Auto-tuning apparatus and method for estimating the parameter of a motor with a load in a roping state in an elevator system
Patent Information
- Authority / Receiving Office
- KR · KR
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-02-05
- Publication Date
- 2026-08-12
Smart Images
Figure PAT00058_ABST
Abstract
Description
Technology Field
[0001] Embodiments of the present invention relate to an auto-tuning device and method for estimating the parameters of a hoisting machine with a load in a roping state in an elevator system. Background Technology
[0002] Generally, in an elevator system, the inverter controls the current of the motor to move the car cage to the destination floor, and for efficient control of the motor, accurate values of the motor parameters, namely the stator resistance (Rs), stator inductance (Ls), and back EMF constant (Ke), are required.
[0003] The elevator system consists of a car cage and a counterweight suspended from the hoist via ropes, and the weight difference between the car cage and the counterweight acts as a load on the hoist.
[0004] Conventionally, it was difficult to estimate the power of a hoisting machine with a load in a roping state, so there was the inconvenience of having to remove the rope and estimate the power of the hoisting machine when necessary. In this case, human and economic losses may occur in apartment complexes and large-scale sites where only the control panel for driving the elevator hoisting machine is replaced. The problem to be solved
[0005] The present invention aims to solve various problems, including the problems described above, by providing an auto-tuning device and method for estimating the parameters of a hoisting machine with a load in a roping state in an elevator system. However, these problems are exemplary and the scope of the present invention is not limited by them. means of solving the problem
[0006] According to one aspect of the present invention, an auto-tuning device for estimating the parameters of a hoisting machine in an elevator system is provided, comprising a control unit that drives an inverter to apply voltage to a hoisting machine with a load applied in a roping state, controls the target current of the hoisting machine to offset a voltage distortion component of the output voltage of the inverter and estimates the stator resistance of the hoisting machine according to Ohm's law, estimates the stator inductance of the hoisting machine using the d-axis voltage equation of the synchronous motor, estimates the back EMF constant of the hoisting machine by applying the voltage distortion component or offsetting the voltage distortion component while the hoisting machine is in operation using the q-axis voltage equation of the synchronous motor, and sequentially estimates the stator resistance, the stator inductance, and the back EMF constant.
[0007] The above control unit can offset the voltage distortion component, which is the difference between the actual output voltage value and the voltage command value of the inverter, by controlling the first target current and the second target current having different values of the above hoisting machine.
[0008] The control unit can estimate the stator resistance by dividing the difference between the first actual output voltage and the second actual output voltage of the inverter, corresponding to the first target current and the second target current respectively, by the difference between the first target current and the second target current.
[0009] The control unit can estimate the stator resistance using the first target current, which is 100% of the rated current of the hoist, and the second target current, which is 70% of the rated current of the hoist.
[0010] The control unit can estimate the stator inductance by dividing the magnitude of the d-axis stator voltage in the d-axis voltage equation by the magnitude of the product of the angular frequency of the d-axis stator voltage and the d-axis stator current.
[0011] The control unit can estimate the stator inductance using the magnitude of the d-axis stator voltage, which represents a value where the d-axis stator current is 50% of the rated current of the hoist.
[0012] The control unit can estimate the back EMF constant from the q-axis voltage equation by applying the voltage distortion component to the q-axis voltage command value applied to the inverter.
[0013] The control unit can estimate the back EMF constant by driving the hoist at two speeds, a first angular velocity and a second angular velocity, and using the difference between the first q-axis voltage and the second q-axis voltage of the q-axis voltage equation for the first angular velocity and the second angular velocity.
[0014] According to one aspect of the present invention, an auto-tuning method for estimating the parameters of a hoisting machine in an elevator system is provided, comprising the steps of: applying a voltage using an inverter to a hoisting machine that is loaded in a roping state; controlling the target current of the hoisting machine to offset a voltage distortion component of the output voltage of the inverter and estimating the stator resistance of the hoisting machine according to Ohm's law; estimating the stator inductance of the hoisting machine using the d-axis voltage equation of a synchronous motor; and estimating the back EMF constant of the hoisting machine by applying the voltage distortion component or offsetting the voltage distortion component while the hoisting machine is in operation using the q-axis voltage equation of a synchronous motor.
[0015] The step of estimating the stator resistance includes the step of offsetting the voltage distortion component, which is the difference between the actual output voltage value and the voltage command value of the inverter, by controlling a first target current and a second target current having different values of the hoisting machine, wherein the first target current is 100% of the rated current of the hoisting machine and the second target current is 70% of the rated current of the hoisting machine.
[0016] The step of estimating the back EMF constant may include driving the hoist at two speeds, a first angular velocity and a second angular velocity, and estimating the back EMF constant using the difference between the first q-axis voltage and the second q-axis voltage of the q-axis voltage equation for the first angular velocity and the second angular velocity.
[0017] According to one aspect of the present invention, a computer program stored in a recording medium is provided to execute the above-described method using a computer.
[0018] Other aspects, features, and advantages other than those described above will become clear from the following specific details, claims, and drawings for implementing the invention. Effects of the invention
[0019] According to one embodiment of the present invention as described above, an auto-tuning device and method can be implemented to effectively estimate the parameters of a hoisting machine without additional hardware in a hoisting machine with a load in a roping state in an elevator system.
[0020] Furthermore, according to the present invention, in apartment complexes and large-scale sites where only the control panel for driving the elevator hoist is replaced, the existing hoist can be used as is, and only the control panel for driving the hoist can be efficiently replaced, thereby reducing human and economic losses. Of course, the scope of the present invention is not limited by these effects. Brief explanation of the drawing
[0021] FIGS. 1 and FIGS. 2 are drawings for explaining the configuration and operation of an elevator system according to an embodiment of the present invention. FIG. 3 is a flowchart showing an auto-tuning method according to one embodiment of the present invention. FIG. 4 is a current control block diagram of a hoisting machine according to one embodiment of the present invention. FIGS. 5A and FIGS. 5B are drawings showing the results of estimating stator resistance according to one embodiment of the present invention. FIGS. 6a and FIGS. 6b are drawings showing the results of estimating the stator inductance according to one embodiment of the present invention. FIGS. 7a to 7c are drawings showing the results of estimating the back EMF constant according to one embodiment of the present invention. FIGS. 8a to 8c are drawings showing the results of estimating the back EMF constant according to another embodiment of the present invention. Specific details for implementing the invention
[0022] The present invention is capable of various modifications and may have various embodiments; specific embodiments are illustrated in the drawings and described in detail in the detailed description. The effects and features of the present invention, and the methods for achieving them, will become clear by referring to the embodiments described below in detail together with the drawings. However, the present invention is not limited to the embodiments disclosed below but can be implemented in various forms.
[0023] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. When describing with reference to the drawings, identical or corresponding components are given the same reference numerals, and redundant descriptions thereof will be omitted.
[0024] In the following embodiments, terms such as "first," "second," etc. are used not in a limiting sense, but for the purpose of distinguishing one component from another. Also, singular expressions include plural expressions unless the context clearly indicates otherwise. Furthermore, terms such as "include" or "have" mean that the feature or component described in the specification exists, and do not exclude the possibility that one or more other features or components may be added.
[0025] In the drawings, the size of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, so the present invention is not necessarily limited to what is illustrated.
[0026] In the following embodiments, when a part such as a region, component, section, block, or module is described as being on or above another part, it includes not only cases where it is directly on top of the other part, but also cases where another region, component, section, block, or module is interposed therein. Furthermore, when a region, component, section, block, or module is described as being connected, it includes not only cases where the region, component, section, block, or module is directly connected, but also cases where other regions, components, sections, blocks, or modules are interposed therein to indirectly connect them.
[0027] Hereinafter, in order to enable a person skilled in the art to easily practice the present invention, various embodiments of the present invention will be described in detail with reference to the attached drawings.
[0028] FIGS. 1 and FIGS. 2 are drawings for explaining the configuration and operation of an elevator system according to an embodiment of the present invention.
[0029] Referring to FIG. 1, an auto-tuning device according to one embodiment of the present invention may include a control unit (100). For example, as shown in FIG. 1, an auto-tuning device according to one embodiment of the present invention may include a control unit (100) that is provided in an elevator system and controls an inverter (50). However, the present invention is not limited thereto, and the auto-tuning device may include other components, or some components may be omitted. Some components of the auto-tuning device may be separated into a plurality of devices, or a plurality of components may be merged into a single device.
[0030] An auto-tuning device according to one embodiment of the present invention can estimate the number of hoisting machines (10) in an elevator system.
[0031] For example, as illustrated in FIG. 1, an elevator system according to one embodiment of the present invention has a car cage (40) and a counterweight (30) suspended from a hoist (10) via a rope (20), and the difference in weight between the car cage (40) and the counterweight (30) can act as a load on the hoist (10). For example, in FIG. 1, if the car cage (40) is heavier than the counterweight (30), a load acts on the lower right, and conversely, if the car cage (40) is lighter than the counterweight (30), a load acts on the lower left.
[0032] In order to move the car cage (40) to the destination floor in an elevator system, the hoist (10) must generate torque to handle the weight difference so that it does not slide to one side due to this weight difference. To this end, the inverter (50) inside the control panel controls the current to generate torque in the hoist (10), and this current is called the load current. The greater the weight difference between the car cage (40) and the counterweight (30), the greater the load, and the more load current is required for driving.
[0033] Generally, when there are no passengers or cargo in the car cage (40), the counterweight (30) is heavier than the car cage (40), and when there are no passengers or cargo, the weight difference can generally be designed to be about 50% of the elevator capacity (kg) to increase driving efficiency. When the weight of the car cage (40) and the counterweight (30) are the same, it is in a balanced state, and the current required for driving in a normal state is ideally 0.
[0034] Referring to FIG. 1 and FIG. 2 together, a control unit (100) according to one embodiment of the present invention may include a processor (110), a communication unit (120), a user interface unit (130), and a memory (140).
[0035] The processor (110) can control the overall operation of the control unit (100). For example, to perform the above-described operation, the processor (110) may be implemented in a form that optionally includes a processor, an ASIC (Application-Specific Integrated Circuit), other chipsets, logic circuits, registers, a communication modem, and / or a data processing device known in the art. For example, the processor (110) may perform basic arithmetic, logic, and input / output operations, and, for example, execute program code stored in memory.
[0036] The communication unit (120) may provide a function for communicating with an external device through a network. For example, a request generated by the processor (110) according to program code stored in a recording device such as memory (140) may be transmitted to an external device through a network under the control of the communication unit (120). Conversely, control signals, commands, content, files, etc. provided by an external device may be received by the processor (110) through the communication unit (120) via a network.
[0037] The communication method is not limited and may include not only communication methods utilizing communication networks that the network may include (e.g., mobile communication networks, wired internet, wireless internet, broadcasting networks), but also short-range wireless communication between devices. For example, the network may include any one or more networks such as a PAN (personal area network), LAN (local area network), CAN (campus area network), MAN (metropolitan area network), WAN (wide area network), BBN (broadband network), and the Internet. Additionally, the network may include any one or more network topologies such as a bus network, star network, ring network, mesh network, star-bus network, tree or hierarchical network, but is not limited thereto.
[0038] Additionally, the communication unit (120) can communicate with an external server via a network. The communication method is not limited, but the network may be a short-range wireless communication network. For example, the network may be a Bluetooth, BLE (Bluetooth Low Energy), or Wi-Fi network.
[0039] The user interface unit (130) may be a means for interfacing with an input / output device. For example, the input device may include a device such as a keyboard or a mouse, and the output device may include a device such as a display for displaying a communication session of an application. As another example, the user interface unit (130) may be a means for interfacing with a device in which the functions for input and output are integrated into one, such as a touchscreen. As a more specific example, a service screen or content configured using data provided by an external device may be displayed on a display through the user interface unit (130) when the processor (110) processes instructions of a computer program loaded in memory (140).
[0040] The memory (140) is a computer-readable recording medium and may include a non-perishable mass storage device such as RAM (random access memory), ROM (read only memory), and a disk drive. Additionally, program code for controlling an elevator system may be stored in the memory (140) temporarily or permanently.
[0041] The control unit (100) can drive an inverter that applies voltage to a hoisting machine with a load in a roping state.
[0042] The control unit (100) controls the target current of the hoisting machine to offset the voltage distortion component of the output voltage of the inverter and can estimate the stator resistance of the hoisting machine according to Ohm's law.
[0043] The control unit (100) can estimate the stator inductance of the hoist using the d-axis voltage equation of the synchronous motor.
[0044] The control unit (100) can estimate the back EMF constant of the hoist by applying a voltage distortion component or canceling out a voltage distortion component while the hoist is in operation using the q-axis voltage equation of the synchronous motor.
[0045] The control unit (100) can sequentially estimate the stator resistance, stator inductance, and back EMF constant.
[0046] A control unit (100) according to one embodiment of the present invention can control a first target current and a second target current having different values of a hoisting machine to offset a voltage distortion component which is the difference between the actual output voltage value and the voltage command value of the inverter.
[0047] A control unit (100) according to one embodiment of the present invention can estimate the stator resistance of a hoisting machine by dividing the difference between the first actual output voltage and the second actual output voltage of an inverter corresponding to the first target current and the second target current, respectively, by the difference between the first target current and the second target current.
[0048] A control unit (100) according to one embodiment of the present invention can estimate the stator resistance of a hoist using a first target current which is 100% of the rated current of the hoist and a second target current which is 70% of the rated current of the hoist.
[0049] A control unit (100) according to one embodiment of the present invention can estimate the stator inductance of a hoisting machine by dividing the magnitude of the d-axis stator voltage in the d-axis voltage equation by the magnitude of the product of the angular frequency of the d-axis stator voltage and the d-axis stator current.
[0050] A control unit (100) according to one embodiment of the present invention can estimate the stator inductance of a hoist using the magnitude of a d-axis stator voltage that represents a value where the d-axis stator current is 50% of the rated current of the hoist.
[0051] A control unit (100) according to one embodiment of the present invention can estimate the back EMF constant of a hoisting machine from a q-axis voltage equation by applying a voltage distortion component to a q-axis voltage command value applied to an inverter.
[0052] A control unit (100) according to one embodiment of the present invention can estimate the back EMF constant of a hoisting machine by driving the hoisting machine at two speeds, a first angular velocity and a second angular velocity, and using the difference between the first q-axis voltage and the second q-axis voltage of the q-axis voltage equation for the first angular velocity and the second angular velocity.
[0053] The specific operation of the control unit (100) below will be explained with reference to the flowchart of the auto-tuning method of FIG. 3.
[0054] FIG. 3 is a flowchart showing an auto-tuning method for estimating the parameters of a hoisting machine in an elevator system according to one embodiment of the present invention.
[0055] Referring to FIG. 3, in step S110, an auto-tuning device according to one embodiment of the present invention can apply voltage to a hoisting machine loaded in a roping state using an inverter.
[0056] In step S120, the auto-tuning device according to one embodiment of the present invention controls the target current of the hoist to offset the voltage distortion component of the output voltage of the inverter and can estimate the stator resistance of the hoist according to Ohm's law.
[0057] An auto-tuning device according to one embodiment of the present invention can offset a voltage distortion component, which is the difference between the actual output voltage value and the voltage command value of an inverter, by controlling a first target current and a second target current having different values of a hoisting machine. For example, the first target current may be 100% of the rated current of the hoisting machine, and the second target current may be 70% of the rated current of the hoisting machine.
[0058] In step S130, an auto-tuning device according to one embodiment of the present invention can estimate the stator inductance of a hoisting machine using the d-axis voltage equation of a synchronous motor.
[0059] In step S140, the auto-tuning device according to one embodiment of the present invention can estimate the back EMF constant of the hoist by applying a voltage distortion component or canceling out a voltage distortion component while the hoist is in operation using the q-axis voltage equation of the synchronous motor.
[0060] An auto-tuning device according to one embodiment of the present invention can drive a hoist at two speeds, a first angular velocity and a second angular velocity. In addition, an auto-tuning device according to one embodiment of the present invention can estimate a back EMF constant by using the difference between the first q-axis voltage and the second q-axis voltage of the q-axis voltage equation for the first angular velocity and the second angular velocity.
[0061] A procedure for estimating numerical values according to one embodiment of the present invention may be performed in the order of estimating the stator resistance (Rs) of the hoisting machine, estimating the stator inductance (Ls), and estimating the back EMF constant (Ke).
[0062] First, a method for estimating the stator resistance (Rs) value of a hoist according to one embodiment of the present invention is as follows.
[0063] In the present invention, a process of flowing a target current through the windings of a three-phase hoisting machine using a three-phase inverter is required, and to calculate the resistance value, it is based on Ohm's law, which divides the voltage by the current as shown in Equation 1 below.
[0064] (Formula 1)
[0065]
[0066] Here, R is resistance, V is voltage, and I is current.
[0067] However, the output voltage of a three-phase inverter is distorted due to non-ideal characteristics such as dead time and dv / dt. Due to this distorted voltage, the resistance value in Equation 1 may differ significantly from the actual resistance value.
[0068] In the present invention, to reduce the error in the estimated value of stator resistance (Rs) caused by such distorted voltage, a method is used to offset the distorted voltage by flowing two target currents through the hoist.
[0069] In order to supply the target current to the hoisting machine in the inverter, a current controller is used as shown in Fig. 4, and a PI (Proportional-Integral) type controller is mainly used as the current controller, and it can be implemented as a program through the control unit that drives the inverter.
[0070] Here, I * is the current command (target value), V * represents the voltage command, d represents the disturbance, and G(s) represents the hoisting machine; in the present invention, it is assumed that there is no disturbance.
[0071] Current command I * When this is input, the PI controller, implemented as a program algorithm that receives feedback of the actual current I through the current sensor and makes the actual current I the value of the current command, the voltage command V * It outputs. The inverter outputs this voltage command V * It generates a voltage V to output and controls the current by applying voltage to the hoist.
[0072] V * Assuming =V, the stator resistance (Rs) value can be calculated as follows.
[0073] (Equation 2)
[0074]
[0075] Here, R s is the stator resistance, V *is the voltage command, and I can represent the actual current.
[0076] However, the inverter's output voltage experiences distortion due to non-ideal characteristics such as dead time, dv / dt, and reverse voltage recovery, and the actual output voltage V is the voltage command V * It may differ from, that is, V * V, and in this case, the resistance value obtained from Equation 2 may differ from the actual resistance value. In this case, the relationship between the voltage command and the actual voltage can be briefly expressed as follows.
[0077] (Equation 3)
[0078]
[0079] Here, V dist is a voltage distortion component caused by dead time, dv / dv, etc., and has an almost constant value regardless of the magnitude of the voltage command.
[0080] Meanwhile, since the current flowing through the resistor is proportional to the voltage, the resistance value can be expressed as a voltage fluctuation and a current fluctuation as shown in Equation 4 below.
[0081] (Equation 4)
[0082]
[0083] Here, I1 and I2 are currents that flow when voltages V1 and V2 are applied to the resistors, respectively, and can be obtained from the current sensor.
[0084] In the present invention, the distorted component V of the three-phase inverter output voltage dist To offset this, the current is controlled with two target currents, and the actual resistance value and the approximate resistance value can be obtained through the following Equation 5. In the present invention, the two current target values can be set to 70% and 100% of the rated current of the hoisting machine, respectively.
[0085] (Equation 5)
[0086]
[0087] Here, I 100%, I 70% are 100% and 70% of the rated current, respectively, and are respectively I 100%, I 70% It represents the voltage command required to supply. Through Equation 5, it can be seen that the stator resistance Rs can be accurately calculated even with a distorted voltage using the method of the present invention.
[0088] For example, referring to FIGS. 5a and 5b, a comparison of the results of the method of the present invention and a conventional method for determining the stator resistance Rs according to one embodiment of the present invention is shown. The current is controlled at 70% of the rated current for 0 to 1 second and at 100% of the rated current for 1 to 2 seconds, and the resistance obtained by the conventional method is labeled Rs est1, and the resistance obtained by the method according to the present invention is labeled Rs est2. Rs est1 obtained by the conventional method is approximately 0.71, and the value of Rs est2 obtained by the method according to the present invention is approximately 0.215, so it can be seen that the value obtained by the method according to the present invention is almost similar to the actual Rs value of the hoisting machine, which is 0.21.
[0089] The magnitude of the distorted voltage can be obtained as shown in the following Equation 6.
[0090] (Equation 6)
[0091]
[0093] A method for estimating the stator inductance (Ls) value of a hoist according to one embodiment of the present invention is as follows.
[0094] In the present invention, the d-axis stator voltage equation of a synchronous motor is used to estimate the stator inductance Ls value of a hoisting machine. The d-axis voltage equation of a synchronous motor is given by Equation 7 below.
[0095] (Equation 7)
[0096]
[0097] Here, ds is the d-axis stator, qs is the q-axis stator, d-axis stator current, is the q-axis stator current, represents the electrical rotational angular velocity of the hoisting machine.
[0098] In the present invention, when the hoisting machine stops, i.e. This is performed when is 0, and for this purpose, the hoisting machine is fixed by a brake. In this case, Equation 7 can be expressed as the following Equation 8.
[0099] (Equation 8)
[0100]
[0101] Here, Is It represents the angular frequency of the stator voltage, When it gets bigger go It can become larger, and if it is sufficiently large, that is In the case of d-axis stator voltage It can be expressed as shown in the following Equation 9.
[0102] (Equation 9)
[0103]
[0104] In the present invention, using the simplified d-axis voltage above, the stator inductance Ls of the hoist can be obtained with the following Equation 10.
[0105] (Equation 10)
[0106]
[0107] In the present invention It is selected as 3 to 4 times the rated angular frequency, and The size of can be selected as a value where the stator current becomes half of the rated current.
[0108] For example, referring to FIGS. 6a and 6b, the result of a method for calculating stator inductance Ls according to one embodiment of the present invention is illustrated. Up to 0 to 1 second The angular frequency can be set to 3 times the rated angular frequency, and to 4 times the rated angular frequency for 1 to 2 seconds. As shown in FIGS. 6a and 6b, the estimated stator inductance Ls is approximately 2.4 mH, which is nearly equal to the actual stator inductance of the hoist, which is 2.37 mH.
[0109] A method for estimating the value of the back EMF constant (Ke) of a hoist according to one embodiment of the present invention is as follows. For example, the present invention presents two methods for estimating the back EMF constant (Ke) of a hoist.
[0110] First, the method for estimating the value of the back EMF constant (Ke) of the hoisting machine using the estimated stator resistance (Rs) of the present invention is as follows.
[0111] The back EMF constant (Ke) of the hoisting machine is obtained using the d-axis and q-axis stator voltage equations of the synchronous motor in the following Equations 11 and 12.
[0112] (Equation 11)
[0113]
[0114] (Equation 12)
[0115]
[0116] In the case of a surface-mounted synchronous motor, the d-axis current is controlled to zero regardless of the load, and The current is a current that increases in proportion to the gravitational load acting on the hoist, and in the case of no load, the q-axis current when the hoist is driven is is 0, and when the elevator car is suspended from the hoisting machine via the rope, the q-axis current varies depending on the number of passengers due to the gravitational load; accordingly, the q-axis current It changes. That is, the q-axis current is the load current, and this current can be obtained from the current sensor. Meanwhile, =0, In the case of no load where =0, the magnitude of Vs obtained by the combination of the d-axis stator voltage and the q-axis stator voltage can be expressed as shown in the following Equation 13.
[0117] (Equation 13)
[0118]
[0119] From Equation 13, the value of the back EMF constant (Ke) of the hoist can be obtained as follows.
[0120] (Equation 14)
[0121]
[0122] (Equation 15)
[0123]
[0124] Here, , represent the d-axis stator voltage command and the q-axis stator voltage command, respectively. However, when a load is present, i.e. In the case of 0, the stator voltage Vs cannot be simplified as in Equation 13 above, and as a result, the back EMF constant Ke cannot be obtained from Equation 15.
[0125] In this invention, the distortion component of the inverter and the load condition are considered to accurately determine the value of the back EMF constant Ke of the hoist even when a load is present. To determine the value of the back EMF constant Ke of the hoist of this invention, Equation 12 is used as the basis, and the d-axis current in the steady state If we consider the case where α is 0 and rearrange it into an equation for the back EMF constant Ke, it can be expressed as Equation 16.
[0126] (Equation 16)
[0127]
[0128] However, q-axis command voltage Ke obtained from Equation 16 using may differ from the actual value due to output voltage distortion phenomena, similar to those described in Equation 3. Therefore, to obtain an accurate Ke, voltage distortion components must be considered, and in this invention, Ke can be obtained as follows by utilizing the voltage distortion component of Equation 6.
[0129] (Equation 17)
[0130]
[0131] FIGS. 7a to 7c illustrate the results of the method for estimating the back EMF constant Ke of the present invention. From FIGS. 7a to 7c, it can be seen that the Ke est value obtained by the method of the present invention is approximately equal to the back EMF constant of an actual hoisting machine, which is 0.56.
[0132] Next, the method for calculating the back EMF constant (Ke) of the hoist by canceling out the distorted voltage component through operation at two driving speeds is as follows.
[0133] In the present invention, the second method for determining the back EMF constant Ke of the hoisting machine involves two operating speeds to offset the distortion components of the synchronous motor's q-axis voltage equation and the inverter output voltage. r1, The back EMF constant Ke can be estimated by driving with r2.
[0134] In the q-axis voltage equation of Equation 12, the d-axis current is zero, and when the load (e.g., car load, gravity load) is constant in the steady state, the two operating speeds r1, The difference in the q-axis voltage equation of the synchronous motor with respect to r2 can be obtained as shown in the following Equation 18.
[0135] (Equation 18)
[0136]
[0137]
[0138] Here, , Each under the same load situation r1, This is the command voltage required for driving when operating at speed r2. Similar to the explanation of Equation 5 above, it can be seen that the distorted component is canceled out through the difference between the two voltages.
[0139] Using the above Equation 18, the back EMF constant (Ke) of the hoisting machine is estimated as follows in Equation 19.
[0140] (Equation 19)
[0141]
[0142] For example, referring to FIGS. 8a to 8c, the results of the method for estimating the back EMF constant Ke of the present invention are illustrated. It can be seen that the Ke est value obtained by the method of the present invention is approximately equal to the back EMF constant of an actual hoist, which is 0.56. Although this method requires two operating speeds, it can be implemented more simply than the first method for calculating the back EMF constant Ke. For example, the specifications of the hoist used in the experiment of the present invention may be Rated Power [kW] 13.8, Rated Current [Arms] 29.4, Rated Voltage [Vrms] 323, Rated Speed [rpm] 649, Rs [Ω] 0.21, Ls [mH] 2.37, and Ke 0.56.
[0143] The device and / or system described above may be implemented as a hardware component, a software component, and / or a combination of a hardware component and a software component. The device and component described in the embodiments may be implemented using one or more general-purpose or special-purpose computers, such as, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing unit may execute an operating system (OS) and one or more software applications executed on the operating system. Additionally, the processing unit may access, store, manipulate, process, and generate data in response to the execution of the software. For ease of understanding, the processing unit may be described as being used as a single unit, but those skilled in the art will understand that the processing unit may include multiple processing elements and / or multiple types of processing elements. For example, the processing unit may include multiple processors or one processor and one controller. Additionally, other processing configurations, such as parallel processors, are also possible.
[0144] Software may include computer programs, code, instructions, or a combination of one or more of these, and may configure a processing unit to operate as desired or command the processing unit independently or collectively. Software and / or data may be permanently or temporarily embodied in any type of machine, component, physical device, virtual equipment, computer storage medium or device, or transmitted signal wave so as to be interpreted by the processing unit or to provide instructions or data to the processing unit. Software may be distributed over networked computer systems and may be stored or executed in a distributed manner. Software and data may be stored on one or more computer-readable recording media.
[0145] The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc., either alone or in combination. The program instructions recorded on the medium may be those specifically designed and configured for the embodiment, or they may be those known and available to those skilled in the art of computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes; optical recording media such as CD-ROMs and DVDs; magneto-optical media such as floptical disks; and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, and flash memory. Examples of program instructions include machine code, such as that generated by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc. The hardware devices described above may be configured to operate as one or more software modules to perform the operation of the embodiment, and vice versa.
[0146] Although the embodiments have been described above with reference to limited examples and drawings, those skilled in the art can make various modifications and variations from the description above. For example, suitable results can be achieved even if the described techniques are performed in a different order than described, and / or the components of the described system, structure, device, circuit, etc. are combined or assembled in a form different from described, or replaced or substituted by other components or equivalents.
[0147] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims set forth below. Explanation of the symbols
[0148] 10: Kwon Sang-gi 20: Rope 30: Counterweight 40: Car Cage 50: Inverter 100: Control unit
Claims
Claim 1 An auto-tuning device for estimating the parameters of a hoisting machine in an elevator system, comprising: driving an inverter that applies voltage to a hoisting machine loaded in a roping state; controlling the target current of the hoisting machine to offset a voltage distortion component of the output voltage of the inverter and estimating the stator resistance of the hoisting machine according to Ohm's law; estimating the stator inductance of the hoisting machine using the d-axis voltage equation of a synchronous motor; estimating the back EMF constant of the hoisting machine by applying the voltage distortion component or offsetting the voltage distortion component while the hoisting machine is in operation using the q-axis voltage equation of a synchronous motor; and including a control unit that sequentially estimates the stator resistance, the stator inductance, and the back EMF constant. Claim 2 In claim 1, the control unit controls a first target current and a second target current having different values of the hoisting machine to offset the voltage distortion component, which is the difference between the actual output voltage value and the voltage command value of the inverter, in an auto-tuning device. Claim 3 In claim 2, the control unit estimates the stator resistance by dividing the difference between the first actual output voltage and the second actual output voltage of the inverter, corresponding to the first target current and the second target current respectively, by the difference between the first target current and the second target current. Claim 4 In claim 3, the control unit is an auto-tuning device that estimates the stator resistance using the first target current which is 100% of the rated current of the hoisting machine and the second target current which is 70% of the rated current of the hoisting machine. Claim 5 In claim 1, the control unit estimates the stator inductance by dividing the magnitude of the d-axis stator voltage in the d-axis voltage equation by the magnitude of the product of the angular frequency of the d-axis stator voltage and the d-axis stator current. Claim 6 In claim 5, the control unit is an auto-tuning device that estimates the stator inductance using the magnitude of the d-axis stator voltage, which represents a value where the d-axis stator current becomes 50% of the rated current of the hoisting machine. Claim 7 In claim 1, the control unit is an auto-tuning device that estimates the back EMF constant from the q-axis voltage equation by applying the voltage distortion component to the q-axis voltage command value applied to the inverter. Claim 8 An auto-tuning device according to claim 1, wherein the control unit drives the hoisting machine at two speeds, a first angular velocity and a second angular velocity, and estimates the back EMF constant using the difference between the first q-axis voltage and the second q-axis voltage of the q-axis voltage equation for the first angular velocity and the second angular velocity. Claim 9 An auto-tuning method for estimating the parameters of a hoisting machine in an elevator system, comprising: a step of applying voltage using an inverter to a hoisting machine that is loaded in a roping state; a step of controlling the target current of the hoisting machine to offset the voltage distortion component of the output voltage of the inverter and estimating the stator resistance of the hoisting machine according to Ohm's law; a step of estimating the stator inductance of the hoisting machine using the d-axis voltage equation of a synchronous motor; and a step of estimating the back EMF constant of the hoisting machine by applying the voltage distortion component or offsetting the voltage distortion component while the hoisting machine is in operation using the q-axis voltage equation of a synchronous motor. Claim 10 In claim 9, the step of estimating the stator resistance includes the step of offsetting the voltage distortion component, which is the difference between the actual output voltage value and the voltage command value of the inverter, by controlling a first target current and a second target current having different values of the hoisting machine, wherein the first target current is 100% of the rated current of the hoisting machine and the second target current is 70% of the rated current of the hoisting machine, an auto-tuning method. Claim 11 An auto-tuning method according to claim 9, wherein the step of estimating the back EMF constant comprises: driving the hoist at two speeds, a first angular velocity and a second angular velocity; and estimating the back EMF constant using the difference between the first q-axis voltage and the second q-axis voltage of the q-axis voltage equation for the first angular velocity and the second angular velocity. Claim 12 A computer program stored on a recording medium to execute the method of any one of claims 9 to 11 using a computing device.