ANOMALITY DETECTION DEVICE AND ANOMALITY DETECTION METHOD FOR A SYNCHRONOUS RELUCTANCE MOTOR

Abstract

An anomaly detection device (40) is applied to a sensorless control system (100) that performs control for detecting a rotor position by superimposing a high-frequency current on a synchronous reluctance motor (1). The anomaly detection device (40) comprises a computation unit (41) that calculates a physical quantity representing an anomaly state in a rotor (1b) of the synchronous reluctance motor (1), based on the current value of a motor current flowing through the synchronous reluctance motor (1), and a determination unit (42) that determines an anomaly in the rotor (1b) based on the physical quantity. The anomaly detection device (40) maintains a threshold, determined based on the physical quantity, when the rotor (1b) behaves normally.The determination unit (42) determines the presence or absence of an anomaly in the rotor (1b) by comparing the physical quantity calculated by the computation unit (41) with the threshold.

Description

Area

[0001] The present disclosure relates to an anomaly detection device and an anomaly detection method for a synchronous reluctance motor using a salience or pole characteristic of a rotor. background

[0002] The main trend in synchronous motors in recent years has been the internal permanent magnet synchronous motor and the synchronous reluctance motor. The internal permanent magnet synchronous motor utilizes both magnetic torque and reluctance torque, while the synchronous reluctance motor utilizes only reluctance torque. Since reluctance torque is proportional to a salience ratio, the motor utilizing reluctance torque requires a rotor structure to ensure the salience ratio is maintained.

[0003] In the case of the synchronous reluctance motor, to ensure sufficient centrifugal force resistance while maintaining the required salience ratio, the rotor is equipped with a magnetic path for the passage of a magnetic flux, an air slot that forms a magnetic barrier, and a reinforcing element that supports the air slot. This means that in the synchronous reluctance motor, the salience ratio and centrifugal force resistance are in a balanced relationship to each other. Therefore, the synchronous reluctance motor is designed to maximize the salience ratio while ensuring sufficient centrifugal force resistance. However, this design does not provide for protection against failure due to aging, unexpected malfunctions, or similar events.Therefore, in the synchronous reluctance motor, it is desirable to monitor the condition of the rotor and detect an anomaly in the rotor at an early stage in order to further improve safety.

[0004] The patent literature 1 below discloses a technique for detecting the presence or absence of an anomaly in a rotor based on a component extracted by subtracting from each other two waveforms of the same phase of a current flowing through an AC motor. List of citations from patent literature

[0005] Patent literature 1: Japanese patent no. 4062939 Summary of the invention Problem to be solved by the invention

[0006] However, if the technique described in patent literature 1 is used to subtract the two current waveforms of the same phase, the AC motor must rotate at a constant speed. Therefore, with the technique described in patent literature 1, it is difficult to detect an anomaly in the rotor during the start-up or ramp-up of the AC motor. Unlike during start-up, the rotational speed also fluctuates slightly due to load ripples. Consequently, the technique described in patent literature 1 may not achieve sufficient detection accuracy.

[0007] The present disclosure was made in light of the above, and one objective of the present disclosure is to provide an anomaly detection device for a synchronous reluctance motor which is capable of detecting an anomaly in the rotor even when the synchronous reluctance motor is not rotating at a constant speed. Means to solve the problem

[0008] To solve the problem described above and achieve the objective, an anomaly detection device for a synchronous reluctance motor according to the present disclosure is an anomaly detection device for a synchronous reluctance motor applied to a sensorless control system that performs control to detect a rotor position by superimposing a high-frequency current on the synchronous reluctance motor, wherein the anomaly detection device comprises a computation unit and a determination unit. The computation unit calculates a physical quantity that represents an anomaly state in a rotor of the synchronous reluctance motor based on a current value of a motor current flowing through the synchronous reluctance motor. The determination unit determines an anomaly in the rotor based on the physical quantity. Effects of the invention

[0009] The anomaly detection device for the synchronous reluctance motor according to the present disclosure enables an anomaly in the rotor to be detected even when the synchronous reluctance motor is not rotating at a constant speed. Brief description of the drawings Fig. Figure 1 shows a diagram illustrating a functional configuration of an anomaly detection device for a synchronous reluctance motor according to a first embodiment. Fig. Figure 2 shows a diagram illustrating an exemplary configuration of a sensorless control system that includes the anomaly detection device according to the first embodiment. Fig. Figure 3 presents a set of graphs illustrating an example of waveforms of high-frequency voltages or high-frequency voltages generated from a position estimation voltage generation unit in Fig. 2 will be issued. Fig. Figure 4 shows a cross-sectional view used to describe the structure of a rotor core in the synchronous reluctance motor used in the first embodiment. Fig. Figure 5 shows a graph illustrating the inductance change of a general synchronous reluctance motor. Fig. Figure 6 presents a graph illustrating an example of current vector locations when a high-frequency current flows through the synchronous reluctance motor, which includes the rotor core located in Fig. 4 is illustrated. Fig. 7 represents a diagram that is used for the in Fig. Figure 4 illustrates a flux of magnetic flux generated by a component of a high-frequency current when a component of a harmonic fundamental current is small. Fig. Figure 8 presents a table illustrating an example of a coefficient value table used in a high-frequency boost control of the first embodiment. Fig. Figure 9 presents a graph illustrating an example of current vector locations in a case where there is no anomaly in the rotor of the synchronous reluctance motor located in Fig. 2 is illustrated. Fig. Figure 10 presents a graph illustrating an example of current vector locations in a case where there is an anomaly in the rotor of the synchronous reluctance motor located in Fig. 2 is illustrated. Fig. Figure 11 presents a block diagram illustrating an example of a hardware configuration implementing the functions of the anomaly detection device according to the first embodiment. Fig. Figure 12 presents a block diagram illustrating another example of the hardware configuration implementing the functions of the anomaly detection device according to the first embodiment. Fig. 13 represents a set of graphs intended to illustrate a determination processing in an anomaly detection processing of the first embodiment. Fig. Figure 14 presents a flowchart illustrating a processing sequence for the anomaly detection processing of the first embodiment. Description of the embodiments

[0010] The following section describes in detail, with reference to the drawings, an anomaly detection device and an anomaly detection method for a synchronous reluctance motor according to embodiments of the present disclosure. Hereinafter, the “anomaly detection device for a synchronous reluctance motor” and the “anomaly detection method for a synchronous reluctance motor” may be referred to simply as the “anomaly detection device” and the “anomaly detection method”. First embodiment.

[0011] Fig. Figure 1 shows a diagram illustrating a functional configuration of an anomaly detection device 40 according to a first embodiment. Fig. Figure 2 shows a diagram illustrating an exemplary configuration of a sensorless control system 100, which includes the anomaly detection device 40 according to the first embodiment. As in Fig. As illustrated in Figure 1, the anomaly detection device 40 comprises a processing unit 41 and a determination unit 42. Furthermore, the sensorless control system 100 comprises, as shown in Figure 1. Fig. Figure 2 illustrates a current sensing unit 2, a voltage applicator 3, a position estimation unit 4, a current control unit 5, a DC power supply 12, an anomaly detection device 25, and a position estimation voltage generation unit 30. Fig. 1 the calculation unit 41 is set up, a function of a high-frequency high-frequency current amplitude calculation unit 7, which is in Fig. 2 is illustrated, and includes a function of a computational processing of the anomaly detection device 25, which is in Fig. 2 is illustrated, and the determination unit 42 is set up, a function of a determination processing of the in Fig. 2 illustrated anomaly detection device 25 to include.

[0012] In Fig. 2 is a synchronous reluctance motor 1, a device that can be controlled or driven by the sensorless control system 100. The synchronous reluctance motor 1 comprises a stator 1a and a rotor 1b, which is arranged inside the stator 1a. The sensorless control system 100 is a control system that performs a control to detect a rotor position as position information of the rotor 1b by superimposing a high-frequency current 1 on the synchronous reluctance motor without using a speed sensor or a position sensor. It should be noted that in the present description, a synchronous reluctance motor, as an example of the synchronous reluctance motor 1, is assumed to use reluctance, but the synchronous reluctance motor 1 is not limited to this. The synchronous reluctance motor 1 could be a synchronous reluctance motor using an internal permanent magnet.

[0013] The DC power supply 12 feeds DC power to the voltage sender 3. In a case where the synchronous reluctance motor 1 is a motor, the voltage sender 3 generates an AC voltage to control or drive the motor by using an applied DC voltage V. dc and applies the generated alternating current voltage to the motor.

[0014] The current sensing unit 2 detects motor currents i u , i v and i w , which flow between the voltage applicator 3 and the synchronous reluctance motor 1. The motor currents i u , i v and i w These are stator currents flowing to the corresponding phases of stator 1a, i.e., to a u-phase, a v-phase, and a w-phase. A current detector is arranged for each phase of the current sensing unit 2. The current detector is, for example, a current transformer. It should be noted that the current sensing unit 2 is in Fig. 2. All three-phase currents are recorded, but the present disclosure is not limited to this. The currents for any two of the three phases could be recorded, and the current for the remaining one phase could be obtained by calculation using the fact that the motor currents i u , i v and i w are in a three-phase equilibrium. Alternatively, instead of the current sensing unit 2 being in Fig. 2. The acquisition process performs a bus current that flows through a DC bus (not illustrated) connecting the voltage applicator 3 and the DC power supply 12, and the motor currents i u , i v and i w could be obtained by calculating the bus stream.

[0015] As in Fig. As illustrated in Figure 1, the calculation unit receives 41 current values ​​as recorded or calculated values ​​of the motor currents i u, i v and i w The calculation unit 41 calculates a physical quantity that represents an anomaly state in the rotor 1b of the synchronous reluctance motor 1, based on the current values ​​of the motor currents i u , i v and i w The determination unit 42 determines an anomaly in the rotor 1b of the synchronous reluctance motor 1 based on the physical quantity calculated by the computation unit 41, and gives a determination result J. d An example of the physical quantity calculated by the calculation unit 41 will be described later.

[0016] The description refers to Fig. 2 back. The position estimation unit 4 calculates an estimated value θ. L the rotor position, which is the position information of rotor 1b, based on the current values ​​of the motor currents i u , i v and i wBased on the current values ​​of the motor currents i u , i v and i w and the estimated value θ L The current control unit generates 5 first voltage commands V based on the rotor position u *, V v * and V w *, the command values ​​of a synchronous reluctance motor voltage for controlling or driving the synchronous reluctance motor 1. The position estimation voltage generation unit 30 generates high-frequency voltages V uh , V vh and V wh , which are higher frequencies than the first voltage commands V u *, V v * and V w * exhibit, based on a q-axis current command i q *, which is a momentary-axis current command. The high-frequency voltages V uh , V vh and V wh These are position estimation voltages used to estimate the rotor position. The current control unit 5 superimposes the first voltage commands V. u *, V v * and V w* the high-frequency voltages V uh , V vh and V wh and outputs the superimposed voltages to the voltage applicator 3 as second voltage commands V up *, V vp * and V wp * off. The voltage applicator 3 generates a control or drive voltage based on the second voltage commands V. up *, V vp * and V wp * and applies the control voltage to the synchronous reluctance motor 1. It should be noted that in the present description, the voltage applicator 3 is assumed to be a two-stage three-phase inverter, but is not limited to this. In the present description, the voltage applicator 3 could be a three-stage three-phase inverter, or it could be a multi-phase two-stage or three-stage inverter.

[0017] The current control unit 5 comprises subtracting devices 13d and 13q, a d-axis current control device 14d, a q-axis current control device 14q, a first coordinate converter 15, a two-phase-to-three-phase converter 16, a second coordinate converter 17, a three-phase-to-two-phase converter 18 and adding devices 23u, 23v and 23w.

[0018] The subtractor unit 13d calculates a deviation Δi d between a d-axis current command i d *, which is an excitation axis current command, and a d-axis current i d , which is output from the second coordinate converter 17. The d-axis current control device 14d in the subsequent stage performs a proportional-integral control such that the deviation Δi d becomes zero, resulting in a d-axis tension command V d * is calculated. The subtractor 13q calculates a deviation Δi. q between the q-axis current command i q* and a q-axis current i q , which is output from the second coordinate converter 17. The q-axis current control device 14q in the subsequent stage performs a proportional-integral control such that the deviation Δi q becomes zero, resulting in a q-axis voltage command V q * is calculated. The d-axis current command i d * is a command value of the d-axis current for controlling the synchronous reluctance motor 1, and the q-axis current command i q * is a command value of the q-axis current for controlling the synchronous reluctance motor 1. The d-axis current command i d * and the q-axis current command i q * Both are supplied from outside the power control unit 5.

[0019] The first coordinate converter 15 converts the d-axis tension command V d * and the q-axis tension command V q*, which are output from the corresponding d-axis current control unit 14d or the q-axis current control unit 14q, into voltage commands V α * and V β * in stationary two-axis coordinates. The two-phase-to-three-phase converter 16 converts the voltage commands V α * and V β *, which are output from the first coordinate converter 15, into the first voltage commands V u *, V v * and V w *, which are the control voltage commands for three-phase AC coordinates. It should be noted that the processing of the first coordinate converter 15 also includes the estimated value θ L the rotor position, which is output by the position estimation unit 4.

[0020] The three-phase-to-two-phase converter 18 converts the motor currents i u , i v and i w , which are detected by the current detection unit 2, into an α-axis current i αand a β-axis current i β on the stationary two-axis coordinates. The second coordinate converter 17 converts the α-axis current i α and the β-axis current i β , which are output by the three-phase-to-two-phase converter 18, into the d-axis current i d and the q-axis current i q on rotational coordinates that are synchronous with the estimated value θ L rotate the rotor position, which is output by the position estimation unit 4, and outputs the d-axis current i. d and the q-axis current i q to the subtraction devices 13d and 13q.

[0021] The first voltage commands V u *, V v * and V w *, which are output by the two-phase-to-three-phase converter 16, and the high-frequency voltages V uh , V vh and V whThe outputs from the position estimation voltage generation unit 30 are summed in the adding units 23u, 23v, and 23w, respectively. The outputs from the adding units 23u, 23v, and 23w are sent to the voltage applicator 3 as the second voltage commands V. up *, V vp * and V wp * applied. Therefore, in the second voltage commands V up *, V vp * and V wp *, which are applied to the voltage applicator 3, the high-frequency voltages V uh , V vh and V wh as position estimation voltage commands the first voltage commands V u *, V v * and V w * superimposed. It should be noted that details of the high-frequency voltages V uh , V vh and V wh will be described later.

[0022] The position estimation unit 4 comprises the high-frequency current amplitude calculation unit 7 and a position computer or position calculation device 8. The high-frequency current amplitude calculation unit 7 also includes current extractors 6u, 6v and 6w, multiplier devices 9u, 9v and 9w, integrator devices 10u, 10v and 10w and square root calculators 22u, 22v and 22w. These components are arranged according to the phases.

[0023] As described above, the second voltage commands V up *, V vp * and V wp *, which are applied to the voltage applicator 3, the high-frequency voltages V uh , V vh and V wh , which are output from the position estimation voltage generation unit 30, the first voltage commands V u *, V v * and V w * superimposed, which are output from the two-phase-to-three-phase converter 16. Therefore, the motor currents include iu , i v and i w , which are detected by the current detection unit 2, high-frequency currents i uh , i vh and i wh with the same frequency components as the high-frequency voltages V uh , V vh and V wh .

[0024] Thus, the current extractors extract 6u, 6v and 6w from the corresponding motor currents i u , i v and i w , which are detected by the current detection unit 2, the corresponding high-frequency currents i uh , i vh and i wh with the same frequency components as the high-frequency voltages V uh , V vh and V wh The high-frequency currents i uh , i vh and i wh can be extracted using a bandpass filter or a notch filter. It should be noted that in a case where the notch filter is used, the motor currents i u, i v and i w The notch filter should be entered in such a way that the same frequency components as the high-frequency voltages V are used. uh , V vh and V wh can be attenuated. Then the high-frequency currents can i uh , i vh and i wh can be extracted by separating the currents that have passed through the notch filter from the motor currents. u , i v and i w to be subtracted.

[0025] The multiplier devices 9u, 9v and 9w calculate autocorrect values ​​by squaring the high-frequency currents i uh , i vh or i whThe integrators 10u, 10v, and 10w each perform an integration operation with respect to a time Tn of one integration period, multiply the calculated value by (2 / Tn), and output an integral value. The square root calculators 22u, 22v, and 22w calculate the square roots of the outputs of the corresponding integrators 10u, 10v, and 10w to estimate position current amplitudes I. uh , I vh and I wh to generate. The position estimation current amplitudes I uh , I vh and I wh are output to the position computer 8 and to the anomaly detection device 25.

[0026] It can be noted that the high-frequency current amplitude calculation unit 7 in Fig. 2 the autocorrect values ​​of the high-frequency currents i uh , i vh and i wh integrated and the square roots of the integral values ​​calculated to determine the position estimation current amplitudes I uh , I vhand I wh to generate, although the present disclosure is not limited thereto. The position estimation current amplitudes I uh , I vh and I wh could be generated by adjusting the autocorrect values ​​of the high-frequency currents i uh , i vh and i wh pass through a low-pass filter.

[0027] The position calculator 8 calculates the estimated value θ L the rotor position based on the position estimation current amplitudes I uh , I vh and I wh , which are calculated by the high-frequency current amplitude calculation unit 7. The estimated value θ LThe rotor position is calculated using a known method, and a detailed description of this method is omitted here. It should be noted that for a specific calculation procedure, reference is made to the contents of the publication disclosed, for example, in Japanese patent no. 5324646.

[0028] The anomaly detection device 25 determines the presence or absence of an anomaly in rotor 1b based on the position estimation current amplitudes I uh , I vh and I wh Details of anomaly detection processing by the anomaly detection unit 25 will be described later.

[0029] Next, the high-frequency voltages V uh , V vh and V wh , which are output from the position estimation voltage generation unit 30, are described. Fig. Figure 3 represents a set of graphs that provide an example of waveforms of high-frequency voltages V uh , V vh and V wh illustrated by the position estimation voltage generation unit 30 in Fig. 2 will be output. It can be noted that the waveforms in Fig. 3 is an example in a case where the voltage applicator 3 includes a pulse width modulation (PWM) inverter for a triangle wave comparison.

[0030] The horizontal axes in Fig. 3 represent time. Also illustrated Fig. 3, in order from above, the waveforms of a triangular wave carrier, the high-frequency voltage V uh for the u-phase, the high-frequency voltage V vh for v-phase and the high-frequency voltage V wh for the w-phase. If half a period Tc of the triangular wave carrier corresponds to a region or section, the high-frequency voltages V representuh , V vh and V wh Each signal has a duration or period Th and is represented in six ranges (=6·Tc). In the example of the Fig. 3 are the high-frequency voltages V uh , V vh and V wh The system is set to shift two regions (=2·Tc) relative to each other across the phases in order to achieve a three-phase equilibrium. It should be noted that Fig. 3 represents an example and that the present disclosure is not limited to this example. As long as the high-frequency voltages V uh , V vh and V wh If the system is in a three-phase equilibrium, any waveforms could be used.

[0031] Returning to Fig. Section 2 describes the position estimation voltage generation unit 30. The position estimation voltage generation unit 30 comprises a high-frequency amplitude calculator 31 and a high-frequency voltage generator 32. The high-frequency amplitude calculator 31 receives information from the q-axis current command i. q *. The high-frequency amplitude calculator 31 selects or calculates a coefficient value W. h based on the q-axis current command i q *. The coefficient value W h is a positive real number used to determine the voltage amplitude of high-frequency voltages V uh , V vh and V wh is fixed. The coefficient value W h can be selected using a table in which the coefficient value W h is stored. Alternatively, the coefficient value W could be used. h can be calculated using a function calculation without using the table.

[0032] The q-axis current command i q * is an example of a physical quantity that correlates with the magnetic saturation of rotor 1b. A physical quantity that differs from the q-axis current command i q * differs, could be used as long as the physical quantity correlates with the magnetic saturation of rotor 1b. Other examples of physical quantities that correlate with the magnetic saturation of rotor 1b include the q-axis current i. q , the q-axis tension command V q * and the like. It should be noted that the d-axis current command i d *, the d-axis current i d , the d-axis tension command V d * and the like may also be the physical quantity that correlates with the magnetic saturation of rotor 1b.

[0033] The high-frequency voltage generator 32 uses the coefficient value W h , to generate the high-frequency voltages V described aboveuh , V vh and V wh to generate. The operation of the high-frequency voltage generator 32 will be described using the following various formulas.

[0034] When describing the operation of the high-frequency voltage generator 32, for example, a formula is derived that represents a high-frequency current. First, a voltage equation of a synchronous motor on an α-β axis as stationary coordinates is expressed by the following formula (1). Formula 1: [VαVβ]=[R+pLαpLαβpLαβR+pLβ][iαiβ]+ωKE[−sinθcosθ]Lα=L0+L1 cos(2θ)Lβ=L0−L1 cos(2θ)Lαβ=L1 sin(2θ)L0=Ld+Lq2L1=Ld−Lq2

[0035] In formula (1) above, “i α “ and “i β “The α-axis current and the β-axis current described above. Also, “V” represent α “ and “V β“an α-axis voltage or a β-axis voltage. Furthermore, “R” and “K” represent E “a stator resistance or an induced voltage coefficient. Furthermore, “L” represents α “L β “L αβ “L d “ and “L q “an α-axis inductance, a β-axis inductance, a mutual inductance between αβ-axes, a d-axis inductance, and a q-axis inductance, respectively. Also, “L0” is defined by the fifth expression of formula (1) above, and “L1” is defined by the sixth expression of formula (1) above. Furthermore, “p” denotes a differential operator.”

[0036] Formula (1) above is applicable to both the synchronous reluctance motor and the synchronous motor with an internal permanent magnet. It should be noted that in the case of the synchronous reluctance motor, which does not use a magnet, the induced voltage coefficient K Ein formula (1) above is zero, so that the second term of formula (1) above, which is the induced stress coefficient K E can be omitted. Furthermore, considering only high-frequency components in formula (1) above, the following formula (2) is obtained. Formula 2: [VαhVβh]=p[LαLαβLαβLβ][iαhiβh]

[0037] In formula (2) above, “V” represents αh “, “V βh “, „i αh “ and “i βh “The high-frequency components of the α-axis voltage, the β-axis voltage, the α-axis current, and the β-axis current. It should be noted that the modification of formula (1) above to formula (2) above also applies to the synchronous reluctance motor, which does not use a magnet.”

[0038] If formula (2) above is solved for the current derivative term, the following formula (3) is obtained. Formula 3: p[iαhiϕh]=1L02−L12{L0I−L1[cos(2θ)sin(2θ)sin(2θ)−cos(2θ)]}[VαhVβh]

[0039] Furthermore, the α-axis voltage V α and the β-axis voltage V β on the α-β axis defined by the following formula (4). Formula 4: [VαhVβh]=Vhαβ[cos(ωht)sin(ωht)]

[0040] In formula (4) above, “V” represents hαβ “ a high-frequency voltage amplitude on the α-β axis, and “ω h “ represents an angular frequency on the α-β axis. It should be noted that the angular frequency is also called “angular velocity”.

[0041] When formula (4) above is expressed in three-phase coordinates, high-frequency setpoint voltages V are obtained. uh1 , V vh1 and V wh1 obtained by the following formula (5). Formula 5: [Vuh1Vvh1Vwh1]=Vhuvw[sin(ωht)sin(ωht−2π / 3)sin(ωht+2π / 3)]

[0042] The high-frequency voltage generator 32 uses the coefficient value W h , which is calculated by the high-frequency amplitude calculator 31, and multiplies the high-frequency input voltages V uh1 , V vh1 and V wh1 with the coefficient value W h , to reduce the high-frequency voltages V uh , V vh and V wh to generate which are expressed by the following formula (6). Formula 6: [VuhVvhVwh]=Wh[Vuh1Vvh1Vwh1]

[0043] Next, a structure of a rotor core will be described that forms the rotor 1b of the synchronous reluctance motor 1. Fig. Figure 4 shows a cross-sectional view used to describe the structure of a rotor core 50 in the synchronous reluctance motor 1, which is used in the first embodiment. Fig. 4. The rotor core 50 is formed by stacking a multitude of electromagnetic steel sheets as plate material. A shaft 51 is attached to an inner diameter side of the rotor core 50. The rotor core 50 is formed by a stacked body in which core segments 53 are stacked as ring-shaped thin plates. The core segment 53 can be formed by stamping the electromagnetic steel sheet, which is a thin steel sheet, using a press. In an assembled state of the synchronous reluctance motor 1, the thin plates forming the rotor core 50 are stacked in the same direction as an axial direction of the shaft 51.

[0044] In the rotor core 50, in which the plurality of core segments 53 are stacked, a plurality of slots 52 are formed, creating a magnetic barrier. The slot 52 has a convex arc shape in the direction of a shaft hole into which the shaft 51 is fitted, and is formed from one side by a d-axis to the other by a q-axis with a center. In the rotor core 50, a d-axis is an axis through which a magnetic flux passes relatively easily, and the q-axis is an axis through which a magnetic flux passes less easily. The d-axis and the q-axis are magnetically and electrically orthogonal to each other.

[0045] Slot groups 54, each comprising the plurality of slots 52, are formed at intervals in a circumferential direction of the rotor core 50, wherein the slot groups 54 are equal to the number of poles with respect to a number. Fig. Figure 4 illustrates an example where rotor 1b has four poles, and in Fig. The slot groups 54 are designed for the four poles.

[0046] The rotor core 50 must have sufficient strength to withstand the centrifugal force when the synchronous reluctance motor 1 rotates. Therefore, a central rib 55a is formed in the slot 52, acting as a reinforcing element. Furthermore, in each of the slots 52, except for the outermost slot, two side ribs 55b are provided in addition to the central rib 55a, also acting as reinforcing elements. The central rib 55a and the side ribs 55b can be formed by omitting sections, in order to be the central rib 55a and the side ribs 55b, during the punching of the thin steel sheet to form the slot 52. It should be noted that the layout of the central rib 55a and the side ribs 55b, which are in Fig. Figure 4 illustrates an example and shows that the layout is not limited to this. Any layout could be adapted as long as the desired strength can be maintained.

[0047] Furthermore, the slot 52 in the rotor core 50 is not formed between the slot groups 54 and an edge 56 of the rotor core 50 on the outer circumferential side, so that an annular section 57 is formed as a section with a ring shape. In the rotor core 50, the annular section 57 also acts as a reinforcing element. It should be noted that in the present description, the central rib 55a, the side rib 55b, and the annular section 57, and the like, which act as reinforcing elements, could collectively also be referred to as "bridge sections".

[0048] The fifth and sixth expressions of formula (1) above contain the d-axis inductance L d and the q-axis inductance Lq . Fig. Figure 5 shows a graph illustrating the inductance change of a general synchronous reluctance motor. The horizontal axis represents the rotor position and the vertical axis represents the magnitude of the inductance.

[0049] In a general synchronous reluctance motor, the inductance changes with an electrical angle. More specifically, this means that, as in Fig. Figure 5 illustrates that the maximum and minimum values ​​of the inductance each occur twice during a rotation through an electrical angle. The maximum value of the inductance is the d-axis inductance L. d and the minimum value of the inductance is the q-axis inductance L q This means that the d-axis inductance L d greater than the q-axis inductance L q is. If the ratio of the q-axis inductance L q to the d-axis inductance L ddefined as a saliency ratio, the saliency ratio L exhibits q / L d Here, a value greater than one appears. This is because the synchronous reluctance motor 1 is configured such that the flux linkage due to the q-axis current i q higher than the flux chain due to the d-axis flow i d of the current flowing through the synchronous reluctance motor 1.

[0050] Fig. Figure 6 presents a graph illustrating an example of current vector locations when a high-frequency current flows through the synchronous reluctance motor 1, which drives the in Fig. The 4 illustrated rotor core comprises 50. Fig. 6 represents the horizontal axis and the d-axis current i d and the vertical axis represents the q-axis current i q As in Fig. Figure 6 illustrates when the q-axis current i qSince the current flowing through the synchronous reluctance motor 1 is relatively large, the current vector locus has an elliptical shape. Meanwhile, when the q-axis current i is relatively large, the current vector locus has a different shape. q , which flows through the synchronous reluctance motor 1, is small, as shown in the lower left part of the Fig. Figure 6 illustrates that the current vector does not have an elliptical shape, but is essentially circular. The center of the current vector locus represents a component of a harmonic fundamental current flowing through the synchronous reluctance motor 1, and the distance from the center in each expression of the current vector locus represents the component of the high-frequency current flowing through the synchronous reluctance motor 1. Thus, in the region where the q-axis current i q small, a small momentary command is issued to the synchronous reluctance motor 1.

[0051] In the case where the current vector location has an elliptical shape, the rotor position can be determined based on a difference or ratio between the length in a major axis direction of the ellipse and the length in a minor axis direction of the ellipse. Fig. 6. It can also be seen that the larger the q-axis current i q The greater the harmonic base current, the greater the accuracy of rotor position detection. The reason for this is explained with reference to Fig. 7 will be described in more detail. Fig. 7 represents a diagram based on the one in Fig. Figure 4 illustrates the rotor core 50, illustrating a flux of magnetic flux generated by the component of the high-frequency current when the component of the harmonic fundamental current is small.

[0052] In Fig. 7 represents a solid arrow line representing the flux of magnetic flux that can be generated by the component of the high-frequency current in the q-axis current i. q is contained within. In the present description, this magnetic flux component is referred to as the "momentary magnetic flux" for simplicity. Furthermore, a dashed arrow line represents the flux of the magnetic flux that can be generated by the component of the high-frequency current contained in the d-axis current i. d is contained within. In the present description, this magnetic flux component is referred to as the "excitation magnetic flux" for simplicity. As described above, the in Fig. Figure 4 illustrates the structure of rotor core 50 with a salience. Therefore, during steady-state operation, where the harmonic base current component is large, the bridge sections of rotor core 50 are sufficiently magnetically saturated, such that the q-axis magnetic flux is reduced, as indicated by the solid arrow. On the other hand, when the harmonic base current component is small, the degree of magnetic saturation in the bridge sections is low, so the instantaneous magnetic flux passing through the bridge sections is not significantly reduced. As a result, the instantaneous magnetic flux passing through the bridge sections increases to exhibit a smaller difference compared to the excitation magnetic flux, resulting in no salience.

[0053] The sensorless control system 100 described above, according to the in Fig. The first embodiment illustrated in section 2 is designed to solve the salience problem described above. More specifically, this means that in a case where a desired detection accuracy for the estimated value θ is required, L Since the rotor position cannot be obtained, the sensorless control system 100 is a control to determine the coefficient value W. h to increase, which is calculated by the high-frequency amplitude calculator 31, and performs a control to adjust the voltage amplitude of the high-frequency voltages V uh , V vh and V wh to increase. For the sake of simplicity, this control is referred to in the present description as a "high-frequency boost control".

[0054] Considering a case where there is no high-frequency current when the harmonic base current is small, the magnetic flux component of this current simply passes through the bridge section. If the width of the bridge section is reduced, the magnitude of the magnetic flux passing through it is also reduced, but the strength of the rotor core 50 is reduced. If the harmonic base current increases, the area of ​​the bridge section also becomes magnetically saturated. However, in this case, an unnecessary current is passed through, causing a reduction in efficiency, and an unnecessary torque is also applied to the synchronous reluctance motor 1, which is not desirable for operation. On the other hand, if the high-frequency current is increased, the bridge section can become magnetically saturated without changing the magnitude of the harmonic base current.As a result, the property that the salience is hardly noticeable due to the harmonic background current can be solved by means of a control system.

[0055] Specific processing takes place as described above, where the high-frequency amplitude calculator 31 calculates the coefficient value W. h calculated and the high-frequency setpoint voltages V uh1 , V vh1 and V wh1 with the coefficient value W h must be multiplied to calculate the high-frequency voltages V uh , V vh and V wh to generate. The coefficient value W can also be h calculated using a table. Fig. Figure 8 presents a table illustrating an example of a coefficient value table used in the high-frequency boost control of the first embodiment.

[0056] In Fig. 8 contains current values ​​i in the coefficient value table above. d1 *, i d2 *, id3 *,... and i dM * of the d-axis current command i d *, which can be set, and the side of the coefficient value table contains current values ​​i q1 *, i q2 *, i q3 *, ... and i qN * of the q-axis current command i q *, which can be set. The step sizes, the intervals of the current values ​​i d1 *, i d2 *, i d3 *, ... and i dM * are not necessarily equal intervals and could be unequal intervals. The same applies to the current values ​​i. q1 *, i q2 *, i q3 *, ... and i qN *.

[0057] The coefficient value table stores values ​​of the coefficient value W. h (W h11 , W h12 , W h13 ,..., W h1M , W h21 , W h22 , W h23 , ..., W h2M , W h31 , W h32 , W h33 ,..., W h3M , ..., W hN1 , W hN2 , WhN3 ... and W hNM ), which is determined by a ratio between the d-axis current command i d * and the q-axis current command i q * is determined. It can be stated that if the current values ​​i q1 *, i q2 *, i q3 *, ... i qN * the condition i q1 * q2 * q3 *<, ..., qN * fulfill, then W h11 , W h21 , W h31 ...and W hN1 in a ratio of W h11 >W h21 >W h31 >, ... , >W hN1 This means that the coefficient value W h a negative correlation with the q-axis current command i q * exhibits. The same applies to the coefficient value W. h in the other columns. If the current values ​​i d1 *, i d2 *, i d3 *,... and i dM * furthermore i d1 * d2 * d3* <,... , dM * fulfill, then W h11 , W​​​​​​h12 , W h13 ...and W h1M in a ratio of W h11 >W h12 >W h13 >, ..., >W h1M This means that the coefficient value W h a negative correlation with the d-axis current command i d * exhibits. The same applies to the coefficient values ​​W. h in the other lines.

[0058] Furthermore, the values ​​stored in the coefficient table can be obtained through simulation. It should be noted that not all stored values ​​need to be obtained through simulation, and those that cannot be obtained through simulation could be obtained through arithmetic processing by performing interpolation, extrapolation, or interpolation on some of the simulation results.

[0059] Next, the selection of the coefficient value W will be carried out. hdescribed in the high-frequency boost control. First, the coefficient value table of the Fig. Section 8, the section in the thick frame, is defined as a template. It is assumed here that i d1 *=0 applies. The high-frequency amplitude calculator 31 selects the coefficient value W. h with regard to the section in the thick frame in the coefficient value table of the Fig. 8 based on the q-axis current command i q * off. If the value of the q-axis current command i q * for example “i q3 *“ is, then “W h31 “selected. If the value of the q-axis current command i q * between “i q2 *“ and “i q3 *“ lies, the coefficient value could be obtained through interpolation processing or by selecting either “i q2 *“ or “i q3 *“ will be obtained.

[0060] The d-axis current command i could also be the physical quantity that correlates with the magnetic saturation of rotor 1b. d * in addition to the q-axis current command i q * can be used. In this case, the entire coefficient value table is in Fig. 8 is used. If the value of the q-axis current command is i q * for example “i q3 *“ is and the value of the d-axis current command i d * “i d2 *“ is, then “W h32 “selected. It goes without saying that in a case where the coefficient value is not in the coefficient value table, the coefficient value could be obtained through interpolation processing or the like.

[0061] Next, a general idea of ​​an anomaly detection processing of the first embodiment will be presented with reference to the Fig. 9 and Fig. 10 will be described. Fig. Figure 9 presents a graph illustrating an example of current vector locations in a case where there is no anomaly in rotor 1b of the in Fig. 2 illustrated synchronous reluctance motor 1 is given. Fig. Figure 10 presents a graph illustrating an example of current vector locations in a case where there is an anomaly in rotor 1b of the in Fig. 2 illustrated synchronous reluctance motor 1 is given.

[0062] In Fig. 9 represents the horizontal axis and the d-axis current i d and the vertical axis represents the q-axis current i q Furthermore, the left side of the Fig. 9 the current vector locations, if the q-axis current i q =0 applies and if the d-axis current i d =0 for cases where the coefficient value W h W h =0.1, W n =0.3 and W h =0.5. The right side of the Fig. Figure 9 illustrates the three identical coefficient values ​​Wh the current vector locations when the q-axis current is i q =0 applies and the d-axis current i d >0 applies.

[0063] If W h Since W = 0.1, the surfaces or areas of the central rib 55a, the side rib 55b, and the annular section 57 of the rotor core 50 are not magnetically saturated, so the instantaneous magnetic flux passing through these areas increases, resulting in no salience. Consequently, the current vector locus does not exhibit a pronounced elliptical shape, but rather a shape close to a perfect circle. On the other hand, if W h =0.3 and W h Since the magnetic flux density is 0.5, the surfaces or areas of the central rib 55a, the side rib 55b and the annular section 57 of the rotor core 50 are magnetically saturated by the high-frequency current, so that the instantaneous magnetic flux passing through these areas decreases, resulting in a salience and a pronounced elliptical shape of the current vector locus.

[0064] Meanwhile, the current vector location differs in a case where there is an anomaly in rotor 1b, from that during normal time. Fig. Figure 10 indicates that a dashed line K1 shows that the current vector location, which is close to a perfect circle in shape, has changed to an elliptical shape. A dashed line K2 indicates that the current vector location, which is close to a perfect circle in shape, has changed to an elliptical shape and has also been distorted.

[0065] In a case where, for example, the central rib 55a, the side rib 55b, and / or the annular section 57 of the rotor core 50 have a crack, the magnetic flux passing through the cracked area is interrupted, causing the inductance component of the area to decrease, resulting in a state equivalent to a saturated state. Therefore, if the change in the current vector position compared to that at normal time can be detected, the anomaly in rotor 1b can be determined.

[0066] Fig. Figure 11 presents a block diagram illustrating an example of a hardware configuration implementing the functions of the anomaly detection device 40 according to the first embodiment. When the functions of the anomaly detection device 40 according to the first embodiment are implemented as shown in Figure 11, the hardware configuration is shown in Figure 11. Fig. As illustrated in Figure 11, the hardware configuration can include a processor 400 that performs an arithmetic operation, a memory 402 that stores programs to be read by the processor 400, an interface 404 that inputs and outputs signals, and a display 406 that shows a capture result.

[0067] The Processor 400 represents an example of an arithmetic device. The Processor 400 could be an arithmetic device referred to as a microprocessor, a microcomputer, a microcontroller, a central processing unit (CPU), or a digital signal processor (DSP). The Memory 402 could be, for example, non-volatile or volatile semiconductor memory, such as random-access memory (RAM), read-only memory (ROM), flash memory, erasable programmable ROM (EPROM), or electrical EPROM (EEPROM (registered trademark)), a magnetic disk, a flexible disk, an optical disk, a compact disc, a minidisc, or a DVD (digital versatile disc).

[0068] Memory 402 stores the programs for executing the functions of the anomaly detection device 40 according to the first embodiment. Processor 400 transmits and receives necessary information via interface 404, executes the programs stored in memory 402, and accesses data stored in memory 402, thereby performing the processing described above. The result of an arithmetic operation performed by processor 400 can be stored in memory 402. A processing result performed by processor 400 can also be displayed on the display 406. It should be noted that the display 406 could be located outside the anomaly detection device 40.

[0069] Alternatively, if the functions of the anomaly detection device 40 are implemented according to the first embodiment, which are in Fig. The 12 illustrated configurations are assumed. Fig. Figure 12 presents a block diagram illustrating another example of the hardware configuration implementing the functions of the anomaly detection device 40 according to the first embodiment. Fig. The processor will be 400 and the memory 402, which are in 12. Fig. 11 are illustrated, replaced by a processing circuit 403.

[0070] The processing circuit 403 corresponds to a single circuit, a complex circuit, an application-specific integrated circuit (ASIC), a custom-programmable gate array (FPGA), or a combination thereof. Information to be inputted to and output from the processing circuit 403 can be received and transmitted via interface 404.

[0071] Fig. Figure 13 represents a set of graphs intended to illustrate a determination process in the anomaly detection processing of the first embodiment. The left side of the Fig. Figure 13 illustrates waveforms of the position estimation current amplitudes I uh , I vh and I wh during a normal time. The right side of the Fig. Figure 13 illustrates, in addition to the waveforms of the position estimation current amplitudes I uh , I vh and I wh at normal time, dashed lines, the waveforms of the position estimation current amplitudes I uh , I vh and I wh Specify if rotor 1b exhibits an anomaly. Fig. Figure 11 represents the horizontal axes in both the left and right graphs, representing the rotor position during one electrical angular duration or period. The position estimation current amplitudes I uh , I vh and I whrepresent outputs of the high-frequency current amplitude calculation unit 7, which are calculated by the square root calculators 22u, 22v and 22w, which are in Fig. Figure 2 illustrates this. The outputs of the high-frequency current amplitude calculation unit 7 are entered into the anomaly detection device 25.

[0072] The position estimation current amplitudes I uh , I vh and I wh , which are obtained by the high-frequency current amplitude calculation unit 7, is a DC component I h superimposed, as in Fig. 11 illustrates the direct current component I. h changes during half the duration of the rotor position, i.e., during half the duration of the rotor position.

[0073] The anomaly detection device 25 calculates the DC component I hduring a normal time according to the following formula (7) and averages the calculated value over one period or half a period of the rotor position to obtain a time-averaged value of the DC component I h to calculate and to store the calculated time-averaged value in memory 402. Formula 7: Ih=Iuh+Ivh+Iwh3

[0074] If an anomaly occurs in rotor 1b, the DC component I changes. h , as shown by the dotted line waveforms on the right side of the Fig. 13 indicated. Fig. 10 the change in the DC component I occurs h as a change in the center position of the ellipse. When the anomaly detection processing is performed, the anomaly detection unit 25 calculates a time-averaged value of the DC component I. h and compares the calculated time-averaged value of the DC component I hThe time-averaged value over a normal period, stored in memory 402, determines the presence or absence of an anomaly in rotor 1b. The anomaly detection device 25 displays the result on the display 406. The result of the anomaly detection device 25 could be stored in memory 402.

[0075] It can be stated that the direct current component I h a DC component that controls the motor currents i u , i v and i w contains, and represents an example of the physical quantity that represents an anomaly state in rotor 1b. In the determination processing of the anomaly detection processing in the first embodiment, a different physical quantity could be used instead of the DC component I. hcan be used. The other physical quantity representing the anomalous state in rotor 1b could be an alternating current component present in the motor currents i u , i v and i w is contained, or be a distortion component present in the motor currents i u , i v and i w is included.

[0076] Fig. Figure 14 presents a flowchart illustrating a processing sequence for the anomaly detection processing of the first embodiment. The process of Fig. 14 will be described in conjunction with the calculation unit 41 and the determination unit 42, the components of which are in Fig. 1 illustrated anomaly detection device 40 are.

[0077] The calculation unit 41 calculates the position estimation current amplitudes I uh , I vh and I wh based on the motor currents i u , i v and i w(Step S11). The calculation unit 41 also calculates the DC component I. h according to formula (7) above (step S12). Furthermore, the calculation unit 41 calculates a time-averaged value I. ha the DC component I h by averaging the direct current component I h over one period or half a period of rotor position (step S13). The determination unit 42 compares the time-averaged value I. ha with a threshold A (step S14). Threshold A is a threshold based on the time-averaged value I. ha the DC component I h The value is determined, which is recorded at a normal time, and is held or stored in advance in memory 402.

[0078] In a case where the time-averaged value I haIf the threshold A is smaller than (Yes in step S15), the determination unit 42 determines that rotor 1b is normal (step S16). In a case where the time-averaged value I ha If the value is greater than or equal to threshold A (No in step S15), the determination unit 42 determines that rotor 1b is not normal (step S17). After processing steps S16 and S17, the determination unit 42 displays the determination result on the display 406 (step S18). When the processing of step S18 is complete, the process returns to step S11, and the processing is repeated from step S11.

[0079] It can be noted that in the determination processing of step S15 above, the case is where the time-averaged value I ha If the value is equal to the threshold A, it is determined as "no", but could also be determined as "yes". This means that the case where the time-averaged value I haThe result is equal to threshold A and could be determined as either "yes" or "no".

[0080] An additional description of the processing procedure will be given above. The one in Fig. The illustrated processing sequence 14 can be performed, for example, during the startup of the sensorless control system 100. During startup, the sensorless control system 100 is often accelerated to increase the rotational speed of the synchronous reluctance motor 1, and thus its rotational speed is not constant. As described above, in conventional technology, the synchronous reluctance motor 1 must rotate at a constant speed. Therefore, with conventional technology, it is difficult to detect an anomaly in the rotor 1b during startup of the sensorless control system 100. On the other hand, in the anomaly detection device 40 according to the first embodiment, since the synchronous reluctance motor 1 does not need to rotate at a constant speed, an anomaly in the rotor 1b can be detected during startup of the sensorless control system 100.

[0081] As described above, the anomaly detection device according to the first embodiment can be applied to the sensorless control system, which performs rotor position detection by superimposing a high-frequency current on the synchronous reluctance motor. The anomaly detection device according to the first embodiment can be configured to include a calculation unit, which calculates the physical quantity representing the anomaly state in the rotor of the synchronous reluctance motor based on the current value of the motor current flowing through the motor, and a determination unit, which determines an anomaly in the rotor based on this physical quantity. The anomaly detection device maintains or stores the threshold determined based on this physical quantity when the rotor is behaving normally.The detection unit determines the presence or absence of an anomaly in the rotor by comparing the physical quantity calculated by the computation unit with the threshold. The anomaly detection device according to the first embodiment has no limitation regarding the rotational speed of the synchronous reluctance motor and can therefore detect an anomaly in the rotor even if the synchronous reluctance motor is not rotating at a constant speed. Furthermore, the anomaly detection device according to the first embodiment can detect an anomaly in the rotor during the startup of the sensorless control system and can thus detect the anomaly in the rotor quickly.

[0082] Furthermore, the anomaly detection device according to the first embodiment can be configured using some of the functions of the existing high-frequency boost control. As a result, the configuration of the anomaly detection device can be implemented simply.

[0083] It should be noted that in the processing described above, the physical quantity representing the anomaly in the rotor of the synchronous reluctance motor can be the DC component contained in the motor current, the AC component contained in the motor current, or the distortion component contained in the motor current. For each of these physical quantities, the position estimation current amplitude, calculated during sensorless control, can be used, thus simplifying the configuration of the anomaly detection device.

[0084] Furthermore, the anomaly detection method according to the first embodiment can be applied to the sensorless control system, which performs rotor position detection by superimposing a high-frequency current on the synchronous reluctance motor. The anomaly detection method according to the first embodiment can include processing that comprises a calculation step to determine the physical quantity representing the anomaly state in the rotor of the synchronous reluctance motor, based on the current value of the motor current flowing through the synchronous reluctance motor, and a determination step to identify an anomaly in the rotor based on this physical quantity. The device performing the anomaly detection method maintains or stores the threshold determined based on the physical quantity when the rotor behaves normally.In the determination step, the presence or absence of an anomaly in the rotor is determined by comparing the physical quantity calculated in the computation step with the threshold. The anomaly detection method according to the first embodiment has no limitation regarding the rotational speed of the synchronous reluctance motor and can therefore detect an anomaly in the rotor even if the synchronous reluctance motor is not rotating at a constant speed. Furthermore, the anomaly detection method according to the first embodiment can detect an anomaly in the rotor during the startup of the control system, which performs sensorless control, and can thus detect the anomaly in the rotor quickly. Second embodiment.

[0085] The anomaly detection device 40 according to a second embodiment has a configuration similar to that of the first embodiment. In the second embodiment, the configuration of the anomaly detection device 40 is similar to that in the Fig. 1 and Fig. 2, and a configuration of the sensorless control system 100 is similar to that in Fig. 2. The second embodiment will describe a method that improves the detection accuracy of the anomaly detection method according to the first embodiment.

[0086] In a case where the processing flow of Fig. 14. During the startup of the sensorless control system 100, the determination result regarding the presence or absence of an anomaly could change each time the anomaly determination is performed. This means that it is possible for an anomaly to be detected in one period when the rotor position is being recorded, and for no anomaly to be detected in another period when the rotor position is being recorded. In such a case, the anomaly determination for rotor 1b could be performed multiple times, and the determination result could be output if the determination result is the same each time. This can reduce the probability of an erroneous determination that rotor 1b has an anomaly when rotor 1b is behaving normally.

[0087] Furthermore, the current vector location must be as described with reference to Fig. 6 described when the q-axis current iq small, not elliptical in shape, but essentially circular. As also with reference to Fig. As described in section 10, if rotor 1b exhibits an anomaly, the current vector position changes from a circle to an ellipse. Therefore, the smaller the q-axis current i q The greater the change in the shape of the current vector location, the greater the accuracy of anomaly detection. Therefore, in the second embodiment, if the anomaly determination for rotor 1b is performed several times or multiple times, and the result of the determination changes during the multiple performances, a command is issued to the current control unit 5, so that the q-axis current command i q * is reduced, which is output by the current control unit 5. The smaller the q-axis current command i qThe greater the value of the asterisk (*), the greater the change in the shape of the current vector location, thus increasing the stability of the anomaly detection processing. As a result, the accuracy of anomaly detection can be improved.

[0088] As described above for the anomaly detection device according to the second embodiment, the determination unit performs the anomaly determination for the rotor multiple times and outputs the determination result if the result is the same each time. By adding this processing to the anomaly detection device according to the first embodiment, it is possible to reduce the probability of an erroneous determination that the rotor has an anomaly when the rotor is behaving normally.

[0089] Furthermore, during the determination process, which is performed multiple times, if the determination result changes during the multiple runs, a command could be issued to the current control unit, thus reducing the moment axis current command issued by the current control unit. This can improve the stability of the anomaly determination processing and increase the accuracy of anomaly detection.

[0090] Furthermore, in the anomaly detection method according to the second embodiment, the anomaly determination for the rotor is performed multiple times in the determination step, and the determination result is output if the result is the same each time. By adding this processing to the anomaly detection method according to the first embodiment, it is possible to reduce the probability of an erroneous determination that the rotor has an anomaly when the rotor is behaving normally.

[0091] Furthermore, in the determination processing, which is performed multiple times, if the determination result changes during the multiple executions, a command step to issue a command to the current control unit could be included, thus reducing the moment axis current command issued by the current control unit. Adding such a command step can improve the stability of the anomaly determination processing and increase the accuracy of anomaly detection.

[0092] The configurations illustrated in the embodiments above each represent an example, so that another known technique can be combined, the embodiments can be combined together, or the configurations can be partially omitted and / or modified without deviating from the scope of the present disclosure. Reference symbol list

[0093] 1 Synchronous reluctance motor; 1a Stator; 1b Rotor; 2 Current sensing unit; 3 Voltage applicator; 4 Position estimation unit; 5 Current control unit; 6u, 6v, 6w Current extractor; 7 High-frequency current amplitude calculation unit; 8 Position calculation device; 9u, 9v, 9w Multiplication device; 10u, 10v, 10w Integration device; 12 DC power supply; 13d, 13q Subtraction device; 14d d-axis current control device; 14q q-axis current control device; 15 First coordinate converter; 16 Two-phase-to-three-phase converter; 17 Second coordinate converter; 18 Three-phase-to-two-phase converter; 22u, 22v, 22w Square root calculator; 23u, 23v, 23w Adding device; 25 Anomaly detection device; 30 Position estimation voltage generation unit; 31 High-frequency amplitude calculator; 32 High-frequency voltage generator; 40 Anomaly detection device; 41 Calculation unit; 42 Determination unit; 50 Rotor core; 51 Shaft; 52 Slot; 53 Core segment; 54 Slot group; 55a Center rib;55b Side rib; 56 Edge; 57 Ring-shaped section; 100 Sensorless control system; 400 Processor; 402 Memory; 403 Processing circuit; 404 Interface; 406 Display.; QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 4062939

[0005] JP 5324646

[0027]

Claims

[1] Anomaly detection device for a synchronous reluctance motor, wherein the anomaly detection device is applied to a sensorless control system which performs control to detect a rotor position by superimposing a high-frequency current on the synchronous reluctance motor, wherein the anomaly detection device comprises: a unit of calculation for calculating a physical quantity that represents an anomalous state in a rotor of the synchronous reluctance motor, based on a current value of a motor current flowing through the synchronous reluctance motor; and a unit of determination for identifying an anomaly in the rotor based on the physical quantity. [2] Anomaly detection device for a synchronous reluctance motor according to claim 1, wherein a threshold, determined based on the physical quantity, when the rotor is normal, is held, and The determination unit determines the presence or absence of the anomaly in the rotor by comparing the physical quantity calculated by the computation unit with the threshold. [3] Anomaly detection device for a synchronous reluctance motor according to claim 1 or 2, wherein the physical quantity is a DC component contained in the motor current. [4] Anomaly detection device for a synchronous reluctance motor according to claim 1 or 2, wherein the physical quantity is an alternating current component contained in the motor current. [5] Anomaly detection device for a synchronous reluctance motor according to claim 1 or 2, wherein the physical quantity is a distortion component contained in the motor current. [6] Anomaly detection device for a synchronous reluctance motor according to claim 5, wherein the detection unit performs an anomaly detection for the rotor multiple times and outputs a determination result if the determination result is the same each time. [7] Anomaly detection device for a synchronous reluctance motor according to claim 6, wherein the sensorless control system includes a current control unit to generate a voltage command to control the synchronous reluctance motor based on the current value of the motor current and an estimated value of the rotor position, and, If the determination result changes during the multiple passes, a command is issued to the current control unit, so that a moment axis current command issued by the current control unit is reduced. [8] Anomaly detection method for a synchronous reluctance motor, wherein the anomaly detection method is applied to a sensorless control system which performs control to detect a rotor position by superimposing a high-frequency current on the synchronous reluctance motor, wherein the anomaly detection method comprises: a calculation step to calculate a physical quantity representing an anomaly state in a rotor of the synchronous reluctance motor, based on a current value of a motor current flowing through the synchronous reluctance motor; and a determination step to identify an anomaly in the rotor based on the physical quantity. [9] Anomaly detection method for a synchronous reluctance motor according to claim 8, wherein in the determination step an anomaly determination for the rotor is carried out multiple times and a determination result is output if the determination result is the same each time. [10] Anomaly detection method for a synchronous reluctance motor according to claim 9, wherein The sensorless control system includes a current control unit for generating a voltage command to control the synchronous reluctance motor based on the current value of the motor current and on an estimated value of the rotor position, and The determination step includes a command step to issue a command to the current control unit, such that a moment axis current command issued by the current control unit is reduced, with the command being issued when the determination result changes during the multiple executions in the determination step.

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