Control device for electric motor

Abstract

An error occurs in the temperature of the coil estimated based on the internal resistance data, and appropriate control for coil protection cannot be performed in some cases.SOLUTION: A control device for a motor includes a voltage command generation unit that generates a voltage command value by PI control so that a value of current flowing through the motor follows a current command value, a gain calculation unit that calculates a P gain and an I gain of the PI control such that a closed-loop characteristic from the current command value to the value of current flowing through the motor is a first-order lag system, an estimation unit that estimates a resistance value of the motor using the P gain, the I gain, and an inductance of the motor and outputs a resistance estimated value, and a resistance correction unit that corrects a temperature change amount of the inductance according to the resistance estimated value and outputs a resistance correction value. And a temperature estimation unit configured to estimate a temperature of the coil of the electric motor using a resistance correction value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a control device for controlling an electric motor. [Background technology]

[0002] There are technologies that detect the coil temperature of elevator door motors and protect the coils. For example, the control device described in Patent Document 1 applies a predetermined voltage to the door motor when the elevator doors are fully closed, and estimates internal resistance data by detecting the motor current. Based on this internal resistance data, the winding temperature is estimated, and if an abnormality occurs, temperature rise is suppressed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-290507 Summary of the Invention [Problem to be solved by the invention]

[0004] In a motor control device, a command value is given to control the voltage to be applied. However, an error occurs between this command value and the voltage value actually applied to the motor. In a control method such as that described in Patent Document 1, this error causes an error in the calculated internal resistance data. Therefore, an error also occurs in the coil temperature estimated based on this internal resistance data, which raises the concern that appropriate coil protection control cannot be performed.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a control device that can estimate the temperature of a coil of an electric motor with high accuracy. [Means for solving the problem]

[0006] The electric motor control device according to the present disclosure includes a power conversion unit that converts power from a power source and supplies it to the electric motor; a voltage command generation unit that generates a voltage command value by PI control so that the current value flowing through the electric motor follows the current command value; a gain calculation unit that calculates the P gain and I gain of the PI control so that the closed loop characteristics from the current command value to the current value flowing through the electric motor become a first-order lag system; an estimation unit that estimates the resistance value of the electric motor using the P gain, I gain and the inductance of the electric motor and outputs an estimated resistance value; a correction unit that corrects the amount of temperature change in inductance according to the estimated resistance value and outputs a resistance correction value; and a temperature estimation unit that estimates the temperature of the electric motor coil using the resistance correction value. [Effects of the Invention]

[0007] According to the present disclosure, when estimating a resistance value from the P gain and I gain, it is possible to eliminate the error between the voltage command value and the voltage actually applied to the motor, and it is possible to accurately estimate the resistance value and the coil temperature. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram showing the configuration of an electric motor and a control device according to a first embodiment. [Figure 2] 4 is a diagram showing an example of a test current command value generated by a d-axis current command unit in the first embodiment, and an actual current value and voltage command value at that time. FIG. [Figure 3] 4 is a diagram showing a model of a current control loop focusing on the d-axis while the motor is stopped in the control device in the first embodiment. FIG. [Figure 4] FIG. 4 is a diagram showing the temperature dependency of inductance in the first embodiment. [Figure 5] FIG. 10 is a diagram showing the relationship between a true resistance value, an estimated resistance value, and a corrected resistance value in the control device according to the first embodiment. [Figure 6] 5 is a flowchart showing the operation of coil temperature estimation in the control device according to the first embodiment. [Figure 7]5 is a flowchart showing details of the steps for calculating a resistance estimated value in the control device according to the first embodiment. [Figure 8] 3 is a block diagram showing an example of the configuration of a gain calculation unit of the control device according to the first embodiment. FIG. [Figure 9] 3 is a block diagram showing an example of the configuration of a gain calculation unit of the control device according to the first embodiment. FIG. [Figure 10] 3 is a block diagram showing an example of the configuration of a gain calculation unit of the control device according to the first embodiment. FIG. [Figure 11] 10 is a flowchart showing the operation of coil temperature estimation in the control device according to the second embodiment. [Figure 12] FIG. 10 is a diagram showing the relationship between the true resistance value, the estimated resistance value, and the corrected resistance value in the control device according to the second embodiment. [Figure 13] FIG. 11 is a block diagram showing the configuration of a control device for an elevator door device and its peripheral devices in the third embodiment. [Figure 14] 11 is a flowchart showing the operation of temperature estimation when the elevator doors are open in the third embodiment. [Figure 15] 11 is a flowchart showing the operation of temperature estimation when the elevator doors are closed in the third embodiment. [Figure 16] FIG. 10 is a block diagram showing the overall configuration of a system including an elevator and a control device according to a fourth embodiment. [Figure 17] 10 is a flowchart showing the operation of estimating the temperature of the electric motor of the hoisting machine in the elevator in the fourth embodiment. [Figure 18] FIG. 2 illustrates an example of hardware resources of a control device. [Figure 19] FIG. 10 is a diagram illustrating another example of hardware resources of a control device. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will be simplified or omitted.

[0010] Embodiment 1 FIG. 1 is a block diagram showing the configuration of an electric motor and a control device according to a first embodiment. A control device 100 in FIG. 1 controls the operation of an electric motor 1. The electric motor 1 shown in FIG. 1 is a permanent magnet synchronous motor that is rotationally driven by three-phase AC. The electric motor 1 includes coils corresponding to the phases of the three-phase AC. That is, the electric motor 1 includes a U-phase coil, a V-phase coil, and a W-phase coil. The rotational position θ, rotational speed, rotational torque, etc. of the electric motor 1 are controlled by the power supplied to the electric motor 1.

[0011] The electric motor 1 is equipped with a rotation sensor 2. The rotation sensor 2 detects the rotational position θ, speed, etc. of the electric motor 1. An encoder or resolver is used as the rotation sensor 2. However, other types of rotation sensors may also be used as the rotation sensor 2. Information on the rotational position and speed detected by the rotation sensor 2 is used for controlling the rotational position and speed, as a control standard for current, etc.

[0012] The control device 100 includes a d-axis current command unit 3, a d-axis current control unit 4, a q-axis current control unit 8, a first coordinate converter 9, a second coordinate converter 10, a duty calculation unit 11, a power conversion unit 12, a current sensor 13, a gain calculation unit 14, an estimation unit 15, a correction unit 16, a temperature estimation unit 17, and a state detection unit 18.

[0013] The state detection unit 18 detects the state based on the rotational position θ, the speed, etc. detected by the rotation sensor 2, and outputs a gain adjustment command. The states of the electric motor 1 detected by the state detection unit 18 include, for example, a rotating state, a stopped state, and other states. The rotating state is a state in which the electric motor 1 rotates at a speed greater than 0, or a state in which the electric motor 1 is rotated by a load on the electric motor 1. The stopped state is a state in which the electric motor 1 is completely stopped with a speed of 0. The stopped state may also be a state in which the electric motor 1 is mechanically stopped by a brake that stops the rotation of the electric motor 1, or by a load on the electric motor.

[0014] Note that the state detection unit 18 may use other methods to detect the state of the electric motor 1. For example, the state detection unit 18 may detect the state based on a brake that brakes the electric motor 1 or information on the load side.

[0015] The d-axis current command unit 3 calculates and outputs a d-axis current command value Id* of the electric motor 1. The d-axis current of the electric motor 1 is a current value that does not contribute, or contributes little, to rotational torque. When controlling the electric motor 1, which is a permanent magnet synchronous motor, the d-axis current command unit 3 normally sets the current command value Id* to 0. However, when operating the electric motor 1 in a specific operating range with high speed and high torque, the current command value Id* may be set to a value other than 0 in order to perform flux-weakening control.

[0016] The d-axis current control unit 4 includes a P gain unit 5, an I gain unit 6, and an integrator 7. The d-axis current control unit 4 functions as a voltage command unit. That is, it generates a voltage command value Vd* by PI control so that the d-axis current flowing through the electric motor 1 follows the current command value Id*.

[0017] The d-axis current control unit 4 receives an input of the difference Id*-Id between the current command value Id* from the d-axis current command unit 3 and the actual d-axis current value Id from the second coordinate converter 10. The P gain unit 5 multiplies this difference by a P gain. The I gain unit 6 multiplies this difference by an I gain. The output of the I gain unit 6 is then integrated by an integrator 7. The output of the P gain unit 5 and the output of the integrator 7 are added together and output as a voltage command value Vd*.

[0018] The P gain is set to ωc×L using the inductance L of the motor 1. The I gain is set to ωc×R using the resistance R of the motor 1. Here, ωc is the current control band.

[0019] Here, when the inductance L set for the P gain and the resistance R set for the I gain are equal to the inductance and resistance of the motor 1, the closed-loop characteristics of the actual current value Id relative to the current command value Id*, which is the output of the d-axis current command unit 3, are a first-order lag system. Hereinafter, this is referred to as the ideal response. Conversely, when the characteristics from the current command value Id* to the actual current value Id are not a first-order lag, this indicates that the inductance L of the P gain and the resistance R of the I gain are different from the inductance and resistance of the motor 1. Therefore, if the P gain and I gain that result in the ideal response can be found, the resistance of the motor 1 can be determined. Then, the temperature of the motor 1 can be determined based on this resistance value.

[0020] The q-axis current control unit 8 controls the q-axis current flowing through the electric motor 1. For example, the q-axis current control unit 8 controls the q-axis current by PI control, similar to the d-axis current control unit 4. Note that the q-axis current control unit 8 is not limited to PI control and may be realized by any control such as PID control. Furthermore, the q-axis current control unit 8 may include position control for controlling the rotational position of the electric motor 1 and speed control for controlling the rotational speed.

[0021] The current sensor 13 detects the value of the current flowing through each phase of the electric motor 1. That is, the current sensor 13 detects the value of the current flowing through the U phase, the value of the current flowing through the V phase, and the value of the current flowing through the W phase of the electric motor 1. Hereinafter, the value of the current flowing through the U phase detected by the current sensor 13 will be referred to as the actual current value Iu, the value of the current flowing through the V phase will be referred to as the actual current value Iv, and the value of the current flowing through the W phase will be referred to as the actual current value Iw. Note that only two of the actual current values ​​Iu, Iv, and Iw may be detected by the current sensor 13. Furthermore, the actual current values ​​Iu, Iv, and Iw may be used as feedback signals for current control of the electric motor 1.

[0022] The second coordinate converter 10 receives the rotational position θ detected by the rotation sensor 2 and the actual current values ​​Iu, Iv, and Iw detected by the current sensor 13. Based on the rotational position θ, the second coordinate converter 10 converts the coordinate system of the actual current values ​​Iu, Iv, and Iw into a dq coordinate system. That is, based on the input rotational position θ and the input actual current values ​​Iu, Iv, and Iw, the second coordinate converter 10 calculates and outputs the corresponding d-axis actual current value Id and q-axis actual current value Iq. The output d-axis actual current value Id is input to a gain calculation unit 14. In addition, the difference between the output d-axis actual current value Id and the current command value Id* is input to the d-axis current control unit 4. The q-axis actual current value Iq is input to the q-axis current control unit 8.

[0023] The first coordinate converter 9 receives as input the value of the rotational position θ detected by the rotation sensor 2, the d-axis voltage command value Vd* generated by the d-axis current control unit 4, and the q-axis voltage command value Vq* generated by the q-axis current control unit 8. The first coordinate converter 9 converts the coordinate system of the voltage command values ​​Vd* and Vq* into a UVW coordinate system based on the rotational position θ. That is, the first coordinate converter 9 calculates and outputs a U-phase voltage command value Vu*, a V-phase voltage command value Vv*, and a W-phase voltage command value Vw* based on the rotational position θ and the voltage command values ​​Vd* and Vq*.

[0024] Duty calculation unit 11 calculates and outputs a U-phase duty ratio Du* using the U-phase voltage command value Vu* that is the output of first coordinate converter 9 and the bus voltage design value Vdc* that is the design value of the bus voltage Vdc supplied to power conversion unit 12. Similarly, duty calculation unit 11 calculates and outputs a V-phase duty ratio Dv* using the V-phase voltage command value Vv* and the bus voltage design value Vdc*. Duty calculation unit 11 calculates and outputs a W-phase duty ratio Dw* using the W-phase voltage command value Vw* and the bus voltage design value Vdc*.

[0025] That is, the duty ratios Du*, Dv*, Dw* are calculated by dividing each of the voltage command values ​​Vu*, Vv*, and Vw* by the bus voltage design value Vdc*.

[0026] The power conversion unit 12 is an amplifier that supplies power for controlling the electric motor 1. As an example, the power conversion unit 12 has a function of a PWM inverter. The power conversion unit 12 is supplied with a bus voltage Vdc from a power supply system. The power conversion unit 12 generates a corresponding PWM signal by performing carrier comparison of the duty ratios Du*, Dv*, and Dw* from the duty calculation unit 11. The power conversion unit 12 uses the generated PWM signal as a switching command for the switching elements of the inverter. The power conversion unit 12 converts power from the operating power source based on the switching command and supplies the power to the electric motor 1.

[0027] Here, the bus voltage Vdc supplied to the power conversion unit 12 varies depending on the system power supply and the operating state of the electric motor 1. For example, if the power conversion unit 12 uses a diode rectifier as a rectifier, the rectified voltage, i.e., the bus voltage Vdc, varies when the system voltage changes. Furthermore, when the electric motor 1 is in power running operation, the bus voltage Vdc decreases because electric power is supplied to the electric motor 1. Conversely, when the electric motor is in regenerative operation, the bus voltage Vdc increases because electric power is returned to the power conversion unit 12.

[0028] As described above, it is conceivable that the bus voltage Vdc will change. However, the duty calculation unit 11 calculates the duty ratio using the bus voltage design value Vdc*. Therefore, a difference between the actual voltage and the command voltage occurs due to the difference between the actual bus voltage Vdc and the bus voltage design value Vdc*. It is true that if the bus voltage Vdc is measured and used in the duty calculation unit 11, the difference between the actual voltage and the command voltage can be reduced. However, there are cases where it is not possible to install a sensor to measure the bus voltage due to cost or other reasons.

[0029] Next, a configuration relating to temperature estimation of the electric motor 1 will be described. First, the operation of the d-axis current command unit 3 when performing temperature estimation of the coil of the electric motor 1 will be described. The state detection unit 18 detects the stopped state of the electric motor 1 and outputs a gain adjustment command corresponding to the detected state. The d-axis current command unit 3 outputs a test current command value Id* in response to the input of the gain adjustment command. That is, the test current command value Id* is generated when the electric motor 1 is stopped. In normal control, the d-axis current command value Id* is set to 0. However, when performing temperature estimation of the electric motor 1, the d-axis current command unit 3 sets the test current command value Id* to a value other than 0.

[0030] Specifically, the d-axis current command unit 3 generates a test current command value Id* having a waveform such as a pulse wave, a triangular wave, a sawtooth wave, a sweep sine wave, or an M-sequence signal. The test current command value Id* may be generated so as to be added to a constant current command value. The test current command value Id* is generated so as to include a sufficient number of frequency components required when the gain calculation unit 14 calculates the gain.

[0031] FIG. 2 is a diagram showing an example of the test current command value Id* generated by the d-axis current command unit 3 in FIG. 1, and the actual current value Id and voltage command value Vd* at that time. In the example of FIG. 2, a pulse wave is given as the test current command value Id*. In order for the gain calculation unit 14 to calculate the P gain and I gain such that the characteristics from the current command value to the actual current Id match the ideal response, it is desirable that the test current command value Id* include various frequency components. Although FIG. 2 shows an example of a pulse wave, various test current command values ​​Id* can be used, such as a triangular wave, a sawtooth wave, or an M-sequence signal.

[0032] In addition, a dead time is provided in the power conversion unit 12 to prevent short circuits between the upper and lower arms. This is generally corrected using control software, but correction is difficult when the current is near zero. If the dead time cannot be corrected properly, a difference will occur between the voltage command value Vd* and the actual voltage value Vd, resulting in errors in the P gain and I gain calculated by the gain calculation unit 14. To avoid this, an offset current may be applied in advance and a test current command value Id* such as a pulse wave or triangular wave may be added to it. By applying the offset current, the gain calculation unit 14 will not use data when the current is near zero. In other words, it is possible to adjust the gain while avoiding situations where an error occurs between the actual voltage and the command voltage.

[0033] The gain calculation unit 14 receives the d-axis voltage command value Vd*, the d-axis actual current value Id, and a gain adjustment command from the state detection unit 18. Then, it calculates a P gain and an I gain such that the response characteristic from the d-axis current command value Id* to the d-axis actual current value Id becomes an ideal response. The gain calculation unit 14 determines whether to calculate the P gain and the I gain based on the output of the state detection unit 18. That is, the calculation is performed when the state detection unit 18 outputs a gain adjustment command corresponding to the stopped state of the electric motor 1. At this time, the d-axis current command unit 3 outputs the test current command value Id*.

[0034] Here, when the bus voltage Vdc supplied to the power conversion unit 12 varies from the bus voltage design value Vdc*, a difference occurs between the command voltage and the actual voltage. In other words, the voltage command value Vd* that is the output of the d-axis current control unit 4 becomes a value that differs from the voltage actually applied to the motor 1. Then, since the gain calculation unit 14 uses the voltage command value Vd*, the calculated P gain and I gain may include an error between the bus voltage design value Vdc* and the actual bus voltage Vdc.

[0035] The estimation unit 15 calculates an estimated resistance value R^ using the P gain and I gain calculated by the gain calculation unit 14. The P gain and I gain calculated by the gain calculation unit 14 include an error between the design bus voltage value Vdc* and the actual bus voltage Vdc. That is, the P gain is ωc×L×Vdc* / Vdc, and the I gain is ωc×R×Vdc* / Vdc. In this case, the ratio of the I gain to the P gain, or I gain / P gain, is R / L, which is the reciprocal of the electrical time constant. Therefore, by calculating the ratio of the I gain to the P gain, the influence of the bus voltages Vdc and Vdc* is eliminated, and by multiplying this by the inductance, the estimated resistance value R^ can be calculated.

[0036] The correction unit 16 receives the resistance estimated value R^ from the estimation unit 15. The correction unit 16 calculates the resistance correction value R~ by correcting the temperature change of the inductance L used in the estimation unit 15.

[0037] This resistance correction value R~ is input to the temperature estimation unit 17. The temperature estimation unit 17 estimates the coil temperature T according to the resistance correction value R~. One method for calculating the temperature from this resistance value is to use a matrix that experimentally determines the correlation between resistance value and temperature. Another method is to perform calculations using an experimentally derived relational expression.

[0038] In this way, the gain calculation unit 14, the estimation unit 15, the correction unit 16, and the temperature estimation unit 17 estimate the resistance estimate value R^ while eliminating the influence of the bus voltage. Furthermore, the resistance estimate value R^ is used to correct for temperature changes in the inductance L, and the resistance correction value R~ is calculated. These processes improve the accuracy of estimating the resistance value. Therefore, the resistance value of the electric motor 1 can be determined with high accuracy, and the temperature of the electric motor 1 can be grasped with high accuracy.

[0039] Next, the principle of temperature estimation will be described in detail using mathematical expressions. FIG. 3 shows a model of a current control loop focusing on the d-axis in FIG. 1 while the electric motor 1 is stopped. When motor 1 is stopped, the d-axis and q-axis of motor 1 can be considered independently. In addition, motor 1, which is the object to be controlled, exhibits first-order lag characteristics determined by inductance L and resistance value R.

[0040] Here, ωc is the control band of the current control, L' is the design value of the inductance set in the P gain unit 5, and R' is the design value of the resistance set in the I gain unit 6. Using Figure 3, the open-loop characteristic Gop(s) of the d-axis current control is calculated as shown in equation (1).

[0041]

number

[0042] Here, consider the case where L'=L, R'=R, and Vdc*=Vdc, i.e., an ideal situation where there is no error between the parameter settings of the control system and the actual parameters of the motor 1. The open-loop characteristic Gop*(s) in this ideal situation is expressed by equation (2).

[0043]

number

[0044] The gain calculation unit 14 calculates the P gain and I gain such that the loop characteristic of equation (1) becomes the ideal response of equation (2). Therefore, the P gain Kp and I gain KI calculated by the gain calculation unit 14 satisfy the relationships of the following equations (3) and (4).

[0045]

number

[0046]

number

[0047] The estimation unit 15 calculates the resistance value using equation (5) derived from equations (3) and (4), and sets this as the resistance estimate value R^.

[0048]

number

[0049] Here, the P gain Kp and the I gain KI are the results of calculation by the gain calculation unit 14. Furthermore, L0 represents the design value of the inductance L of the motor 1. In this way, the ratio of the P gain in equation (3) to the I gain in equation (4) is calculated. This makes it possible to calculate the estimated resistance value R^ while eliminating the influence of the error between the design value Vdc* of the bus voltage and the actual bus voltage Vdc. Furthermore, when the design value L0 of the inductance is equal to the true value L, the estimated resistance value R^ in equation (5) coincides with the true value R. The estimation unit 15 assumes that the inductance of the motor 1 has little temperature dependency and calculates the estimated resistance value R^ using the inductance L0. Note that L0 can be measured in advance using a measuring instrument such as an LCR meter.

[0050] The estimation unit 15 calculates the estimated resistance value R^ using the design inductance value L0 in equation (5), but the actual inductance L is temperature-dependent. Figure 4 shows the temperature-dependent characteristics of inductance L. Generally, inductance L exhibits a characteristic that increases by several percent as the coil temperature T of the electric motor 1 increases. For example, if equation (5) is calculated using inductance L0 at temperature T0, the estimated resistance value R^ can be calculated without error as the true resistance value R at temperature T0. However, at temperatures other than T0, an error occurs between the estimated resistance value R^ and the true resistance value R due to temperature changes in inductance. If the inductance L is modeled as changing linearly with temperature T, the inductance L can be expressed as a linear function of temperature T, as shown in equation (6).

[0051]

number

[0052] Here, α and β are coefficients determined by the characteristics of the electric motor 1.

[0053] Therefore, the correction unit 16 corrects the estimated resistance value R^ obtained by the estimation unit 15 to calculate the corrected resistance value R~. Specifically, when the estimated resistance value R^ exceeds the resistance value R1 at temperature T1, which is a preset reference value, it is considered that the inductance L changes according to equation (6). Then, the estimated resistance value R^ is proportionally multiplied to obtain the corrected resistance value R~.

[0054] To use a numerical example, let's say the resistance value R1 at temperature T1 is the reference value, which is 10 Ω. When the estimated resistance value R^ is below 10 Ω, the resistance estimation error due to inductance change is considered small, and the resistance correction value R~ = R^. On the other hand, when the estimated resistance value R^ is above 10 Ω, the resistance estimation error due to inductance change is considered large, and the resistance correction value R~ = 1.1 x R^. Note that the proportionality coefficient 1.1 is merely a value used to show a concrete example and has no special meaning. In practice, it is determined individually by the designer.

[0055] Figure 5 shows the relationship between the true resistance value R, the estimated resistance value R^, and the resistance correction value R~. The estimated resistance value R^ matches the resistance value R at the reference temperature T0. However, at temperatures lower than T0, R^ becomes larger than R due to the influence of temperature changes in inductance. Conversely, at temperatures higher than T0, R^ becomes smaller than R due to the influence of temperature changes in inductance. Therefore, when R^ reaches the reference value R1, the resistance correction value R~ is calculated by proportionally multiplying the estimated resistance value R^. By setting an optimal proportionality coefficient at the point when the estimated resistance value R^ reaches R1, the resistance correction value R~ can be made to roughly match the resistance value R. This improves accuracy when the estimated resistance value R^ is larger than R1.

[0056] The temperature estimation unit 17 estimates the temperature of the coil based on the resistance correction value R~ from the correction unit 16.

[0057] Next, the operation of the control device in the first embodiment for estimating the coil temperature will be described with reference to the flowchart of FIG. First, in step S001, the state detection unit 18 determines whether the electric motor 1 is stopped based on the rotational position θ and the speed detected by the rotation sensor 2.

[0058] If it is determined that the vehicle is not stopped, the process ends. If it is determined that the motor is stopped, the d-axis current command unit 3 receives a gain adjustment command from the state detection unit 18, generates a test current command value Id*, and outputs it in step S002.

[0059] Next, in step S003, the gain calculation unit 14 calculates the P gain Kp and the I gain KI that satisfy the equations (3) and (4).

[0060] Next, in step S004, the estimation unit 15 calculates the resistance estimation value R^ using equation (5) based on the P gain Kp and the I gain KI.

[0061] Next, in step S005, the correction unit 16 calculates a resistance correction value R~ based on the resistance estimation value R^. Details of step S005 will be described with reference to the flowchart of FIG.

[0062] First, in step S051, the correction unit 16 determines whether the resistance estimate R^ exceeds a resistance value R1 that is set in advance as a reference value. If the resistance estimate R^ is greater than the resistance value R1, in step S052, the resistance estimate R^ is multiplied by a predetermined proportionality coefficient A to obtain a resistance correction value R~. The proportionality coefficient is a value that is arbitrarily set by the designer depending on the characteristics of the electric motor 1 that is actually being targeted. If it is determined in step S051 that the resistance is not exceeded, the estimated resistance value R^ is set as the corrected resistance value R~ in step S053.

[0063] In FIG. 6, in step S006, the temperature estimation unit 17 estimates the temperature of the coil of the electric motor 1 based on the resistance correction value R~ calculated in step S005.

[0064] In this way, by determining the P gain and I gain that match the ideal response, it is possible to eliminate the influence of errors in the bus voltage and determine the estimated resistance value R^ of the coil of the electric motor 1. This makes it possible to estimate the resistance value of the electric motor 1 with high accuracy even when the voltage command value Vd* and the actual voltage value Vd do not match or when the actual voltage value Vd is not measured.

[0065] The estimated resistance value R^ obtained here is the resistance value of each phase coil of the motor 1 converted to the d-axis. This is the average value of the U-, V-, and W-phase coil resistance values. Therefore, what can be obtained using equation (5) is an estimated average resistance value of the U-, V-, and W-phase coils.

[0066] As described above, in embodiment 1, by generating a test current command value Id* on the d-axis that is unrelated to the torque of the electric motor 1 while the electric motor 1 is stopped, it is possible to estimate the temperature of the electric motor coil without operating the electric motor 1.

[0067] 5 and 7, the correction unit 16 corrects the resistance at a single resistance value R1, but multiple reference resistance values ​​may be provided and the estimated resistance value R^ may be corrected at multiple resistance values. By utilizing the tendency that inductance increases as the temperature rises, the estimated resistance value R^ can be roughly corrected, thereby improving the estimation accuracy.

[0068] Note that various methods can be used for the gain calculation unit 14 as long as they can calculate the P gain and I gain such that the characteristic from the current command value Id* to the actual current value Id becomes an ideal response. An example of the configuration of the gain calculation unit 14 will be described below.

[0069] Fig. 8 is a block diagram showing an example of the configuration of a gain calculation unit. Gain calculation unit 14A in Fig. 8 stores data on the voltage command value Vd* and the actual current value Id, and calculates the P gain and the I gain by processing the stored data offline. One method of gain calculation is called data-driven control, and gain calculation unit 14A in Fig. 8 calculates the gain using this method. In data-driven control, the gain can be adjusted by performing optimization calculations using input and output data.

[0070] Specifically, the gain calculation unit 14A includes a data storage unit 141, a data processing unit 142, and a first optimization calculation unit 143.

[0071] The data storage unit 141 stores the d-axis actual current value Id, i.e., output data, and the d-axis voltage command value Vd*, i.e., input data, for multiple sampling periods. The length of time for storage is, for example, the time during which the d-axis current command unit 3 generates the test current command value Id*. Furthermore, the sampling for storing data needs to be appropriately set according to the period of the test current command value Id* and the control band to be adjusted. The input data stored at this time is designated u0, and the output data is designated y0. These data are sent to the data processing unit 142.

[0072] The data processing unit 142 performs filtering. This filtering cuts out high-frequency noise that is not necessary for adjusting the P gain and I gain, and cuts out low-frequency offsets, and uses information on the ideal response. Filtering in the data processing unit 142 improves the adjustment accuracy of the P gain and I gain. The filtered signal is sent to the first optimization calculator 143.

[0073] Since the first optimization calculator 143 stores and calculates data, it uses the lumped least squares method. Note that the first optimization calculator 143 can use various methods, and methods other than the lumped least squares method may be used as long as they can perform offline optimization calculations. Through this series of operations, it is possible to find the P gain and I gain that will make the response from the current command value Id* to the actual current value Id match the ideal response.

[0074] FIG. 9 is a block diagram showing an example of the configuration of a gain calculation unit different from that shown in FIG. 8. The gain calculation unit 14B in FIG. 9 includes a data processing unit 144 and a second optimization calculator 145. The data processing unit 144 receives the d-axis actual current value Id, i.e., output data, and the d-axis voltage command value Vd*, i.e., input data. The data processing unit 144 performs online filtering on the input actual current value Id and voltage command value Vd*. This processing cuts out high-frequency noise and low-frequency offsets. The filtered signal is sent to the second optimization calculator 145.

[0075] The second optimization calculator 145 uses the recursive least squares method because it performs online calculations without saving data. Note that the second optimization calculator 145 can use various methods, and methods other than the recursive least squares method are also acceptable as long as they can perform online optimization calculations. Through this series of operations, it is possible to find the P gain and I gain that will make the response from the current command value Id* to the actual current value Id match the ideal response.

[0076] Fig. 10 is a block diagram showing an example of the configuration of a gain calculation unit different from those shown in Fig. 8 and Fig. 9. While a method using data-driven control has been described in Fig. 8 and Fig. 9, gain calculation unit 14C in Fig. 10 uses an arbitrary optimization algorithm. Gain calculation unit 14C in Fig. 10 includes a third optimization calculator 146.

[0077] The third optimization calculator 146 receives the d-axis voltage command value Vd* and the actual current value Id as inputs and calculates, using an optimization algorithm, P gain and I gain that make the characteristic from the current command value Id* to the actual current value Id an ideal response. The optimization algorithm can be realized by various methods such as PSO (Particle Swarm Optimization) and CMAES (Covariance Matrix Adaptation Evolution Strategy). Note that these optimization algorithms may also be used in the first optimization calculator 143 in FIG. 8 and the second optimization calculator 145 in FIG. 9.

[0078] The P gain and I gain calculated by the gain calculation unit 14 are used to make the characteristics from the current command value Id* to the actual current value Id into an ideal response. Therefore, the P gain unit 5 and I gain unit 6 of the d-axis current control unit 4 may be rewritten using the calculation results of the gain calculation unit 14. This allows current control to be performed with optimal gains for the conditions in which the P gain and I gain are calculated, i.e., the temperature of the motor 1 when the gain calculation is performed.

[0079] In the first embodiment, a gain calculation method focusing on the d-axis current control loop is described. This determines the resistance value of the electric motor 1, which is a value independent of the d-axis and q-axis of the electric motor 1. Therefore, the calculation result of the gain calculation unit 14 may be used to update the control gain of the q-axis current control unit 8. Furthermore, the calculation result of the gain calculation unit 14 may be used for other control gains.

[0080] Embodiment 2 In the second embodiment, the operation of the correction unit 16 differs from that of the first embodiment, and the resistance correction value R~ is calculated using equation (6). First, there is a relationship between temperature T and resistance value R as shown in equation (7).

[0081]

number

[0082] Here, R is the resistance at temperature T, and R0 is the resistance at temperature T0. If the resistance R0 at temperature T0 is measured, it is possible to calculate the resistance R corresponding to temperature T. Solving equation (7) for temperature T gives the following equation.

[0083]

number

[0084] Substituting equation (8) into equation (6) to find the ratio to the inductance L0 at temperature T0 gives equation (9). Equation (9) requires coefficients α and β that represent the temperature change of inductance, as well as the inductance L0 and resistance R0 at reference temperature T0. These are all parameters that can be obtained by measuring them in advance using a measuring instrument or the like.

[0085]

number

[0086] Using equations (9) and (5), the resistance correction value R^ can be calculated as follows:

[0087]

number

[0088] To realize equation (10), the temperature change of the inductance is measured and the coefficients α and β of equation (6) are first calculated. Then, coefficients C1 and C2 are calculated using α, β, the inductance L0 used to calculate the estimated resistance value R^, and the resistance value R0 at temperature T0 when the inductance L becomes L0. C1 and C2 are stored in the correction unit 16, and the resistance correction value R~ is calculated using the estimated resistance value R^ of the estimation unit 15. This method requires the use of prior information on the temperature change of the inductance. However, since the resistance value can be accurately calculated at any temperature, accuracy is high.

[0089] 11 is a flowchart showing the operation of coil temperature estimation in the control device according to embodiment 2. In FIG. 11, only the processing in correction unit 16 is different from the flowchart in FIG.

[0090] In FIG. 11, first, steps S001 to S004 are executed. Next, in step S007, the correction unit 16 uses the coefficients C1 and C2 to calculate a resistance correction value R~ based on the resistance estimation value R^ calculated in step S004 using equation (10). The coefficients C1 and C2 indicate the temperature change of inductance stored in advance in the correction unit 16.

[0091] FIG. 12 shows the relationship between the true resistance value R, the estimated resistance value R^, and the resistance correction value R~ in the correction method of the second embodiment. The estimated resistance value R^ matches the resistance value R at the reference temperature T0. However, at temperatures lower than T0, R^ becomes larger than R due to the influence of temperature changes in inductance. Conversely, at temperatures higher than T0, R^ becomes smaller than R due to the influence of temperature changes in inductance. Then, by correcting R^ taking into account the temperature changes in inductance, the resistance value R and the resistance correction value R~ can be made to match. The resistance correction value R~ improves the accuracy of resistance estimation by correcting the slope of the estimated resistance value R^, which changes due to temperature changes in inductance, to the correct slope. This improves accuracy over the entire temperature range compared to FIG. 5.

[0092] If the resistance value is known, the coil temperature of the electric motor 1 can be calculated using a temperature equation model that represents the relationship between the resistance and the coil temperature. For this purpose, equation (8) can be used.

[0093] The temperature estimation unit 17 can obtain the coil temperature T of the electric motor 1 at that time by using the resistance correction value R~ as the resistance value R. Note that since the resistance value is obtained as the average value of the U-, V-, and W-phase coils, the temperature in equation (8) indicates the average value of the temperatures of the U-, V-, and W-phase coils.

[0094] Embodiment 3 Fig. 13 is a block diagram showing the configuration of a control device for an elevator door device and its peripheral devices in embodiment 3. In embodiment 3, the control device of embodiment 1 is applied to an electric motor 1 used in an elevator door device, and performs temperature estimation of the electric motor 1. Note that the same parts as in Fig. 1 are given the same reference numerals, and explanations thereof will be simplified or omitted.

[0095] Door 19 is an elevator car door. Motor 1 drives door 19 to open and close. Motor 1 is equipped with a rotation sensor 2. Rotation sensor 2 may be configured to detect the position of door 19 based on the rotation position θ of motor 1. Information on the position of door 19 detected by rotation sensor 2 is used to determine, for example, the acceleration position and deceleration position of door 19.

[0096] The state detection unit 18 detects the state of the electric motor 1 or the door 19 and outputs a gain adjustment command. The state detection unit 18 detects the state of the electric motor 1 based on the rotational position θ and speed detected by the rotation sensor 2. The detected states may include a rotating state, a stopped state, and other states. The rotating state is a state in which the electric motor 1 rotates at a speed greater than 0, or a state in which the electric motor 1 is rotated by a load. The stopped state is a state in which the electric motor 1 is completely stopped with a speed of 0. The stopped state may also be a state in which the electric motor 1 is mechanically stopped by a brake that stops the rotation of the electric motor 1 or a load on the electric motor.

[0097] Furthermore, the state of the door 19 detected by the state detection unit 18 may include, for example, a fully open state, a fully closed state, an operating state, and other states. The operating state may include an opening operation state and a closing operation state. The opening operation state is a state in which the door 19 is moving in an opening direction. For example, the period from when the door 19 in a fully closed state starts to open until it reaches the fully open state is the opening operation state. The closing operation state is a state in which the door 19 is moving in a closing direction. For example, the period from when the door 19 in a fully open state starts to close until it reaches the fully closed state is the closing operation state. Note that the method by which the state detection unit 18 detects the state of the door 19 may be any method. For example, the state detection unit 18 may perform state detection using a sensor attached at the fully closed position and a sensor attached at the fully open position.

[0098] The d-axis current command unit 3 calculates and outputs a d-axis current command value Id* of the electric motor 1. The d-axis current of the electric motor 1 is a current value that does not contribute to, or contributes little to, the rotational torque. Normally, the d-axis current command unit 3 sets the current command value Id* to 0 when performing control to open the door 19, control to close the door 19, control to maintain the door 19 in a fully open state, and control to maintain the door 19 in a fully closed state. Note that when operating the electric motor 1 in a specific operating range of high speed and high torque to open or close the door 19, the current command value Id* may be set to a value other than 0 in order to perform flux-weakening control.

[0099] Here, the operation of the d-axis current command unit 3 when performing temperature estimation of the electric motor 1 of the door device will be described. Normally, the current command value Id* is set to 0 in the fully open or fully closed state. However, when performing temperature estimation of the electric motor 1, the current command value Id* is set to a value other than 0. Specifically, the test current command value Id* is generated as a pulse wave, triangular wave, sawtooth wave, sweep sine, M-sequence signal, or the like. The test current command value Id* is generated so as to include a sufficient number of frequency components required when the gain calculation unit 14 adjusts the gain.

[0100] Whether or not to generate the test current command value Id* is determined based on the detection signal of the state detection unit 18. Specifically, when the state detection unit 18 determines that the door 19 is in a fully open state or a fully closed state, the d-axis current command unit 3 generates the test current command value Id*.

[0101] The q-axis current control unit 8 controls the q-axis current flowing through the electric motor 1, and for example, controls the q-axis current by PI control, similar to the d-axis current control unit 4. The q-axis current control unit 8 is not limited to PI control and can be realized by any control such as PID control. Since the operation of the door 19 requires position control and speed control of the door, the q-axis current control unit 8 in the third embodiment is assumed to include position control and speed control of the door 19.

[0102] Fig. 14 is a flowchart showing the operation of estimating temperature when the door is open. In the control operation of Fig. 14, first, in step S301, it is determined whether or not the door 19 has started to open. This is determined, for example, using a signal from the rotation sensor 2 or a position sensor attached to the door device. If the door 19 has not started to open, the process ends.

[0103] When the door-opening operation is performed and it is determined in step S301 that the door opening has started, it is then determined in step S302 whether the door 19 is fully open. If the door 19 is not fully open, the door-opening operation continues, and the process returns to step S302, where it is repeatedly determined at predetermined control intervals whether the door 19 is fully open. In elevator service, this is the operation performed when passengers get on and off the elevator.

[0104] When the door 19 is in a fully open state and is determined to be fully open in step S302, the d-axis current command unit 3 then generates and outputs a test current command value Id* in step S303. This process is performed while the door 19 is fully open, for example, while passengers are getting on and off the elevator.

[0105] Once the test current command value Id* is output, the gain calculation unit 14 calculates the P gain and the I gain in step S304. Once the calculation of the P gain and the I gain is complete, the estimation unit 15 calculates the resistance estimated value R^ in step S305. Once the calculation of the resistance estimated value R^ is complete, the correction unit 16 calculates the resistance correction value R~ in step S306. Once the calculation of the resistance correction value R~ is complete, the temperature estimation unit 17 estimates the temperature T of the coil of the electric motor 1 in step S307. Thereafter, the current processing ends.

[0106] In this way, by generating a test current command value Id* on the d-axis that is unrelated to the torque of the electric motor 1 while the door 19 is fully open and stopped, the temperature can be estimated without operating the electric motor 1, i.e., without operating the door 19.

[0107] FIG. 15 is a flowchart showing the operation of estimating the temperature when the door is closed. In the example shown in Fig. 15, first, in step S401, it is determined whether or not the door 19 has started closing. This is determined, for example, using a signal from the rotation sensor 2 or a position sensor attached to the door device. If it is determined in step S401 that the door has not started closing, the process ends.

[0108] If it is determined in step S401 that the doors have started to close, it is then determined in step S402 whether the doors 19 are fully closed. If it is determined in step S402 that the doors are not fully closed, the process returns to step S402, the door closing operation continues, and it is repeatedly determined at predetermined control intervals whether the doors 19 are fully closed. In elevator service, this is an operation that is performed after passengers have boarded and disembarked and before the elevator starts moving.

[0109] When the door 19 is in a fully closed state and it is determined in step S402 that the door 19 is fully closed, it is then determined in step S403 whether the elevator is running. If there are no passengers in the elevator or if there are no calls from any floor, the elevator is not running, and the determination in step S403 is "NO." At this time, the door 19 does not operate and the electric motor 1 is stopped, so temperature estimation is not necessary. Therefore, if the determination result in step S403 is "NO," the processing ends. However, it is also possible to skip the determination in step S403 and perform temperature estimation of the electric motor 1 even when the elevator is stopped.

[0110] If the determination result in step S403 is "YES", that is, if it is determined that the elevator is traveling, then in step S404, the d-axis current command unit 3 generates and outputs a test current command value Id*. This process is executed while the elevator is traveling.

[0111] After the test current command value Id* is generated, the gain calculation unit 14 calculates the P gain and the I gain in step S405. After the calculation of the P gain and the I gain is completed, the estimation unit 15 calculates the resistance estimated value R^ in step S406. After the calculation of the resistance estimated value R^ is completed, the correction unit 16 calculates the resistance correction value R~ in step S407. After the calculation of the resistance correction value R~ is completed, the temperature estimation unit 17 estimates the temperature T of the coil of the electric motor 1 in step S408. Then, the processing ends.

[0112] Note that steps S303 and S404 are the same as step S002 in Fig. 6. Steps S304 and S405 are the same as step S003 in Fig. 6. Steps S305 and S406 are the same as step S004 in Fig. 6. Steps S306 and S407 are the same as step S005 in Fig. 6. Steps S307 and S408 are the same as step S006 in Fig. 6.

[0113] As described above, in the third embodiment, when the elevator door 19 is not being opened or closed while the elevator is in service, the test current command value Id* is generated on the d-axis, which is unrelated to the torque of the electric motor 1. This makes it possible to estimate the resistance value and the coil temperature without operating the electric motor 1, i.e., without operating the door 19. This makes it possible to estimate the coil temperature of the electric motor 1 without causing discomfort to elevator passengers.

[0114] Embodiment 4 In the fourth embodiment, the control device for the motor 1 in the first embodiment is applied to the motor 1 of an elevator hoisting machine, and the temperature of the motor 1 is estimated. Fig. 16 is a block diagram showing the overall configuration of a system including an elevator and a control device in the fourth embodiment. In the fourth embodiment, the motor 1 functions as the motor of the elevator hoisting machine, and the control device estimates the temperature of the motor 1. Note that the same parts as those in Figs. 1 and 13 are given the same reference numerals, and the explanations thereof will be simplified or omitted.

[0115] Elevator car 20 and counterweight 21 are connected by rope 22. Rope 22 is wound around sheave 23. The rotation of sheave 23 is controlled by electric motor 1. Therefore, as electric motor 1 rotates, sheave 23 also rotates, and car 20 moves up and down to the destination floor. Sheave 23 is equipped with brake 24 for braking. Brake 24 is released while the elevator is running, and when it arrives at the floor, brake 24 applies braking to sheave 23 to maintain the stationary state. Note that electric motor 1, rotation sensor 2, sheave 23, brake 24, etc. make up hoisting machine 25; that is, electric motor 1, rotation sensor 2, sheave 23, and brake 24 are provided in hoisting machine 25.

[0116] The state detection unit 18 detects the state of the electric motor 1 or the brake 24 and outputs a gain adjustment command. The state detection unit 18 detects the state of the electric motor 1 based on the rotational position θ and speed detected by the rotation sensor 2. The detected states may include a rotating state, a stopped state, and other states. The rotating state is a state in which the electric motor 1 rotates at a speed greater than 0, or a state in which the electric motor 1 is rotated by a load. The stopped state is a state in which the electric motor 1 is completely stopped with a speed of 0. The stopped state may also be a state in which the electric motor 1 is mechanically stopped by a brake that stops the rotation of the electric motor 1, or a load on the electric motor.

[0117] The state of the brake 24 detected by the state detection unit 18 may include, for example, a braking state, a released state, and other states. The braking state includes a state in which the motor 1 is braked by the brake 24 via the sheave 23 when the elevator car 20 has arrived at the destination floor or when the elevator is not moving. The released state is a state in which the elevator is moving.

[0118] Any method may be used for detecting the state by the state detection unit 18. For example, the state detection unit 18 may detect the braking or stopping state using a sensor that detects the position of the brake 24.

[0119] The d-axis current command unit 3 calculates and outputs a d-axis current command value Id* of the electric motor 1. The d-axis current of the electric motor 1 is a current value that does not contribute, or contributes little, to the rotational torque. Normally, the d-axis current command unit 3 sets the current command value Id* to 0 while the elevator is running. On the other hand, when the weight of the passengers and the weight of the counterweight 21 are balanced and there is a margin of torque, the elevator increases its running speed. At this time, the current command value Id* may be set to a value other than 0 in order to perform flux-weakening control.

[0120] Here, the operation of the d-axis current command unit 3 when performing temperature estimation of the elevator motor 1 will be described. Normally, when the elevator is running, the current command value Id* is set to 0 or a value based on flux-weakening control. However, when performing temperature estimation of the motor 1, the current command value Id* is set to a value other than 0. Specifically, a test current command value Id* such as a pulse wave, triangular wave, sawtooth wave, sweep sine, or M-sequence signal is generated. The test current command value Id* is generated so as to include a sufficient number of frequency components required when the gain calculation unit 14 adjusts the gain.

[0121] Whether or not to generate the test current command value Id* is determined based on the detection signal of the state detection unit 18. Specifically, when the state detection unit 18 determines that the elevator is in a stopped state, it generates the test current command value Id* for gain adjustment.

[0122] The q-axis current control unit 8 controls the q-axis current flowing through the motor 1, and for example, controls the q-axis current by PI control, similar to the d-axis current control unit 4. Furthermore, the q-axis current control unit 8 is not limited to PI control and can be realized by any control such as PID control. In elevator operation, it is necessary to control the position and speed of the car 20. Therefore, the q-axis current control unit 8 in FIG. 16 includes position control and speed control.

[0123] Next, a description will be given of the control operation for estimating the temperature of the electric motor 1 of the elevator hoisting machine 25. Fig. 17 is a flowchart showing the operation for estimating the temperature of the electric motor 1 of the hoisting machine 25 in the elevator according to the fourth embodiment.

[0124] In Fig. 17, first, in step S501, it is determined whether the elevator is stopped. This is determined by the state detection unit 18. That is, it is determined whether the electric motor 1 is stopped or whether the brake 24 is in a braking state. If it is determined in step S501 that the elevator is not stopped, temperature estimation is not performed and the process ends.

[0125] On the other hand, if it is determined in step S501 that the elevator is stopped, then in step S502, the d-axis current command unit 3 generates and outputs a test current command value Id*. After the test current command value Id* is generated, the gain calculation unit 14 then calculates a P gain and an I gain that will result in an ideal response of the current control loop in step S503. After the calculation of the P gain and I gain is complete, the estimator 15 calculates an estimated resistance value R^ in step S504. After the calculation of the estimated resistance value R^ is complete, the corrector 16 calculates a resistance correction value R~ in step S505. After the calculation of the resistance correction value R~ is complete, the temperature estimator 17 estimates the temperature T of the coil of the electric motor 1 in step S506.

[0126] Note that step S502 is the same as step S002 in Fig. 6. Step S503 is the same as step S003 in Fig. 6. Step S504 is the same as step S004 in Fig. 6. Step S505 is the same as step S005 in Fig. 6. Step S506 is the same as step S006 in Fig. 6.

[0127] As described above, according to the fourth embodiment, when the elevator is in service and stopped, the d-axis current command unit 3 generates the test current command value Id* on the d-axis that is unrelated to the torque of the electric motor 1. This makes it possible to estimate the resistance value and temperature without operating the electric motor 1. Therefore, it is possible to estimate the temperature without operating the elevator car 20.

[0128] 18 is a diagram showing an example of hardware resources of the control device 100. The control device 100 includes, as hardware resources, a processor 101 and a memory 102. Note that there may be a plurality of processors 101 and a plurality of memories 102.

[0129] In the first to fourth embodiments, the control device 100 performs calculations and stores information. The storage of this information is performed in the memory 102. Furthermore, calculation processing is performed by the processor 101 using software, firmware, or a combination of software and firmware written as a program stored in the memory 102.

[0130] The processor 101 is also called a CPU (Central Processing Unit), central processing unit, arithmetic unit, microprocessor, microcomputer, or DSP. The memory 102 may be a semiconductor memory, a magnetic disk, a flexible disk, an optical disk, a compact disk, a minidisk, or a DVD. Usable semiconductor memories include RAM, ROM, flash memory, EPROM, and EEPROM.

[0131] Fig. 19 is a diagram showing another example of hardware resources of the control device 100. In the example of Fig. 19, the control device 100 includes a processing circuit including a processor 101, a memory 102, and dedicated hardware 103. Fig. 19 shows an example in which some of the functions of the control device 100 are realized by the dedicated hardware 103. Note that all of the functions of the control device 100 may also be realized by the dedicated hardware 103. The dedicated hardware 103 may be a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof.

[0132] Although the preferred embodiments have been described in detail above, the present invention is not limited to these embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the disclosure.

[0133] Furthermore, when the number, quantity, amount, range, etc. of each element is mentioned in the embodiments, the control device of this disclosure is not limited to the mentioned number unless otherwise specified or clearly specified in principle. Furthermore, the structures, etc. described in the embodiments are not necessarily essential unless otherwise specified or clearly specified in principle.

[0134] Various aspects of the present disclosure are summarized below as appendices. (Appendix 1) A control device for an electric motor including a power conversion unit that converts electric power from a power source and supplies the converted electric power to an electric motor, and a voltage command generation unit that generates a voltage command value by PI control so that a current value flowing through the electric motor follows a current command value, a gain calculation unit that calculates a P gain and an I gain of the PI control such that a closed loop characteristic from the current command value to a current value flowing through the electric motor becomes a first-order delay system; an estimation unit that estimates a resistance value of the motor using the P gain, the I gain, and the inductance of the motor, and outputs an estimated resistance value; a correction unit that corrects the temperature change amount of the inductance in accordance with the resistance estimation value and outputs a resistance correction value; a temperature estimation unit that estimates a temperature of a coil of the electric motor using the resistance correction value; A control device for an electric motor comprising: (Appendix 2) 2. The motor control device according to claim 1, wherein the current command value is a d-axis current command value. (Appendix 3) 3. The motor control device according to claim 1, wherein the correction unit sets the resistance correction value to a value proportional to the resistance estimation value when the resistance estimation value exceeds a reference value. (Appendix 4) 3. The motor control device according to claim 1, wherein the correction unit stores a mathematical model representing an amount of change in the inductance due to temperature, and calculates the resistance correction value using the mathematical model and the resistance estimation value. (Appendix 5) a state detection unit that detects a state of the electric motor; a current command unit that generates the current command value, the current command unit generates a test current command value for estimating a temperature of the coil when the state detection unit detects that the electric motor is in a stopped state; 5. The motor control device according to claim 1, wherein the gain calculation unit calculates the P gain and the I gain using the voltage command value generated based on the test current command value and a current value flowing through the motor. (Appendix 6) 6. The motor control device according to any one of appendixes 1 to 5, wherein the closed-loop characteristics become a first-order lag system when an inductance and a resistance value of the motor match an inductance and a resistance value set in the voltage command generating unit. (Appendix 7) 7. The motor control device according to claim 1, wherein the temperature estimation unit estimates the temperature of the coil based on a temperature mathematical model that indicates a relationship between a resistance value of the motor and a temperature of the coil. (Appendix 8) 8. The motor control device according to claim 1, wherein the gain calculation unit calculates the P gain and the I gain using data-driven control. (Appendix 9) 9. The motor control device according to any one of claims 1 to 8, wherein the motor opens and closes elevator doors. (Appendix 10) 9. The motor control device according to any one of claims 1 to 8, wherein the motor is provided in an elevator hoist. [Explanation of symbols]

[0135] 1 electric motor, 2 rotation sensor, 3 d-axis current command unit, 4 d-axis current control unit, 5 P gain section, 6 I gain section, 7 integrator, 8 q-axis current control section, 9 first coordinate converter, 10 second coordinate converter, 11 duty calculation unit, 12 power conversion unit, 13 current sensor, 14 gain calculation unit, 15 estimation unit, 16 correction unit, 17 temperature estimation unit, 18 status detection unit, 19 Door, 20 Cage, 21 Counterweight, 22 Rope, 23 Sheave, 24 Brake, 25 Hoist, 100 control device, 101 processor, 102 memory, 103 dedicated hardware, 141 data storage unit, 142 data processing unit, 143 first optimization calculator, 144 data processing unit, 145 second optimization calculator, 146 Third Optimization Operator

Claims

1. A control device for an electric motor including a power conversion unit that converts electric power from a power source and supplies the converted electric power to an electric motor, and a voltage command generation unit that generates a voltage command value by PI control so that a current value flowing through the electric motor follows a current command value, a gain calculation unit that calculates a P gain and an I gain of the PI control such that a closed loop characteristic from the current command value to a current value flowing through the electric motor becomes a first-order delay system; an estimation unit that estimates a resistance value of the motor using the P gain, the I gain, and an inductance of the motor, and outputs an estimated resistance value; a correction unit that corrects the temperature change amount of the inductance in accordance with the resistance estimation value and outputs a resistance correction value; a temperature estimation unit that estimates a temperature of a coil of the electric motor using the resistance correction value; A motor control device comprising:

2. 2. The motor control device according to claim 1, wherein the current command value is a d-axis current command value.

3. 2. The motor control device according to claim 1, wherein the correction unit sets the resistance correction value as a proportional multiplication of the estimated resistance value when the estimated resistance value exceeds a reference value.

4. 2. The motor control device according to claim 1, wherein the correction unit stores a mathematical model representing the amount of change in the inductance due to temperature, and calculates the resistance correction value using the mathematical model and the estimated resistance value.

5. a state detection unit that detects a state of the electric motor; a current command unit that generates the current command value, the current command unit generates a test current command value for estimating a temperature of the coil when the state detection unit detects that the electric motor is in a stopped state; 2. The motor control device according to claim 1, wherein the gain calculation unit calculates the P gain and the I gain using the voltage command value generated based on the test current command value and a current value flowing through the motor.

6. 2. The motor control device according to claim 1, wherein the closed loop characteristic becomes a first-order lag system when the inductance and resistance values ​​of the motor match the inductance and resistance values ​​set in the voltage command generating unit.

7. 2. The motor control device according to claim 1, wherein the temperature estimation unit estimates the temperature of the coil based on a temperature mathematical model that indicates a relationship between a resistance value of the motor and a temperature of the coil.

8. 2. The motor control device according to claim 1, wherein the gain calculation unit calculates the P gain and the I gain using data-driven control.

9. 9. The motor control device according to claim 1, wherein the motor opens and closes elevator doors.

10. 9. The motor control device according to claim 1, wherein the motor is provided in an elevator hoist.

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