic component of the line-to-line voltage from the amplitude and phase of each frequency; and an estimation calculation unit for estimating the magnetic gap length of the rotating motor based on the amplitude and phase of the fundamental component and the Nth harmonic component of the line-to-line voltage. Therefore, the magnetic gap length estimation device of this embodiment does not require a current sensor or a current load, and it does not require measuring the voltage at the neutral point of the wiring.

[0069] Furthermore, although this embodiment shows an example using phase U1 as the reference phase, the same effect can be obtained by using any other phase as the reference phase. Additionally, this embodiment shows an example of static eccentricity where the gap length decreases in the direction of group 3. The gap length estimation device of this embodiment can also achieve the same effect when static eccentricity occurs in a direction other than this. Furthermore, for dynamic eccentricity, this gap length estimation device estimates the gap length at unit intervals, taking into account the change in the direction of gap length decreases or increases over time, thereby achieving the same effect. Moreover, in cases where an imbalance in the gap length occurs due to factors other than static or dynamic eccentricity, and a difference in the unloaded induced voltage between the reference phase and other phases arises, the gap length estimation device of this embodiment can also achieve the same effect.

[0070] In this embodiment, the voltage acquisition unit of the magnetic gap length estimation device is connected to all nine wires of the three groups of three-phase windings. As the magnetic gap length estimation device of this embodiment, as long as the voltage acquisition unit is connected to at least two of the three wires in each group, the magnetic gap length can still be estimated even though the number of measurement points is reduced.

[0071] Figure 14This is a structural diagram of another rotating electric machine that is the object of measurement for the magnetic gap length estimation device in this embodiment. Furthermore, in Figure 14 The rotor is omitted. Additionally, in Figure 14 In this diagram, the direction of the current flowing through each coil is indicated by two symbols. Figure 14 The stator 51 shown is a 6-pole, 9-slot structure with the coils wound in a concentrated manner on a single tooth. In this rotary motor 5, when the k-th coil of the n-th phase in the m-th group is denoted as C(m, n, k), 1 ≤ m ≤ M, 1 ≤ n ≤ N, 1 ≤ k ≤ K, and M = 3, N = 3, K = 1. Furthermore, the coils of this rotary motor 5 are arranged counterclockwise from group 1 in the order C(1, 1, 1), C(1, 2, 1), C(1, 3, 1), C(2, 1, 1), C(2, 2, 1), C(2, 3, 1), C(3, 1, 1), C(3, 2, 1), C(3, 3, 1). In such a concentrated-winding rotary motor, the coils of each phase in each group are arranged continuously circumferentially, thus increasing the amplitude difference of the voltage waveforms of each phase due to the imbalance of the magnetic gap length caused by eccentricity. Therefore, since the difference in the third harmonic components of the voltage between each line also increases, the estimation accuracy of the magnetic gap length can be further improved.

[0072] Furthermore, in the magnetic gap length estimation device of this embodiment, the line-to-line voltage between other phases and the reference phase is measured. This line-to-line voltage also includes the line-to-line voltage between two phases belonging to different groups. The coils of each group are configured with their own independent Y-connection. Therefore, the offset component of the potential difference caused by the independent electrical properties of the coils in each group may be included in the line-to-line voltage between two phases belonging to different groups. To eliminate this offset component, the neutral points of the Y-connections of the coils in each group can be electrically connected to each other.

[0073] Implementation method 2.

[0074] Figure 15 This is a structural diagram of the drive device for the rotating electric machine according to Embodiment 2. The drive device 10 for the rotating electric machine in this embodiment includes the gap length estimation device 1 of Embodiment 1 and a control parameter calculation unit 7 that sends control parameters to the three inverters 4a, 4b, and 4c. The control parameter calculation unit 7 sends control parameters to the three inverters 4a, 4b, and 4c, respectively, to adjust the current input values ​​for each group of the rotating electric machine 5 based on the gap length estimated by the gap length estimation device 1. Furthermore, the control parameter calculation unit 7 has an external output terminal 8. For example, by connecting an external monitor to this external output terminal 8, the state of the gap and the control parameters can be visualized.

[0075] For example, as described in Embodiment 1, when the rotary motor 5 has a static eccentricity in the direction of decreasing magnetic gap length in group 3, the current input value for the coil belonging to group 3 is set to be less than the current input value for the coils belonging to groups 1 and 2. By controlling it in this way, vibration and noise caused by eccentricity can be reduced.

[0076] Furthermore, in this embodiment, the voltage acquisition unit of the magnetic gap length estimation device is connected to all nine wires of the three sets of three-phase windings. As the drive device for the rotating electric machine in this embodiment, as long as the voltage acquisition unit is connected to at least one of the three wires in each set, the direction of magnetic gap length displacement can still be estimated and control parameters can be calculated even though the number of measurement points is reduced.

[0077] Implementation method 3.

[0078] Figure 16 This is a structural diagram of the magnetic gap length estimation device according to Embodiment 3. The magnetic gap length estimation device of this embodiment uses a set of three-phase rotating motors driven by an inverter as the object of measurement. The magnetic gap length estimation device 1 of this embodiment includes a voltage acquisition unit 2 and a magnetic gap estimation unit 3. The structure of the magnetic gap length estimation device 1 of this embodiment is the same as that of the magnetic gap length estimation device of Embodiment 1. However, the voltage acquisition unit 2 acquires the voltage of the three wires connecting the inverter 4a and the rotating motor 5. The method for estimating the magnetic gap length of the magnetic gap length estimation device 1 of this embodiment is the same as the estimation method of Embodiment 1.

[0079] Figure 17 This is a structural diagram of the rotary motor 5, which is the object of measurement in this embodiment. Figure 17 The rotary motor 5 shown is a 3-phase, 2-pole, 36-slot rotary motor with an inverter-driven structure. Furthermore, Figure 17 The rotor is omitted. Stator 51 is a structure consisting only of group 1. Additionally, in... Figure 17 In this diagram, the direction of the current flowing through each coil is indicated by two symbols. The stator 51 of the rotary electric machine 5 has a distributed winding structure with coils arranged across multiple slots. Group 1 consists of three phases: U, V, and W, and each phase consists of six coils. For example, U1, representing the U-phase coil, has six coils: U11, U12, U13, U14, U15, and U16. Each coil is wound continuously circumferentially in the order of U, V, and W phases. The coils of the rotary electric machine 5 are arranged counterclockwise in the order of U11, U12, U13, U14, U15, U16, V11, V12, V13, V14, V15, V16, W11, W12, W13, W14, W15, W16.

[0080] That is, when the k-th coil of the n-th phase in the m-th group of a rotating electric machine consisting of M groups and N phases, each phase composed of K coils, is recorded as C(m, n, k), in Figure 17 In the rotary electric motor 5 shown, 1≤m≤M, 1≤n≤N, 1≤k≤K, and M=1, N=3, K=6. Furthermore, the coils of this rotary electric motor 5 are arranged counterclockwise in the order C(1,1,1), C(1,1,2), C(1,1,3), C(1,1,4), C(1,1,5), C(1,1,6), C(1,2,1), C(1,2,2), C(1,2,3), C(1,2,4), C(1,2,5), C(1,2,6), C(1,3,1), C(1,3,2), C(1,3,3), C(1,3,4), C(1,3,5), C(1,3,6). By continuously arranging the coils of each phase in this circumferential direction, the amplitude difference of the phase voltage waveform caused by the imbalance of the magnetic gap length increases. As the amplitude difference of the voltage waveforms of each phase increases, the difference of the third harmonic component of the inter-line voltage used to estimate the magnetic gap length also increases, thus further improving the estimation accuracy of the magnetic gap length.

[0081] Figure 18 This is a structural diagram of another rotary motor 5, which is the object of measurement in this embodiment. Figure 18 The rotary motor 5 shown is a 3-phase, 2-pole, 3-slot rotary motor with an inverter-driven structure. Furthermore, Figure 18 The rotor is omitted. Stator 51 has only group 1. Additionally, in Figure 18 In the diagram, the direction of the current flowing through each coil is indicated by two symbols. The stator 51 of the rotary electric machine 5 is constructed such that each phase coil is wound in a concentrated manner around a single tooth. Group 1 consists of three phases: U, V, and W.

[0082] When the k-th coil of the n-th phase in the m-th group of a rotating electric machine consisting of M groups and N phases, each phase composed of K coils, is denoted as C(m, n, k), Figure 18 In the rotary motor 5 shown, 1≤m≤M, 1≤n≤N, 1≤k≤K, and M=1, N=3, K=1. Furthermore, the coils of this rotary motor 5 are arranged counterclockwise in the order C(1,1,1), C(1,2,1), C(1,3,1). By arranging the three-phase coils continuously circumferentially in this concentrated winding rotary motor, the amplitude difference of the phase voltage waveforms caused by the imbalance of the magnetic gap length increases, further improving the accuracy of the estimation of the magnetic gap length.

[0083] Figure 19 This is a structural diagram of another rotary motor 5, which is the object of measurement in this embodiment. Figure 19The rotary motor 5 shown is a 3-phase, 8-pole, 9-slot rotary motor with an inverter-driven structure. Furthermore, in Figure 19 The rotor is omitted. Stator 51 has only group 1. Additionally, in Figure 19 In the diagram, the direction of the current flowing through each coil is indicated by two symbols. The stator 51 of the rotary electric machine 5 is constructed such that each phase coil is wound in a concentrated manner around a single tooth. Group 1 consists of three phases: U, V, and W.

[0084] When the k-th coil of the n-th phase in the m-th group of a rotating electric machine consisting of M groups and N phases, each phase composed of K coils, is denoted as C(m, n, k), Figure 19 In the rotary motor 5 shown, 1≤m≤M, 1≤n≤N, 1≤k≤K, and M=1, N=3, K=3. Furthermore, the coils of this rotary motor 5 are arranged counterclockwise in the order C(1,1,1), C(1,1,2), C(1,1,3), C(1,2,1), C(1,2,2), C(1,2,3), C(1,3,1), C(1,3,2), C(1,3,3). By arranging the three-phase coils continuously circumferentially in this way in a centrally wound rotary motor, the amplitude difference of the voltage waveforms of each phase caused by the imbalance of the magnetic gap length increases, further improving the accuracy of the estimation of the magnetic gap length.

[0085] In the magnetic gap length estimation device constructed in this way, similar to Embodiment 1, there is no need for a current sensor and current load, nor is it necessary to measure the voltage of the neutral point of the wiring.

[0086] Furthermore, in this embodiment, the voltage acquisition unit of the magnetic gap length estimation device is connected to all three wires of a three-phase winding. As the magnetic gap length estimation device of this embodiment, as long as the voltage acquisition unit is connected to at least two of the three wires, the magnetic gap length can still be estimated although the number of measurement points is reduced.

[0087] Furthermore, the magnetic gap length estimation device of this embodiment is used to construct the drive device for the rotary electric motor shown in Embodiment 2, and this drive device is applied to... Figure 19 When using the 8-pole, 9-slot rotary motor shown, even rotary motors with a combination of poles and slots that have low winding coefficients for the spatial harmonic order components can further reduce vibration and noise.

[0088] Implementation method 4.

[0089] Figure 20This is a structural diagram of the magnetic gap length estimation device according to Embodiment 4. The magnetic gap length estimation device of this embodiment uses a set of six-phase rotating motors driven by an inverter as the object of measurement. The magnetic gap length estimation device 1 of this embodiment includes a voltage acquisition unit 2 and a magnetic gap estimation unit 3. The structure of the magnetic gap length estimation device 1 of this embodiment is the same as that of the magnetic gap length estimation device of Embodiment 1. However, the voltage acquisition unit 2 acquires the voltage of the six wires connecting the inverter 4a and the rotating motor 5. Furthermore, the method for estimating the magnetic gap length of the magnetic gap length estimation device 1 of this embodiment differs in some aspects from the estimation method of Embodiment 1.

[0090] Figure 21 This is a structural diagram of the rotary motor 5, which is the object of measurement in this embodiment. Figure 21 The rotary motor 5 shown is a 6-phase, 2-pole, 6-slot rotary motor with an inverter-driven structure. Furthermore, in... Figure 21 The rotor is omitted. Stator 51 has only group 1. Additionally, in Figure 21 In this embodiment, the direction of the current flowing through each coil is indicated by two symbols. The stator 51 of the rotary electric machine 5 in this embodiment is constructed such that each phase coil is wound in a concentrated manner around one tooth. Group 1 includes six phases: A, B, C, D, E, and F, and each coil is arranged in a counterclockwise order of A1, B1, C1, D1, E1, and F1.

[0091] That is, when the k-th coil of the m-th group and n-th phase in a rotary electric machine consisting of M groups and N phases, each phase composed of K coils, is denoted as C(m, n, k), in the rotary electric machine 5 of this embodiment, 1 ≤ m ≤ M, 1 ≤ n ≤ N, 1 ≤ k ≤ K, and M = 1, N = 6, K = 1. Furthermore, the coils of this rotary electric machine 5 are arranged counterclockwise in the order C(1, 1, 1), C(1, 2, 1), C(1, 3, 1), C(1, 4, 1), C(1, 5, 1), C(1, 6, 1). By continuously arranging the coils of each group and each phase in this circumferential direction, the amplitude difference of the phase voltage waveform caused by the imbalance of the magnetic gap length increases. Since the difference in the amplitude of the phase voltage waveform increases, the difference in the Nth harmonic component of the inter-line voltage used to estimate the magnetic gap length also increases, thus further improving the estimation accuracy of the magnetic gap length.

[0092] Figure 22 This is a vector representation of the fundamental component of the phase voltage in the rotating electric motor 5 of this embodiment. Figure 22 The fundamental component of the phase voltage shown represents the vector when no eccentricity occurs. The electrical phase difference between each phase is 360 / 6 = 60°, when applying Implementation Method 1. Figure 7 and Figure 8When considering the relationship, it can be seen that when no eccentricity occurs, the sixth harmonic component of the phase voltage is in phase and the vector of the sixth harmonic component overlaps. That is, it can be seen that in the rotating motor of this embodiment, the sixth harmonic component of the line voltage is a characteristic quantity exhibited when the magnetic gap length is uneven. Therefore, in the magnetic gap length estimation method of this embodiment, the sixth harmonic component of the line voltage is used, which is different from the magnetic gap length estimation method of Embodiment 1. In other words, in the magnetic gap length estimation device of this embodiment, compared with Embodiment 1, the sixth harmonic component of the line voltage is used. Figure 6 In the flowchart, the 6th harmonic component is used as the Nth harmonic component in steps S4 and S5. Otherwise, it is the same as in embodiment 1.

[0093] In the magnetic gap length estimation device constructed in this way, similar to Embodiment 1, there is no need for a current sensor and current load, nor is it necessary to measure the voltage of the neutral point of the wiring.

[0094] Furthermore, in this embodiment, the voltage acquisition unit of the magnetic gap length estimation device is connected to all six wires of a set of six-phase windings. As the magnetic gap length estimation device of this embodiment, as long as the voltage acquisition unit is connected to at least two of the six wires, the magnetic gap length can still be estimated although the number of measurement points is reduced.

[0095] Implementation method 5.

[0096] Figure 23 This is a structural diagram of the magnetic gap length estimation device according to Embodiment 5. The magnetic gap length estimation device of this embodiment uses four sets of five-phase rotating motors driven by inverters as the measurement targets. The magnetic gap length estimation device 1 of this embodiment includes a voltage acquisition unit 2 and a magnetic gap estimation unit 3. The structure of the magnetic gap length estimation device 1 of this embodiment is the same as that of the magnetic gap length estimation device of Embodiment 1. However, the voltage acquisition unit 2 acquires the voltage of the 20 wires connecting the four inverters 4a, 4b, 4c, and 4d to the rotating motor 5. Furthermore, the method for estimating the magnetic gap length of the magnetic gap length estimation device 1 of this embodiment differs in some aspects from the estimation method of Embodiment 1.

[0097] Figure 24 This is a structural diagram of the rotary motor 5, which is the object of measurement in this embodiment. Figure 24 The rotary motor 5 shown is a rotary motor with a 4-group, 5-phase, 8-pole, 80-slot structure, assumed to be driven by an inverter. Furthermore, in Figure 24 The rotor is omitted. The stator 51 has coils in groups 1 to 4, each group configured with a mechanical angular phase difference of 360 / 4 = 90°. Additionally, in... Figure 24In this embodiment, the direction of the current flowing through each coil is indicated by two symbols. The stator 51 of the rotary electric machine 5 is a distributed winding structure with coils arranged across multiple slots. Each group of coils consists of five phases: A, B, C, D, and E, and each phase consists of two coils. For example, phase A of group 1 has two coils, A11 and A12. The coils of each group are wound continuously in the circumferential direction in the order of phases A, D, B, E, and C. For example, the coils of group 1 are arranged counterclockwise in the order of A11, A12, D11, D12, B11, B12, E11, E12, C11, and C12.

[0098] That is, when the k-th coil of the n-th phase in the m-th group of a rotating electric machine consisting of M groups and N phases, each phase composed of K coils, is recorded as C(m, n, k), in Figure 24 In the rotary motor 5 shown, 1≤m≤M, 1≤n≤N, 1≤k≤K, and M=4, N=5, K=2. Furthermore, the coils of this rotary motor 5 rotate counterclockwise in the following order: C(1,1,1), C(1,1,2), C(1,2,1), C(1,2,2), C(1,3,1), C(1,3,2), C(1,4,1), C(1,4,2), C(1,5,1), C(1,5,2), C(2,1,1), C(2,1,2), C(2,2,1), C(2,2,2), C(2,3,1), C(2,3,2), C(2,4,1), C(2,4,2), C(2,5,1), C(2... The coils are arranged in the following sequence: C(3,1,1), C(3,1,2), C(3,2,1), C(3,2,2), C(3,3,1), C(3,3,2), C(3,4,1), C(3,4,2), C(3,5,1), C(3,5,2), C(4,1,1), C(4,1,2), C(4,2,1), C(4,2,2), C(4,3,1), C(4,3,2), C(4,4,1), C(4,4,2), C(4,5,1), C(4,5,2). By continuously arranging the coils of each phase in this circumferential manner, the amplitude difference of the phase voltage waveform caused by the imbalance of the magnetic gap length increases. As the amplitude difference of the voltage waveforms of each phase increases, the difference of the Nth harmonic component of the inter-line voltage used to estimate the magnetic gap length also increases, thus further improving the estimation accuracy of the magnetic gap length.

[0099] Figure 25 This is a structural diagram of another rotary motor 5, which is the object of measurement in this embodiment. Figure 25 The rotary motor 5 shown is a rotary motor with a 4-group, 5-phase, 8-pole, 20-slot structure, assumed to be driven by an inverter. Furthermore, in Figure 25The rotor is omitted. The stator 51 has coils in groups 1 to 4, each group configured with a mechanical angular phase difference of 360 / 4 = 90°. Additionally, in... Figure 25 In this diagram, the direction of the current flowing through each coil is indicated using two different symbols. The stator 51 of this rotary electric machine 5 has a distributed winding structure with coils arranged across multiple slots. Each group of coils consists of five phases: A, B, C, D, and E. The coils of each group are wound continuously circumferentially in the order of phases A, B, C, D, and E.

[0100] That is, when the k-th coil of the n-th phase in the m-th group of a rotating electric machine consisting of M groups and N phases, each phase composed of K coils, is recorded as C(m, n, k), in Figure 25 In the rotary motor 5 shown, 1≤m≤M, 1≤n≤N, 1≤k≤K, and M=4, N=5, K=1. Moreover, the coils of the rotary motor 5 are arranged counterclockwise in the order C(1,1,1), C(1,2,1), C(1,3,1), C(1,4,1), C(1,5,1), C(2,1,1), C(2,2,1), C(2,3,1), C(2,4,1), C(2,5,1), C(3,1,1), C(3,2,1), C(3,3,1), C(3,4,1), C(3,5,1), C(4,1,1), C(4,2,1), C(4,3,1), C(4,4,1), C(4,5,1). By continuously arranging the coils of each phase in a circumferential manner, the amplitude difference of the phase voltage waveforms caused by the imbalance of the magnetic gap length increases. Since the difference in the amplitude of the phase voltage waveforms increases, the difference in the Nth harmonic components of the inter-line voltage used to estimate the magnetic gap length also increases, thus further improving the estimation accuracy of the magnetic gap length.

[0101] Figure 26 This is a vector representation of the fundamental component of the phase voltage in the rotating electric motor 5 of this embodiment. Figure 26 The fundamental component of the phase voltage shown represents the vector when no eccentricity occurs. The electrical phase difference between each phase is 360 / 5 = 72°, when applying Implementation Method 1. Figure 7 and Figure 8 When considering the relationship, it can be seen that when no eccentricity occurs, the fifth harmonic component of the phase voltage is in phase and the vector of the fifth harmonic component overlaps. That is, it can be seen that in the rotating motor of this embodiment, the fifth harmonic component of the line voltage is a characteristic quantity exhibited when the magnetic gap length is uneven. Therefore, in the magnetic gap length estimation method of this embodiment, the fifth harmonic component of the line voltage is used, which is different from the magnetic gap length estimation method of Embodiment 1. In other words, in the magnetic gap length estimation device of this embodiment, compared with Embodiment 1, the fifth harmonic component of the line voltage is used. Figure 6In the flowchart, the 5th harmonic component is used as the Nth harmonic component in steps S4 and S5. Otherwise, it is the same as in embodiment 1.

[0102] In the magnetic gap length estimation device constructed in this way, similar to Embodiment 1, there is no need for a current sensor and current load, nor is it necessary to measure the voltage of the neutral point of the wiring.

[0103] Furthermore, in this embodiment, the voltage acquisition unit of the magnetic gap length estimation device is connected to all 20 wires of the 4 groups of 5-phase windings. As the magnetic gap length estimation device of this embodiment, as long as the voltage acquisition unit is connected to at least 2 of the 5 wires in each group, the magnetic gap length can still be estimated although the number of measurement points is reduced.

[0104] Implementation method 6.

[0105] Figure 27 This is a structural diagram of the drive device for the rotating electric machine according to Embodiment 6. The drive device 10 for the rotating electric machine in this embodiment includes the gap length estimation device 1 of Embodiment 5 and a control parameter calculation unit 7 that sends control parameters to the four inverters 4a, 4b, 4c, and 4d. The control parameter calculation unit 7 sends control parameters to the four inverters 4a, 4b, 4c, and 4d, respectively, to adjust the current input values ​​for each group of the rotating electric machine 5 based on the gap length estimated by the gap length estimation device 1. Furthermore, the control parameter calculation unit 7 has an external output terminal 8. For example, by connecting an external monitor to this external output terminal 8, the state of the gap and the control parameters can be visualized.

[0106] For example, when the rotary motor 5 has a static eccentricity in the direction of the narrowing magnetic gap length of group 3, the current input value for the coil belonging to group 3 is set to be less than the current input value for the coils belonging to groups 1, 2, and 4. By controlling it in this way, vibration and noise caused by eccentricity can be reduced.

[0107] Furthermore, in this embodiment, the voltage acquisition unit of the magnetic gap length estimation device is connected to all 20 wires of the four groups of five-phase windings. As the drive device for the rotating electric machine in this embodiment, as long as the voltage acquisition unit is connected to at least one of the five wires in each group, the direction of magnetic gap length displacement can still be estimated and control parameters calculated even though the number of measurement points is reduced.

[0108] The magnetic gap length estimation device described in Embodiments 1, 3 to 5 uses the third harmonic component of the line voltage for three groups of three-phase or one group of three-phase rotating motors, the sixth harmonic component of the line voltage for one group of six-phase rotating motors, and the fifth harmonic component of the line voltage for four groups of five-phase rotating motors to estimate the magnetic gap length. The magnetic gap length estimation device described so far can estimate the magnetic gap length using the Nth harmonic component of the line voltage for M groups of N-phase rotating motors, which are other than these types of rotating motors.

[0109] Furthermore, if the k-th coil of the n-th phase in the m-th group of a rotating electric machine consisting of M groups and N phases, each phase composed of K coils, is denoted as C(m, n, k), where 1 ≤ m ≤ M, 1 ≤ n ≤ N, and 1 ≤ k ≤ K, and the coils are arranged counterclockwise in the order C(1, 1, 1), C(1, 1, 2)...C(1, 1, K), C(1, 2, 1)...C(1, 2, K)...C(1, N, K), C(2, 1, 1)...C(M, N, K), then the amplitude difference of the voltage waveforms of each phase caused by the imbalance of the magnetic gap length increases. Since the difference in the amplitude of the voltage waveforms of each phase increases, the difference in the Nth harmonic components of the inter-line voltages used to estimate the magnetic gap length also increases, thus further improving the estimation accuracy of the magnetic gap length.

[0110] In addition, such as Figure 28 The hardware shown includes, for example, the magnetic gap length estimation device 1 of embodiments 1, 3 to 5 and the drive device 10 of the rotary motor of embodiments 2 and 6, a processor 100 and a storage device 101. Although not shown, the storage device 101 includes a volatile storage device such as random access memory and a non-volatile auxiliary storage device such as flash memory. Alternatively, a hard disk can be used as an auxiliary storage device instead of flash memory. The processor 100 executes a program input from the storage device 101. In this case, the program is input to the processor 100 from the auxiliary storage device via the volatile storage device. Furthermore, the processor 100 can output data such as calculation results to the volatile storage device of the storage device 101, or it can save data to the auxiliary storage device via the volatile storage device.

[0111] Although this application describes various exemplary embodiments, the various features, forms and functions described in one or more embodiments are not limited to the application in a specific embodiment, but can be applied to the embodiment alone or in various combinations.

[0112] Therefore, numerous variations not illustrated are contemplated within the scope of the technology disclosed in this application. These include variations, additions, or omissions of at least one constituent element, as well as extraction of at least one constituent element and combination with constituent elements of other embodiments.

Claims

1. A magnetic gap length estimation device for estimating the magnetic gap length in an M-group N-phase rotating motor, wherein M is a natural number and N is a natural number greater than 2, the M-group N-phase rotating motor is configured with a phase difference of 360 / N degrees between each phase and is driven by an inverter, the magnetic gap length estimation device being characterized by comprising: The voltage acquisition unit acquires the line-to-line no-load induced voltage induced in the wiring when there is no load; and The magnetic gap estimation section estimates the length of the magnetic gap. The magnetic gap estimation unit includes: The spectrum analysis unit converts the line-to-line no-load induced voltage acquired by the voltage acquisition unit into the amplitude and phase of each frequency; The frequency analysis unit extracts the amplitude and phase of the fundamental component and the Nth harmonic component of the unloaded induced voltage between lines from the amplitude and phase of each frequency obtained by the frequency spectrum analysis unit; and The estimation calculation unit estimates the magnetic gap length based on the amplitude and phase of the fundamental component and the Nth harmonic component of the unloaded induced voltage between the lines extracted by the frequency analysis unit.

2. The magnetic gap length estimation device according to claim 1, characterized in that, Each group of the rotary motor consists of coils configured with a mechanical angular phase difference of 360 / M degrees.

3. The magnetic gap length estimation device according to claim 2, characterized in that, Let K be a natural number. The rotary motor is composed of M groups and N phases, and each phase is composed of K coils. When the kth coil of the nth phase of the mth group is recorded as C(m, n, k), 1≤m≤M, 1≤n≤N, 1≤k≤K. The spatial arrangement of the coils is in the order of C(1,1,1), C(1,1,2)……C(1,1,K), C(1,2,1)……C(1,2,K)……C(1,N,K), C(2,1,1)……C(M,N,K) in a counterclockwise direction.

4. The magnetic gap length estimation device according to claim 2 or 3, characterized in that, The coils of each group of the rotating electric motor are configured in a Y-shaped connection where each phase is connected in series.

5. The magnetic gap length estimation device according to claim 4, characterized in that, In the rotary motor, the neutral points of each group connected by Y-connection are electrically connected to each other.

6. The magnetic gap length estimation device according to any one of claims 1 to 5, characterized in that, The estimation calculation unit has an external output terminal, which outputs the estimation result to the outside.

7. A drive device for a rotary electric motor, characterized in that, have: The magnetic gap length estimation device according to any one of claims 1 to 6; and The control parameter calculation unit calculates the control parameters of the inverter based on the magnetic gap length estimated by the magnetic gap length estimation device.

8. The drive device for the rotary electric motor according to claim 7, characterized in that, The control parameter calculation unit has an external output terminal, which outputs the calculation result to the outside.

9. A method for estimating the magnetic gap length, for estimating the magnetic gap length in an M-group N-phase rotating motor, wherein M is a natural number and N is a natural number greater than 2, the M-group N-phase rotating motor is configured with a phase difference of 360 / N degrees between each phase and is driven by an inverter, the magnetic gap length estimation method being characterized by having: The voltage acquisition step acquires the no-load induced voltage between the lines at the connection point; and the magnetic gap estimation step estimates the length of the magnetic gap. The magnetic gap estimation step includes: The spectrum analysis step transforms the line-to-line unloaded induced voltage obtained through the voltage acquisition step into the amplitude and phase of each frequency; The frequency analysis step extracts the amplitude and phase of the fundamental component and the Nth harmonic component of the unloaded induced voltage between lines from the amplitude and phase of each frequency obtained through the spectrum analysis step; and The estimation calculation step involves estimating the magnetic gap length based on the amplitude and phase of the fundamental component and the Nth harmonic component of the unloaded induced voltage between the lines extracted through the frequency analysis step.

10. The method for estimating the magnetic gap length according to claim 9, characterized in that, The estimation calculation steps include: Step 1: Estimate the absolute value of the displacement of the magnetic gap length based on the amplitude of the Nth harmonic component of the unloaded induced voltage between the lines; and In step 2, if the phase difference between the Nth harmonic component of the unloaded induced voltage between the lines and the Nth harmonic component of the phase voltage is greater than 90° and less than 270°, then the sign of the displacement of the magnetic gap length is determined to be negative; if the phase difference is greater than 0° and less than 90° or greater than 270° and less than 360°, then the sign of the displacement of the magnetic gap length is determined to be positive.

11. A drive device for a rotating electric motor, comprising M groups of N-phase rotating electric motors, wherein M is a natural number and N is a natural number greater than 2, the M groups of N-phase rotating electric motors are configured with a phase difference of 360 / N degrees between each phase, and are driven by an inverter, the drive device for the rotating electric motor being characterized by comprising: The voltage acquisition unit acquires the line-to-line no-load induced voltage induced in the wiring when there is no load; and The magnetic gap estimation section estimates the length of the magnetic gap in the rotating electric motor. The magnetic gap estimation unit includes: The spectrum analysis unit converts the line-to-line no-load induced voltage acquired by the voltage acquisition unit into the amplitude and phase of each frequency; The frequency analysis unit extracts the amplitude and phase of the fundamental component and the Nth harmonic component of the unloaded induced voltage between lines from the amplitude and phase of each frequency obtained by the frequency spectrum analysis unit; and The estimation calculation unit estimates the magnetic gap length based on the amplitude and phase of the fundamental component and the Nth harmonic component of the unloaded induced voltage between the lines, extracted by the frequency analysis unit. The drive unit of the rotating electric motor includes a control parameter calculation unit, which calculates the control parameters of the inverter based on the magnetic gap length estimated by the magnetic gap estimation unit.

12. The drive device for a rotary electric motor according to claim 11, characterized in that, The control parameter calculation unit has an external output terminal, which outputs the calculation result to the outside.

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