Control device

Abstract

A control device (20) comprises a door state detection unit (24), a voltage command unit (27), a voltage estimation unit (33), a resistance estimation unit (30), and a temperature estimation unit (31). The voltage estimation unit (33) estimates a bus voltage value Vdc^ when the door state detection unit (24) detects that a door (13) is in an operating state. The resistance estimation unit (30) estimates the electric resistance value R^ when the door state detection unit (24) detects that the door (13) is in a fully open or a fully closed state. The temperature estimation unit (31) estimates the temperature of a coil T included in a motor (21) by correcting the electric resistance value R^ using the bus voltage value Vdc^.

Description

Control device

[0001] The present disclosure relates to a control device for controlling elevator doors.

[0002] Patent Document 1 describes a control device for controlling elevator doors. In the control device described in Patent Document 1, the resistance value of a motor that drives a door is estimated based on the value of the current flowing through the motor and the value of the voltage applied to the motor. Furthermore, the temperature of the coil of the motor is estimated based on the estimated resistance value.

[0003] Japanese Patent Application Publication No. 2006-290507

[0004] However, there is an error between the command value of the voltage applied to the motor and the value of the voltage actually applied, which makes it impossible to accurately estimate the motor's resistance value and therefore the temperature of the motor coil.

[0005] The present disclosure has been made to solve the above-mentioned problems, and an object of the present disclosure is to provide a control device that can accurately estimate the temperature of a coil included in a motor that drives an elevator door.

[0006] The control device according to the present disclosure includes a door state detection unit that detects the state of an elevator door; a voltage command unit that generates a voltage command value so that the value of the current flowing through the motor that drives the door follows the current command value; a voltage estimation unit that estimates a bus voltage value supplied to an inverter for driving the motor when the door state detection unit detects that the door is in an operating state; a resistance estimation unit that estimates an electrical resistance value of the motor when the door state detection unit detects that the door is in a fully open state or a fully closed state; and a temperature estimation unit that estimates the temperature of a coil included in the motor by correcting the electrical resistance value estimated by the resistance estimation unit using the bus voltage value estimated by the voltage estimation unit.

[0007] According to the present disclosure, it is possible to accurately estimate the temperature of a coil included in a motor that drives an elevator door.

[0008] 1 is a diagram showing an example of an elevator system equipped with a control device in embodiment 1. FIG. 1 is a diagram showing an example of a control device. FIG. 2 is a flowchart showing an example of an operation of the control device. FIG. 3 is a flowchart showing a preferred example of a voltage estimation process. FIG. 4 is a diagram for explaining the function of a voltage estimation unit. FIG. 5 is a flowchart showing a preferred example of a resistance estimation process. FIG. 6 is a diagram showing examples of a test current command value and a test voltage command value. FIG. 7 is a diagram showing other examples of the test current command value and the test voltage command value. FIG. 8 is a flowchart showing another example of an operation of the control device. FIG. 9 is a flowchart showing another example of an operation of the control device. FIG. 10 is a diagram showing examples of hardware resources of the control device. FIG. 11 is a diagram showing other examples of hardware resources of the control device.

[0009] The following detailed description will be given with reference to the drawings. Duplicate descriptions will be simplified or omitted as appropriate. In each drawing, the same reference numerals indicate the same or corresponding parts.

[0010] Embodiment 1. Figure 1 is a diagram showing an example of an elevator system 1 equipped with a control device 20 according to embodiment 1. The elevator system 1 shown in Figure 1 includes a car 2 and a counterweight 3. The car 2 moves up and down in a hoistway 4. The hoistway 4 is a space formed in a building 5. The hoistway 4 is formed so as to pass through each floor of the building 5. As an example, a landing 6 at which the car 2 can stop is provided on each floor of the building 5.

[0011] The car 2 and counterweight 3 are suspended in the hoistway 4 by a rope 7. The rope 7 is wound around a drive sheave 9 of a hoisting machine 8. The hoisting machine 8 is controlled by a control panel 10. That is, the hoisting machine 8 rotates the drive sheave 9 based on commands from the control panel 10. When the drive sheave 9 rotates, the rope 7 moves in a direction corresponding to the direction in which the drive sheave 9 rotates. The car 2 moves upward or downward in the hoistway 4 depending on the direction in which the rope 7 moves. The counterweight 3 moves up and down in the hoistway 4 in the direction opposite to the direction in which the car 2 moves.

[0012] 1 shows an example in which a machine room 11 is provided above the hoistway 4. The hoisting machine 8 and the control panel 10 are provided in the machine room 11. If the building 5 does not have a machine room 11, the hoisting machine 8 and the control panel 10 may be provided in the hoistway 4. Note that the control panel 10 not only controls the hoisting machine 8 but also controls the overall operation of the elevator system 1.

[0013] The car 2 includes a car chamber 12, a door 13, a control device 20, and a motor 21. An entrance / exit for passengers to get on and off is formed in the car chamber 12. The door 13 opens and closes the entrance by moving horizontally relative to the car chamber 12. The door 13 is driven by the motor 21. The motor 21 is controlled by the control device 20. In other words, the control device 20 is a device for controlling the door 13. Specifically, the control device 20 controls the position, movement speed, etc. of the door 13.

[0014] FIG. 1 shows a state in which car 2 is stopped at a landing 6 on a certain floor. While car 2 is moving, door 13 is in a fully closed state. When car 2 moving from another floor stops at landing 6, control device 20 opens door 13. Note that door 14 provided at landing 6 is linked to door 13 when car 2 is stopped at that landing 6. Passengers board and disembark car 2 when door 13 is fully open. While passengers are boarding and disembarking, control device 20 maintains door 13 in a fully open state. Thereafter, control device 20 closes door 13.

[0015] 2 is a diagram illustrating an example of the control device 20. The motor 21 is a motor that is rotationally driven by, for example, three-phase AC. The motor 21 includes coils corresponding to the phases of the three-phase AC. That is, the motor 21 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 motor 21 are controlled by the supplied power.

[0016] As shown in Fig. 2, the motor 21 includes a rotation sensor 22. The rotation sensor 22 detects a rotational position θ of the motor 21. An encoder or a resolver is used as the rotation sensor 22. Other types of sensors may also be used as the rotation sensor 22. Information about the rotational position θ detected by the rotation sensor 22 is input to the control device 20. The information about the rotational position θ is used by the control device 20 for controlling the rotational position, as a control standard for current, and the like.

[0017] The rotation sensor 22 may detect the position of the door 13 based on the rotation position θ of the motor 21. Information on the position of the door 13 detected by the rotation sensor 22 is input to the control panel 10. The information on the position of the door 13 is used by the control panel 10 to determine the acceleration position, deceleration position, etc. of the door 13.

[0018] The control device 20 includes a current sensor 23, a door state detection unit 24, a current coordinate conversion unit 25, a current command unit 26, a voltage command unit 27, a voltage coordinate conversion unit 28, a power conversion unit 29, a resistance estimation unit 30, a temperature estimation unit 31, a protection control unit 32, and a voltage estimation unit 33. The devices for realizing these functions of the control device 20 may be housed in a single housing or may be housed separately in multiple housings.

[0019] The current sensor 23 detects the value of the current flowing through each phase of the motor 21. That is, the current sensor 23 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 motor 21. Hereinafter, the value of the current flowing through the U phase detected by the current sensor 23 will also be referred to as the actual current value Iu. The value of the current flowing through the V phase detected by the current sensor 23 will also be referred to as the actual current value Iv. The value of the current flowing through the W phase detected by the current sensor 23 will also be referred to as the actual current value Iw. Only two of the actual current values ​​Iu, Iv, and Iw may be detected by the current sensor 23. The actual current values ​​Iu, Iv, and Iw may be used as feedback signals for current control of the motor 21 in the control device 20.

[0020] The door state detection unit 24 detects the state of the door 13. The states of the door 13 detected by the door state detection unit 24 include, for example, a fully open state, a fully closed state, an operating state, and other states. The operating states include an opening operation state and a closing operation state. The opening operation state is a state in which the door 13 is moving in an opening direction. For example, the period from when the door 13 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 13 is moving in a closing direction. For example, the period from when the door 13 in a fully open state starts to close until it reaches the fully closed state is the closing operation state.

[0021] Any method may be used for the door state detection unit 24 to detect the state of the door 13. As an example, the door state detection unit 24 detects the state based on the rotation position θ detected by the rotation sensor 22. The door state detection unit 24 may also detect the state using a sensor attached at the fully closed position and a sensor attached at the fully open position.

[0022] The value of the rotational position θ detected by the rotation sensor 22 is input to the current coordinate converter 25. The actual current values ​​Iu, Iv, and Iw detected by the current sensor 23 are input to the current coordinate converter 25. The current coordinate converter 25 converts the coordinate system of the actual current values ​​Iu, Iv, and Iw into a dq coordinate system based on the rotational position θ. That is, the current coordinate converter 25 calculates and outputs the corresponding actual current value Id on the d axis and the actual current value Iq on the q axis based on the input rotational position θ and the actual current values ​​Iu, Iv, and Iw.

[0023] The current command unit 26 includes the functions of a control system for the motor 21. The functions of the control system include, for example, a position control system and a speed control system. The current command unit 26 generates a current command value for controlling the current flowing through the motor 21. The current command value is generated based on, for example, a command from the control panel 10, a signal from a position control system for the motor 21, a signal from a speed control system for the motor 21, etc. In the example shown in FIG. 2 , the current command unit 26 generates a current command value expressed in a dq coordinate system. That is, the current command unit 26 generates and outputs a d-axis current command value Id* and a q-axis current command value Iq*.

[0024] The actual current value Iq on the q-axis is a current value related to the rotational torque of the motor 21. When performing control to open the door 13 and control to maintain the door 13 in a fully open state, the current command unit 26 generates a current command value Iq* such that the motor 21 generates torque in the direction to open the door 13. When performing control to close the door 13 and control to maintain the door 13 in a fully closed state, the current command unit 26 generates a current command value Iq* such that the motor 21 generates torque in the direction to close the door 13.

[0025] The actual current value Id of the d-axis is a current value that does not contribute to rotational torque. The current command unit 26 sets the current command value Id* to 0 when performing control to open the door 13, control to close the door 13, control to maintain the door 13 in a fully open state, and control to maintain the door 13 in a fully closed state. Note that when the motor 21 is operated in a specific operating range with high speed and high torque to open or close the door 13, the current command value Id* may be set to a value other than 0 in order to perform flux-weakening control. However, even when the motor 21 operates in that operating range, the current command unit 26 sets the current command value Id* to 0 when control to maintain the door 13 in a fully open or fully closed state is performed.

[0026] The voltage command unit 27 controls the current flowing through the motor 21. The voltage command unit 27 generates a voltage command value so that the value of the current flowing through the motor 21 follows the current command value from the current command unit 26. For example, the voltage command unit 27 generates and outputs a voltage command value for controlling the voltage applied to the motor 21 as a value expressed in a dq coordinate system based on the actual current value and the current command value. In the example shown in FIG. 2 , the voltage command unit 27 may include the function of a subtractor 34.

[0027] As an example, the actual current values ​​Id and Iq calculated by the current coordinate conversion unit 25 are input to the voltage command unit 27. The current command values ​​Id* and Iq* generated by the current command unit 26 are input to the voltage command unit 27. The voltage command unit 27 calculates and outputs a d-axis voltage command value Vd* and a q-axis voltage command value Vq* such that the actual current values ​​Id and Iq follow the current command values ​​Id* and Iq*. For example, the voltage command unit 27 performs a control calculation such that the actual current values ​​Id and Iq match the current command values ​​Id* and Iq*. The control performed by the voltage command unit 27 can be realized by any control method such as PID control.

[0028] The value of the rotational position θ detected by the rotation sensor 22 is input to the voltage coordinate converter 28. The voltage command values ​​Vd* and Vq* generated by the voltage command unit 27 are input to the voltage coordinate converter 28. The voltage coordinate converter 28 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, based on the input rotational position θ and voltage command values ​​Vd* and Vq*, the voltage coordinate converter 28 calculates and outputs a corresponding U-phase voltage command value Vu*, V-phase voltage command value Vv*, and W-phase voltage command value Vw*. Note that the voltage coordinate converter 28 may convert the voltage command values ​​Vu*, Vv*, and Vw* into duty ratios in accordance with design values ​​of the power converter 29 and output the duty ratios.

[0029] The power conversion unit 29 is electrically connected to the motor 21. The current sensor 23 is provided between the power conversion unit 29 and the motor 21. The power conversion unit 29 is supplied with power from an operating power supply (not shown). Hereinafter, as shown in FIG. 2 , the voltage value of the power supplied to the power conversion unit 29 from the operating power supply will also be referred to as a bus voltage value Vdc.

[0030] The power conversion unit 29 is an amplifier that supplies power for controlling the rotation of the motor 21. As an example, the power conversion unit 29 has a function of a PWM inverter. The power conversion unit 29 generates corresponding PWM signals by performing carrier comparison of the voltage command values ​​Vu*, Vv*, and Vw* from the voltage coordinate conversion unit 28. The power conversion unit 29 uses the generated PWM signals as switching commands for the switching elements of the inverter. The power conversion unit 29 converts power from the operating power source based on the switching commands and supplies the power to the motor 21.

[0031] In addition to the control process for the motor 21, the control device 20 also performs a temperature estimation process. The temperature estimation process is a process for estimating the temperature of a coil included in the motor 21. Hereinafter, the coil included in the motor 21 will also be referred to simply as coil C. The temperature estimation process includes a resistance estimation process and a voltage estimation process. The resistance estimation process is a process for estimating the electrical resistance value of the motor 21. The voltage estimation process is a process for estimating the bus voltage value supplied to the power conversion unit 29. The control device 20 may further perform an overheat protection process after the temperature estimation process.

[0032] The resistance estimation unit 30, the temperature estimation unit 31, and the voltage estimation unit 33 are functions provided in the control device 20 to perform temperature estimation processing. The protection control unit 32 is a function provided in the control device 20 to perform overheat protection processing.

[0033] Specifically, the resistance estimation unit 30 estimates the electric resistance value R^ of the motor 21. That is, R^ represents the estimated value of the electric resistance. The resistance estimation unit 30 estimates the electric resistance value R^ when the door state detection unit 24 detects that the door 13 is in a fully open state or a fully closed state.

[0034] The actual current value Id calculated by the current coordinate conversion unit 25 is input to the resistance estimation unit 30. The voltage command value Vd* generated by the voltage command unit 27 is input to the resistance estimation unit 30. The resistance estimation unit 30 estimates an electrical resistance value R^ based on the input actual current value Id and voltage command value Vd*. As an example, the resistance estimation unit 30 estimates the overall electrical resistance value of the electrical circuit consisting of the U-phase coil, the V-phase coil, and the W-phase coil as the electrical resistance value R^.

[0035] The voltage estimation unit 33 estimates a bus voltage value Vdc^ supplied to the power conversion unit 29, i.e., the inverter for driving the motor 21. That is, Vdc^ represents an estimated value of the bus voltage. The voltage estimation unit 33 estimates the bus voltage value Vdc^ when the door state detection unit 24 detects that the door 13 is in an operating state, i.e., an open operating state or a closed operating state.

[0036] The actual current values ​​Id and Iq calculated by the current coordinate conversion unit 25 are input to the voltage estimation unit 33. The voltage command value Vq* generated by the voltage command unit 27 is input to the voltage estimation unit 33. The rotational angular velocity ω based on the rotational position θ detected by the rotation sensor 22 is input to the voltage estimation unit 33. The voltage estimation unit 33 estimates the bus voltage value Vdc^ based on the input actual current values ​​Id and Iq, voltage command value Vq*, and rotational angular velocity ω.

[0037] The temperature estimation unit 31 estimates the temperature T of the coil C included in the motor 21. The electrical resistance value R^ estimated by the resistance estimation unit 30 is input to the temperature estimation unit 31. The bus voltage value Vdc^ estimated by the voltage estimation unit 33 is input to the temperature estimation unit 31. The temperature estimation unit 31 estimates the temperature T of the coil C based on the input electrical resistance value R^ and bus voltage value Vdc^. Specifically, the temperature estimation unit 31 corrects the electrical resistance value R^ using the bus voltage value Vdc^. The temperature estimation unit 31 estimates the temperature T of the coil C based on the corrected electrical resistance value R^.

[0038] The value of the temperature T estimated by the temperature estimation unit 31 is input to the protection control unit 32. Based on the temperature T estimated by the temperature estimation unit 31, the protection control unit 32 determines whether or not to execute protection control for the coil C.

[0039] The principles of the functions of the control device 20 will be described in detail below. First, the principles of how the electrical resistance value R^ is calculated in the resistance estimation process will be described.

[0040] Generally, the following equations (1) and (2) hold true for the motor 21. Equation (1) is the voltage equation for the d-axis, and Equation (2) is the voltage equation for the q-axis.

[0041]

[0042]

[0043] R is the total resistance value of the coils included in the motor 21. Ld is the inductance of the d-axis. Lq is the inductance of the q-axis. ω is the electrical angular velocity. φ is the induced voltage constant.

[0044] When the door 13 is fully open or fully closed, the rotational position θ of the motor 21 does not change over time. Therefore, the electrical angular velocity ω is 0. In this case, equation (1) can be interpreted as equation (3), and equation (2) can be interpreted as equation (4).

[0045]

[0046]

[0047] From equations (3) and (4), if the door 13 is in a fully open or fully closed state, the resistance value R can be calculated based on Ohm's law from the set of Vd and Id or the set of Vq and Iq.

[0048] The values ​​used to calculate the resistance value R must be reliable. In the control device 20, the actual current values ​​Id and Iq are calculated by the current coordinate conversion unit 25 based on the actual current values ​​Iu, Iv, and Iw and the rotational position θ. The actual current values ​​Iu, Iv, and Iw and the rotational position θ are measured values. In other words, the actual current values ​​Id and Iq are calculated based on measured values, and therefore can be considered to be accurate values.

[0049] On the other hand, it is difficult to actually measure the applied voltage values ​​Vd and Vq. For this reason, in the temperature estimation process, the voltage command values ​​Vd* and Vq* generated by the voltage command unit 27 are used instead of the applied voltage values ​​Vd and Vq. However, if the voltage command values ​​Vd* and Vq* are directly applied to equation (3) or (4), the estimated resistance value R may contain various estimation errors.

[0050] For example, if there is a design difference between the bus voltage value supplied from the power supply to power conversion unit 29 and the voltage value used as a design value in the control system of motor 21, the design difference may cause an error between voltage command values ​​Vd* and Vq* and the voltage value actually applied to motor 21. Furthermore, the design difference may cause an error in the dead time correction performed by power conversion unit 29.

[0051] The voltage command unit 27 generates the voltage command values ​​Vd* and Vq* so as to reduce or eliminate various errors caused by the design difference. Specifically, the voltage command unit 27 calculates and generates the voltage command values ​​Vd* and Vq* so as to absorb the difference between the bus voltage value supplied to the power conversion unit 29 and the voltage value used as the design value. The voltage command unit 27 calculates and generates the voltage command values ​​Vd* and Vq* so as to compensate for the error in dead time correction caused by the design difference. However, even if such calculation is performed, an error will occur between the voltage command values ​​Vd* and Vq* and the voltage value actually applied.

[0052] This error can be divided into additive error and multiplicative error. Additive error includes the error in dead time correction. Multiplicative error includes the error between the design value of the bus voltage and the actual voltage value in the duty ratio calculation.

[0053] For example, to correct the error between the design value and actual voltage value of the bus voltage, a voltage sensor for measuring the bus voltage value is required. The voltage sensor may not be included in the control device 20 due to constraints such as manufacturing costs or board space. In such cases, the actual voltage value cannot be used to calculate the duty ratio, and the design value of the bus voltage must be used. Equation (5) shows the relationship between the voltage command value Vd* and the applied voltage value Vd. Equation (6) shows the relationship between the voltage command value Vq* and the applied voltage value Vq.

[0054]

[0055]

[0056] γ is a coefficient indicating a multiplicative error, ΔVd is an additive error on the d-axis, and ΔVq is an additive error on the q-axis.

[0057] In the example shown in the present embodiment, in order to prevent the accuracy of the estimated value from being deteriorated due to an error, the difference between the voltage command value and the actual current value is used in the resistance estimation process. For example, the following equation (7) is used in the resistance estimation process.

[0058]

[0059] The difference ΔV is the amount of change in the d-axis voltage command value or the amount of change in the q-axis voltage command value. The difference ΔI is the amount of change in the d-axis actual current value or the amount of change in the q-axis actual current value. The difference ΔV is the difference between two voltage command values. Therefore, the difference ΔV is a value in which the additive errors ΔVd and ΔVq that exist between the voltage command values ​​Vd* and Vq* and the values ​​of the actually applied voltages are canceled out. It is preferable to use such values ​​in the resistance estimation process.

[0060] To calculate the difference ΔV, at least two sets of voltage command values ​​Vd* and Vq* are required. Three or more sets of voltage command values ​​Vd* and Vq* may be used to calculate the difference ΔV. A specific example of generating multiple sets of voltage command values ​​Vd* and Vq* will be described later. For example, when the q-axis current command value Iq* is set to a constant value, and the first value Vd1* and the second value Vd2*, which are voltage command values, and the first value Id1 and the second value Id2, which are corresponding actual current values, are applied to equation (7), equation (8) can be obtained.

[0061]

[0062] From equation (8), the resistance estimation unit 30 can estimate the electrical resistance value R^ of the motor 21.

[0063] Next, the principle of calculation of the bus voltage value Vdc^ in the voltage estimation process will be described.

[0064] Using the design value Vdc* of the bus voltage and the actual bus voltage value Vdc, the relationship between the applied voltage value Vd and the voltage command value Vd* is expressed as in equation (9). The relationship between the applied voltage value Vq and the voltage command value Vq* is expressed as in equation (10).

[0065]

[0066]

[0067] Vd* / Vdc* and Vq* / Vdc* are values ​​equivalent to the so-called duty ratio. The duty ratio is calculated in the control device 20, and the voltage value applied to the motor 21 is determined by multiplying the calculation result by the actual value Vdc of the bus voltage. If the actual bus voltage value Vdc matches the design value Vdc* of the bus voltage, the applied voltage value matches the voltage command value. By solving equation (9) for the voltage command value Vd*, the relationship between the voltage command value Vd* and the applied voltage value Vd can be obtained as shown in equation (11). By solving equation (10) for the voltage command value Vd*, the relationship between the voltage command value Vq* and the applied voltage value Vq can be obtained as shown in equation (12).

[0068]

[0069]

[0070] Vdc / Vdc* is the coefficient γ in equations (5) and (6). Thus, the multiplicative voltage error cannot be canceled out by calculating the resistance value using the voltage difference as in equation (7). Therefore, the voltage error becomes an estimation error of the resistance value, i.e., an estimation error of the temperature.

[0071] As shown in equations (1) and (2), the voltage of the motor 21 is expressed by a voltage equation. By substituting the applied voltage value Vd in equation (11), i.e., the actual voltage value of the motor 21, into the voltage equation in equation (1), equation (13) can be obtained. By substituting the applied voltage value Vq in equation (12), i.e., the actual voltage value of the motor 21, into the voltage equation in equation (2), equation (14) can be obtained.

[0072]

[0073]

[0074] Since the resistance value R is unknown, it cannot be used as a parameter in the voltage estimation process. Therefore, a condition for estimating the bus voltage value is that the current value be small enough to ignore terms including the resistance value R. Furthermore, the inductance L changes depending on the current due to the influence of magnetic saturation. Therefore, a condition that also makes the term including the inductance L negligible is preferable, but this condition can also be achieved by reducing the current value. If the current value is small, equation (13) can be approximated as equation (15), and equation (14) can be approximated as equation (16).

[0075]

[0076]

[0077] As shown in equation (15), if the current value is small, the voltage command value Vd* is approximately 0. Therefore, when the current value is small, equation (15) cannot be used in the voltage estimation process. On the other hand, if the rotational angular velocity ω of the motor 21 is relatively large, the voltage command value Vq* does not become 0. Therefore, the voltage estimator 33 can estimate the bus voltage value Vdc^ from equation (17), which is a modification of equation (16).

[0078]

[0079] Note that, under conditions where the current is small, the actual q-axis voltage value of the motor 21 can be expressed as the product of the rotational angular velocity ω and the induced voltage constant φ. Hereinafter, this value will also be referred to as the theoretically calculated q-axis voltage value ωφ.

[0080] Next, the temperature estimation process performed by the control device 20 will be described in detail with reference to Figures 3 to 8. Figure 3 is a flowchart showing an example of the operation of the control device 20. The control device 20 determines whether the door 13 has started to open (S001). When the state of the door 13 detected by the door state detection unit 24 changes from a fully closed state to an opening state, a Yes determination is made in S001.

[0081] If the determination in S001 is Yes, the voltage estimation process is started (S002). In the voltage estimation process, the voltage estimator 33 estimates the bus voltage value Vdc^.

[0082] Furthermore, if the determination in S001 is Yes, it is determined whether the door 13 is fully open (S003). If the door state detection unit 24 detects that the door 13 is fully open after the determination in S001 is Yes, the determination in S003 is Yes. The voltage estimation process continues until the determination in S003 is Yes. If the determination in S003 is Yes, the voltage estimation process ends.

[0083] The processes shown in S001 to S003 in Fig. 3 show an example in which the voltage estimation process is performed when the door 13 is being opened. The voltage estimation process may also be performed when the door 13 is being closed. In such a case, it is determined in S001 whether the door 13 has started to close. It is determined in S003 whether the door 13 is fully closed. After a Yes determination is made in S001, the voltage estimation process continues until a Yes determination is made in S003.

[0084] Fig. 4 is a flowchart showing a preferred example of the voltage estimation process. Fig. 4 shows an example of the process performed in S002 of Fig. 3. As described above, it is preferable that the bus voltage value Vdc^ be estimated when the rotational angular velocity ω of the motor 21 is relatively large and the value of the current flowing through the motor 21 is small.

[0085] In the voltage estimation process, the voltage estimator 33 determines whether the rotational angular velocity ω of the motor 21 is equal to or greater than a first reference value Th1 (S101). The first reference value Th1 is set in advance. If the rotational angular velocity ω is equal to or greater than the first reference value Th1, the determination in S101 is Yes.

[0086] The sign of the rotational angular velocity ω is different when the door 13 is opening and when it is closing. Taking into consideration the case where the door 13 is closing, in S101, if the absolute value of the rotational angular velocity ω is equal to or greater than the first reference value Th1, the determination is Yes. To make the determination in S101, different values ​​may be used as the first reference value Th1 when the door 13 is opening and when it is closing.

[0087] If S101 returns "Yes," the voltage estimation unit 33 determines whether the value of the current flowing through the motor 21 is equal to or less than a second reference value Th2 (S102). The second reference value Th2 is set in advance. If the value of the current flowing through the motor 21 is equal to or less than the second reference value Th2, the determination in S102 returns "Yes."

[0088] The sign of the current flowing through the motor 21 differs between when the door 13 is opening and when it is closing. Taking into consideration the case where the door 13 is closing, in S102, if the absolute value of the current is equal to or less than the second reference value Th2, the determination is Yes. To make the determination in S102, different values ​​may be used as the second reference value Th2 when the door 13 is opening and when it is closing.

[0089] If the determination in S102 is Yes, the bus voltage value Vdc^ is estimated (S103). That is, when the absolute value of the rotational angular velocity ω is equal to or greater than the first reference value Th1 and the absolute value of the current flowing through the motor 21 is equal to or less than the second reference value Th2, the voltage estimator 33 calculates the bus voltage value Vdc^ using equation (17).

[0090] In the example shown in Fig. 4, if the absolute value of the rotational angular velocity ω is not equal to or greater than the first reference value Th1, a No determination is made in S101. If a No determination is made in S101, the voltage estimator 33 does not perform an estimation calculation of the bus voltage value Vdc^. If a No determination is made in S102, the voltage estimator 33 does not perform an estimation calculation of the bus voltage value Vdc^.

[0091] Fig. 5 is a diagram for explaining the function of the voltage estimation unit 33. The upper part of Fig. 5 shows the change over time in the rotational angular velocity ω of the motor 21 when the door 13 is opened or closed. The middle part of Fig. 5 shows the change over time in the actual current value Id on the d-axis when the door 13 is opened or closed. The lower part of Fig. 5 shows the change over time in the actual current value Iq on the q-axis when the door 13 is opened or closed.

[0092] 5, the rotational angular velocity ω increases after the start of the opening or closing operation of the door 13, and then decreases. If the motor 21 is a general permanent magnet synchronous motor, the actual current value Id on the d-axis is controlled to 0 when the opening or closing operation of the door 13 is performed. The actual current value Iq on the q-axis is a value equivalent to the torque required for the rotational angular velocity ω to follow the command value.

[0093] The estimation condition for estimating the bus voltage value Vdc^ is met when both a first condition related to the rotational angular velocity ω and a second condition related to the current flowing through the motor 21 are met. The first condition is a condition where the rotational angular velocity ω is equal to or greater than a first reference value Th1, i.e., a condition where ωφ is sufficiently large in the voltage equation of the motor 21. The second condition is a condition where each of the actual current values ​​Id and Iq is equal to or less than a second reference value Th2, i.e., a condition where the voltage equation of the motor 21 is not affected by the resistance value R and the inductance L.

[0094] When the first condition and the second condition are satisfied, the voltage estimator 33 estimates the bus voltage value Vdc^ based on equation (17). In the estimation based on equation (17), the q-axis voltage command value Vq* and the theoretically calculated q-axis voltage value ωφ calculated based on the q-axis voltage equation of the motor 21 are used. More specifically, the estimation uses the ratio of the theoretically calculated q-axis voltage value ωφ to the q-axis voltage command value Vq*. That is, in S103 of FIG. 4 , the voltage estimator 33 multiplies the rotation angular velocity ω by the induced voltage constant φ and the design value Vdc* of the bus voltage, and divides the result by the voltage command value Vq* to obtain the bus voltage value Vdc^.

[0095] If the determination in S003 in Fig. 3 is Yes, the resistance estimation process is started (S004). The resistance estimation process is started on the condition that the door 13 is fully open or fully closed. Fig. 3 shows an example in which the resistance estimation process is performed when the door 13 is fully open. As will be described in detail later, the resistance estimation process may also be performed when the door 13 is fully closed.

[0096] As described above, the resistance estimation unit 30 can estimate the electrical resistance value R^ of the motor 21 from equation (8). In order to estimate the electrical resistance value R^ using equation (8), multiple sets of voltage command values ​​are required. Therefore, when the resistance estimation process is started, the current command unit 26 generates multiple sets of current command values ​​(S005). The current command values ​​are values ​​generated to estimate the temperature T of the coil C. Hereinafter, the current command values ​​will also be referred to as test current command values.

[0097] When the resistance estimation process is performed when the door 13 is fully open, the current command unit 26 generates, in S005, a plurality of sets of test current command values ​​that maintain the fully open state of the door 13. When the resistance estimation process is performed when the door 13 is fully closed, the current command unit 26 generates, in S005, a plurality of sets of test current command values ​​that maintain the fully closed state of the door 13.

[0098] Each test current command value includes a d-axis test current command value Id* and a q-axis test current command value Iq*. The test current command values ​​Iq* included in the multiple sets of test current command values ​​have the same magnitude. The test current command values ​​Id* included in the multiple sets of test current command values ​​have different magnitudes. That is, the current command unit 26 fixes the test current command value Iq* to a constant value and generates multiple sets of test current command values ​​Id* and Iq* in which the test current command value Id* is set to different values. The test current command value Iq* is fixed to a constant value because changing the test current command value Iq* may make it impossible to maintain the door 13 in a fully open or fully closed state. The current command unit 26 generates the test current command values ​​Id* and Iq* one set at a time in sequence.

[0099] If the motor 21 has a surface permanent magnet (SPM) structure, no rotational torque is generated even when a d-axis current flows. On the other hand, if the motor 21 has an interior permanent magnet (IPM) structure, reluctance torque is generated when a d-axis current flows. Reluctance torque is often relatively smaller than magnet torque, and its influence is small. However, if the motor 21 has an interior permanent magnet structure, the d-axis test current command value Id* may be generated taking into account the influence of reluctance torque.

[0100] When multiple sets of test current command values ​​Id* and Iq* are generated in S005, the voltage command unit 27 generates multiple corresponding sets of voltage command values ​​Vd* and Vq*. Hereinafter, these voltage command values ​​will also be referred to as test voltage command values. The motor 21 operates in accordance with the generated test voltage command values ​​Vd* and Vq*. The actual current values ​​Iu, Iv, and Iw at this time are detected by the current sensor 23. The resistance estimation unit 30 estimates the electrical resistance value R^ from equation (8) based on the test voltage command value Vq* from the voltage command unit 27 and the actual current values ​​Id and Iq from the current coordinate conversion unit 25 (S006).

[0101] Fig. 6 is a flowchart showing a preferred example of the resistance estimation process. Fig. 7 shows a specific example of the process performed in S005 and S006 of Fig. 3. As described above, in the resistance estimation process, multiple sets of test current command values ​​are generated. For example, the current command unit 26 generates multiple sets of test current command values ​​in which the d-axis current value is not 0. Below, an example will be described in which three sets of test current command values ​​with different values ​​are generated in sequence at regular time intervals.

[0102] When the resistance estimation process is started in S004, the current command unit 26 generates a first set of test current command values, i.e., a first test current command value Id1* on the d-axis and a first test current command value Iq1* on the q-axis (S201). The voltage command unit 27 generates a first test voltage command value Vd1* on the d-axis corresponding to the first test current command value Id1*. The voltage command unit 27 generates a first test voltage command value Vq1* on the q-axis corresponding to the first test current command value Iq1*. As a result, the resistance estimation unit 30 acquires the first test voltage command value Vd1* from the voltage command unit 27.

[0103] The power conversion unit 29 supplies power based on the first test voltage command values ​​Vd1* and Vq1* to the motor 21. As a result, the current sensor 23 detects actual current values ​​Iu1, Iv1, and Iw1 corresponding to the first test voltage command values ​​Vd1* and Vq1*, and the corresponding first actual current value Id1 on the d-axis and first actual current value Iq1 on the q-axis are output from the current coordinate conversion unit 25. The resistance estimation unit 30 acquires the first actual current value Id1, which is the current value of the motor 21 that follows the first test current command value Id1*, from the current coordinate conversion unit 25 (S202).

[0104] Next, the current command unit 26 generates a second set of test current command values, i.e., a second test current command value Id2* on the d-axis and a second test current command value Iq2* on the q-axis (S203). The second test current command value Id2* has a magnitude different from that of the first test current command value Id1*. The voltage command unit 27 generates a second test voltage command value Vd2* on the d-axis corresponding to the second test current command value Id2*. The voltage command unit 27 generates a second test voltage command value Vq2* on the q-axis corresponding to the second test current command value Iq2*. As a result, the resistance estimation unit 30 acquires the second test voltage command value Vd2* from the voltage command unit 27.

[0105] The power conversion unit 29 supplies power based on the second test voltage command values ​​Vd2* and Vq2* to the motor 21. As a result, the current sensor 23 detects actual current values ​​Iu2, Iv2, and Iw2 corresponding to the second test voltage command values ​​Vd2* and Vq2*, and the corresponding second actual current value Id2 on the d-axis and second actual current value Iq2 on the q-axis are output from the current coordinate conversion unit 25. The resistance estimation unit 30 acquires the second actual current value Id2, which is the current value of the motor 21 that follows the second test current command value Id2*, from the current coordinate conversion unit 25 (S204).

[0106] Next, the current command unit 26 generates a third set of test current command values, i.e., a third test current command value Id3* on the d-axis and a third test current command value Iq3* on the q-axis (S205). The third test current command value Id3* has a magnitude different from that of the first test current command value Id1* and the second test current command value Id2*. The voltage command unit 27 generates a third test voltage command value Vd3* on the d-axis corresponding to the third test current command value Id3*. The voltage command unit 27 generates a third test voltage command value Vq3* on the q-axis corresponding to the third test current command value Iq3*. As a result, the resistance estimation unit 30 acquires the third test voltage command value Vd3* from the voltage command unit 27.

[0107] The power conversion unit 29 supplies power based on the third test voltage command values ​​Vd3* and Vq3* to the motor 21. As a result, the current sensor 23 detects actual current values ​​Iu3, Iv3, and Iw3 corresponding to the third test voltage command values ​​Vd3* and Vq3*, and the corresponding third actual current value Id3 on the d-axis and third actual current value Iq3 on the q-axis are output from the current coordinate conversion unit 25. The resistance estimation unit 30 acquires the third actual current value Id3, which is the current value of the motor 21 that follows the third test current command value Id3*, from the current coordinate conversion unit 25 (S206).

[0108] The resistance estimation unit 30 estimates the electrical resistance value R^ from equation (8) based on the information acquired in S202, S204, and S206 (S207).

[0109] Fig. 7 is a diagram showing examples of test current command values ​​and test voltage command values. The upper part of Fig. 7 shows an example of the test current command value Id* of the d-axis generated by the current command unit 26. Note that the upper part of Fig. 7 also shows an example of the actual current value Id when the actual current value Id quickly follows the test current command value Id*. The lower part of Fig. 7 shows an example of the test voltage command value Vd* of the d-axis generated by the voltage command unit 27.

[0110] In the example shown in Fig. 7, the current command unit 26 outputs a pulse waveform as the test current command value Id* on the d axis. That is, of the three pulse outputs shown in the upper part of Fig. 7, the left pulse output corresponds to the first test current command value Id1*. The center pulse output corresponds to the second test current command value Id2*. The right pulse output corresponds to the third test current command value Id3*. The current command unit 26 intermittently generates pulse outputs of different magnitudes as the test current command value Id* on the d axis. The voltage command unit 27 outputs a pulse waveform as the test voltage command value Vd* on the d axis.

[0111] The width of each pulse output is set to be equal to or greater than the settling time. The settling time is the time required for the actual current value Id to follow and settle with respect to the current command value Id*. The settling time is determined by the design of the control gain of the current command unit 26. The settling time is set in advance.

[0112] 7 , the second test current command value Id2* is generated after the first test current command value Id1* is generated. Between the end of generation of the first test current command value Id1* and the start of generation of the second test current command value Id2*, there is a time during which the d-axis current command value Id* becomes 0. Furthermore, after the second test current command value Id2* is generated, the third test current command value Id3* is generated. Between the end of generation of the second test current command value Id2* and the start of generation of the third test current command value Id3*, there is a time during which the d-axis current command value Id* becomes 0.

[0113] Since the first test current command value Id1*, the second test current command value Id2*, and the third test current command value Id3* are generated in sequence, the first test voltage command value Vd1*, the second test voltage command value Vd2*, and the third test voltage command value Vd3* are also generated in sequence. Similarly, the first actual current value Id1, the second actual current value Id2, and the third actual current value Id3 are also detected in sequence.

[0114] It should be noted that as the actual current value Id on the d-axis increases, the amount of heat generated by the coil C increases. In the example shown in Fig. 7, the voltage applied to the motor 21 is pulsed, so that the amount of heat generated can be suppressed.

[0115] Fig. 8 is a diagram showing other examples of the test current command value and the test voltage command value. The upper part of Fig. 8 shows an example of the test current command value Id* of the d-axis generated by the current command unit 26. Note that the upper part of Fig. 8 also shows an example of the actual current value Id when the actual current value Id quickly follows the test current command value Id*. The lower part of Fig. 8 shows an example of the test voltage command value Vd* of the d-axis generated by the voltage command unit 27.

[0116] In the example shown in Fig. 8, the current command unit 26 outputs a ramp waveform as the test current command value Id* of the d axis. That is, the current command unit 26 outputs a test current command value Id* of the d axis that continuously increases from 0. The example shown in Fig. 8 can be applied when heat generation in the coil C is not an issue, when a delay in the response of the actual current value Id to the test current command value Id* is not an issue, and so on.

[0117] The method of generating the d-axis test current command value Id* is not limited to the examples shown in FIGS. 7 and 8.

[0118] As shown in equation (8), the electrical resistance value R^ is estimated by dividing the amount of change in the d-axis test voltage command value Vd* caused by the d-axis test current command value Id* by the amount of change in the current flowing through the motor 21 caused by the d-axis test current command value Id*. As an example, the amount of change in the test voltage command value can be calculated as the difference between the first test voltage command value Vd1* and the second test voltage command value Vd2*. The amount of change in the current can be calculated as the difference between the first actual current value Id1 and the second actual current value Id2.

[0119] 7 and 8, when three test current command values ​​Id*, i.e., the first test current command value Id1*, the second test current command value Id2*, and the third test current command value Id3*, are generated, it is possible to derive three values ​​as the resistance value R. That is, the following three resistance values ​​R can be calculated from equation (8): R=(Vd2*-Vd1*) / (Id2-Id1) R=(Vd3*-Vd2*) / (Id3-Id2) R=(Vd1*-Vd3*) / (Id1-Id3)

[0120] If multiple resistance values ​​R can be calculated, in S207, the resistance estimation unit 30 may estimate the average value of the calculated multiple resistance values ​​R as the electrical resistance value R. To achieve safer operation, in S207, the resistance estimation unit 30 may estimate the largest of the calculated multiple resistance values ​​R as the electrical resistance value R.

[0121] When calculating the electrical resistance value R^, filtering may be performed on the current and voltage. This makes it possible to suppress high-frequency noise contained in the current and voltage values, improving the accuracy of estimating the electrical resistance value R^. If filtering is performed, filtering must be performed with the same cutoff frequency. This is to ensure that the temporal correspondence between the current value and the voltage value is consistent. After filtering is performed and multiple resistance values ​​R are calculated, the average value of the calculated multiple resistance values ​​R may be estimated as the electrical resistance value R^.

[0122] 3, a process of correcting the electrical resistance value R^ estimated in S006 is started. The temperature estimation unit 31 corrects the electrical resistance value R^ estimated in S006 using the bus voltage value Vdc^ estimated in S002 (S007).

[0123] As shown in equation (7), by performing calculations using the voltage difference ΔV, the influence of additive error can be eliminated from the electrical resistance value R^ estimated by the resistance estimation unit 30. However, the influence of multiplicative error remains in the electrical resistance value R^ estimated by the resistance estimation unit 30. Therefore, when the temperature T of the coil C is calculated based on this electrical resistance value R^, the result includes an error due to the multiplicative error. The temperature estimation unit 31 suppresses this error by using the bus voltage value Vdc^ estimated in S002.

[0124] By substituting equation (5) into equation (8) and rearranging, equation (18) can be obtained.

[0125]

[0126] As shown in equation (18), the estimated electrical resistance value R^ has an error corresponding to the ratio between the design value Vdc* of the bus voltage and the actual bus voltage value Vdc. Using the bus voltage value Vdc^ in equation (17), equation (19) can be obtained. Equation (19) indicates that by performing correction using the bus voltage value Vdc^, the corrected value coincides with the true value of the resistance.

[0127]

[0128] The temperature estimation unit 31 corrects the electrical resistance value R^ estimated in S006 using equation (19).

[0129] Once the electrical resistance value R^ is corrected in S007, processing is started to estimate the temperature T of the coil C. The temperature estimation unit 31 estimates the temperature T of the coil C using the electrical resistance value R^ corrected in S007 (S008).

[0130] As an example, the temperature estimation unit 31 estimates the temperature T based on a temperature formula model that indicates the relationship between the electrical resistance value of the motor 21 and the temperature of the coil C. The temperature formula model is stored in advance in a storage area of ​​the control device 20. The temperature formula model may be created by a test that measures the resistance value of the motor 21 while changing the temperature of the coil C. A theoretically derived model may also be used as the temperature formula model. Equation (20) shows an example of the temperature formula model.

[0131]

[0132] Equation (20) shows an example of a model in which there is a linear relationship between the temperature T of the coil C and the resistance value R of the motor 21. α and β are constants. α and β are set in advance. Equation (21) shows another example of the temperature mathematical model.

[0133]

[0134] Equation (21) is a logical model of the temperature T of the coil C. T0' is the reference temperature. R0 is the reference resistance value of the coil C at the reference temperature. Note that the temperature mathematical model may be expressed by an equation other than equations (20) and (21). For example, the temperature mathematical model may be a function of higher order than first order.

[0135] Fig. 9 is a flowchart showing another example of the operation of the control device 20. Fig. 9 shows another example of the temperature estimation process. Specifically, Fig. 9 shows an example in which the voltage estimation process is performed when the door 13 is closing. Fig. 9 also shows an example in which the resistance estimation process is performed when the car 2 is traveling. Note that matters not described in detail below are the same as those in the above-mentioned example.

[0136] The control device 20 determines whether the door 13 has started closing (S301). When the state of the door 13 detected by the door state detection unit 24 changes from a fully open state to a closing state, a Yes determination is made in S301. When a Yes determination is made in S301, a voltage estimation process is started (S302). The voltage estimation process performed in S302 is the same as the voltage estimation process performed in S002. In the voltage estimation process, the voltage estimation unit 33 estimates the bus voltage value Vdc^.

[0137] Furthermore, if S301 returns Yes, it is determined whether the door 13 is fully closed (S303). If the door state detection unit 24 detects that the door 13 is fully closed after S301 returns Yes, S303 returns Yes. The voltage estimation process continues until S303 returns Yes. If S303 returns Yes, the voltage estimation process ends.

[0138] If the determination in S303 is Yes, the control device 20 determines whether or not the car 2 is traveling (S304). As an example, the control device 20 acquires information for determining whether or not the car 2 is traveling from the control panel 10. The determination in S304 is made based on this information. As another example, the current command unit 26 may make the determination in S304.

[0139] When car 2 starts traveling after S303 is determined as Yes, S304 is determined as Yes. When S304 is determined as Yes, resistance estimation processing is started (S305). While car 2 is traveling, the control device 20 performs control to maintain the door 13 in a fully closed state. In the example shown in FIG. 9, resistance estimation processing is performed during this time. If S303 is not determined as Yes, resistance estimation processing is not started. Note that the processing shown in S305 to S309 in FIG. 9 is the same as the processing shown in S004 to S008 in FIG. 3.

[0140] Next, the overheat protection process will be described with reference to Fig. 10. Fig. 10 is a flowchart showing another example of the operation of the control device 20. Fig. 10 shows an example of the overheat protection process that is performed after the temperature T of the coil C is estimated in the temperature estimation process. The overheat protection process is a process for preventing an accident such as the motor 21 burning out due to an increase in the temperature T of the coil C.

[0141] The following examples are possible causes of the temperature T of the coil C rising.

[0142] For example, the temperature T of the coil C may rise due to an abnormality occurring in the body of the motor 21. Specifically, the temperature T rises when the bearings of the motor 21 are worn out, when the motor 21 is nearing the end of its life, etc.

[0143] As another example, the temperature T of the coil C may rise when the door 13 is frequently opened and closed. Specifically, the temperature T rises when calls to the car 2 are made frequently, when the door 13 is frequently reversed, etc.

[0144] As another example, the temperature T of the coil C may rise due to a malfunction of the door 13. For example, when a malfunction occurs in the mechanical system of the door 13, the movement resistance of the door 13 increases. When the movement resistance of the door 13 increases, the rotation load of the motor 21 increases. This causes the temperature T of the coil C to rise.

[0145] As another example, the temperature T of the coil C may rise when the environmental temperature, i.e., the temperature in the hoistway 4, is high.

[0146] When the temperature T of the coil C is rising, the amount of heat generated by the motor 21 becomes larger than normal. If the motor 21 continues to be driven in this state, there is a possibility that the motor 21 will burn out.

[0147] As described above, the overheat protection process is a process for preventing an accident such as burning out of the motor 21, and is performed following the temperature estimation process. Therefore, when the overheat protection process is started, the door 13 is either fully open or fully closed.

[0148] The protection control unit 32 acquires the temperature T estimated by the temperature estimation process (S401). Next, the protection control unit 32 determines whether the temperature T estimated by the temperature estimation unit 31 is equal to or greater than a third reference value (S402). The third reference value is a value for determining whether the temperature of the coil C has risen to a temperature that may lead to burnout of the motor 21. The third reference value is set in advance based on the thermal design of the coil C, etc.

[0149] If the temperature T is smaller than the third reference value, the determination in S402 is No. If the determination in S402 is No, the drive control of the motor 21 continues (S403). For example, the voltage command unit 27 generates voltage command values ​​Vd* and Vq* based on the current command values ​​Id* and Iq* from the current command unit 26 and the actual current values ​​Id and Iq from the current coordinate conversion unit 25. That is, the elevator system 1 continues normal operation.

[0150] If the temperature T is equal to or greater than the third reference value, a Yes determination is made in S402. If a Yes determination is made in S402, the voltage command unit 27 stops the drive control of the motor 21 as protective control (S404). The voltage command unit 27 also transmits information to the control panel 10 indicating that the temperature T of the coil C is equal to or greater than the third reference value. Upon receiving this information, the control panel 10 starts control to bring the car 2 to an emergency stop.

[0151] When the drive control of the motor 21 is stopped, the door 13 cannot be opened or closed. Therefore, the drive control of the motor 21 may be stopped after control is performed to allow the passenger to exit the car 2. The control panel 10 may provide information to the passenger that the service will be stopped.

[0152] In the example shown in the present embodiment, the temperature estimation unit 31 corrects the electrical resistance value R^ estimated by the resistance estimation unit 30 using the bus voltage value Vdc^ estimated by the voltage estimation unit 33. Then, the temperature estimation unit 31 estimates the temperature T of the coil C based on the corrected electrical resistance value R^. Therefore, the temperature T of the coil C can be estimated with high accuracy.

[0153] In the example shown in the present embodiment, the voltage estimator 33 estimates the bus voltage value Vdc^ when the door 13 is in an operating state, the absolute value of the rotational angular velocity ω is equal to or greater than the first reference value Th1, and the absolute value of the current flowing through the motor 21 is equal to or less than the second reference value Th2. Therefore, the bus voltage value Vdc^ can be calculated with high accuracy using the simple equation (17).

[0154] In the example shown in this embodiment, the voltage estimator 33 estimates the bus voltage value Vdc^ using the q-axis voltage command value Vq* and the theoretically calculated q-axis voltage value ωφ. The voltage estimator 33 also estimates the bus voltage value Vdc^ using the ratio between the q-axis voltage command value Vq* and the theoretically calculated q-axis voltage value ωφ. Therefore, the bus voltage value Vdc^ can be calculated with high accuracy using the simple equation (17).

[0155] In the example shown in this embodiment, the current command unit 26 generates a first test current command value and a second test current command value. The voltage command unit 27 generates a first test voltage command value corresponding to the first test current command value and a second test voltage command value corresponding to the second test current command value. The resistance estimation unit 30 then estimates the electrical resistance value R^ using the first test voltage command value and the second test voltage command value. In this example, values ​​suitable for estimating the electrical resistance value R^ can be adopted as the first test voltage command value and the second test voltage command value. Therefore, the electrical resistance value R^ can be estimated with high accuracy.

[0156] The current command unit 26 may newly generate only one test current command value. In this case, the current command value generated immediately before the test current command value may be regarded as another test current command value, and the electric resistance value R^ may be generated.

[0157] In the example shown in this embodiment, the current command unit 26 generates a first test current command value and a second test current command value in which the d-axis current value is not 0. Even if the d-axis current value changes, it has almost no effect on the open / closed state of the door 13. Therefore, even if such test current command values ​​are used, the electrical resistance value R^ can be estimated with high accuracy.

[0158] In the example shown in Fig. 9, the resistance estimation process is performed while car 2 is traveling. That is, a test current command value is generated while car 2 is traveling. When the test current command value is generated, a d-axis current flows in motor 21, but when a d-axis current flows, noise due to magnetostriction may be generated from motor 21. In the example shown in Fig. 9, this noise can be drowned out by the running sound of car 2. Therefore, it is possible to prevent passengers in car 2 from feeling uncomfortable due to noise due to magnetostriction.

[0159] In the example shown in this embodiment, the temperature estimation unit 31 estimates the temperature T of the coil C based on a temperature mathematical model. Therefore, the temperature T can be estimated with high accuracy.

[0160] In the example shown in this embodiment, when the temperature T of the coil C estimated by the temperature estimator 31 becomes equal to or greater than the third reference value, drive control of the motor 21 is stopped. Therefore, it is possible to prevent the motor 21 from burning out, and the safety of the elevator system 1 can be improved.

[0161] Other functions that can be employed by the control device 20 will be described below. In the example shown below, only differences from the example described above will be described in detail. Explanations of the same points as the example described above will be omitted.

[0162] The voltage estimator 33 may estimate the bus voltage value Vdc^ based on a state estimation observer without using equation (17).

[0163] In this example, the voltage estimation unit 33 can also estimate the bus voltage value Vdc^ based on the operation flow shown in Fig. 4. That is, the voltage estimation unit 33 estimates the bus voltage value Vdc^ when the door state detection unit 24 detects that the door 13 is in an operating state. Furthermore, it is preferable that the voltage estimation unit 33 estimates the bus voltage value Vdc^ when the absolute value of the rotational angular velocity ω is equal to or greater than the first reference value Th1 and the absolute value of the current flowing through the motor 21 is equal to or less than the second reference value Th2.

[0164] As described above, the relationship between the applied voltage value Vd and the voltage command value Vd* is expressed by equation (9). The relationship between the applied voltage value Vq and the voltage command value Vq* is expressed by equation (10). Furthermore, in the voltage estimation process, the resistance value R and the inductance L are not used as parameters, i.e., the current value must be small. Under this condition, the voltage command value for the d axis is approximately 0, so only the q axis will be described below.

[0165] By substituting the bus voltage value Vdc in equation (10) with the estimated value Vdc^, equation (22) can be obtained for the estimated value Vq^ of the applied voltage.

[0166]

[0167] Equation (23) shows the difference between equations (10) and (22). If equation (23) becomes 0, the estimated value Vdc^ of the bus voltage and the actual bus voltage value Vdc will match.

[0168]

[0169] From equation (23), equation (24) can be obtained as an example of a state estimation observer for estimating the bus voltage value Vdc^. As described above, the actual q-axis applied voltage value Vq of the motor 21 can be expressed as ωφ under conditions where the current is small. Furthermore, the estimated applied voltage value Vq^ is as shown in equation (22).

[0170]

[0171] In S103, the voltage estimation unit 33 can estimate the bus voltage value Vdc^ based on the state estimation observer shown in equation (24) that uses the theoretically calculated q-axis voltage value ωφ and the q-axis voltage command value Vq*. In equation (24), K is a gain that determines the convergence speed of the state estimation observer; the larger K is, the shorter the time required for convergence, but if it is too large, oscillation occurs. Conversely, if it is small, the time required for convergence becomes longer, but the observer becomes stable. The gain K must be set appropriately by the designer, taking into account the convergence speed and stability.

[0172] 11 is a diagram illustrating an example of hardware resources of the control device 20. The control device 20 includes, as hardware resources, a processing circuit 40 including a processor 41 and a memory 42. The processing circuit 40 may include multiple processors 41. The processing circuit 40 may include multiple memories 42.

[0173] In this embodiment, the units denoted by reference numerals 24 to 33 indicate functions possessed by the control device 20. The functions of the units denoted by reference numerals 24 to 33 can be realized by software written as a program, firmware, or a combination of software and firmware. The program is stored in memory 42. The control device 20 realizes the functions of the units denoted by reference numerals 24 to 33 by executing the program stored in memory 42 using a processor 41 (computer).

[0174] The processor 41 is also called a CPU (Central Processing Unit), central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, or DSP. The memory 42 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.

[0175] FIG. 12 is a diagram illustrating another example of hardware resources of the control device 20. In the example illustrated in FIG. 12, the control device 20 includes a processing circuit 40 including a processor 41, a memory 42, and dedicated hardware 43. FIG. 12 illustrates an example in which some of the functions of the control device 20 are implemented by the dedicated hardware 43. All of the functions of the control device 20 may be implemented by the dedicated hardware 43. As an example, of the units indicated by reference numerals 24 to 33, only the current command unit 26 may be implemented by the dedicated hardware 43. In such a case, the units indicated by reference numerals 24, 25, and 27 to 33 are implemented by the processor 41 (computer) executing a program stored in the memory 42. The dedicated hardware 43 may be a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof.

[0176] The present disclosure is applicable to a control device that controls elevator doors.

[0177] REFERENCE SIGNS LIST 1 Elevator system, 2 Cage, 3 Counterweight, 4 Hoistway, 5 Building, 6 Landing, 7 Rope, 8 Hoisting machine, 9 Driving sheave, 10 Control panel, 11 Machine room, 12 Cage, 13 Door, 14 Door, 20 Control device, 21 Motor, 22 Rotation sensor, 23 Current sensor, 24 Door state detection unit, 25 Current coordinate conversion unit, 26 Current command unit, 27 Voltage command unit, 28 Voltage coordinate conversion unit, 29 Power conversion unit, 30 Resistance estimation unit, 31 Temperature estimation unit, 32 Protection control unit, 33 Voltage estimation unit, 34 Subtractor, 40 Processing circuit, 41 Processor, 42 Memory, 43 Dedicated hardware

Claims

1. a door state detection unit that detects the state of the elevator door; a voltage command unit that generates a voltage command value so that the value of a current flowing through a motor that drives the door follows a current command value; a voltage estimation unit that estimates a bus voltage value supplied to an inverter that drives the motor when the door state detection unit detects that the door is in an operating state; a resistance estimation unit that estimates an electrical resistance value of the motor when the door state detection unit detects that the door is in a fully open state or a fully closed state; a temperature estimation unit that estimates a temperature of a coil included in the motor by correcting the electrical resistance value estimated by the resistance estimation unit using the bus voltage value estimated by the voltage estimation unit; and A control device comprising:

2. 2. The control device according to claim 1, wherein the voltage estimation unit estimates the bus voltage value when the door state detection unit detects that the door is in an operating state, and when the absolute value of the rotational angular velocity of the motor is equal to or greater than a first reference value and the absolute value of the current flowing through the motor is equal to or less than a second reference value.

3. 3. The control device according to claim 1, wherein the voltage estimator estimates the bus voltage value using a theoretically calculated q-axis voltage value calculated based on a q-axis voltage equation of the motor and a q-axis voltage command value generated by the voltage commander.

4. 3. The control device according to claim 1, wherein the voltage estimator estimates the bus voltage value using a ratio between a theoretically calculated q-axis voltage value calculated based on a q-axis voltage equation of the motor and a q-axis voltage command value generated by the voltage commander.

5. 3. The control device according to claim 1, wherein the voltage estimator estimates the bus voltage value based on a state estimation observer that uses a theoretically calculated q-axis voltage value calculated based on a q-axis voltage equation of the motor and a q-axis voltage command value generated by the voltage commander.

6. 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 door state detection unit detects that the door is in a fully open state or a fully closed state; 3. The control device according to claim 1, wherein the resistance estimation unit estimates the electrical resistance value by dividing an amount of change in the voltage command value, which is changed in response to the test current command value, by an amount of change in the current flowing through the motor, which is changed in response to the test current command value.

7. the current command unit generates, as the test current command value, a first test current command value and a second test current command value, each of which has a d-axis current value that is not 0; The control device according to claim 6 , wherein the magnitude of the second test current command value is different from the magnitude of the first test current command value.

8. the voltage command unit generates a first test voltage command value corresponding to the first test current command value and a second test voltage command value corresponding to the second test current command value; 8. The control device according to claim 7, wherein the resistance estimation unit calculates, as the amount of change in the voltage command value, a difference between the first test voltage command value and the second test voltage command value, and calculates, as the amount of change in the current flowing through the motor, a difference between a current value of the motor that follows the first test current command value and a current value of the motor that follows the second test current command value.

9. 3. The 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 an electrical resistance value of the motor and a temperature of the coil.

10. 3. The control device according to claim 1, wherein the voltage command unit stops drive control of the motor when the temperature of the coil estimated by the temperature estimation unit is equal to or higher than a third reference value.