Elevator energy storage system control method, elevator energy storage system and storage medium

Abstract

The invention relates to an elevator energy storage system control method, an elevator energy storage system and a storage medium, and is applied to the field of elevators, and the elevator energy storage system control method comprises the steps that a bus voltage signal of an elevator frequency converter is collected within a preset sampling period, and the bus voltage signal carries a plurality of bus sampling voltage values; and determining the fluctuation amplitude and the fluctuation frequency of the bus voltage signal fluctuation based on the plurality of bus sampling voltage values. According to the fluctuation amplitude and the fluctuation frequency, the charging and discharging process of the energy storage device to the elevator frequency converter bus is switched and controlled under a preset hysteresis control mechanism; according to the hysteresis control mechanism, a charging threshold value is set and used for controlling the energy storage device to be charged through an elevator frequency converter bus; and setting a discharge threshold value for controlling the energy storage device to discharge to the elevator frequency converter bus. By means of the elevator energy storage system, the problem that in the prior art, the system stability and the energy efficiency of the elevator energy storage system need to be improved in the charging and discharging process is solved.

Description

Technical Field

[0001] The present application relates to the field of elevators, and in particular, to an elevator energy storage system control method, an elevator energy storage system, and a storage medium. Background Art

[0002] With the acceleration of the urbanization process, elevators in high-rise buildings have become an indispensable vertical transportation tool. Among them, the energy consumption of elevators accounts for an important share of building energy efficiency, especially the problem of energy waste generated during the braking process of elevators is particularly prominent.

[0003] Although existing elevator energy storage systems can partially recover the braking energy during elevator operation, in the case of frequent voltage fluctuations, the charge and discharge judgment of traditional elevator energy storage systems is easily affected by power noise and voltage fluctuations. Power noise and voltage fluctuations will lead to a low accuracy rate of identifying the charge and discharge state of the elevator energy storage system, resulting in untimely charge and discharge, causing energy efficiency waste; and frequent switching of the charge and discharge state reduces the system stability and increases unnecessary power consumption. Therefore, the system stability and energy efficiency of the elevator energy storage system during the charge and discharge process need to be improved urgently.

[0004] In view of the problem that the system stability and energy efficiency of the elevator energy storage system during the charge and discharge process in the related art need to be improved, no effective solution has been proposed yet. Summary of the Invention

[0005] In this embodiment, an elevator energy storage system control method, an elevator energy storage system, and a storage medium are provided to solve the problem that the system stability and energy efficiency of the elevator energy storage system during the charge and discharge process in the related art need to be improved.

[0006] In a first aspect, in this embodiment, an elevator energy storage system control method is provided. The elevator energy storage system includes a voltage converter, an energy storage device connected to the voltage converter, and an elevator frequency converter; the method includes:

[0007] Collect the bus voltage signal of the elevator frequency converter at a preset sampling period, where the bus voltage signal carries a plurality of bus sampling voltage values;

[0008] Based on the plurality of bus sampling voltage values, determine the fluctuation amplitude and fluctuation intensity of the bus voltage signal fluctuation;

[0009] According to the fluctuation amplitude and the fluctuation intensity, switch and control the charge and discharge process of the energy storage device to the elevator frequency converter bus under a preset hysteresis control mechanism; the hysteresis control mechanism is: set a charging threshold for controlling the energy storage device to charge through the elevator frequency converter bus; set a discharging threshold for controlling the energy storage device to discharge to the elevator frequency converter bus.

[0010] In some of these embodiments, determining the fluctuation amplitude and fluctuation intensity of the bus voltage signal based on the multiple bus sampling voltage values includes:

[0011] Determining the voltage peak difference between the voltage peak and voltage valley among the multiple bus sampling voltage values, and determining the fluctuation amplitude of the bus voltage signal fluctuation according to the voltage peak difference;

[0012] Determining the voltage average value of the multiple bus sampling voltage values, and determining the fluctuation intensity of the bus voltage signal fluctuation according to the voltage average value.

[0013] In some of these embodiments, switching and controlling the charge and discharge process of the energy storage device to the elevator frequency converter bus under a preset hysteresis control mechanism according to the fluctuation amplitude and the fluctuation intensity includes:

[0014] Based on the comparison results of the voltage peak difference with the charge threshold and the discharge threshold, and the comparison results of the voltage average value with the charge threshold and the discharge threshold, switching and controlling the charge and discharge process of the energy storage device to the elevator frequency converter bus.

[0015] In some of these embodiments, the charge threshold includes a first charge threshold and a second charge threshold; the discharge threshold includes a first discharge threshold and a second discharge threshold; the first charge threshold is greater than the first discharge threshold; the second charge threshold is greater than the second discharge threshold;

[0016] The switching and controlling the charge and discharge process of the energy storage device to the elevator frequency converter bus based on the comparison results of the voltage peak difference with the charge threshold and the discharge threshold, and the comparison results of the voltage average value with the charge threshold and the discharge threshold includes:

[0017] When it is determined that the voltage peak difference is greater than the first charge threshold and the voltage average value is greater than the second charge threshold, controlling the energy storage device to receive the electric energy of the elevator frequency converter bus;

[0018] When it is determined that the voltage peak difference is not greater than the first discharge threshold and the voltage average value is not greater than the second discharge threshold, controlling the energy storage device to release electric energy to the elevator frequency converter bus.

[0019] In some of these embodiments, determining the voltage peak difference between the voltage peak and voltage valley among the multiple bus sampling voltage values includes:

[0020] Obtaining multiple bus sampling voltage values within a preset time range;

[0021] Traverse the multiple bus sampled voltage values to determine the voltage peak value greater than the first voltage value and the voltage valley value not greater than the second voltage value; the first voltage value includes other bus sampled voltage values among the multiple bus sampled voltage values except the voltage peak value, and the second voltage value includes other bus sampled voltage values among the multiple bus sampled voltage values except the voltage valley value;

[0022] Determine the voltage peak difference according to the voltage peak value and the voltage valley value.

[0023] In some embodiments, the determining the voltage average value of the multiple bus sampled voltage values includes:

[0024] Calculate the multiple squared values of the multiple bus sampled voltage values to obtain multiple voltage squared values;

[0025] Sum the multiple voltage squared values to obtain the sum of voltage squares;

[0026] According to the number of the multiple bus sampled voltage values, calculate the mean square value of the sum of voltage squares and calculate the square root of the mean square value to obtain the voltage average value.

[0027] In some embodiments, the method further includes:

[0028] Obtain the bus voltage signal under different elevator loads to obtain the bus voltage measurement value; the different elevator loads include elevator heavy load and elevator light load;

[0029] Determine the charging threshold and the discharging threshold according to the bus voltage measurement value.

[0030] In a second aspect, in the present embodiment, an elevator energy storage system is provided, and the system includes: a voltage converter, and an energy storage device and an elevator frequency converter connected to the voltage converter; the voltage converter is used for bidirectionally transmitting electric energy between the energy storage device and the bus of the elevator frequency converter; the voltage converter is configured to execute the elevator energy storage system control method according to any one of the first aspect.

[0031] In some embodiments, the voltage converter includes a controller and a memory, and a computer program is stored in the memory, and the controller is configured to run the computer program to execute the elevator energy storage system control method according to any one of the first aspect.

[0032] In a third aspect, in the present embodiment, a storage medium is provided, on which a computer program is stored, and when the program is executed by a processor, the elevator energy storage system control method according to the first aspect is implemented.

[0033] Compared with the related technologies, a control method for an elevator energy storage system, an elevator energy storage system, and a storage medium provided in this embodiment collect the bus sampling voltage values of multiple elevator inverters during a sampling period through a voltage converter respectively connected to an energy storage device and an elevator inverter, calculate the fluctuation amplitude and fluctuation intensity of the bus sampling voltage value, and combine a preset hysteresis control mechanism to control the charging and discharging process of the energy storage device, and then correspondingly start the charging mode or the discharging mode, so as to accurately judge the charging and discharging state of the energy storage device in the elevator according to the actual operation situation of the elevator, optimize the energy efficiency and system stability of the elevator energy storage system, solve the problem that the system stability and energy efficiency of the elevator energy storage system need to be improved during the charging and discharging process, and improve the energy efficiency management of the entire elevator energy storage system.

[0034] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more concise and understandable. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings described herein are used to provide a further understanding of the present application and form a part of the present application. The illustrative embodiments and descriptions thereof of the present application are used to explain the present application and do not constitute an improper limitation of the present application. In the drawings:

[0036] Figure 1 is a schematic structural diagram of an elevator energy storage system provided by an embodiment of the present application;

[0037] Figure 2 is a flowchart of a control method for an elevator energy storage system provided by an embodiment of the present application;

[0038] Figure 3 is a schematic diagram of a judgment method for switching the charging and discharging mode provided by an embodiment of the present application;

[0039] Figure 4 is a connection schematic diagram of a charging and discharging device provided by this specific embodiment;

[0040] Figure 5 is a module connection diagram of voltage detection provided by this specific embodiment.

[0041] BRIEF DESCRIPTION OF THE DRAWINGS: 100, elevator energy storage system; 10, energy storage device; 20, elevator inverter; 30, voltage converter; 31, controller; 32, memory. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] To understand the purpose, technical solution, and advantages of the present application more clearly, the present application will be described and explained below with reference to the drawings and embodiments.

[0043] Unless otherwise defined, technical terms or scientific terms involved in this application shall have the ordinary meanings understood by those with ordinary skills in the technical field to which this application belongs. In this application, words such as "a", "an", "one kind", "the", "these", etc. do not indicate a limitation in quantity, and they can be singular or plural. The terms "include", "comprise", "have" and any variations thereof involved in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product or device including a series of steps or modules (units) is not limited to the listed steps or modules (units), but may include unlisted steps or modules (units), or may include other steps or modules (units) inherent in these processes, methods, products or devices. The terms "connect", "be connected", "couple" and other similar words involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether directly or indirectly. The term "plurality" involved in this application means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, "A and / or B" may mean: A exists alone, A and B exist simultaneously, and B exists alone. Usually, the character " / " indicates that the objects associated before and after are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific order for the objects.

[0044] An elevator is a balanced system that generates electricity when the car is ascending empty or descending fully loaded, and the elevator energy storage system can be charged; when the car is descending empty or ascending fully loaded, it consumes electricity, and the elevator energy storage system can discharge. During the daily operation of the elevator, the elevator needs to start, stop, and change speed continuously, so it needs to continuously switch between the power generation mode and the power consumption mode. The continuous switching of the mode will cause frequent fluctuations in the bus voltage; in addition, at the application site of the elevator, there is often a lot of electrical noise in the power supply voltage of the elevator. Further, the elevator energy storage system in the prior art can partially recover the braking energy generated during the operation of the elevator. However, in the case of frequent voltage fluctuations, the judgment of the charge and discharge switching of the traditional energy storage system is easily affected by electrical noise and voltage fluctuations, resulting in a low accuracy rate of charge and discharge state recognition, untimely charge and discharge, and energy efficiency waste; and the frequent switching of the charge and discharge state reduces the system stability and increases unnecessary power consumption.

[0045] In this embodiment, an elevator energy storage system is provided, which relates to energy efficiency optimization technology. Figure 1 It is a schematic structural diagram of the elevator energy storage system provided by the embodiment of this application. Refer to Figure 1, the elevator energy storage system 100 includes: an energy storage device 10, an elevator frequency converter 20, and a voltage converter 30 respectively connected to the energy storage device 10 and the elevator frequency converter 20; the voltage converter 30 is used for bidirectional power transmission between the energy storage device 10 and the bus of the elevator frequency converter 20.

[0046] Furthermore, a controller 31 and a memory 32 are also provided in the voltage converter 30; wherein, in the voltage converter 30, the controller 31 controls the charge-discharge mode of the energy storage device 10 to the bus of the elevator frequency converter 20; a computer program is stored in the memory 32, and the controller 31 obtains the bus sampling voltage value of the elevator frequency converter 20 by running the computer program in the memory 32, and determines the bus voltage signal fluctuation condition during the operation of the elevator energy storage system 100 according to the bus sampling voltage value, and then combines a preset hysteresis control mechanism to switch and control the charge-discharge process of the energy storage device 10 to the bus of the elevator frequency converter 20 to execute the elevator energy storage system control method.

[0047] Furthermore, the elevator energy storage system control method executed by the voltage converter 30 specifically relates to an intelligent energy storage method based on the bus voltage signal fluctuation detection and hysteresis control mechanism of the elevator frequency converter 20. This method combines time-domain analysis methods, hysteresis control techniques, and bidirectional energy management solutions, can intelligently judge the charge-discharge state of the elevator, optimize the working efficiency of the elevator energy storage system, provide stable and efficient energy management during elevator operation, braking, and emergency power supply, improve elevator energy efficiency, and ensure the safety and reliability of the elevator in any operating state.

[0048] Among them, the controller 31 may include, but is not limited to, a processing device such as a microcontroller MCU or a field programmable gate array FPGA. Those of ordinary skill in the art can understand that Figure 1 the structure shown is only schematic and does not limit the structure of the above elevator energy storage system 100. For example, the elevator energy storage system 100 may further include more or fewer components than Figure 1 shown in the figure, or have the same as Figure 1The different configurations shown. The memory 32 can be used to store computer programs, for example, software programs and modules of application software, such as the computer program corresponding to the elevator energy storage system control method in this embodiment. The controller 31 executes various functional applications and data processing by running the computer program stored in the memory 32, that is, implements the above method. The memory 32 can include a high-speed random access memory, and can also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memories. In some instances, the memory 32 can further include a memory 32 that is remotely set relative to the controller 31, and these remote memories can be connected to the terminal through a network. Examples of the above network include but are not limited to the Internet, enterprise intranet, local area network, mobile communication network, and combinations thereof.

[0049] Based on the above elevator energy storage system, a control method for the elevator energy storage system is provided in this embodiment. The elevator energy storage system includes a voltage converter, and an energy storage device and an elevator frequency converter connected to the voltage converter; this method is applied to the voltage converter in the elevator energy storage system. The voltage converter determines whether the energy storage device in the elevator energy storage system needs to charge or discharge the bus of the elevator frequency converter based on the bus voltage signal fluctuations of the elevator frequency converter including voltage amplitude and ripple, combined with the hysteresis effect and the voltage control algorithm, so as to optimize the charge and discharge control of the elevator energy storage system and solve the problems of low charge and discharge identification efficiency or stability and energy efficiency problems caused by frequent switching.

[0050] Figure 2 is a flowchart of the elevator energy storage system control method provided by the embodiment of the present application. As Figure 2 shown, the elevator energy storage system control process includes the following steps:

[0051] Step S210, collect the bus voltage signal of the elevator frequency converter at a preset sampling period. The bus voltage signal carries multiple bus sampling voltage values.

[0052] Among them, during the operation of the elevator, a voltage sensor is set in the elevator energy storage system to collect the bus voltage signal of the elevator frequency converter including multiple bus sampling voltage values. The bus voltage signal can reflect the changes in the elevator operation state, such as starting, stopping, accelerating, decelerating, etc., and provide a basis for the charge and discharge control of the elevator energy storage system. Among them, the sampling period needs to be determined according to the dynamic characteristics of the elevator energy storage system and the response speed of the energy storage device. Generally, the shorter the preset sampling period, the faster the elevator energy storage system responds to the bus voltage signal fluctuations, but it will also increase the burden of calculation and data processing. The setting of the preset sampling period needs to be determined according to the actual operation conditions of the elevator energy storage system, and no specific limitation is made here.

[0053] Step S220: Determine the fluctuation amplitude and fluctuation intensity of the bus voltage signal based on multiple bus sampled voltage values.

[0054] Among them, when the elevator energy storage system acquires multiple bus sampled voltage values through a voltage sensor, the multiple bus sampled voltage values under a preset sampling period constitute a time series data set, and each bus sampled voltage value corresponds to a timestamp; two indicators, namely the fluctuation amplitude and the fluctuation intensity of the bus voltage signal fluctuation, are extracted from the multiple bus sampled voltage values. Among them, the fluctuation amplitude represents the maximum change amplitude of the voltage signal within a certain time period. The fluctuation amplitude reflects the voltage change during the operation of the elevator. The fluctuation intensity represents the overall fluctuation range of the bus voltage signal within a period of time and is used to evaluate the persistence of the bus voltage signal fluctuation. The fluctuation intensity reflects the power demand during the operation of the elevator.

[0055] Among them, during the operation of the elevator energy storage system, the fluctuation amplitude of the elevator frequency converter voltage fluctuation can be represented by the voltage peak difference, root mean square deviation, volatility, or amplitude spectral density in the multiple bus sampled voltage values. Here, the voltage peak difference is taken as an example; the fluctuation intensity of the voltage fluctuation can be represented by the voltage average value including the voltage effective value, standard deviation, volatility, kurtosis, coefficient of variation, etc. in the multiple bus sampled voltage values. Here, the voltage average value including the voltage effective value is taken as an example. Combining the voltage peak and the voltage average value in the bus sampled voltage values, the bus voltage conditions of the elevator frequency converter in different time periods are analyzed. It is also possible to represent the fluctuation amplitude by the volatility in the multiple bus sampled voltage values and represent the fluctuation intensity by the voltage standard deviation, and analyze the bus voltage conditions of the elevator frequency converter in different time periods by combining the volatility and the voltage standard deviation.

[0056] Furthermore, if the data volume of the bus sampled voltage values is too large, the bus sampled voltage values can be divided according to a time window smaller than the preset sampling period, and the fluctuation amplitude and fluctuation intensity of each time window are calculated respectively.

[0057] Step S230: Switch and control the charging and discharging process of the energy storage device to the elevator frequency converter bus under a preset hysteresis control mechanism; the hysteresis control mechanism is: set a charging threshold for controlling the energy storage device to charge through the elevator frequency converter bus; set a discharging threshold for controlling the energy storage device to discharge to the elevator frequency converter bus.

[0058] Among them, when the fluctuation amplitude and fluctuation intensity of the bus voltage signal fluctuation are calculated, combined with the charging threshold and discharging threshold set in the hysteresis control mechanism, judge the current charging or discharging demand of the elevator energy storage system, and then accurately control the charge and discharge mode control in the elevator energy storage system, which is beneficial to improving the stability of the elevator energy storage system.

[0059] Through the above steps, multiple bus sampling voltage values of elevator inverters are collected within a sampling period, the fluctuation amplitude and fluctuation intensity of the bus sampling voltage values are calculated, and in combination with the charging threshold and discharging threshold set in the preset hysteresis control mechanism, the charging and discharging processes of the switching energy storage device are controlled, and then the charging mode or discharging mode is correspondingly started to accurately judge the charging and discharging states of the energy storage device in the elevator and optimize the operating stability of the elevator energy storage system.

[0060] In some of these embodiments, based on multiple bus sampling voltage values, the fluctuation amplitude and fluctuation intensity of the bus voltage signal during the operation of the elevator energy storage system are determined, including: determining the voltage peak difference between the voltage peak value and the voltage valley value among multiple bus sampling voltage values, and determining the fluctuation amplitude of the bus voltage signal according to the voltage peak difference; determining the voltage average value of multiple bus sampling voltage values, and determining the fluctuation intensity of the bus voltage signal according to the voltage average value.

[0061] Among them, the voltage peak difference of the bus voltage can reflect the significant fluctuations during the elevator braking process, and the voltage average value of the bus voltage can reflect the power demand of the elevator in the operating state. Combining the two can accurately find the charge-discharge switching node in the elevator working process.

[0062] In some of these embodiments, according to the fluctuation amplitude and fluctuation intensity, the charging and discharging processes of the energy storage device to the elevator inverter bus are switched and controlled under the preset hysteresis control mechanism, including: based on the comparison results of the voltage peak difference with the charging threshold and the discharging threshold, and the comparison results of the voltage average value with the charging threshold and the discharging threshold, switching and controlling the charging and discharging processes of the energy storage device to the elevator inverter bus.

[0063] Among them, by respectively comparing the voltage peak difference and the voltage average value with the charging threshold and the discharging threshold in the preset hysteresis control mechanism, and then switching and controlling the charging and discharging modes of the energy storage device to the elevator inverter bus, the accuracy of judging the charging and discharging modes of the energy storage system is realized, and through the charging threshold and the discharging threshold in the hysteresis control mechanism, the frequent triggering of the charge-discharge mode switching due to small fluctuations is avoided, and the operating stability of the elevator energy storage system is further improved.

[0064] In some of these embodiments, the charging threshold includes a first charging threshold and a second charging threshold; the discharging threshold includes a first discharging threshold and a second discharging threshold; the first charging threshold is greater than the first discharging threshold; the second charging threshold is greater than the second discharging threshold.

[0065] Among them, no charge-discharge mode switching is triggered when the voltage peak difference and the voltage average value are between their respective charging thresholds and discharging thresholds.

[0066] Figure 3 It is a schematic diagram of the judgment method for charge-discharge mode switching provided by the embodiments of the present application. Refer toFigure 3 , based on the comparison results of the voltage peak difference with the charging threshold and the discharging threshold, and the comparison results of the average voltage with the charging threshold and the discharging threshold, the charging and discharging process of the energy storage device to the elevator frequency converter bus is switched, including steps S310 to S320.

[0067] Step S310, when it is determined that the voltage peak difference is greater than the first charging threshold and the average voltage is greater than the second charging threshold, control the energy storage device to receive the electric energy of the elevator frequency converter bus.

[0068] Step S320, when it is determined that the voltage peak difference is not greater than the first discharging threshold and the average voltage is not greater than the second discharging threshold, control the energy storage device to release electric energy to the elevator frequency converter bus.

[0069] Among them, when it is determined that the voltage peak difference is greater than the first charging threshold and the average voltage is greater than the second charging threshold, it indicates that the elevator is operating in the power generation mode at this time, and there is too much energy in the elevator frequency converter bus, and it is necessary to charge the energy storage device, that is, control the energy storage device to receive the electric energy of the elevator frequency converter. When it is determined that the voltage peak difference is not greater than the first discharging threshold and the average voltage is not greater than the second discharging threshold, it indicates that the elevator is operating in the power consumption mode at this time, and the elevator energy storage system should switch to the discharging mode to discharge to the elevator frequency converter bus to provide additional energy support.

[0070] In some of the embodiments, determining the voltage peak difference between the voltage peak and the voltage valley among multiple bus sampling voltage values includes: within a preset time range, obtaining multiple bus sampling voltage values; traversing the multiple bus sampling voltage values to determine the voltage peak greater than the first voltage value and the voltage valley not greater than the second voltage value; the first voltage value includes other bus sampling voltage values among the multiple bus sampling voltage values except the voltage peak, and the second voltage value includes other bus sampling voltage values among the multiple bus sampling voltage values except the voltage valley; determining the voltage peak difference according to the voltage peak and the voltage valley.

[0071] Among them, in this embodiment, taking the voltage peak difference as an example to represent the fluctuation amplitude of the bus voltage signal of the bus sampling voltage value of the elevator frequency converter, the amplitude of the bus voltage signal fluctuation is measured by calculating the difference between the maximum value and the minimum value of the bus sampling voltage value (i.e., the peak difference), so as to directly reflect the voltage change during the operation of the elevator, especially the significant fluctuation during the elevator braking process.

[0072] Exemplarily, within the time window of one acquisition cycle, such as within a time window of 100 ms or 200 ms, the maximum value and the minimum value of multiple bus sampling voltage values in the voltage signal are calculated in real time to obtain the peak difference.

[0073] In some of these embodiments, determining the voltage average value of a plurality of bus sampling voltage values includes: calculating a plurality of squared values of the plurality of bus sampling voltage values to obtain a plurality of voltage squared values; summing the plurality of voltage squared values to obtain a voltage sum of squares; calculating the mean square value of the voltage sum of squares according to the number of the plurality of bus sampling voltage values, and calculating the square root of the mean square value to obtain the voltage average value.

[0074] Wherein, in this embodiment, taking the voltage average value including the effective voltage as an example to represent the bus voltage signal fluctuation intensity of the bus sampling voltage value of the elevator frequency converter. Specifically, the continuous intensity of the bus voltage signal fluctuation of the bus sampling voltage value of the elevator frequency converter is represented by the root mean square value (RMS), which is applicable to capturing the power demand of the elevator in the running state.

[0075] Exemplarily, within the time window of one acquisition period, such as a time window of 100 ms or 200 ms, calculate the total squared value of each bus sampling voltage value, average the total squared value, and perform square root processing on the averaged total squared value to obtain the root mean square value of the bus sampling voltage value.

[0076] In some of these embodiments, the elevator energy storage system control method further includes: obtaining the bus voltage signal under different elevator loads to obtain a bus voltage measurement value; different elevator loads include elevator heavy load and elevator light load; determining a charging threshold and a discharging threshold according to the bus voltage measurement value.

[0077] Wherein, in the elevator energy storage system, the load of the elevator will directly affect the energy consumption demand of the motor and the operating state of the elevator frequency converter, thereby affecting the change of the bus voltage. When the elevator is in the heavy load running state, both the fluctuation amplitude and the fluctuation intensity of the bus voltage fluctuation are higher than those in the light load running state. Therefore, in order to accurately detect the charge and discharge states, the setting of the charging threshold and the discharging threshold needs to combine the light load (including no load) working condition and the heavy load (including full load) working condition. Specifically, by observing the measured value of the bus voltage of the actual frequency converter operation, set the charging threshold and the discharging threshold, so as to accurately realize the charge and discharge switching.

[0078] The following describes and illustrates this embodiment through specific examples.

[0079] In Figure 1 On the basis of the shown elevator energy storage system, by setting a bus voltage monitoring module of the elevator frequency converter, the bus voltage signal of the elevator frequency converter is collected in real time, and a plurality of bus voltage sampling values carried in the bus voltage signal are processed and analyzed.

[0080] In one specific embodiment, the fluctuation amplitude and intensity of the bus voltage signal are calculated through time-domain analysis method and RMS value method. Combining with a preset hysteresis control mechanism, the current charging or discharging demand of the elevator energy storage system is judged. When switching the charge and discharge modes, the threshold difference is increased to avoid frequent state switching due to the fluctuation of the bus voltage signal, thereby enhancing the system stability.

[0081] Specifically, the time-domain analysis method mainly sets a bus voltage monitoring module for the elevator frequency converter to collect the bus voltage signal of the elevator frequency converter in real time and obtain multiple bus voltage acquisition values carried in the bus voltage signal. Usually, multiple samplings are performed per second to ensure that the instantaneous voltage fluctuations can be captured. Within a time window (such as 100 ms or 200 ms), the maximum value (voltage peak value) and minimum value (voltage valley value) of the bus voltage acquisition values are calculated in real time. By calculating the difference between the maximum value and the minimum value of the voltage in the bus voltage signal, that is, the peak difference, the fluctuation amplitude of the bus voltage signal fluctuation is measured, which directly reflects the voltage change during the operation of the elevator energy storage system, especially the significant fluctuation during the elevator braking process.

[0082] The RMS value method mainly performs a square process on multiple bus voltage acquisition values carried in the bus voltage signal, that is, for each bus voltage acquisition value at the sampling point, a square calculation is performed to obtain the voltage square value. Then, the average of the voltage square values of all sampling points is calculated to obtain the mean square value (MSV, Mean Square Value), and the square root of the mean square value is taken to obtain the RMS value. The formula for the RMS value is as follows:

[0083] RMS(V)=sqrt(1 / N×Σ[V i 2 )

[0084] where N represents the number of sampling points of the bus voltage acquisition value, V i represents the voltage value at the sampling point, sqrt represents the square root operation, and Σ represents the summation operation.

[0085] The RMS value represents the average energy size of the voltage signal and is a quantization standard for the voltage change intensity. The RMS value method can reflect the continuous intensity of the bus voltage signal fluctuation and is applicable to capturing the power demand of the elevator in the operating state. The RMS value here is the voltage average value in the foregoing embodiment.

[0086] Furthermore, when the voltage peak difference and voltage average value corresponding to the bus voltage signal of the elevator frequency converter are monitored, to avoid the system frequently switching the charge and discharge states due to small fluctuations, the system adopts a hysteresis control mechanism to set two independent voltage thresholds, that is, the charging threshold and discharging threshold in the foregoing embodiment.

[0087] ​When it is determined that the fluctuation amplitude (peak difference) of the bus voltage signal is greater than the set first charging threshold (e.g., 30V), and when it is determined that the fluctuation intensity (RMS value) of the bus voltage signal is greater than the set second charging threshold (e.g., 600V), the charging mode is started.

[0088] When it is determined that the fluctuation amplitude (peak difference) of the bus voltage signal is less than the set first discharging threshold (e.g., 15V), and when it is determined that the fluctuation intensity (RMS value) of the bus voltage signal is less than the set second discharging threshold (e.g., 505V), the discharging mode is started.

[0089] The above-mentioned hysteresis control mechanism ensures that when the bus voltage signal fluctuates within a certain range, that is, when the voltage fluctuates between the charging threshold and the discharging threshold, namely the hysteresis threshold, the elevator energy storage system will not trigger the switching of the charging and discharging modes of the energy storage device. Only when the voltage exceeds the set hysteresis threshold, the energy storage device will switch from the charging state to the discharging state, or from the discharging state to the charging state.

[0090] By continuously monitoring the peak difference and the RMS value, when both of them exceed the set charging threshold, it can be determined that the elevator is feeding back energy and entering the charging state; when both of them are less than the set discharging threshold, the system believes that the elevator is consuming electrical energy and entering the discharging state.

[0091] In one specific embodiment, Figure 4 is a schematic diagram of the connection of the charging and discharging device provided in this specific embodiment. Refer to Figure 4 , in the elevator energy storage system, a bidirectional voltage converter, an energy storage unit including a super capacitor or a battery, and an elevator frequency converter are provided. The energy storage unit is connected to the elevator frequency converter through the bidirectional voltage converter. When the energy storage unit discharges, electrical energy flows into the bus of the elevator frequency converter through the bidirectional voltage converter, realizing the discharge of the energy storage unit to the bus of the elevator frequency converter; when the energy storage unit charges, electrical energy flows out from the bus of the elevator frequency converter through the bidirectional voltage converter, realizing the charging of the bus of the elevator frequency converter to the energy storage unit.

[0092] Among them, the bidirectional voltage converter is specifically a bidirectional DC-DC converter. This voltage converter can intelligently adjust the charging and discharging process of the energy storage unit in the energy storage device according to the real-time change of the bus voltage in the elevator frequency converter, ensuring efficient energy transmission. In the charging mode, this voltage converter feeds back electrical energy from the elevator frequency converter to the energy storage unit, and energy storage media such as lithium-ion capacitors are installed in the energy storage unit to realize the charging of the energy storage unit; in the discharging mode, this voltage converter transmits the energy of the energy storage unit to the elevator frequency converter to support the operation of the elevator.

[0093] When the elevator brakes, the bus voltage of the elevator frequency converter rises significantly. The bidirectional DC-DC converter switches to the charging mode to transfer the energy of the elevator frequency converter to the energy storage unit. When the elevator is running, if the bus voltage drops and the RMS value is small, the elevator energy storage system controls the energy storage unit to switch to the discharging mode to supply the stored electric energy to the elevator frequency converter through the energy storage unit to support the power demand of the elevator frequency converter.

[0094] Furthermore, a power management module is configured in the elevator energy storage system, a voltage monitoring threshold is set, and a hysteresis control mechanism is enabled to ensure that frequent charge and discharge switching does not occur within the range of the bus voltage signal fluctuation threshold.

[0095] Furthermore, the voltage converter dynamically adjusts the PWM (Pulse Width Modulation) frequency according to the elevator load demand, bus voltage, and energy storage unit voltage using PID (Proportional Integral Derivative) control to control the switching frequency and reduce the system power consumption. Among them, the load demand can be detected by the current detection module to detect the current value at one end of the voltage converter connected to the elevator frequency converter, and this current value reflects the elevator load demand; the energy storage unit voltage can be fed back to the current voltage value of the energy storage unit through the Battery Management System (BMS) or voltage detection module. The PID control module in the voltage converter dynamically adjusts the PWM frequency and duty cycle according to the error between the preset target voltage and the detected real-time voltage, thereby improving the power conversion efficiency.

[0096] The PID control formula is expressed as:

[0097] u(t) = Kp × e(t) + Ki × ∫e(t)dt + Kd × de(t) / dt

[0098] Among them, u(t) is the PID control output signal, e(t) is the error of the bus voltage, and Kp, Ki, and Kd are the proportional, integral, and differential gains of PID respectively. The control output signal u(t) is used to adjust the PWM frequency.

[0099] The PID control module adjusts the frequency according to the real-time voltage error: when the voltage error is large or the load is high, the PID control module increases the PWM frequency by adjusting Kp, Ki, and Kd to improve the voltage feedback efficiency; when the voltage error is small or the load is low, the PID control module reduces the PWM frequency by adjusting Kp, Ki, and Kd to reduce the switching loss and energy consumption.

[0100] Figure 5 It is the module connection diagram of the voltage detection provided by this specific embodiment. Refer to Figure 5, the voltage detection involves multiple modules to implement a charge and discharge control method, including an elevator frequency converter bus voltage detection module, a time domain analysis module, an RMS analysis module, a hysteresis control module, a bidirectional voltage converter module, an energy storage unit, and an elevator frequency converter. Among them, the elevator frequency converter bus voltage detection module is respectively connected to the time domain analysis module and the RMS analysis module. Combining with the preset hysteresis control mechanism in the hysteresis control module, according to the bidirectional voltage converter that is respectively bidirectionally connected to the energy storage unit and the elevator frequency converter, the elevator frequency converter bus voltage detection module detects the bus voltage of the elevator frequency converter, and through the time domain analysis method and the root mean square value method, combining with the hysteresis control mechanism, according to the bidirectional voltage converter, controls the charge and discharge mode of, for example, a lithium-ion capacitor in the energy storage unit to the elevator frequency converter.

[0101] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementation manners, and will not be elaborated in this embodiment.

[0102] In addition, in combination with the elevator energy storage system control method provided in the above embodiments, a storage medium can also be provided to implement in this embodiment. A computer program is stored on the storage medium; when the computer program is executed by a processor, any one of the elevator energy storage system control methods in the above embodiments is implemented.

[0103] It should be understood that the specific embodiments described here are only used to explain this application, rather than to limit it. According to the embodiments provided in this application, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the protection scope of this application.

[0104] Obviously, the drawings are only some examples or embodiments of this application. For those of ordinary skill in the art, this application can also be applied to other similar situations according to these drawings without creative work. In addition, it can be understood that although the work done during this development process may be complex and time-consuming, for those of ordinary skill in the art, some design, manufacturing, or production changes based on the technical content disclosed in this application are only conventional technical means and should not be regarded as insufficient disclosure of this application.

[0105] The term "embodiment" in this application means that the specific features, structures, or characteristics described in combination with the embodiment can be included in at least one embodiment of this application. The phrase appears in various positions in the specification does not necessarily mean the same embodiment, nor does it mean being independent or alternative to other embodiments and mutually exclusive. Those of ordinary skill in the art can clearly or implicitly understand that the embodiments described in this application can be combined with other embodiments without conflict.

[0106] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of patent protection. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A control method for an elevator energy storage system, characterized in that: The elevator energy storage system includes a voltage converter, an energy storage device connected to the voltage converter, and an elevator frequency converter; the method includes: Collecting a bus voltage signal of the elevator inverter at a preset sampling period, wherein the bus voltage signal carries a plurality of bus sampling voltage values; Based on the plurality of bus sampling voltage values, determining the fluctuation amplitude and fluctuation intensity of the bus voltage signal fluctuation; According to the fluctuation amplitude and the fluctuation intensity, the charging and discharging process of the energy storage device to the elevator inverter bus is switched and controlled under a preset hysteresis control mechanism; the hysteresis control mechanism is: setting a charging threshold value for controlling the energy storage device to charge through the elevator inverter bus; setting a discharging threshold value for controlling the energy storage device to discharge to the elevator inverter bus.

2. The elevator energy storage system control method according to claim 1, characterized in that: The determining the fluctuation amplitude and fluctuation intensity of the bus voltage signal fluctuation based on the plurality of bus sampling voltage values ​​comprises: Determine a voltage peak value difference between a voltage peak value and a voltage valley value in the plurality of bus sampling voltage values, and determine a fluctuation amplitude of the bus voltage signal fluctuation according to the voltage peak value difference; A voltage average value of the plurality of bus sampling voltage values ​​is determined, and a fluctuation intensity of the bus voltage signal fluctuation is determined according to the voltage average value.

3. The elevator energy storage system control method according to claim 2, characterized in that: The process of switching and controlling the charging and discharging of the energy storage device to the elevator inverter busbar under a preset hysteresis control mechanism according to the fluctuation amplitude and the fluctuation intensity includes: Based on the comparison result of the voltage peak difference with the charging threshold and the discharging threshold, and the comparison result of the voltage average with the charging threshold and the discharging threshold, the charging and discharging process of the energy storage device to the elevator inverter bus is switched and controlled.

4. The elevator energy storage system control method according to claim 3, characterized in that: The charging threshold includes a first charging threshold and a second charging threshold; the discharging threshold includes a first discharging threshold and a second discharging threshold; the first charging threshold is greater than the first discharging threshold; the second charging threshold is greater than the second discharging threshold; The process of switching and controlling the energy storage device to charge and discharge the elevator inverter bus based on the comparison result of the voltage peak difference with the charging threshold and the discharging threshold, and the comparison result of the voltage average with the charging threshold and the discharging threshold, includes: When it is determined that the voltage peak difference is greater than the first charging threshold and the voltage average value is greater than the second charging threshold, controlling the energy storage device to receive the electric energy of the elevator inverter bus; When it is determined that the voltage peak difference is not greater than the first discharge threshold and the voltage average is not greater than the second discharge threshold, the energy storage device is controlled to release electric energy to the elevator inverter bus.

5. The elevator energy storage system control method according to claim 2, characterized in that: The step of determining a voltage peak value difference between a voltage peak value and a voltage valley value in the plurality of bus sampling voltage values ​​comprises: Acquire multiple bus sampling voltage values ​​within a preset time range; Traversing the multiple bus sampling voltage values, determining a voltage peak value greater than a first voltage value, and a voltage valley value not greater than a second voltage value; the first voltage value includes other bus sampling voltage values ​​among the multiple bus sampling voltage values ​​except the voltage peak value, and the second voltage value includes other bus sampling voltage values ​​among the multiple bus sampling voltage values ​​except the voltage valley value; The voltage peak value difference is determined according to the voltage peak value and the voltage valley value.

6. The elevator energy storage system control method according to claim 2, characterized in that: The step of determining the voltage average value of the plurality of bus sampling voltage values ​​comprises: Calculating a plurality of square values ​​of the plurality of bus sampling voltage values ​​to obtain a plurality of voltage square values; Summing the plurality of voltage square values ​​to obtain a voltage square sum; According to the number of the plurality of bus sampling voltage values, a mean square value of the sum of the squares of the voltages is calculated, and a square root of the mean square value is calculated to obtain the voltage average value.

7. The elevator energy storage system control method according to any one of claims 1 to 6, characterized in that: The method further comprises: Obtaining the bus voltage signal under different elevator loads to obtain a bus voltage measurement value; the different elevator loads include heavy elevator loads and light elevator loads; The charging threshold and the discharging threshold are determined according to the bus voltage measurement value.

8. An elevator energy storage system, characterized in that: The system includes: a voltage converter, and an energy storage device and an elevator inverter connected to the voltage converter, wherein the voltage converter is used to bidirectionally transmit electric energy between the energy storage device and the elevator inverter bus; wherein the voltage converter is configured to execute the elevator energy storage system control method described in any one of claims 1 to 7.

9. The elevator energy storage system according to claim 8, characterized in that: The voltage converter comprises a controller and a memory, wherein a computer program is stored in the memory, and the controller is configured to run the computer program to execute the elevator energy storage system control method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the elevator energy storage system control method according to any one of claims 1 to 7 are implemented.

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