Motor test method and motor test device

Abstract

To provide a motor test method and a motor test device capable of improving identification accuracy of a parameter of a motor.SOLUTION: In a motor test method in which a current corresponding to a current command value is passed through a motor to measure a voltage applied to the motor and a magnetic flux or an inductance of the motor is identified based on a measured value of the voltage, under speed conditions of the motor including a plurality of speed command values (S1 and S5), the current corresponding to the current command value is passed through the motor (S2 and S6), a voltage applied to the motor is measured for each of the plurality of speed command values (S3 and S7), and a magnetic flux or inductance of the motor is identified based on the plurality of measurements of the voltage.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a motor testing method and a motor testing device for identifying motor parameters. [Background technology]

[0002] In a motor drive system, in order to control torque according to a command value, a controller is configured using motor parameters such as inductance and magnetic flux. Because inductance and magnetic flux change due to the influence of magnetic saturation of the motor, it is necessary to identify these parameters, including their changes according to the current.

[0003] A known prior art technique for identifying motor parameters is described in Patent Document 1. In this prior art technique, magnetic flux is calculated based on the stator voltage, stator current, and rotor electrical speed, and inductance is identified using the calculated magnetic flux value. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-184868 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned prior art, the magnetic flux is calculated using the winding resistance value, and errors occur in the magnetic flux value due to variations in individual resistance values and temperature changes.

[0006] Therefore, the present invention provides a motor testing method and testing device that can improve the accuracy of identifying motor parameters. [Means for solving the problem]

[0007] In order to solve the above problems, the motor testing method of the present invention is a method of passing a current corresponding to a current command value through a motor, measuring the voltage applied to the motor, and identifying the magnetic flux or inductance of the motor based on the measured voltage value, in which under motor speed conditions including a plurality of speed command values, a current corresponding to a current command value is passed through the motor, measuring the voltage applied to the motor for each of the plurality of speed command values, and identifying the magnetic flux or inductance of the motor based on the plurality of measured voltage values.

[0008] In order to solve the above problems, a motor testing device according to the present invention comprises an inverter connected to a motor, a motor control device that controls the motor, a load motor that rotates the motor, a load motor control device that controls the load motor, and a measurement control device that performs parameter identification of the motor, wherein the load motor control device controls the load motor so that the speed of the load motor matches a plurality of speed command values included in speed conditions, the motor control device controls the inverter so that the current flowing through the motor matches a current command value, and the measurement control device sets a current command value for each of the plurality of speed command values, measures the voltage applied to the motor from the inverter, and identifies the magnetic flux or inductance of the motor based on the plurality of measured voltage values. [Effects of the Invention]

[0009] According to the present invention, the influence of the winding resistance value is reduced, and the accuracy of identifying the motor parameters is improved.

[0010] Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a block diagram showing the configuration of a motor testing device according to a first embodiment; [Figure 2] 4 is a flowchart showing the operation of the measurement control device in the first embodiment. [Figure 3]FIG. 10 is a waveform diagram showing the time changes in speed and current of a test motor in a comparative example. [Figure 4] FIG. 3 is a waveform diagram showing an example of time changes in speed and current of a test motor in Example 1. [Figure 5] FIG. 3 is a waveform diagram showing the time changes in the speed and current of a test motor when the first process and the second process in FIG. 2 are executed under full current conditions. [Figure 6] 10 is a graph showing an example of the results of regression analysis in Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0012] A motor testing device according to one embodiment of the present invention will be described below with reference to the drawings in Examples 1 and 2. In each drawing, the same reference numerals indicate the same components or components with similar functions. [Example]

[0013] FIG. 1 is a block diagram showing the configuration of a motor testing device according to a first embodiment of the present invention.

[0014] The test inverter 33 converts DC power from a DC voltage source (not shown) into AC power in accordance with a drive signal from the test motor control device 35. The test inverter 33 drives the test motor 31 with this AC power.

[0015] In Example 1, the test motor 31 is a permanent magnet synchronous motor, and the test motor control device 35 applies vector control.

[0016] The test phase current detector 37 detects the three-phase motor current I flowing from the test inverter 33 to the test motor 31. ut (U phase), I vt (V phase), I wt The test magnetic pole position detector 39 detects the magnetic pole position of the test motor 31 and outputs magnetic pole position information θ t Output.

[0017] The phase current detector 37 under test is composed of a Hall current transformer (CT), etc. The magnetic pole position detector 39 under test is composed of a resolver, etc.

[0018] The test motor control device 35 detects the I ut , I vt , I wt The magnetic pole position information θ detected by the test magnetic pole position detector 39 t The dq-axis current detection value I in the rotating coordinate system is calculated by coordinate transformation based on dt (d-axis), I qt Calculate (q axis).

[0019] The test motor control device 35 is dt , I qt are the d-axis current command values I dt * (d-axis), I qt * (q axis) so that the dq axis voltage command value V dt * (d-axis), V qt * (q axis). Furthermore, the test motor control device 35 calculates V dt * (d-axis), V qt * (q axis) θ t By converting the coordinates based on ut * (U phase), V vt * (V phase), I wt * (W phase) is calculated.

[0020] The test motor control device 35 calculates the V ut * , V vt * , V wt *is used as a modulating wave, and a drive signal is generated by PWM control to drive the semiconductor switching elements that make up the inverter under test 33. The motor control device under test 35 outputs the generated drive signal to the inverter under test 33.

[0021] After the test is completed, the above-mentioned test motor 31, test inverter 33, test motor control device 35, test phase current detector 37, and test magnetic pole position detector 39 are mounted on an actual vehicle (e.g., an electric vehicle) to form a drive system in the actual vehicle.

[0022] The load inverter 43 converts DC power from a DC voltage source (not shown) into AC power in accordance with a drive signal from the load motor control device 45. The load inverter 43 drives the load motor 41 with this AC power.

[0023] In the first embodiment, the load motor 41 is a permanent magnet synchronous motor. Vector control is applied to the load motor control device 45. The load motor 41 may have different performance and specifications from the test motor 31. The load motor 41 may also be a different type of synchronous motor from the test motor 31.

[0024] The load phase current detector 47 detects the three-phase motor current I flowing from the load inverter 43 to the load motor 41. ul (U phase), I vl (V phase), I wl The load magnetic pole position detector 49 detects the magnetic pole position of the load motor 41 and outputs magnetic pole position information θ l Output.

[0025] The load phase current detector 47 is configured with a Hall CT (Current Transformer), etc. The load magnetic pole position detector 49 is configured with a resolver, etc.

[0026] The load motor control device 45 receives magnetic pole position information θ l From this, the load motor speed ω l The load motor control device 45 calculates the calculated ωl is the speed command value ω output from the measurement control device 21 l * The dq-axis current command value I dl * (d-axis), I ql * Calculate (q axis).

[0027] The load motor control device 45 detects the load phase current I detected by the load phase current detector 47. ul , I vl , I wl The magnetic pole position information θ detected by the load magnetic pole position detector 49 l The dq-axis current detection value I in the rotating coordinate system is calculated by coordinate transformation based on dl (d-axis), I ql Calculate (q axis).

[0028] The load motor control device 45 is dl , I ql is the calculated dq-axis current command value I dl * , I ql * The dq-axis voltage command value V dl * (d-axis), V ql * (q axis). Furthermore, the load motor control device 45 calculates V dl * (d-axis), V ql * (q axis) θ l By converting the coordinates based on ul * (U phase), V vl * (V phase), I wl * (W phase) is calculated.

[0029] The load motor control device 45 calculates the V ul * , V vl * , V wl *Using this as a modulated wave, the load motor control device 45 generates a drive signal that drives the semiconductor switching elements that make up the load inverter 43 through PWM control. The load motor control device 45 outputs the generated drive signal to the load inverter 43.

[0030] The shaft 25 coaxially connects the rotor of the test motor 31 and the rotor of the load motor 41. Therefore, when the speed of the load motor 41 is ω l * When controlled to the same speed (ω l * That is, in the first embodiment, the speed of the test motor 31 can be set by the load motor 41.

[0031] The measurement control device 21 manages the motor test procedure. When identifying parameters, the measurement control device 21 controls the test motor 31 and the load motor 41 under predetermined test conditions to measure the motor parameters. In the first embodiment, as will be described later, the measurement control device 21 measures the magnetic flux and inductance of the motor as the motor parameters.

[0032] The measurement control device 21 outputs the dq-axis current command value I to the test motor control device 35 according to the current conditions in the test. dt * , I qt * In this way, the measurement control device 21 sets the current of the test motor 31.

[0033] The measurement control device 21 outputs a speed command value ω to the load motor control device 45 in accordance with the speed conditions in the test. l * In this way, the measurement control device 21 sets the speed of the motor under test 31.

[0034] The measurement control device 21 detects the I detected by the test phase current detector 37. ut , I vt , I wt and magnetic pole position information θ detected by the test magnetic pole position detector 39. t and the dq-axis voltage command value Vdt * , V qt * and measure the motor parameters based on these.

[0035] The measurement control device 21 uses the temperature sensor 23 to detect the temperature T of the test motor 31. The temperature sensors 23 may be provided at multiple locations on the test motor 31, and the temperatures of these multiple locations, such as the rotor and stator of the test motor 31, may be detected as the temperature of the test motor 31.

[0036] FIG. 2 is a flowchart showing the operation of the measurement control device 21 in the first embodiment.

[0037] When identifying the magnetic flux of the motor, the measurement control device 21 in the first embodiment measures the magnetic flux for a plurality of predetermined current conditions (i: 1 to n) and stores the measured magnetic flux in a magnetic flux table in association with the current conditions.

[0038] 2, the measurement control device 21 executes a first process and a second process to measure the motor voltage under multiple (two in FIG. 2) speed conditions for each current condition. Furthermore, the measurement control device 21 executes a third process to measure the magnetic flux using the voltage values obtained in the first and second processes.

[0039] Each process will be explained below, with reference to FIG. 1 as needed.

[0040] When the measurement control device 21 starts its operation, it first executes a first process including steps S1 to S4.

[0041] In step S1, the measurement control device 21 outputs a first speed command value ω to the load motor control device 45 in accordance with a predetermined speed condition. l1 * Then, the speed of the load motor 41 is ω l1 * By controlling the load motor 41 so that the speed of the test motor 31 is ω l1 * Set to.

[0042] Next, in step S2, the measurement control device 21 outputs the dq-axis current command value I to the test motor control device 35 in accordance with a predetermined current condition (i). dti * , I qti * The test inverter 33 is controlled to energize the test motor 31. That is, the measurement control device 21 controls the current of the test motor 31 to I dti * , I qti * Set to.

[0043] Of the multiple current conditions (i) (i=1 to n: n≧2), immediately after the measurement control device 21 starts operation, I dt1 * , I qt1 * After the magnetic flux is measured for the current condition (1), the magnetic flux is then measured sequentially for the current conditions (2) to (n).

[0044] Next, in step S3, the measurement control device 21 calculates the dq-axis current command value I dti * , I qti * and the dq axis current detection value I dt , I qt When these match, the dq-axis voltage command value V dt * , V qt * Measure the first voltage V dt1 , V qt1 Save as.

[0045] In addition, the measurement control device 21, like the test motor control device 35, detects the I ut , I vt , I wt The magnetic pole position information θ detected by the test magnetic pole position detector 39 t By transforming the coordinates based on dti , I qti Calculate the following.

[0046] Next, in step S4, the measurement control device 21 sets the dq-axis current command value to zero, and stops the power supply to the test motor 31.

[0047] The measurement control device 21 determines the first speed condition (ω l1 * ) first voltage V dt1 , V qt1 After performing the first process to measure the current, under the same current condition (i), the second speed condition (ω l2 * ) at the second voltage V dt2 , V qt2 The second process includes steps S5 to S8.

[0048] In step S5, the measurement control device 21 controls the load motor control device 45 to calculate ω l1 * A second speed command value ω different from l2 * Then, the speed of the load motor 41 is ω l2 * By controlling the load motor 41 so that the speed of the test motor 31 is ω l2 * Set to.

[0049] Next, in step S6, the measurement control device 21 outputs the dq-axis current command value I to the test motor control device 35 according to the same current condition (i) as in the first process. dti * , I qti * The test inverter 33 is controlled to energize the test motor 31. That is, the measurement control device 21 controls the current of the test motor 31 to I dti * , I qti * Set to.

[0050] Next, in step S7, the measurement control device 21 calculates the dq-axis current command value I dti * , Iqti * and the dq axis current detection value I dt , I qt When the d- and q-axis voltage command values V dt * , V qt * Measure the second voltage V dt2 , V qt2 Save as.

[0051] The time from when the test motor 31 is energized and the current starts to rise until the voltage is measured is set equal in steps S3 and S7. As a result, even if the speed of the test motor 31 transiently increases due to energization, as will be described later, the voltage value can be measured before the speed returns to the speed command value.

[0052] Next, in step S8, the measurement control device 21 sets the dq-axis current command value to zero, and stops the power supply to the test motor 31.

[0053] After executing the second process, the measurement control device 21 executes a third process of calculating the magnetic flux as a motor parameter. The third process includes step S9.

[0054] In step S9, the measurement control device 21 detects the stored first voltage V dt1 , V qt1 and the second voltage V dt2 , V qt2 , and the first speed command value ω l1 * , second speed command value ω l2 * Based on this, the dq-axis magnetic flux φ is calculated using equations (1) and (2). d , φ q The measurement control device 21 calculates the calculated φ d , φ q is stored in the dq-axis magnetic flux table in correspondence with the current condition (i).

[0055]

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[0056]

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[0057] As shown in equations (1) and (2), the magnetic flux of the test motor 31 is expressed by the rate of change of voltage with respect to speed. Furthermore, as will be described later, equations (1) and (2) are based on the motor's voltage equation, but do not include the winding resistance R. Therefore, variations in R between individual motors and temperature changes do not cause errors in the calculated magnetic flux value.

[0058] The measurement control device 21 executes step S10 after executing the third process (step S9).

[0059] In step S10, the measurement control device 21 determines whether the calculation of magnetic flux has been completed for all current conditions (1) to (n). If the measurement control device 21 determines that the calculation of magnetic flux has not been completed (NO in step S10), it changes the current condition (step S11) and executes the first process again. If the measurement control device 21 determines that the calculation of magnetic flux has been completed (YES in step S10), it ends the series of processes (steps S1 to S11).

[0060] The magnetic flux table of the test motor 31 created by the measurement control device 21 is set in the test motor control device 35. After the test motor control device 35 is installed in the actual machine together with the test motor 31, it controls the test motor 31 based on the set magnetic flux table.

[0061] Equation (3) is the voltage equation of a permanent magnet synchronous motor that forms the basis of equations (1) and (2).

[0062]

number

[0063] V d and V q are the d-axis voltage and the q-axis voltage, respectively. Id and I q are the d-axis current and the q-axis current, respectively. d and φ q are the d-axis and q-axis fluxes. R is the winding resistance. ω is the speed.

[0064] In the steady state where the current is constant, equation (3) is transformed into equation (4).

[0065]

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[0066] From equation (4), the d-axis magnetic flux φ d and q-axis magnetic flux φ q are expressed by equations (5) and (6), respectively.

[0067]

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[0068]

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[0069] In equation (5), V q , I q , ω are the I in Figure 2, respectively. qti * , V qt1 , ω l1 * and V q , I q , ω are the I in Figure 2, respectively. qti * , V qt2 , ω l2 * From the equation obtained as qti * By eliminating, we obtain equation (1) which does not include R.

[0070] In equation (6), V d , Id , ω are the I in Figure 2, respectively. dti * , V dt1 , ω l1 * and V d , I d , ω are the I in Figure 2, respectively. dti * , V dt2 , ω l2 * From the equation obtained as dti * By eliminating, we obtain equation (2) which does not include R.

[0071] If R is identified, the magnetic flux can also be calculated using equations (5) and (6). Therefore, the operation of the comparative example and example 1 will be described below using a motor testing device that calculates the magnetic flux using equations (5) and (6) as a comparative example.

[0072] 3 is a waveform diagram showing the time change in speed and current of the test motor when identifying the magnetic flux in the comparative example. Note that "current" in the diagram represents the dq axis current (similarly to FIG. 4).

[0073] By controlling the speed of the load motor, the speed of the test motor is controlled by ω l * When the test motor is energized under current condition i, the speed fluctuates transiently due to the torque generated in the test motor. As a result, the speed fluctuations settle down and the speed reaches the set value ω l * The voltage value of the test motor is measured when the speed returns to . The current will reach a constant value according to current condition i before the speed fluctuations subside, but current continues to flow through the test motor until the voltage value is measured.

[0074] The measured voltage value, current value, and ω l * and the identified winding resistance value, the magnetic flux is calculated using equations (5) and (6).

[0075] In this comparative example, since equations (5) and (6) include the winding resistance R, individual variations in R and temperature changes in R cause errors in the identified value of the magnetic flux.

[0076] In this comparative example, the temperature of the test motor changes due to the current flow through the winding resistance R, which causes an error in the identified value of the magnetic flux. In addition, when the speed is fluctuating, the speed detection error is large, so the speed of the test motor is controlled to a steady value (ω l * ) before measuring the voltage, an error will occur in the identified value of the magnetic flux.

[0077] In this comparative example, since the magnetic flux changes depending on the temperature, it is necessary to make the temperature uniform when measuring the magnetic flux for each current condition. For this reason, when measuring the magnetic flux by changing the current condition, as in FIG. 3, when changing from current condition i to current condition i+1 and measuring the magnetic flux, a waiting time (t w ) is required. Here, the waiting time (t w ) is the duration of the non-energization period from the point at which energization according to current condition i stops to the point at which energization according to current condition i+1 starts.

[0078] FIG. 4 is a waveform diagram showing an example of time changes in speed and current of a test motor when identifying magnetic flux in the first embodiment.

[0079] In FIG. 4, the magnetic flux is measured under current condition i. The second speed command value is smaller than the first speed command value (ω l1 * >ω l2 * ).

[0080] In the first embodiment, since equations (1) and (2) do not include the winding resistance R, the influence of individual variations in R and temperature changes in R on the identification of the magnetic flux is reduced.

[0081] As shown in FIG. 4, when the test motor is energized under current condition i, the speed transiently fluctuates due to the torque generated in the test motor, similar to the comparative example described above.

[0082] When the response of the current controller in the test motor control device 35 is set to a constant value and the response of the speed controller in the load motor control device 45 is set to a constant value, the torque waveform in the current flow is l1 * ,ω l2 * ) is constant. Therefore, the waveform of the speed fluctuation is also constant depending on the speed command value (ω l1 * ,ω l2 * ) is constant. That is, the speed is constant when the speed command value is ω l1 * and ω l2 * If this is the case, the current will fluctuate during current flow, but will follow the same path to reach the steady state (ω l1 * ,ω l2 * ) and the voltage command value is ω l1 * and ω l2 * When the speed starts to fluctuate, that is, when current is applied (t r1 ,t r2 ) and the difference in velocity value Δω' at the point (t1, t2) after the same time (Δt) has passed, is ω l1 * and ω l2 * The difference Δω(=ω l1 * -ω l2 * )

[0083] Therefore, when calculating the magnetic flux using equations (1) and (2), as shown in Figure 4, the first voltage V dt1 , V qt1 and the second voltage V dt2 , V qt2 (steps S3 and S7 in FIG. 2), the difference between the speed at the time of the first voltage measurement and the speed at the time of the second voltage measurement is ω l1 * and ωl2 * The difference between (ω l1 * -ω l2 * ) Furthermore, since the response of current control is generally faster than the response of speed control, the current will reach a constant value according to the current condition i before the speed fluctuations settle down. Therefore, the first voltage and the second voltage can be measured before the speed fluctuations settle down, and the magnetic flux can be calculated using equations (1) and (2).

[0084] In addition, since the first and second voltages can be measured before the speed fluctuations settle down, the current conduction width Δt i Therefore, the temperature rise of the test motor 31 is reduced. As a result, the waiting time (t in FIG. 3) for regulating the temperature between the end of the current supply and the start of the next current supply is reduced. w In FIG. 4, after the power supply is stopped during the first voltage measurement, the speed of the test motor 31 is reduced by the speed control of the load motor 41. l1 * Therefore, the temperature becomes uniform when the speed of the test motor 31 reaches ω l1 * When the speed of the load motor 41 is ω l2 * is controlled by.

[0085] As shown in FIG. 4, in the first embodiment, the first voltage and the second voltage are measured at t1 and t2, respectively. r1 =t2-t r2 ) is set to the time required for the current to reach a constant value according to the current condition i.

[0086] When measuring the first voltage and the second voltage, the current width is the same, so the winding temperature rise trajectory is also the same. Therefore, it is possible to reduce the identification error of the magnetic flux due to the temperature change of the winding resistance R.

[0087] As described above, in the first embodiment, the speed of the test motor 31 is controlled to a plurality of different speed values (first and second speed command values ω l1 * , ω l2 * ), and when each speed value is set, a predetermined current is passed through the test motor 31 and the voltage of the test motor 31 is measured. The magnetic flux is measured by calculating the rate of change of voltage with respect to speed from the obtained multiple voltage measurement values and multiple speed values. This makes it possible to identify the magnetic flux without using an identified value for the winding resistance R. This improves the accuracy of magnetic flux identification.

[0088] Furthermore, according to the first embodiment, the magnetic flux is calculated using the difference between the first and second speed values as the change in speed. This allows the voltage to be measured when the speed of the test motor 31 is fluctuating as current is applied to the test motor 31. This reduces the width of the current flowing through the test motor 31, thereby reducing the temperature rise of the test motor 31. This improves the accuracy of magnetic flux identification and reduces the power application wait time required to equalize the temperature.

[0089] Such a reduction in the power-on waiting time is effective in shortening the test time of the test motor 31 when the current conditions include many current command values and the number of times power is turned on is large.

[0090] Furthermore, according to the first embodiment, the speed and current of the test motor 31 can be set independently, so that the relationship between magnetic flux and current (magnetic flux table) can be measured accurately.

[0091] In order to improve the identification accuracy, it is preferable that the conditions such as the carrier frequency of the test motor control device 35 and the DC input voltage to the test inverter 33 are the same in the first and second processes in FIG.

[0092] In addition, in order to reduce the influence of variations in the voltage measurement values, the voltage is measured multiple times in the first and second processes, and the voltage value obtained by averaging the multiple measurement values is used as the voltage measurement value (V dt1,V qt1 ,V dt2 ,V qt2 ) may be used. In order to reduce the influence of voltage variations, the measured value may be passed through a low-pass filter to obtain the voltage measurement value (V dt1 ,V qt1 ,V dt2 ,V qt2 ) can also be used.

[0093] In addition, in the calculation of equations (1) and (2), the voltage command value may be replaced with a dq-axis voltage calculated by coordinate transformation from the measured values of the three-phase output voltage of the test inverter 33 when the test motor is energized.

[0094] Furthermore, in the calculation of equations (1) and (2), the speed of the test motor 31 measured when current is applied may be used instead of the speed command value. In this case, it is preferable to apply averaging processing or a low-pass filter. This reduces the influence of errors because the trajectories of speed convergence during the first and second processing are the same.

[0095] Furthermore, before setting the first speed command value (after the process starts and before step S1 in FIG. 2) and before setting the second speed command value (between steps S4 and S5 in FIG. 2), the temperature T of the test motor 31 may be monitored using the temperature sensor 23 (FIG. 1), and current flow may be started when the temperature T detected by the temperature sensor 23 (FIG. 1) falls within a predetermined allowable temperature range. This allows the temperatures to be consistent when identifying the motor parameters.

[0096] In the first embodiment, as described above, the magnetic flux is identified, but the inductance of the test motor 31 may also be identified. In identifying the inductance, the dq-axis magnetic flux calculated by the equations (1) and (2) is used to calculate the dq-axis inductance L by the equations (7) and (8). d , L q is calculated. φ in Equation (7) m is the magnet magnetic flux coefficient, which is measured in advance from the induced voltage under the same temperature conditions.

[0097]

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[0098]

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[0099] Note that equations (7) and (8) are known relational expressions, and are calculated, for example, from a magnetic flux vector due to a current, a magnet magnetic flux vector, and a magnetic flux (flux linkage) vector of a motor.

[0100] In the first embodiment, as shown in FIG. 2, the first to third processes are executed for each current condition, but this is not limited thereto. After the first and second processes are executed under all current conditions, the third process may be executed from the results of these processes to calculate the magnetic flux for all current conditions.

[0101] FIG. 5 is a waveform diagram showing an example of the time variation of the speed and current of the test motor when the first process and the second process in FIG. 2 are executed under full current conditions.

[0102] As shown in FIG. 5, a current that changes stepwise according to a plurality of current conditions i (i=1 to 8 in FIG. 5) is set to the test motor 31.

[0103] Under each current condition i, the first voltage (V dt1 , V qt1 ) and the second voltage (V dt2 , V qt2 ) The current width at the time of measurement is equal to Δt i As shown in FIG. 5, the energization width may be the same under all current conditions. In addition, under each current condition i, the timing at which the first voltage is measured, that is, the current rise start time t ri The time elapsed from the time t1 to the measurement time t2, and the timing at which the second voltage is measured, i.e., the current rise start time t ri The time elapsed from the measurement time t1 to the measurement time t2 is equal to Δt.

[0104] In Example 1, as described above (FIG. 1), the shaft 25 coaxially connects the rotor of the test motor 31 and the rotor of the load motor 41 so that the test motor 31 and the load motor 41 rotate at the same speed, but this is not limited to this and they may be connected via a speed change gear.

[0105] The gear ratio of the transmission gear is G r Then, the magnetic flux is calculated using equations (9) and (10) instead of the above equations (1) and (2).

[0106]

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[0107]

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[0108] In the above-described first embodiment, the test motor 31 is rotated at two different speeds (ω l1 * ,ω l2 * ) and the first voltage (V dt1 , V qt1 ) and the second voltage (V dt2 , V qt2 ) is measured, the difference in speed is considered to be the change in speed, and the difference in voltage measurement values is considered to be the change in voltage, and the rate of change of voltage relative to speed is calculated to identify the magnetic flux.

[0109] In contrast, the measurement control device 21 in the motor testing device according to the second embodiment controls the speed of the load motor 41 with a plurality of speed command values, sets a plurality of speed values for the test motor 31, and measures the voltage by energizing the test motor 31 at each speed value under predetermined current conditions. The measurement control device 21 analyzes the correlation between speed and voltage from the plurality of speed values and the corresponding plurality of voltage measurement values, thereby calculating the rate of change of voltage relative to speed and using this as an identified value for the magnetic flux.

[0110] The configuration of the motor testing device according to the second embodiment is the same as that of the first embodiment (FIG. 1).

[0111] According to the above-mentioned equations (5) and (6), the voltage is expressed as a linear function with the speed as a variable, and the slope of this function represents the magnetic flux. The intercept is the product of the winding resistance R and the current value. Therefore, the measurement control device 21 analyzes the correlation between the speed and the voltage using regression analysis.

[0112] 6 is a graph showing an example of the results of the regression analysis in Example 2. The graph also shows the distribution of the measurement data.

[0113] In this example, the speed setting value of the test motor 31 is the speed command value ω l1 * ,ω l2 * ,ω l3 * These three speed command values ω l1 * ,ω l2 * ,ω l3 * are different from each other (ω l1 * >ω l2 * >ω l3 * ) When a current is applied with a current width of Δti under current condition i, ω l1 * ,ω l2 * ,ω l3 * The voltage measurement values for these are the first voltage measurement value, the second voltage measurement value, and the third voltage measurement value in the drawing, respectively.

[0114] The measurement control device 21 calculates the slope of the linear function representing the correlation between voltage and speed, i.e., the rate of change of voltage relative to speed, by regression analysis, for example, the least squares method, from the three pieces of data shown in the figure. The measurement control device 21 uses the calculated value of this slope as the identified value of the magnetic flux.

[0115] As in the first embodiment, when the voltage is measured while the speed is fluctuating due to current flow, the actual speed value differs from the speed command value. As described above, even if the speed command value is different, the speed fluctuates along the same trajectory, and therefore the magnitude of the fluctuation from each speed command value is the same at the same timing during the speed fluctuation. Therefore, if the horizontal axis of FIG. 6 represents the actual speed, the three data points will move by the same fluctuation amount in a direction parallel to the speed axis. Therefore, if the horizontal axis represents the actual speed, the result of the regression analysis will be a straight line obtained by moving the straight line in FIG. 6 in the direction of the horizontal axis, but the slope of the straight line will be the same as the straight line in FIG. 6. In other words, as in the first embodiment, even if the voltage is measured during the speed fluctuation, the magnetic flux can be identified by regression analysis using the speed command value.

[0116] As shown in the above equations (5) and (6), the correlation between speed and voltage is expressed by a linear function, and the slope of the linear function corresponds to the magnetic flux. Furthermore, the winding resistance R does not appear in the slope, but appears in the intercept of the linear function. Therefore, according to the second embodiment, it is possible to reduce the identification error of the magnetic flux caused by individual variations in the winding resistance R and temperature changes.

[0117] The number of speed command values is not limited to three, but may be any number of multiple values.

[0118] The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. Furthermore, it is possible to add, delete, or replace part of the configuration of the embodiments with other configurations.

[0119] For example, the test motor 31 is not limited to a permanent magnet synchronous motor, but may be an AC rotating machine such as a synchronous reluctance motor, a permanent magnet synchronous generator, or a wound-field synchronous machine. Furthermore, various types of power semiconductor switching elements such as IGBTs and power MOSFETs can be used as the semiconductor switching elements that make up the inverter. [Explanation of symbols]

[0120] 21: Measurement and control device 23: Temperature sensor 25: Shaft 31: Test motor 33: Test inverter 35: Test motor control device 37: Test phase current detector 39: Test magnetic pole position detector 41: Load motor 43: Load inverter 45: Load motor control device 47: Load phase current detector 49: Load magnetic pole position detector

Claims

1. A motor testing method for flowing a current corresponding to a current command value into a motor, measuring a voltage applied to the motor, and identifying a magnetic flux or an inductance of the motor based on the measured value of the voltage, comprising: a current that matches the current command value being passed through the motor under speed conditions of the motor that include a plurality of speed command values; measuring the voltage applied to the motor for each of the plurality of speed command values; and identifying the magnetic flux or the inductance of the motor based on the plurality of measured voltage values.

2. 2. The motor testing method according to claim 1, A motor testing method comprising: calculating a rate of change of the voltage applied to the motor with respect to the speed of the motor based on the plurality of measured values.

3. 2. The motor testing method according to claim 1, the speed condition includes a first speed command value and a second speed command value that are different from each other, a first process of setting the speed condition as the first speed command value, causing the current corresponding to the current command value to flow through the motor, and measuring a first voltage applied to the motor; a second process of passing the current corresponding to the current command value through the motor using the speed condition as the second speed command value and measuring a second voltage applied to the motor; A motor testing method comprising:

4. The motor testing method according to claim 3, a third process of calculating the magnetic flux or the inductance based on a difference between the first speed command value and the second speed command value, or a difference between a first speed of the motor when the first voltage is measured and a second speed of the motor when the second voltage is measured, and a difference between the first voltage and the second voltage.

5. The motor testing method according to claim 3, a third process of calculating a rate of change of the voltage applied to the motor with respect to the motor speed, based on a difference between the first speed command value and the second speed command value, or a difference between a first speed of the motor when the first voltage is measured and a second speed of the motor when the second voltage is measured, and a difference between the first voltage and the second voltage.

6. The motor testing method according to claim 4 or 5, A motor testing method, characterized in that in the first process and the second process, the motor is controlled by a speed control means having the same response.

7. In the test method according to claim 3, A motor testing method, characterized in that, in the first process and the second process, the control response of the control for causing the current that matches the current command value to flow through the motor is the same.

8. 2. The motor testing method according to claim 1, A motor testing method comprising: analyzing a correlation between the speed of the motor and the voltage applied to the motor by regression analysis based on the plurality of measured values of the voltage; and identifying the magnetic flux or the inductance of the motor based on the correlation.

9. 9. The motor testing method according to claim 8, A motor testing method, characterized in that the correlation is expressed by a linear function, and a rate of change of the voltage applied to the motor with respect to the speed of the motor is calculated based on the slope of the linear function.

10. A motor testing device comprising: an inverter connected to a motor; a motor control device that controls the motor; a load motor that rotates the motor; a load motor control device that controls the load motor; and a measurement control device that performs parameter identification of the motor, the load motor control device controls the load motor so that the speed of the load motor coincides with a plurality of speed command values included in the speed condition; the motor control device controls the inverter so that the current flowing through the motor coincides with a current command value; The measurement control device sets the current command value for each of the plurality of speed command values, measures the voltage applied to the motor from the inverter, and identifies the magnetic flux or inductance of the motor based on the plurality of measured voltage values.

11. 11. The motor testing device according to claim 10, The motor testing device is characterized in that the measurement control device calculates a rate of change of the voltage applied to the motor with respect to the speed of the motor based on the plurality of measurement values.

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