Method for testing characteristics of motor under test, characteristic test device, and computer program

Abstract

To provide a technology for determining motor characteristics by distinguishing between driving power and braking power.SOLUTION: A disclosed method includes a step (a) of acquiring a voltage measurement value Es[j] and a current measurement value Is[j] of a motor under test, a step (b) of determining, when a driving power generation condition is satisfied, that a driving voltage effective value Ea[jA] and a driving current effective value Ia[jA] are equal to the voltage measurement value Es[j] and the current measurement value Is[j], respectively, a step (c) of determining, when the driving power generation condition is not satisfied, that the braking voltage effective value En[jN] and the braking current effective value In[jN] are equal to the voltage measurement value Es[j] and the current measurement value Is[j], respectively, a step (d) of calculating the driving active power, the driving apparent power, and the driving power factor using the driving voltage effective value Ea[jA] and the driving current effective value Ia[jA], and a step (e) of calculating the braking active power, the braking apparent power, and the braking power factor using the braking voltage effective value En[jN] and the braking current effective value In[jN].SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a method for testing the characteristics of a motor under test, a characteristic testing device, and a computer program. [Background technology]

[0002] Patent Document 1 describes a synchronous motor drive device capable of calculating the power factor of a synchronous motor. Generally, the power factor is calculated by dividing the active power by the apparent power. Furthermore, the power factor decreases when there is a phase lag in the current. Therefore, so-called lead angle control has traditionally been employed to eliminate the phase difference between the voltage and current. However, lead angle control alone cannot bring the power factor sufficiently close to 1.0, and this has been thought to be entirely due to harmonic loss. Therefore, measures have been required for the motor drive control circuit to suppress this harmonic loss, but until now, it has been impossible to improve the power factor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-201805 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors of the present disclosure discovered that when a motor is driven, not only drive power but also braking power is generated, and that conventional techniques have not been able to measure the apparent power or power factor for each of the drive power and braking power. [Means for solving the problem]

[0005] The present disclosure has been made to solve at least part of the above-mentioned problems, and can be realized in the following forms.

[0006] According to a first aspect of the present disclosure, there is provided a method for testing characteristics of a motor under test that is in a driving state in which a driving force is generated. This method includes the steps of: (a) measuring the phase voltage and phase current of the motor under test at M measurement times over a period of N periods of the phase voltage, where N is an integer equal to or greater than 1, M is an integer greater than N, j is an ordinal number indicating M measurement times, jA is an ordinal number indicating a driving power detection time, and jN is an ordinal number indicating a braking power detection time, thereby obtaining a voltage measurement value Es[j] and a current measurement value Is[j] at each measurement time j; and (b) determining a driving voltage value Ea[jA] and a driving current value Ia[jA] at the measurement time j when a driving power generation condition is met, including the voltage measurement value Es[j] and the current measurement value Is[j] having the same sign, by regarding the measurement time j as the driving power detection time jA. (c) if the driving power generation condition is not satisfied, determining that the braking voltage value En[jN] and the braking current value In[jN] are equal to the voltage measurement value Es[j] and the current measurement value Is[j], assuming that the measurement timing j is the braking power detection timing jN, (d) calculating the driving active power, driving apparent power, and driving power factor of the motor under test using the driving voltage value Ea[jA] and the driving current value Ia[jA]; and (e) calculating the braking active power, braking apparent power, and braking power factor of the motor under test using the braking voltage value En[jN] and the braking current value In[jN]. This method allows the calculation of the active power, apparent power, and power factor for each of the driving power and braking power of the motor under test.

[0007] A second aspect of the present disclosure provides a characteristic test device for testing the characteristics of a motor under test that is in a driving state in which it generates driving force. The characteristic test device includes a measurement value acquisition unit that measures the phase voltage and phase current of the motor under test at M measurement times over a period of N phase voltage periods, respectively, to acquire a voltage measurement value Es[j] and a current measurement value Is[j] at each measurement time j, where N is an integer greater than or equal to 1, M is an integer greater than N, j is an ordinal number indicating M measurement times, jA is an ordinal number indicating a driving power detection time, and jN is an ordinal number indicating a braking power detection time, and a characteristic calculation unit that calculates the characteristics of the motor under test using the voltage measurement values ​​Es[j] and the current measurement values ​​Is[j]. The characteristic calculation unit performs a process of determining that the measurement timing j is the driving power detection timing jA and that the driving voltage value Ea[jA] and the driving current value Ia[jA] are equal to the voltage measurement value Es[j] and the current measurement value Is[j], respectively, when a driving power generation condition is met, including the positive / negative signs of the voltage measurement value Es[j] and the current measurement value Is[j] being the same; and, when the driving power generation condition is not met, the characteristic calculation unit performs a process of determining that the measurement timing j is the braking power detection timing jN and that the driving voltage value Ea[jA] and the driving current value Ia[jA] are equal to the voltage measurement value Es[j] and the current measurement value Is[j], respectively, when a driving power generation condition is met, including the positive / negative signs of the voltage measurement value Es[j] and the current measurement value Is[j] are the same. The test circuit is configured to execute the following processes: determining that the braking voltage value En[jN] and the braking current value In[jN] are equal to the voltage measurement value Es[j] and the current measurement value Is[j], respectively; calculating the driving active power, driving apparent power, and driving power factor of the motor under test using the driving voltage value Ea[jA] and the driving current value Ia[jA]; and calculating the braking active power, braking apparent power, and braking power factor of the motor under test using the braking voltage value En[jN] and the braking current value In[jN].

[0008] According to a third aspect of the present disclosure, there is provided a computer program for executing a process of testing the characteristics of a motor under test that is in a driving state in which a driving force is generated. The computer program includes: (a) a process of measuring the phase voltage and phase current of the motor under test at M measurement times over a period of N periods of the phase voltage, where N is an integer equal to or greater than 1, M is an integer greater than N, j is an ordinal number indicating M measurement times, jA is an ordinal number indicating a driving power detection time, and jN is an ordinal number indicating a braking power detection time, thereby obtaining a voltage measurement value Es[j] and a current measurement value Is[j] at each measurement time j; and (b) a process of determining a driving voltage value Ea[jA] and a driving current value Ia[jA] at the measurement time j when a driving power generation condition is satisfied, including the voltage measurement value Es[j] and the current measurement value Is[j] having the same sign, by regarding the measurement time j as the driving power detection time jA. (c) if the driving power generation condition is not satisfied, determining that the braking voltage value En[jN] and the braking current value In[jN] are equal to the voltage measurement value Es[j] and the current measurement value Is[j], respectively, by regarding the measurement timing j as the braking power detection timing jN; (d) calculating the driving active power, driving apparent power, and driving power factor of the motor under test using the driving voltage value Ea[jA] and the driving current value Ia[jA]; and (e) calculating the braking active power, braking apparent power, and braking power factor of the motor under test using the braking voltage value En[jN] and the braking current value In[jN]. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing a configuration of a motor testing system according to an embodiment. [Figure 2] Graphs showing the drive waveform of the motor under test and the measured voltage and current values. [Figure 3] 4 is a flowchart showing the procedure for testing the characteristics of a motor under test. [Figure 4]FIG. 10 is an explanatory diagram showing an example of a first display screen of motor characteristics according to the power separation calculation method. [Figure 5] FIG. 10 is an explanatory diagram showing an example of a second display screen of motor characteristics according to the conventional power calculation method. DETAILED DESCRIPTION OF THE INVENTION

[0010] 1 is a block diagram showing the configuration of a motor testing system according to an embodiment. The motor testing system includes a motor under test 100, a motor testing device 200, and a characteristic testing device 300.

[0011] Any type of motor with any number of phases can be used as the motor under test 100. However, the motor under test 100 uses a permanent magnet rotor that uses a ferromagnetic neodymium magnet, which generates an induced voltage, and the phenomenon that is the subject of this disclosure is particularly noticeable in high-torque motors with small phase coil inductance (small number of turns).

[0012] The motor under test 100 is electrically connected to a drive circuit 120. A DC input voltage Ev is supplied to the drive circuit 120 from a constant-voltage power supply 130. The voltage value of the input voltage Ev can be adjusted by a characteristic test device 300. The drive circuit 120 is a motor driver configured, for example, as an H-bridge circuit. Transistors in the drive circuit 120 are turned on / off in response to a control signal Sd supplied from the characteristic test device 300. The control signal Sd is, for example, a signal for PWM control of the motor under test 100. In PWM control, the rotational position of the motor under test 100 is detected based on the output of the magnetic sensor 104, and a control signal Sd for each phase is generated based on this rotational position. An ammeter 151 for measuring the coil current of the electromagnetic coil and a voltmeter 161 for measuring the coil voltage of the electromagnetic coil are provided in the wiring between the drive circuit 120 and the motor under test 100.

[0013] The motor testing device 200 includes a first coupling 211, a torque meter 220, a second coupling 212, an electric brake 230, an AC / DC conversion unit 240, a DC load unit 250, and a measurement value collection unit 260. The mechanical connection structure including the first coupling 211, the torque meter 220, the second coupling 212, and the electric brake 230 is referred to as a test connection structure 270.

[0014] The rotating shaft 110 of the motor under test 100 and the first rotating shaft 221 of the torque meter 220 are connected by a first coupling 211. The torque meter 220 has a first rotating shaft 221 and a second rotating shaft 222 and measures the torque T between the first rotating shaft 221 and the second rotating shaft 222. The torque meter 220 is preferably configured to further measure the rotation speed Nm of the rotating shafts 221 and 222. Instead of measuring the rotation speed Nm with the torque meter 220, the rotation speed Nm may be measured with high accuracy based on a clock counter value in a sensor signal using a magnetic sensor 104 provided in the motor under test 100. The second rotating shaft 222 of the torque meter 220 and the rotating shaft 232 of the electric brake 230 are connected by a second coupling 212. The electric brake 230 has a coreless motor structure with low iron loss (cogging loss, hysteresis loss, etc.). The electric brake 230 is preferably configured as, for example, a two-phase or three-phase brushless motor. In this embodiment, the electric brake 230 has a magnetic sensor 234 that measures the rotational position of the rotor. In this embodiment, the magnetic sensor 234 is a sensor that is fixed to the stator and measures the magnetic flux density of a permanent magnet provided in the rotor. The magnetic sensor 234 is configured, for example, by a Hall IC. However, the magnetic sensor 234 can be omitted.

[0015] AC / DC conversion unit 240 is electrically connected to the multi-phase coils of electric brake 230, and converts AC induced voltage Vi generated in the coils into DC voltage Vd by full-wave rectification. DC load unit 250 is electrically connected to AC / DC conversion unit 240, and consumes power generated by DC voltage Vd.

[0016] The measurement value collection unit 260 collects the measurement value Es of the coil voltage measured by the voltmeter 161, the measurement value Is of the coil current measured by the ammeter 151, and the torque T and rotation speed Nm measured by the torque meter 220 in synchronization with the control signal Sd of the drive circuit 120, and transfers them to the characteristic test device 300.

[0017] In this disclosure, regardless of whether the motor under test 100 is a two-phase motor or a three-phase motor, the measured phase voltage is used as the measured coil voltage Es, and the measured phase current is used as the measured coil current Is. For example, if the motor under test 100 is a three-phase motor and line voltage is measured, the phase voltage obtained by multiplying the measured line voltage by 1 / √3 is used as the measured coil voltage Es. Similarly, if the motor under test 100 is a three-phase motor and line current is measured, the phase current obtained by multiplying the measured line current by 1 / √3 is used as the measured coil voltage Es. In this disclosure, regardless of the number of phases in the motor, the phase voltage of one phase of the coil is referred to as the "coil voltage." The phase current of one phase of the coil is referred to as the "coil current." Furthermore, this disclosure is not limited to PWM control, and can be applied to motors that operate under control other than PWM control, such as 120-degree conduction control for three-phase motors.

[0018] The characteristic test apparatus 300 includes a measurement value acquisition unit 310, a characteristic calculation unit 320, and a characteristic display unit 330. The characteristic test apparatus 300 also has the function of controlling each unit of the motor testing apparatus 200. The measurement value acquisition unit 310 acquires measurement values, including the measurement values ​​Es and Is of the phase voltage and phase current of the motor under test 100, from the measurement value collection unit 260. The characteristic calculation unit 320 calculates the characteristics of the motor under test 100 using the measurement values ​​Es and Is of the phase voltage and phase current. The characteristic display unit 330 displays the calculated characteristics of the motor under test 100 on a display screen. In this embodiment, the characteristic calculation unit 320 calculates the apparent power and power factor of the motor under test 100. The characteristic test apparatus 300 can be implemented, for example, by a personal computer. The functions of the characteristic test apparatus 300 are implemented by a processor executing a computer program stored in the memory of the characteristic test apparatus 300.

[0019] FIG. 2 is a graph showing the drive waveform, voltage measurement value Es[j], and current measurement value Is[j] of the motor under test 100. The motor under test 100 is in a drive state in which it generates drive force. In this embodiment, the motor under test 100 is a two-phase brushless motor that is PWM-controlled. The A-phase voltage Va and B-phase voltage Vb shown at the top of FIG. 2 represent ideal analog voltage waveforms of the two-phase electromagnetic coils. The voltage waveforms of the A-phase voltage Va and B-phase voltage Vb change periodically every Pw. One Pw period corresponds to 360 electrical degrees. The PWM-controlled A-phase voltage Vapwm is a rectangular wave, as shown in the third graph from the top of FIG. 2. The A-phase voltage Vapwm shown in the fourth graph from the top of FIG. 2 is an enlarged view of a portion of the voltage. The dashed-dotted line indicates measurement timing j, i.e., the sampling timing.

[0020] The two graphs at the bottom of Figure 2 show enlarged voltage measurement values ​​Es[j] and current measurement values ​​Is[j] measured during one cycle Pe of the PWM control square wave. The voltage measurement values ​​Es[j] and current measurement values ​​Is[j] are the phase voltage and phase current of the A-phase coil, and are values ​​measured at measurement timing j, indicated by the dashed dotted line.

[0021] Even when the motor under test 100 is in a driving state in which it generates driving force, there are intervals in which the positive and negative signs of the measured current Is[j] are different, as shown in FIG. 2. In the example of FIG. 2, driving power is generated in the intervals in which the measured current Is[j] is positive, and braking power is generated in the intervals in which the measured current Is[j] is negative. In general, when the positive and negative signs of the measured voltage Es[j] and the measured current Is[j] are the same, driving power is generated, and when the positive and negative signs of the measured voltage Es[j] and the measured current Is[j] are different, braking power is generated. This characteristic is utilized in the present embodiment to distinguish between driving power and braking power when calculating motor characteristics.

[0022] In the following, we will first explain the conventional method for calculating motor characteristics. In this specification, the conventional method for calculating motor characteristics is referred to as the "conventional power calculation method." In the terms used below, the prefix "conventional" means that it is used in the conventional power calculation method.

[0023] <Conventional power calculation method for motor characteristics> The conventional active power Pc of each phase of the motor under test 100 is calculated as follows. Pc = SQRT{ΣPe[j]^2 / M} …(q1) Pe[j] = Ec[j] × Ic[j] …(q2) Here, SQRT{} indicates the operation to find the square root in the parentheses, Σ indicates the operation to add from 1 to M for j, "^2" indicates the operation to square, Ec[j] is the conventional voltage value, and Ic[j] is the conventional current value. The conventional voltage value Ec[j] and the conventional current value Ic[j] are equal to the voltage measurement value Es[j] of the phase voltage and the current measurement value Is[j] of the phase current, respectively.

[0024] In this way, the conventional active power Pc can be calculated by multiplying the conventional voltage value Ec[j] by the conventional current value Ic[j] to obtain the active power value Pe[j], and then calculating the root mean square SQRT{ΣPe[j]^2 / M} of the active power values ​​Pe[j] obtained at M measurement timings.

[0025] The conventional apparent power Sc of the motor under test 100 is calculated as one phase for each phase as follows: Sc = Ec_rms·Ic_rms …(q3) Ec_rms = SQRT(ΣEc[j]^2 / M) …(q4) Ic_rms = SQRT(ΣIc[j]^2 / M) …(q5) In this way, the conventional apparent power Sc can be calculated by multiplying the root mean square Ec_rms of the conventional voltage values ​​Ec[j] obtained at M measurement timings j by the root mean square Ic_rms of the conventional current values ​​Ic[j] obtained at M measurement timings j.

[0026] The conventional power factor ηc is calculated by dividing the conventional active power Pc by the conventional apparent power Sc as follows: ηc = Pc / Sc …(q6)

[0027] 3 is a flowchart showing the procedure for a characteristic test of the motor under test 100. This characteristic test is preferably carried out while the motor under test 100 is rotating at a constant rotation speed Nm and a constant torque T.

[0028] The following parameters are used in the process of Figure 3. The prefix "driving" means that the parameter is related to driving power, and the prefix "braking" means that the parameter is related to braking power. ·N: The number of phase voltage periods Pw during which the phase voltage and phase current are measured, and is an integer of 1 or greater. M: The total number of phase voltage and phase current measurement timings, an integer greater than N. ·j: An ordinal number indicating the measurement timing, an integer from 1 to M. ·jA: An ordinal number indicating the timing of detecting the drive power. · Ma: The total number of drive power detection timings jA. · jN: An ordinal number indicating the timing of detecting braking power. ·Mn: The total number of braking power detection timings jN. Es[j]: The voltage measurement value of the phase voltage measured at timing j. Is[j]: Current measurement value of the phase current measured at timing j. · Ec[j]: conventional voltage value, which is the conventional voltage value at timing j. · Ic[j]: conventional current value, which is the conventional current value at timing j. Ea[jA]: drive voltage value, which is the voltage value of the drive power at timing jA. Ia[jA]: drive current value, which is the current value of the drive power at timing jA. · En[jN]: Braking voltage value, which is the voltage value of the braking power at timing jN. In[jN]: Braking current value, which is the current value of the braking power at timing jN.

[0029] In step S10, the parameter j, which is an ordinal number, is initialized to 1, the parameters jA and jN are each initialized to 0, and the other parameters described above are also initialized. In this embodiment, the number of phase voltage periods N for which measurements of the phase voltage and phase current are performed is set to be equal to 1.

[0030] In step S11, the measurement value acquiring unit 310 acquires the voltage measurement value Es[j] and the current measurement value Is[j] measured at measurement timing j.

[0031] In step S12, the conventional voltage value Ec[j] is determined to be equal to the measured voltage value Es[j], and the conventional current value Ic[j] is determined to be equal to the measured current value Is[j]. The conventional voltage value Ec[j] and the conventional current value Ic[j] are values ​​used in the conventional power calculation method according to the above equations (q1) to (q6).

[0032] In step S13, the characteristics calculation unit 320 determines whether the sign of the measured voltage Es[j] is the same as the sign of the measured current Is[j]. This determination can be made by applying an XNOR or XOR logical operation to the signs of the measured voltage Es[j] and the measured current Is[j]. If the signs of the measured voltage Es[j] and the measured current Is[j] are the same, it is assumed that drive power is being generated, and steps S14 and S15 are executed. In step S14, the detection timing jA of the drive power is incremented by one. In step S15, the drive voltage value Ea[jA] is determined to be equal to the measured voltage Es[j], and the drive current value Ia[jA] is determined to be equal to the measured current Is[j].

[0033] On the other hand, if the sign of the measured voltage Es[j] is different from the sign of the measured current Is[j], it is assumed that braking power is being generated, and steps S16 and S17 are executed. In step S16, the detection timing jN of the braking power is incremented by 1. In step S17, it is determined that the braking voltage value En[jN] is equal to the measured voltage Es[j], and the braking current value In[jN] is equal to the measured current Is[j].

[0034] In step S18, it is determined whether the measurement timing j has reached the maximum value M. If j is smaller than M, the process proceeds to step S19, where j is incremented by 1 and the process returns to step S11, where the processing from step S11 onwards is executed again. If j has reached M, the process proceeds to step S20. In step S20, the parameter Ma is determined to be equal to the final value of the detection timing jA of the driving power, and the parameter Mn is determined to be equal to the final value of the detection timing jN of the braking power. The parameter Ma is the total number of detection timing jA of the driving power, and the parameter Mn is the total number of detection timing jN of the braking power. Note that Ma + Mn = M.

[0035] In step S21, the characteristic calculation unit 320 calculates the motor characteristics according to the power separation calculation method. The motor characteristics related to the driving power and the motor characteristics related to the braking power are calculated as follows.

[0036] <Calculation of motor characteristics related to driving power> The driving active power Pa is calculated according to the following formula: Pa = SQRT{ΣPea[jA]^2 / M} …(q11) Pea[jA] = Ea[jA]×Ia[jA] …(q12) Here, Σ indicates the addition of jA from 1 to Ma. Ma is the total number of drive power detection timings jA. M is the total number of measurement timings j. Equations (q11) and (q12) correspond to the above-mentioned equations (q1) and (q2). That is, the drive active power Pa can be calculated by multiplying the drive voltage value Ea[jA] and drive current value Ia[jA] obtained at the drive power detection timing jA out of the M measurement timings to obtain the drive active power value Pea[jA], and then calculating the root mean square of the drive active power value Pea[jA], SQRT{ΣPea[jA]^2 / M}.

[0037] The driving apparent power Sa is calculated according to the following formula: Sa = Ea_rms·Ia_rms …(q13) Ea_rms = SQRT(ΣEa[jA]^2 / M) …(q14) Ia_rms = SQRT(ΣIa[jA]^2 / M) …(q15) In this way, the drive apparent power Sa can be calculated by multiplying the root mean square Ea_rms of the drive voltage value Ea[jA] obtained at the detection timing jA among the M measurement timings by the root mean square Ia_rms of the drive current value Ia[jA] obtained at the detection timing jA among the M measurement timings.

[0038] The driving power factor ηa is calculated by dividing the driving active power Pa by the driving apparent power Sa as shown in the following equation. ηa = Pa / Sa …(q16)

[0039] <Calculation of motor characteristics related to braking power> The braking active power Pn is calculated according to the following formula: Pn = SQRT{ΣPen[jN]^2 / M} …(q21) Pen[jN] = En[jN]×In[jN] …(q22) Here, Σ indicates the addition of 1 to Mn for jN. Mb is the total number of braking power detection timings jN. M is the total number of measurement timings j. The braking active power Pn can be calculated by multiplying the braking voltage value En[jN] and braking current value In[jN] obtained at braking power detection timing jN out of the M measurement timings to obtain the braking active power value Pen[jN], and then calculating the root mean square of the braking active power value Pen[jN], SQRT{ΣPen[jN]^2 / M}.

[0040] The braking apparent power Sn is calculated according to the following formula: Sn = En_rms·In_rms …(q23) En_rms = SQRT(ΣEn[jN]^2 / M) …(q24) In_rms = SQRT(ΣIn[jN]^2 / M) …(q25) In this way, the braking apparent power Sn can be calculated by multiplying the root mean square En_rms of the braking voltage value En[jN] obtained at the detection timing jN among the M measurement timings by the root mean square In_rms of the braking current value In[jN] obtained at the detection timing jN among the M measurement timings.

[0041] The braking force ratio ηn is calculated by dividing the braking effective power Pn by the braking apparent power Sn as shown in the following equation. ηn = Pn / Sn …(q26)

[0042] In step S22, the characteristic calculation unit 320 calculates the motor characteristics according to the conventional power calculation method. That is, the conventional active power Pc, the conventional apparent power Sc, and the conventional power factor ηc are calculated according to the above-mentioned equations (q1) to (q6).

[0043] In step S23, the characteristic display unit 330 displays the calculated characteristic of the motor under test 100 on the display device of the characteristic test apparatus 300.

[0044] Figure 4 is an explanatory diagram showing an example of the first display screen W1 of motor characteristics calculated using the power separation calculation method. At the top of the first display screen W1, there is a mode selection tool MT for specifying whether to use the power separation calculation method or the conventional power calculation method. In this example, the power separation calculation method has been selected.

[0045] On the first display screen W1, a first measurement result for driving power is displayed, which includes the root mean square of the driving voltage Ea_rms, the root mean square of the driving current Ia_rms, the driving apparent power Sa, the driving active power Pa, and the driving power factor ηa. Also, a second measurement result for braking power is displayed, which includes the root mean square of the braking voltage En_rms, the root mean square of the braking current In_rms, the braking apparent power Sn, the braking active power Pn, and the braking power factor ηn. In this way, in this embodiment, the motor characteristics are calculated and displayed separately for driving power and braking power, allowing the user to learn the motor characteristics of the motor under test 100 in more detail.

[0046] 5 is an explanatory diagram showing an example of a second display screen W2 of motor characteristics calculated by the conventional power calculation method, in which the conventional power calculation method is selected by the mode specification tool MT.

[0047] The second display screen W2 displays the root mean square of the conventional voltage value Ec_rms, the root mean square of the conventional current value Ic_rms, the conventional apparent power Sc, the conventional effective power Pc, and the conventional power factor ηc.

[0048] The first display screen W1 of Fig. 4 and the second display screen W2 of Fig. 5 may be displayed simultaneously. In other words, it is preferable that the characteristics display unit 330 is configured to be able to selectively or simultaneously display the first display screen W1 and the second display screen W2.

[0049] According to the above-described embodiment, it is possible to calculate motor characteristics including effective power, apparent power, and power factor for each of the driving power and braking power of the motor under test 100. Furthermore, it is possible to display the motor characteristics related to driving power and the motor characteristics related to braking power separately.

[0050] As can be seen from the above example, whether or not drive power is being generated can be determined based on whether or not a preset drive power generation condition is met. The drive power generation condition can be set to include at least the condition that "the positive and negative signs of the measured voltage value Es[j] and the measured current value Is[j] are the same." The drive power generation condition may also be set to include other conditions. If the drive power generation condition is met, it is assumed that drive power is being generated. On the other hand, if the drive power generation condition is not met, it is assumed that braking power is being generated.

[0051] In addition, the calculation method and calculation order of various values ​​may be devised to save memory capacity and improve calculation speed. The contents of the present disclosure can also be applied to the calculation of apparent power and power factor using a measuring instrument such as an oscilloscope. In this case, it is preferable to set the calculations using the above-mentioned equations (q1) to (q6), (q11) to (q16), and (q21) to (q26) in the measuring instrument.

[0052] The present disclosure is not limited to the above-described embodiments, embodiments, and variations, and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in the embodiments, embodiments, and variations corresponding to the technical features in each aspect described in the Summary of the Disclosure section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate.

[0053] (1) According to a first aspect of the present disclosure, there is provided a method for testing characteristics of a motor under test that is in a driving state in which a driving force is generated. This method includes the steps of: (a) measuring the phase voltage and phase current of the motor under test at M measurement times over a period of N periods of the phase voltage, where N is an integer equal to or greater than 1, M is an integer greater than N, j is an ordinal number indicating M measurement times, jA is an ordinal number indicating a driving power detection time, and jN is an ordinal number indicating a braking power detection time, thereby obtaining a voltage measurement value Es[j] and a current measurement value Is[j] at each measurement time j; and (b) determining a driving voltage value Ea[jA] and a driving current value Ia[jA] at the measurement time j when a driving power generation condition is met, including the voltage measurement value Es[j] and the current measurement value Is[j] having the same sign, by regarding the measurement time j as the driving power detection time jA. (c) if the driving power generation condition is not satisfied, determining that the braking voltage value En[jN] and the braking current value In[jN] are equal to the voltage measurement value Es[j] and the current measurement value Is[j], assuming that the measurement timing j is the braking power detection timing jN, (d) calculating the driving active power, driving apparent power, and driving power factor of the motor under test using the driving voltage value Ea[jA] and the driving current value Ia[jA]; and (e) calculating the braking active power, braking apparent power, and braking power factor of the motor under test using the braking voltage value En[jN] and the braking current value In[jN]. This method allows the calculation of the active power, apparent power, and power factor for each of the driving power and braking power of the motor under test.

[0054] (2) In the above method, if the positive and negative signs of the voltage measurement value Es[j] and the current measurement value Is[j] are the same, it may be determined that the drive power generation condition is met, and if the positive and negative signs of the voltage measurement value Es[j] and the current measurement value Is[j] are different, it may be determined that the drive power generation condition is not met. According to this method, it is possible to easily determine whether the vehicle is in a driving state or a braking state.

[0055] (3) In the above method, the step (d) may include the steps of: (d1) calculating the active driving power by determining the root mean square of the active driving power value Pea[jA], which is the product of the driving voltage value Ea[jA] and the driving current value Ia[jA]; (d2) calculating the apparent driving power by multiplying the root mean square of the driving voltage value Ea[jA] by the root mean square of the driving current value Ia[jA]; and (d3) calculating the power factor by dividing the active driving power by the driving apparent power. Furthermore, the step (e) may include the steps of: (e1) calculating the braking effective power by determining the root mean square of the braking effective power value Pen[jN], which is the product of the braking voltage value En[jN] and the braking current value In[jN]; (e1) calculating the braking apparent power by multiplying the root mean square of the braking voltage value En[jN] by the root mean square of the braking current value In[jN]; and (e3) calculating the braking force ratio by dividing the braking effective power by the braking apparent power. According to this method, the active power, apparent power, and power factor can be calculated by simple calculations for each of the driving power and braking power.

[0056] (4) The above method may include the steps of: calculating a conventional active power by multiplying a conventional voltage value Ec[j] determined from the voltage measurement value Es[j] by a conventional current value Ic[j] determined from the current measurement value Is[j] to obtain a conventional active power value Pe[j] and calculating the root mean square of the conventional active power value Pe[j]; calculating a conventional apparent power by multiplying the root mean square of the conventional voltage value Ec[j] by the root mean square of the conventional current value Ic[j]; and calculating a conventional power factor by dividing the conventional active power by the conventional apparent power. According to this method, the active power, apparent power and power factor can be calculated in a conventional manner.

[0057] (5) A second aspect of the present disclosure provides a characteristic test device for testing the characteristics of a motor under test that is in a driving state in which it generates driving force. The characteristic test device includes a measurement value acquisition unit that measures the phase voltage and phase current of the motor under test at M measurement times over a period of N phase voltage periods, respectively, to acquire a voltage measurement value Es[j] and a current measurement value Is[j] at each measurement time j, where N is an integer greater than or equal to 1, M is an integer greater than N, j is an ordinal number indicating M measurement times, jA is an ordinal number indicating a driving power detection time, and jN is an ordinal number indicating a braking power detection time, and a characteristic calculation unit that calculates the characteristics of the motor under test using the voltage measurement value Es[j] and the current measurement value Is[j]. The characteristic calculation unit performs a process of determining that the measurement timing j is the driving power detection timing jA and that the driving voltage value Ea[jA] and the driving current value Ia[jA] are equal to the voltage measurement value Es[j] and the current measurement value Is[j], respectively, when a driving power generation condition is met, including the positive / negative signs of the voltage measurement value Es[j] and the current measurement value Is[j] being the same; and, when the driving power generation condition is not met, the characteristic calculation unit performs a process of determining that the measurement timing j is the braking power detection timing jN and that the driving voltage value Ea[jA] and the driving current value Ia[jA] are equal to the voltage measurement value Es[j] and the current measurement value Is[j], respectively, when a driving power generation condition is met, including the positive / negative signs of the voltage measurement value Es[j] and the current measurement value Is[j] are the same. The test circuit is configured to execute the following processes: determining that the braking voltage value En[jN] and the braking current value In[jN] are equal to the voltage measurement value Es[j] and the current measurement value Is[j], respectively; calculating the driving active power, driving apparent power, and driving power factor of the motor under test using the driving voltage value Ea[jA] and the driving current value Ia[jA]; and calculating the braking active power, braking apparent power, and braking power factor of the motor under test using the braking voltage value En[jN] and the braking current value In[jN]. This characteristic test device can calculate the active power, apparent power, and power factor for each of the driving power and braking power of the motor under test.

[0058] (6) The characteristic test device may further include a characteristic display unit that displays the characteristics of the motor under test calculated by the characteristic calculation unit on a display screen, and the characteristic display unit may be configured to be capable of selectively or simultaneously displaying a first display screen that displays a first measurement result including the driving active power, the driving apparent power, and the driving power factor, and a second measurement result including the braking active power, the braking apparent power, and the braking power factor, and a second display screen that displays the conventional active power, conventional apparent power, and conventional power factor calculated by a conventional method. This characteristic testing device can selectively or simultaneously display, depending on the user's specifications, a first display screen that separately displays the measurement results of motor characteristics related to driving power and braking power, and a second display screen that displays the measurement results of conventional motor characteristics.

[0059] (7) According to a third aspect of the present disclosure, there is provided a computer program for executing a process of testing the characteristics of a motor under test that is in a driving state in which a driving force is generated. The computer program includes: (a) a process of measuring the phase voltage and phase current of the motor under test at M measurement times over a period of N periods of the phase voltage, where N is an integer greater than or equal to 1, M is an integer greater than N, j is an ordinal number indicating M measurement times, jA is an ordinal number indicating a driving power detection time, and jN is an ordinal number indicating a braking power detection time, thereby obtaining a voltage measurement value Es[j] and a current measurement value Is[j] at each measurement time j; and (b) a process of determining a driving voltage value Ea[jA] and a driving current value Ia[jA] at the measurement time j when a driving power generation condition is satisfied, including the voltage measurement value Es[j] and the current measurement value Is[j] having the same sign, by regarding the measurement time j as the driving power detection time jA. (c) if the driving power generation condition is not satisfied, determining that the braking voltage value En[jN] and the braking current value In[jN] are equal to the voltage measurement value Es[j] and the current measurement value Is[j], respectively, by regarding the measurement timing j as the braking power detection timing jN; (d) calculating the driving active power, driving apparent power, and driving power factor of the motor under test using the driving voltage value Ea[jA] and the driving current value Ia[jA]; and (e) calculating the braking active power, braking apparent power, and braking power factor of the motor under test using the braking voltage value En[jN] and the braking current value In[jN]. This computer program can calculate the active power, apparent power, and power factor for each of the driving power and braking power of the motor under test. [Explanation of symbols]

[0060] 100...motor under test, 104...magnetic sensor, 110...rotating shaft, 120...drive circuit, 130...constant voltage power supply, 151...ammeter, 161...voltmeter, 200...motor testing device, 211...first coupling, 212...second coupling, 220...torque meter, 221...first rotating shaft, 222...second rotating shaft, 230...electric brake, 232...rotating shaft, 234...magnetic sensor, 240...AC / DC conversion unit, 250...DC load unit, 260...measurement value collection unit, 270...test connection structure, 300...characteristics testing device, 310...measurement value acquisition unit, 320...characteristics calculation unit, 330...characteristics display unit

Claims

1. 1. A method for testing characteristics of a motor under test in a driving state that generates a driving force, comprising: (a) obtaining a voltage measurement value Es[j] and a current measurement value Is[j] at each measurement timing j by measuring the phase voltage and the phase current of the motor under test at M measurement timings over a period of N periods of the phase voltage, where N is an integer equal to or greater than 1, M is an integer greater than N, j is an ordinal number indicating M measurement timings, jA is an ordinal number indicating a driving power detection timing, and jN is an ordinal number indicating a braking power detection timing; (b) when a drive power generation condition is met, including the positive / negative signs of the voltage measurement value Es[j] and the current measurement value Is[j] being the same, determining that the measurement timing j is the drive power detection timing jA and that the drive voltage value Ea[jA] and the drive current value Ia[jA] are equal to the voltage measurement value Es[j] and the current measurement value Is[j], respectively; (c) if the driving power generation condition is not satisfied, determining that the measurement timing j is the braking power detection timing jN and that the braking voltage value En[jN] and the braking current value In[jN] are equal to the voltage measurement value Es[j] and the current measurement value Is[j], respectively; (d) calculating the driving effective power, driving apparent power, and driving power factor of the motor under test using the driving voltage value Ea [jA] and the driving current value Ia [jA]; (e) calculating the braking effective power, braking apparent power, and braking force ratio of the motor under test using the braking voltage value En[jN] and the braking current value In[jN]; A method comprising:

2. 10. The method of claim 1, When the positive and negative signs of the measured voltage Es[j] and the measured current Is[j] are the same, it is determined that the driving power generation condition is met; The method of the present invention determines that the drive power generation condition is not satisfied when the positive and negative signs of the measured voltage Es[j] and the measured current Is[j] are different.

3. 10. The method of claim 1, The step (d) (d1) calculating the active driving power by calculating the root mean square of the active driving power value Pea[jA], which is the product of the driving voltage value Ea[jA] and the driving current value Ia[jA]; (d2) calculating the drive apparent power by multiplying the root mean square of the drive voltage value Ea [jA] by the root mean square of the drive current value Ia [jA]; (d3) calculating the driving power factor by dividing the driving active power by the driving apparent power; Including, The step (e) (e1) calculating the effective braking power by calculating the root mean square of the effective braking power value Pen[jN], which is the product of the braking voltage value En[jN] and the braking current value In[jN]; (e1) calculating the braking apparent power by multiplying the root mean square of the braking voltage value En[jN] by the root mean square of the braking current value In[jN]; (e3) calculating the braking force ratio by dividing the braking active power by the braking apparent power; A method comprising:

4. 4. The method of claim 3, further comprising: a step of multiplying a conventional voltage value Ec[j] determined from the voltage measurement value Es[j] by a conventional current value Ic[j] determined from the current measurement value Is[j] to obtain a conventional active power value Pe[j], and calculating the root mean square of the conventional active power value Pe[j] to calculate a conventional active power; calculating a conventional apparent power by multiplying the root mean square of the conventional voltage value Ec[j] by the root mean square of the conventional current value Ic[j]; calculating a conventional power factor by dividing the conventional real power by the conventional apparent power; A method comprising:

5. A characteristic test device for testing the characteristics of a motor under test in a driving state that generates a driving force, comprising: a measurement value acquisition unit that acquires a voltage measurement value Es[j] and a current measurement value Is[j] at each measurement time j by measuring a phase voltage and a phase current of the motor under test at M measurement times over a period of N periods of the phase voltage, where N is an integer equal to or greater than 1, M is an integer greater than N, j is an ordinal number indicating M measurement times, jA is an ordinal number indicating a driving power detection time, and jN is an ordinal number indicating a braking power detection time; a characteristic calculation unit that calculates the characteristics of the motor under test using the voltage measurement value Es[j] and the current measurement value Is[j]; Equipped with The characteristic calculation unit a process of determining that the drive voltage value Ea[jA] and the drive current value Ia[jA] are equal to the voltage measurement value Es[j] and the current measurement value Is[j], respectively, when a drive power generation condition is met, including the positive / negative signs of the voltage measurement value Es[j] and the current measurement value Is[j] being the same, and regarding the measurement timing j as the drive power detection timing jA; If the driving power generation condition is not satisfied, a process of determining that the measurement timing j is the braking power detection timing jN and that the braking voltage value En[jN] and the braking current value In[jN] are equal to the voltage measurement value Es[j] and the current measurement value Is[j], respectively; a process of calculating the driving effective power, the driving apparent power, and the driving power factor of the motor under test using the driving voltage value Ea [jA] and the driving current value Ia [jA]; a process of calculating a braking effective power, a braking apparent power, and a braking force ratio of the motor under test using the braking voltage value En[jN] and the braking current value In[jN]; A characteristic test device configured to perform the following:

6. The characteristic test apparatus according to claim 5, further comprising: a characteristic display unit that displays the characteristics of the motor under test calculated by the characteristic calculation unit on a display screen, the characteristic display unit is configured to be capable of selectively or simultaneously displaying a first display screen that separately displays a first measurement result including the driving apparent power and the driving power factor and a second measurement result including the braking apparent power and the braking power factor, and a second display screen that displays a conventional apparent power and a conventional power factor calculated by a conventional method.

7. A computer program for executing a process for testing characteristics of a motor under test in a driving state that generates a driving force, (a) a process of obtaining a voltage measurement value Es[j] and a current measurement value Is[j] at each measurement timing j by measuring the phase voltage and the phase current of the motor under test at M measurement timings over a period of N periods of the phase voltage, where N is an integer equal to or greater than 1, M is an integer greater than N, j is an ordinal number indicating M measurement timings, jA is an ordinal number indicating a driving power detection timing, and jN is an ordinal number indicating a braking power detection timing; (b) when a drive power generation condition is met, including the positive / negative signs of the voltage measurement value Es[j] and the current measurement value Is[j] being the same, a process of determining that the measurement timing j is the drive power detection timing jA and that the drive voltage value Ea[jA] and the drive current value Ia[jA] are equal to the voltage measurement value Es[j] and the current measurement value Is[j], respectively; (c) if the driving power generation condition is not satisfied, a process of determining that the measurement timing j is the braking power detection timing jN and that the braking voltage value En[jN] and the braking current value In[jN] are equal to the voltage measurement value Es[j] and the current measurement value Is[j], respectively; (d) calculating the driving effective power, driving apparent power, and driving power factor of the motor under test using the driving voltage value Ea [jA] and the driving current value Ia [jA]; (e) calculating the braking effective power, braking apparent power, and braking force ratio of the motor under test using the braking voltage value En[jN] and the braking current value In[jN]; A computer program that causes a computer to execute the following.

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