Elevator control method and elevator
By acquiring temperature data during elevator operation, determining lifespan loss data and target correction coefficients, and dynamically adjusting the carrier frequency of the inverter, the problem of balancing output capacity and noise control in elevator control is solved. This achieves a balance between inverter output capacity and elevator comfort, improving elevator operating performance and passenger comfort.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-17
- Publication Date
- 2026-06-19
AI Technical Summary
Existing elevator control technology struggles to balance the output capacity of frequency converters with noise control, resulting in a tradeoff between the output capacity of frequency converters and comfort during elevator operation.
By acquiring temperature data during elevator operation, lifespan reduction data and target correction coefficients are determined, and the carrier frequency of the inverter is dynamically adjusted to achieve a balance between inverter output capacity and noise.
While ensuring the lifespan of the frequency converter, a balance is achieved between the output capacity of the frequency converter and the comfort of the elevator, thereby improving the elevator's operating performance and passenger comfort.
Smart Images
Figure CN122233238A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of elevator control technology, and in particular to an elevator control method and an elevator. Background Technology
[0002] The frequency converter is a key component in the elevator control system. It achieves precise control of the elevator's running speed by adjusting the power supply frequency and voltage of the motor.
[0003] When an elevator is running, the frequency converter typically operates at a fixed carrier frequency or switches back and forth using a fixed carrier frequency pattern. However, the output capacity and noise control of the frequency converter are mutually exclusive. If a high-frequency carrier control is used, the noise decreases, but the output capacity of the frequency converter needs to be reduced, otherwise it will damage the frequency converter; if a low-frequency carrier control is used, the noise increases, affecting comfort.
[0004] Therefore, when controlling elevators with existing technology, the frequency converter is usually controlled to operate at a fixed carrier frequency or a fixed carrier frequency pattern, which makes it difficult to achieve a balance between the output capacity of the frequency converter and the noise. Consequently, a balance cannot be achieved between the output capacity of the frequency converter and the comfort of the elevator during operation. Summary of the Invention
[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide an elevator control method and an elevator, which achieves a balance between the output capacity and noise of the frequency converter by dynamically adjusting the carrier frequency of the frequency converter, thereby achieving a balance between the output capacity of the frequency converter and the comfort of the elevator during operation.
[0006] To solve the above problems, the present invention is implemented according to the following solution:
[0007] An elevator control method is provided, including:
[0008] Obtain the temperature dataset for each elevator operation;
[0009] Based on the temperature dataset, determine the lifespan reduction data for each elevator operation;
[0010] Based on the aforementioned lifespan loss data, determine the target correction factor;
[0011] The target carrier frequency is determined based on the temperature dataset and the target correction coefficient.
[0012] The frequency converter that controls the elevator operates at the target carrier frequency.
[0013] Compared with the prior art, the beneficial effects of the elevator control method of the present invention are as follows: by determining the life loss data based on the temperature dataset, and determining the target correction coefficient for adjusting the carrier frequency of the frequency converter based on the life loss data, the carrier frequency of the frequency converter can be dynamically adjusted according to the temperature of the frequency converter while ensuring the life of the frequency converter in the elevator, so as to achieve a balance between the output capacity and noise of the frequency converter, and thus achieve a balance between the output capacity of the frequency converter and the comfort of the elevator.
[0014] Optionally, the frequency converter includes a power module; the power module includes a target device;
[0015] The temperature dataset includes: module temperature, first temperature difference, and device temperature; the module temperature is the casing temperature of the power module; the first temperature difference is the temperature difference between the target device and the power module; and the device temperature is the operating temperature of the target device.
[0016] Optionally, obtaining the temperature dataset for each elevator run includes:
[0017] The module temperature is determined based on the thermistor value within the power module;
[0018] The first temperature difference is determined based on the device parameters of the target device;
[0019] The device temperature is determined based on the module temperature and the first temperature difference.
[0020] Optionally, the device parameters of the target device include: instantaneous power and thermal resistance coefficient;
[0021] The instantaneous power is the sum of the on-state loss, turn-on loss, and turn-off loss of the target device;
[0022] The thermal resistance coefficient is the ratio between the temperature difference across the target device and the power of the heat source.
[0023] Optionally, the temperature dataset includes a subset of the data from each elevator run;
[0024] The step of determining the lifespan reduction data of the elevator for each run based on the temperature dataset includes:
[0025] Based on the subset of data from each elevator run, determine the maximum and minimum component temperatures for each elevator run.
[0026] The second temperature difference is determined based on the maximum and minimum device temperatures.
[0027] Based on the second temperature difference, the lifespan reduction data of the target device during each elevator operation is determined.
[0028] Optionally, determining the lifespan reduction data of the target device during each elevator operation based on the second temperature difference includes:
[0029] Determine the target device model;
[0030] Based on the target device model, determine the lifespan degradation chart of the target device;
[0031] The lifespan loss data is determined based on the second temperature difference and the lifespan loss chart.
[0032] Optionally, determining the target correction factor based on the lifespan loss data includes:
[0033] Determine the number of times the elevator will run within the target time period;
[0034] The lifespan reduction data, the number of runs, and a preset threshold are compared to obtain a numerical relationship; the numerical relationship has a corresponding preset value.
[0035] The target correction coefficient is determined using the preset value corresponding to the numerical relationship.
[0036] Optionally, determining the target carrier frequency based on the temperature dataset and the target correction coefficient includes:
[0037] The target threshold is determined based on the target correction coefficient;
[0038] The target carrier frequency is determined based on the temperature dataset and the target threshold.
[0039] Optionally, the target threshold includes a first threshold and a second threshold;
[0040] Determining the target carrier frequency based on the temperature dataset and the target threshold includes:
[0041] Based on the module temperature in the temperature dataset and the first threshold, the current carrier frequency of the inverter is adjusted to obtain the target carrier frequency;
[0042] Based on the first temperature difference and the second threshold in the temperature dataset, the current carrier frequency of the frequency converter is adjusted to obtain the target carrier frequency.
[0043] An elevator is also provided, including a processor and a memory, wherein the memory stores at least one instruction, at least one program, code set, or instruction set, and the at least one instruction, at least one program, code set, or instruction set is loaded and executed by the processor to implement the elevator control method. Attached Figure Description
[0044] Figure 1 This is a flowchart of the elevator control method of the present invention;
[0045] Figure 2 This is a graph showing the lifespan degradation of the target device, the IGBT chip. Detailed Implementation
[0046] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.
[0047] In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims. In the description of this application, it should be understood that the terms "first," "second," "third," etc., are used only to distinguish similar objects and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0048] See Figure 1 As shown, this invention provides an elevator control method applied to a frequency converter for controlling an elevator. The frequency converter includes a power module, and the power module includes a target device, which is an IGBT chip. The elevator control method includes:
[0049] S1: Obtain the temperature dataset for each elevator operation. This temperature dataset includes the module temperature, the first temperature difference, and the device temperature. The module temperature is the casing temperature of the power module, the first temperature difference is the temperature difference between the target device IGBT chip and the power module, and the device temperature is the operating temperature of the target device IGBT chip. The device temperature is calculated from the module temperature and the first temperature difference using the following formula:
[0050] T j =T c +T jc
[0051] Among them, T j For device temperature, T c For module temperature, T jc This is the first temperature difference.
[0052] Obtain the temperature dataset for each elevator run, including:
[0053] First, the module temperature is determined by continuously monitoring the resistance value of the thermistor NTC inside the power module. The thermistor NTC can also be installed on a heatsink, but there will be a temperature difference compared to installing it inside the power module. Next, the first temperature difference is determined by the device parameters of the target device IGBT chip, including instantaneous power and thermal resistance coefficient. The formula for calculating the first temperature difference is as follows:
[0054] T jc =P igbt *R th
[0055] Among them, T jc For the first temperature difference, P igbt For instantaneous power, R th Where is the thermal resistance coefficient; instantaneous power is the sum of the conduction loss, turn-on loss, and turn-off loss of the target device IGBT chip. The formula for calculating instantaneous power is as follows:
[0056] P igbt =P ss +P on +P off
[0057] Among them, P igbt For instantaneous power, P ss P represents the conduction loss of the target device, the IGBT chip. on For the turn-on loss of the target device IGBT chip, P off The turn-off loss of the target device IGBT chip is given by P. The on-state loss of the target device IGBT chip is given by P. ss The turn-on loss P of the target device IGBT chip can be obtained by looking up a table based on the current. on and turn-off loss P off The calculation can be performed based on the real-time current and the inverter bus voltage. The calculation formula is as follows:
[0058] P on =E on *I*U
[0059] P off =E off *I*U
[0060] Among them, P on E represents the turn-on loss of the target device, the IGBT chip. on P represents the turn-on loss of the target device IGBT chip under unit current and voltage. off E represents the turn-off loss of the target device, the IGBT chip. off I represents the turn-off loss of the target device IGBT chip under unit current and voltage, where I is the real-time current and U is the inverter bus voltage.
[0061] The formula for calculating the thermal resistivity is as follows:
[0062]
[0063] Among them, R th R is the thermal resistance coefficient, t is the pulse width time of the PWM, and r is the pulse length time of the PWM. n τ n Depending on the IGBT chip, see Table 1 for the r values of a certain IGBT chip model. n τ n Examples of possible values.
[0064] Table 1
[0065]
[0066] The temperature dataset includes a subset of data from each elevator run, which includes the module temperature, the first temperature difference, and the device temperature for each elevator run.
[0067] S2: Based on the temperature dataset, determine the elevator's lifespan reduction data for each run, including:
[0068] Based on the subset of data from each elevator operation, the maximum and minimum device temperatures are determined for each elevator operation. Then, based on the maximum and minimum device temperatures, a second temperature difference is determined, which represents the fluctuation of the target device IGBT chip during each elevator operation. This fluctuation data is used to determine the lifespan reduction data of the target device IGBT chip during each elevator operation. Finally, based on the model of the target device IGBT chip, a lifespan reduction chart is determined, and the lifespan reduction data is determined based on the second temperature difference and the lifespan reduction chart.
[0069] The lifespan reduction chart includes a lifespan reduction data table and a lifespan reduction data graph. See Table 2, which shows the lifespan reduction of a certain type of target device IGBT chip. The greater the second temperature difference, the more severe the lifespan reduction of the target device IGBT chip. (See...) Figure 2 The figure shows the lifespan degradation diagram of a certain type of target device, the IGBT chip. This lifespan degradation diagram is a cycle life curve of the IGBT chip. Figure 2The system divides the region corresponding to the second temperature difference into multiple segments of linear relationships. By dividing the system into multiple segments of linear relationships, the lifespan reduction data of the target device IGBT chip can be quickly calculated based on the linear relationships corresponding to the region corresponding to the second temperature difference. This effectively reduces the amount of data that needs to be calculated and greatly improves the calculation speed. The horizontal axis represents the second temperature difference, and the vertical axis represents the number of switching cycles. The larger the number of switching cycles, the longer the lifespan of the target device IGBT chip. That is, the larger the second temperature difference, the smaller the number of switching cycles of the target device IGBT chip, and the more severe its lifespan reduction.
[0070] Table 2
[0071] <![CDATA[Second temperature difference ΔT jc > Lifespan loss data 100 60000 90 70000 80 100000 70 160000 60 250000 50 580000 40 3020000 38 4000000 35 8000000 30 32000000 25 120000000 20 800000000 10 2E+12
[0072] S3: Based on the lifespan reduction data, determine the target correction factor, including:
[0073] First, the correction coefficient is initialized, with an initial value of 0. Next, the number of elevator runs within the target time period is determined. In this invention, the target time period is defined as 15 minutes. Finally, the lifespan depreciation data, the number of runs, and the preset threshold are compared to obtain a numerical relationship. The numerical relationship has a corresponding preset value.
[0074] The target correction coefficient is determined by using preset values corresponding to the numerical relationship.
[0075] The target correction coefficient includes the module temperature correction coefficient and the first temperature difference correction coefficient; the preset threshold includes the number of times threshold and the lifespan loss threshold; in this invention, the number of times threshold is 3 times, which is an empirical value.
[0076] When the numerical relationship is: the number of times the elevator runs within the target time period (15 minutes) is less than the threshold, the current correction coefficient is updated to obtain the target correction coefficient. The preset values corresponding to this numerical relationship are as follows:
[0077] The current module temperature correction coefficient is updated to the maximum value of the module temperature correction coefficient, and the current first temperature difference correction coefficient is updated to the maximum value of the first temperature difference correction coefficient. That is, the target correction coefficient at this time includes the maximum value of the module temperature correction coefficient and the maximum value of the first temperature difference correction coefficient. By updating the current correction coefficient to its maximum achievable value, that is, by determining the maximum value of the correction coefficient as the target correction coefficient, the carrier frequency of the frequency converter can be adjusted to the maximum carrier frequency, so as to improve the response speed of the frequency converter, reduce noise, and improve the operating comfort of the elevator.
[0078] When the numerical relationship is: if the number of times the elevator runs within the target time period (15 minutes) is greater than the number of times threshold, the current correction coefficient will not be updated, and the current correction coefficient will be used as the target correction coefficient.
[0079] The total life loss data for a month is obtained by statistically analyzing the life loss data within that month; the life loss threshold includes an upper limit and a lower limit for life loss.
[0080] When the numerical relationship is: the total lifespan loss of the elevator within one month exceeds the upper limit of lifespan loss, the current correction coefficient is updated to obtain the target correction coefficient. The preset values corresponding to this numerical relationship are as follows:
[0081] The current module temperature correction coefficient is added to the module temperature correction step size to obtain the module temperature correction coefficient. The current first temperature difference correction coefficient is added to the first temperature difference correction step size to obtain the first temperature difference correction coefficient. That is, the target correction coefficient at this time is the sum of the current correction coefficient and the correction step size.
[0082] The target device, the IGBT chip, generates heat and mechanical stress during each switching process. These stresses accumulate with increasing switching frequency, leading to accelerated material fatigue and aging, ultimately affecting the chip's lifespan. When the inverter's carrier frequency decreases, the number of switching operations on the IGBT chip decreases, slowing the accumulation of thermal and mechanical stress, thus extending its lifespan and improving the elevator's stability and reliability. Therefore, while satisfying this numerical relationship, increasing the correction factor to reduce the inverter's carrier frequency can effectively extend its lifespan.
[0083] When the numerical relationship is: the total lifespan loss of the elevator within one month is less than the lower limit of lifespan loss, the current correction coefficient is updated to obtain the target correction coefficient. The preset values corresponding to this numerical relationship are as follows:
[0084] Subtract the current module temperature correction coefficient from the module temperature correction step size to obtain the module temperature correction coefficient. Subtract the current first temperature difference correction coefficient from the first temperature difference correction step size to obtain the first temperature difference correction coefficient. That is, the target correction coefficient at this time is the difference between the current correction coefficient and the correction step size.
[0085] When this numerical relationship is satisfied, it means that the target device IGBT chip has fewer switching cycles and a longer service life, but it will also lead to lower elevator operating comfort. Therefore, it is necessary to reduce the correction factor to increase the carrier frequency of the inverter, thereby reducing noise.
[0086] S4: Determine the target carrier frequency based on the temperature dataset and target correction coefficients, including:
[0087] First, the target threshold is determined based on the target correction coefficient. The target threshold includes a first threshold and a second threshold, and its expression is as follows:
[0088]
[0089] Among them, T c (th) is the first threshold, T c ′ represents the module temperature setpoint, a represents the module temperature correction factor, and T jc (th) is the second threshold, T jc ' is the first temperature difference setpoint, and b is the first temperature difference correction coefficient.
[0090] Next, the target carrier frequency is determined based on the temperature dataset and the target threshold, including:
[0091] Based on the module temperature and the first threshold in the temperature dataset, the current carrier frequency of the inverter is adjusted to obtain the target carrier frequency. Specifically, the module temperature T is monitored in real time. c Is it greater than the first threshold T? c (th), when T c >T c When (th), the current carrier frequency of the frequency converter is reduced by 1kHz to obtain the target carrier frequency; when T c <T c (th)-T cw At that time, the current carrier frequency of the frequency converter is increased by 1kHz to obtain the target carrier frequency; where T cw The set hysteresis module temperature value is used to prevent the carrier frequency from fluctuating.
[0092] Based on the first temperature difference and the second threshold in the temperature dataset, the current carrier frequency of the frequency converter is adjusted to obtain the target carrier frequency. Specifically, the change in the first temperature difference ΔT is detected in real time. jc Is it greater than the second threshold T? jc (th), when ΔT jc >T jc When (th), the current carrier frequency of the frequency converter is reduced by 1kHz to obtain the target carrier frequency; when ΔT jc <T jc (th)-T jcw At that time, the current carrier frequency of the frequency converter is increased by 1kHz to obtain the target carrier frequency; where T jcw The set hysteresis first temperature difference value is used to avoid fluctuations in the carrier frequency. The larger the elevator load, the greater the change in the first temperature difference ΔT. jc The larger the temperature difference, the greater the change; by monitoring the first temperature difference change ΔT jc Without needing to obtain the elevator's weighing data, the carrier frequency can be reduced as the elevator load increases, thus ensuring the reliable operation of the inverter under heavy load through direct temperature control. Furthermore, when the elevator is overloaded, the carrier frequency of the inverter is automatically reduced to achieve overpower output of the inverter.
[0093] S5: Controls the elevator's frequency converter to start at the target carrier frequency.
[0094] This invention determines the target correction coefficient by establishing numerical relationships and corresponding preset values, thereby dynamically adjusting the carrier frequency of the frequency converter. When the elevator operates at low frequencies (when the number of elevator runs within the target time period is less than the threshold), the current correction coefficient is updated to its maximum value, thereby adjusting the carrier frequency of the frequency converter to the maximum carrier frequency, improving the response speed of the frequency converter, reducing noise, and improving passenger comfort.
[0095] Furthermore, while ensuring the elevator's lifespan, if the total lifespan loss of the elevator within a month exceeds the preset upper limit, the lifespan loss of the IGBT chip can be reduced by decreasing the carrier frequency, thus extending its service life. Conversely, if the total lifespan loss is below the lower limit, the elevator's operating efficiency can be improved by increasing the carrier frequency, while ensuring that the lifespan loss of the IGBT chip remains within an acceptable range.
[0096] By dynamically adjusting the target correction coefficient, the carrier frequency of the frequency converter can be dynamically adjusted, thereby optimizing the elevator's operating performance while ensuring the lifespan of the IGBT chip, and achieving a balance between the frequency converter's output capacity and the elevator's comfort.
[0097] The present invention also provides an elevator, including a processor and a memory. The memory stores at least one instruction, at least one program, code set, or instruction set, and the at least one instruction, at least one program, code set, or instruction set is loaded and executed by the processor to implement the elevator control method described above.
[0098] The processor can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.
[0099] The memory can be used to store the programs or modules. The processor implements various functions of the elevator control method by running or executing the programs or modules stored in the memory and calling data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function, etc.; the data storage area may store data created based on the use of the mobile phone, etc. In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, RAM, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.
[0100] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. An elevator control method, characterized in that, include: Obtain the temperature dataset for each elevator operation; Based on the temperature dataset, determine the lifespan reduction data for each elevator operation; Based on the aforementioned lifespan loss data, determine the target correction factor; The target carrier frequency is determined based on the temperature dataset and the target correction coefficient. The frequency converter that controls the elevator operates at the target carrier frequency.
2. The elevator control method according to claim 1, characterized in that, The frequency converter includes a power module; the power module includes a target device; The temperature dataset includes: module temperature, first temperature difference, and device temperature; the module temperature is the casing temperature of the power module; the first temperature difference is the temperature difference between the target device and the power module; and the device temperature is the operating temperature of the target device.
3. The elevator control method according to claim 2, characterized in that, The process of obtaining the temperature dataset for each elevator run includes: The module temperature is determined based on the thermistor value within the power module; The first temperature difference is determined based on the device parameters of the target device; The device temperature is determined based on the module temperature and the first temperature difference.
4. The elevator control method according to claim 3, characterized in that, The device parameters of the target device include: instantaneous power and thermal resistance coefficient; The instantaneous power is the sum of the on-state loss, turn-on loss, and turn-off loss of the target device; The thermal resistance coefficient is the ratio between the temperature difference across the target device and the power of the heat source.
5. The elevator control method according to claim 2, characterized in that, The temperature dataset includes a subset of the dataset from each elevator run. The step of determining the lifespan reduction data of the elevator for each run based on the temperature dataset includes: Based on the subset of data from each elevator run, determine the maximum and minimum component temperatures for each elevator run. The second temperature difference is determined based on the maximum and minimum device temperatures. Based on the second temperature difference, the lifespan reduction data of the target device during each elevator operation is determined.
6. The elevator control method according to claim 5, characterized in that, The step of determining the lifespan reduction data of the target device during each elevator operation based on the second temperature difference includes: Determine the target device model; Based on the target device model, determine the lifespan degradation chart of the target device; The lifespan loss data is determined based on the second temperature difference and the lifespan loss chart.
7. The elevator control method according to claim 1, characterized in that, The step of determining the target correction factor based on the lifespan loss data includes: Determine the number of times the elevator will run within the target time period; The lifespan reduction data, the number of runs, and a preset threshold are compared to obtain a numerical relationship; the numerical relationship has a corresponding preset value. The target correction coefficient is determined using the preset value corresponding to the numerical relationship.
8. The elevator control method according to claim 2, characterized in that, The step of determining the target carrier frequency based on the temperature dataset and the target correction coefficient includes: The target threshold is determined based on the target correction coefficient; The target carrier frequency is determined based on the temperature dataset and the target threshold.
9. The elevator control method according to claim 8, characterized in that, The target threshold includes a first threshold and a second threshold; Determining the target carrier frequency based on the temperature dataset and the target threshold includes: Based on the module temperature in the temperature dataset and the first threshold, the current carrier frequency of the inverter is adjusted to obtain the target carrier frequency; Based on the first temperature difference and the second threshold in the temperature dataset, the current carrier frequency of the frequency converter is adjusted to obtain the target carrier frequency.
10. An elevator, characterized in that, The elevator includes a processor and a memory, the memory storing at least one instruction, at least one program, code set, or instruction set, the at least one instruction, at least one program, code set, or instruction set being loaded and executed by the processor to implement the elevator control method as described in any one of claims 1 to 9.